Pass Labs INT-250 Integrated Amplifier Review.

Pass Labs INT-250 Integrated Amplifier Review. Liquid Gold. 

By Steve Huff

My last big audio review was for the Dynaudio Heritage Special’s and as I said in that review, I will never sell them. I still stand by that as they impress me more and more as time goes on. The best bookshelf speakers I have ever owned in life when it comes to my sound preferences and they will stay with me, just as my Klipsch Heresy IV’s are still with me in my living room TV and music system. As for the Dynaudio Heritage, with my Pass Labs INT-25 powering them, they sound delicious in my 12X18 room. I can not guarantee I will never buy another set of speakers but I will never sell these Heritage Specials. They are that good when set up right, powered right and with the right front end gear. But…being 85db Efficient, could they use more power than my INT-25 is giving them? 

I mean…Could it get Better? 

Many emailed me after posting the Heritage review saying that these Dynaudios would get better still if I fed them more power. I was getting suggestions that were all over the map from a Gryphon Diablo 300 (tried one a while back, was nice but not for me) to big dollar Naim Separates (can’t afford those) to a big $21k Accuphase Integrated amplifier (can’t afford that either) but I am limited by a budget, and besides, I am not interested in spending $20-$30k on amplification, even if I were a millionaire (and I am not).

One suggestion was for something that I knew would be an amazing synergistic match and maybe, just maybe an improvement. I also said that it would be the ONLY amp I would ever upgrade to if I did change from the Pass INT-25. But it would have to offer a pretty big improvement for the cash outlay and honestly…night after night, listening to my INT-25 I did not see how this was possible. Even so, I committed myself to giving it a go.

Before we jump in let me state that the INT-250 (just like the 25) is an integrated amp which houses an amplifier and a pre-amp in one. This saves on space, cost and cables and todays powerhouse integrated amps really give little up in sound to separates, and IMO once you get to these levels it’s more about different than “better”. The Pass Labs Integrated do not have a built in DAC or Phono Stage. It is just doing its job as a power source for your speakers. It has four inputs, and yes it is balanced so you can use your XLR cables or RCA cables to connect. The amp section is said to be a Pass Labs X250.8 which is a killer amp all on its own.

“Big Blue”

The Pass INT-250 presents music much like you would expect. Imagine sitting at the ocean at night with the moonlight glowing on the water. It sucks you in, relaxes you, makes your stress go away. 

Music Feeds the Soul

Before I get started, I also want to say that Music is a huge part of my life. I use it to relax, to relieve stress and even to meditate. I am a huge believer in the healing qualities of music, and listening to it seriously in as high of a quality as possible (but it must always stay musical). I have been at this for most of my life, and am just now, at 51, getting to the point of ultimate satisfaction and not ever wanting for more or different in my audio system, but what a journey it has been. My audio system has been a constant for me throughout life, and it is the one thing in life I spend on as it improves my life in so many ways, even spiritually.

Being able to try and test so many pieces of gear has been a godsend as it has shown me that bigger is not always better and more expensive is usually about being different rather than better. Diminishing returns is also very real, as the more you spend the improvements get smaller and smaller while you spend more and more. I have found it is possible to get 85-90%  of the performance of a top end piece in something that costs so much less within the same brand of gear. But what if you do want that extra 5-15%? It will cost you but it is attainable.

A Sound Demo with the INT-250 powering my Dynaudio Heritage Special’s. Running a Lumin U1 Mini with a Chord Qutest Dac and streaming Qobuz through Roon. 

Yes, high end audio systems can get scary expensive and part of the passion and the hobby is indeed the journey of trying new things and discovering what is to your liking. For example, after trying a few expensive high end music streamers that ranged from $1500-$5000 I found real happiness in a lowly $549 Bluesound Node because if you use an external DAC (as I do) the differences mainly lie in the DAC (not really in the streamer).

I am more than happy with that Node 2i and found little improvement even when testing a streamer in the thousands of dollars as they all went into my external Chord Qutest DAC, which I still enjoy immensely. I do have a $2k Lumin U1 Mini here I am comparing to the Bluesound and when I review it, I will be as honest as I can be, even if it has me telling you the Node 2i is the same sound quality when run into an external DAC (the Lumin has no DAC). : )

But how can a guy like me, a blogger and video creator afford all of this crazy gear? Remember, 98% of what I review is gear I buy and pay for with my own hard earned cashola! Oh, and I make not a cent from these audio reviews.  This is and has been a passion project, and that is all. It comes from the love I have for music, not a way to make money. As for being able to afford this stuff, well, I base my priorities on things that improve my life in a meaningful way rather than a material way so I have extra money because I do not blow it on silly things anymore.

I do not own an expensive house and while I have two beautiful homes that sit on 20 acres of woods, this property cost a fraction of what our starter house in Phx AZ sold for last year. We have one vehicle. No jewels or jewelry, no exotic travel, no designer clothes. We have no vices, addictions or elaborate expenses in life. We will spend when it is for something that will make life better, happier, more peaceful. My philosophy is to live a passionate life, be kind to all, love all you can, and help others who need it when you can. Music seriously improves our life in many ways which is why I am in this hobby to begin with, and how I justify it. Without my system I would lose something, as having one for over 35 years it is like a child of mine whom I love dearly : )  I have had audio systems since I was around 14. I used to spend my $20 allowance back when I was a kid every week on one new record and some fast food. These days I save as much money as I can, and that also helps with my audio passion.

Listening to a high quality two channel quality audio system setup correctly can do things for your soul, and do things no bluetooth speaker could even start to do but this kind of stuff is for those who are like me, and truly appreciate and love music. I listen daily and it can draw you in to the music. It can heal us from within in many ways. Our mind, body, brain and soul.

So yea, to me listening to music for 2 hours a day is mandatory : ) I listened throughout this entire review as I wrote some of not every day during this evaluation.

The “Big One”

Enter the mighty Pass Labs INT-250. An integrated at the top of the heap from Pass Labs, and it comes in at a whopping 105lbs and with a $12,000 retail cost (though it can be had for less), it also packs a crazy punch with 250 WPC into 8 ohms and 500 WPC into 4 ohms. The first 15 of those are in Class A, which is what makes many of these Pass Labs amps so special IMO. Class A amps bring a unique sound that some feel are more tube like. Are they? Well, not really but at the same time, Class A Solid State amps are usually, IMO, the best of Solid State and sound ethereal, warmer, with more body to the sound. Fleshed Out.  One upside to and amp like this is that there is no maintenance for at least 20-30 years unlike tube amps which require new tubes every few years (and the cost can get quite high to do this). I also never have to worry about tubes burning out or replacement costs or a bad tube blowing up my amp. Then again one downside is that Class A amps do burn more energy than others. These are not “green” amps. Class D would be the way to go for that.

Of all of the integrated amps in the world today, no matter the cost, the INT-250 is the only integrated amp I still had a curiosity about. It was still an itch I knew I would have to scratch and I have been curious about it for years. Seeing that I have my Heritage Specials that I adore like mad, I wanted to see if in this case “bigger is indeed better”.

Reno HiFi is THE place for Pass Labs

I knew there was an option for me to try out an INT-250 without a huge cost risk. Yes, It WOULD INDEED cost me just to audition it in my home (to the tune of about $800 if I decide to return it after buying) but I saw it as worth it to scratch the itch and the huge upside was that I could write about it as I am doing right now, so more of you who are like me (you) could understand the difference between something like an INT-25 and INT-250 driving something like an 85db efficient speaker. : )

I contacted none other than Reno HiFi as I knew they had a home demo program where I could try the big bad Pass Labs INT-250 in my own room with my Dynaudios. I could compare it directly to my INT-25 side by side and see for myself if having 500WPC (into 4 ohms) from the INT-250 would truly be better for my ears than having 50 WPC (into 4 ohms) from the INT-25. This demo opportunity means I buy it and then if I want to keep it, well, I already paid for it and can keep it. If I do not feel it is worth it, I could send it back within 10 days for a refund minus a 5% restock fee and the cost of shipping both ways. For this piece that would come in close to around $800 in losses if I did not like it. It would be like an expensive rental. 

Just to note, I would not have been able to do this at all if Mark at Reno did not have a demo model at a substantial discount from new. (I am talking several thousands of dollars discount). He had a like new demo, in factory boxes and at this great price tax and shipping was included so I could not pass it up. I emailed him a while back and added my name to his waiting list for an INT-250, as yes, there is now a wait list for these amps at the time of this writing (March 2021). When he e-mailed me with the offer and stock notice he said if I didn’t jump it would go to the next in line.

I have seen used ones sell for this, and this had a full three year warranty. I had to go for it. So I did.

Another note…I have zero affiliation with Reno HiFi, nor do I get any kickback, discount or commission if any of you buy an amp from him. I feel I should state that so you know what I say is from the heart. Money is not a motivator here in any way, shape or form. I bought and paid for the amp. It wasn’t sent to me for review to say good things about it : )

But I admit, I feel blessed that I am able to do this. I remember in my late 20’s and 30’s lusting after gear like this, dreaming about it and knowing one day I would be able to dabble with this level of audio and I could not wait until those days arrived.

Well, those days of dreaming are now here and reality and as I write this I have both the INT-25 and INT-250 in front of me. I’ve been listening to both, and yes there are differences that are quite obvious (It’s not just the power). 

It Arrives…

When the INT-250 arrived from Reno (who shipped crazy fast and packaged everything perfectly) I told Debby that if I return this after the demo it would be a chore for us to lug this 120lb box to UPS. Just packing it back up would be a chore so I was hoping for great things. Coming in at 105lbs, it makes the INT-25 appear tiny and lightweight (and well, it is in comparison to the INT-250). The 250 is indeed a giant among integrated amps.

The funny thing is I envisioned the UPS guy bringing this up with a dolly but I guess I am just getting old and feeling weak as the driver (in his 20’s) picked it up like it was a loaf of bread, effortlessly. He walked it up my walkway and placed it on my porch. I wondered “Did they send the wrong amp”? I then asked how he did that. He said “It’s only 120 lbs’! I laughed. Ahh, to be young again.

I  (with Debby’s help) managed to get it inside into my audio room, and I unpacked it and was able to place it on the floor in front of the INT-25 which was elevated on its cabinet. As it was a demo model, it did have a super tiny small paint scuff or two on the heatsink, so it was not “perfect” but these were things I would never see or care about. They were tiny and worth the savings from new. It also came with a full 3 year factory warranty so all was good. 

The Glow…

One thing I immediately adored after the first power up was the huge blue meter that glows in the night like a soothing midnight blue moon filled sky would. It’s hypnotic and I really like the deep blue color. I once owned McIntosh Integrated amps (MA-7000 and MA-8000) and also enjoyed that green glow. Something about a soft glowing color light while listening does it for me. What Pass did here…it looks beautiful but without the flash and bling of sone other amps.

Without this meter and light the amp would be rather un-attractive and appear cold and stark. Some will think the design is cold anyway as it’s not anything exotic or fancy. The top plate is rather generic in appearance (not quality) compared to other integrated amps in this price bracket, and again, there is no fancy flash or details. Just thick silver metal, the blue backlit meter and nice big volume dial, which I LOVE. You can tell it was made by those passionate about music, as they do not have to wow you with flash and bling. You will see nothing that screams you paid big bucks for the looks. The build is extraordinary, and looks like it would survive being run over by an 18 wheeler. I think the design is quite nice but it could be better and look more like $12k. It’s simple, and for me at the end of the day what matters most is the sound and dependability.

With that said, I believe if Pass made this in a black matte finish (same thick metal used), the blue meter would absolutely pop, look amazing and somewhat more classy rather than industrial.

As for that blue light…you will notice a meter there as well, but this is not a VU meter that dances with the music as McIntosh, Yamaha and Luxman do. In fact for most listening it will never move. It sticks at about 1/4 of the way up the range…unless you really rock out. This is because the ever so important first 15 watts is running in pure class A. Always on like a water faucet. This means when that needle moves past that mark, you are leaving Class A and going into Class A/B. Pure class A to me always sounds magical. It blooms, it has life, it is organic and ethereal and does wonderful things to the human voice. I would love to own a pair of Pass Labs powerful class A monoblocks but those will never be in the cards, as I do have limits when it comes to funds and I do have pretty good will power these days. : )

But the meter… It lets you know when you leave that magic point of 15 watts, which are the most important first few watts of the sound. The most magical. They are all Class A.

The Cost of Class A

Class A amps will waste the most energy, as they are always “on” so to speak. This energy gets converted into heat, which is why these amps have huge heat sinks on the side. Now, some have said these amps get red hot but I have had the INT-250 running for hours on end during my demo process and they were never even hot to the touch. Warm, yes. Hot, no. I have had hot running amps, and the INT-250 and the INT-25 are merely warm running amps. As for costs, the INT-25 upped my electric bill by about $3 over previous amps in a month. I guess the 250 would bring that to $6 or so. Maybe $10 so these will cost more to run than an amp that is all Class A/B or even Class D. For me the sound of Class A is worth the extra few bucks. I just removed some of the old school light bulbs that were still in my house, and replaced them with LED. This should balance out the extra few bucks on my bill. BTW this piece consumes 450 watts of power when on, or close to five 100 watt bulbs. When in standby it uses about HALF of ONE watt, so mine is in standby when I am not listening.

See the INT-250 in action…

Back to that Meter and Needle. 

Rather amazingly, even when I listened at MUCH louder levels than I did with my INT-25, the needle was not budging! I thought it was more of a gimmick, and didn’t really work! If it was only putting out 15 watts of Class A and I was not leaving Class A (when the meter moves you are moving into Class A/B seamlessly) yet it was sounding more forceful, larger and powerful than the 25 that was putting out 25 watts of Class A? Hmmm. Does this meter really work? Was I really still in Class A?

Just to note, I say it was sounding larger, more forceful and powerful but that is because my speakers did seem to appreciate the extra power. If I was running these with Klipsch Heresy IV’s or any Klipsch Heritage the INT-25 would be the golden ticket and sound just as large and powerful as they are super easy to drive. Even so, with only 15 watts of Class A behind the INT-250 I could not get the needle to move yet.

One day I put on some more challenging music that had volume peaks and loud swings…I turned up the amp to 55 and when the music really kicked in, I saw the needle dance ever so slightly to the right telling me I was now dipping into the Class A/B pond, and the sound remained just as it was but man it was loud, and I could never sit and listen like that for more than a minute or two, maybe one song if I was in a rowdy mood as it was LOUD. Interestingly enough, when it is loud you do not realize just HOW loud it is as there is zero aggressiveness, harshness or bite. I mean, NONE! I have had some amps that as you go up, the sound gets sharper and aggressive (Yamaha and Musical Fidelity have done this for me). Never does that happened here, as when you go up, it keeps the same character and that is one of a smooth operator that retains its grip and composure on the speakers.

Even when I did get it to dip into A/B I heard no difference. This was incredible to me as it was telling me that 99% of my listening would stay in Class A, and I would be using 15 watts of the 500 available to my speakers. Hmmm. So again, why was the 250 doing so well with these challenging speakers with only 15 watts of Class A, making a more powerful sound than the 25 that had even more Class A power? Well…

It’s all about the CURRENT and power supplies. 

The Pass Labs INT-250 is a rated as a Class A/B amp but honestly I would still refer to it as a class A amp as it puts out the first 15 watts (into 8 ohms) in Class A and it seems to have more of those Class A characteristics than the INT-25 (warmth, bloom, midrange magic, oomph and bass power). I am betting anything it has to be higher than that, as Pass always plays down the specs and numbers and usually offer much more power on tap than advertised. They did this with their XA-25 amp and INT-25, which put out more power than you think. It’s a good business model…under promise and over perform. Some manufactures these days do the opposite but it’s always nice when you spend money and get something better than you thought it would be.

With the Dynaudio Heritage Special’s (which are 85 DB efficient) the INT-25 powered them nicely and to very nice volumes. I could not rock out and shake the roof down but that 25 powered these speakers as loud as I would ever need to go, again, in my 12X18 space. I was curious as to how the 250 would do, and since this was a demo amp, meaning it was used in a demo situation much like I was doing here, I assumed it was already burned in and ready to roll (but it wasn’t as I later found out).

It’s no secret that Pass Labs amp sound a bit better when fully warmed up, and from fully cold out of the box it can take about 4-5 hours to juice up so to speak. After that, if left in standby (which I recommend as it uses very minimal power) it usually gets to its best in 45-60 minutes but sounds so so good even when just powered on. When cold, it mighta sound teeny bit stuffy. Give it an 45-60 minutes it opens up dramatically sounding more and more transparent as it goes. Soon it will open a window to the music that is inviting and so so nice.

The big moment arrived. I cued up some tracks I knew well with the INT-25 and listened for a few hours on the new INT-250 after daily listening with the INT-25. Hmmmm. 

I was not immediately blown away and honestly at first I thought I lost some magic of the 25 in the top end. Did I lose some sweetness, sparkle and air? As I listened more I realized what was really happening. 

One thing that was quite different was the bass. The mid bass and the seismic type of lower bass exploded with the 250. This amp was a different beast with bass (and the treble) vs the INT-25. 

Where’s the BEEF? It’s HERE in the 250. 

The INT-250 brings much more bass power, heft and energy and this changed the presentation of the speakers from airy and lighter footed (with the INT-25) to speakers that had much more body, heft, warmth and bass that seemed to go to the core of the earth. I mean, it was shaking my wooden floors at times at moderate volumes and somehow all without ANY bloat or bass problems. It remained tight, explosive and natural and sweet. 

It also did this while staying within the first few watts of Class A and it was besting the 25 in this area due to the power supply and raw current that this amp can deliver.The toroidal transformer in the 25o is about the size of a small cheesecake. 

Remember, amps are much more than watts. Current is much more important as this is what delivers these improvements in bass, smoothness, refinement, noise floor and dynamics. I have heard 500 watt amps that sounded hard, shrill and awful but they did not have the power supply or current of something like the Pass INT-250. They also were not Class A but either Class D or even A/B, which is a different kind of sound from Class A, one which some may even prefer.

The Bass though…it was on another level from the 25 with these speakers but all that means is that it brought a different presentation, one that someone may or may not prefer. It was indeed a little more warm and relaxed but also quite a bit bigger and much fuller with a broader soundstage over the 25.

This integrated amp was fleshing out the voices even more and this is where it did its magic.

It gave more weight to piano notes, strings and still had delicacy where it was needed. The more I listened the more obvious it became and the more I was appreciating this “extra” to all of the notes and sounds emanating from the harder to drive speakers.


The voices were now bigger than ever, much more fleshed out and real than even the INT-25, which is also truly spectacular with the human voice, among the best I have heard.

The bass was making these special speakers sound even more whole and complete and voices had such a realism it was well, eery at times. Again, the more I listened the more I started understating the difference that were happening. As refined as the INT-25 sounds with the Heritage, the INT-250 brings another level of refinement and smoothness, but again, only if you have speakers that are 87DB efficient or less. It sounds like what its retail cost is, which is $12,000. Compared to the Vinnie Rossi L2i SE I once owned ($26k) the INT-250 is more juicy, more relaxed, more 3D and ethereal and with much more grunt to the lows but with a tamer top end. The Rossi was a sharper sounding amp, more detailed, dynamic and analytical in comparison (though it is not an analytical amp at all) with less of the golden hues, which is more desirable to some of course. But these Golden hues are indeed gorgeous and have a way of sucking me into the music like very few HiFi pieces do. It’s like walking through green grass in the summer, approaching a large lay of land with a picnic table that has some fresh fried chicken, green beans and sweet tea. It is so inviting and makes you want to sit and enjoy the moment for hours. Takes you back to the soul of the music.

I am a convert for sure…

I have only heard two Pass pieces and they both have converted me fully to the brand. USA made and designed. Amazing warranty service. Construction that is second to none and they apparently rarely ever break down. I remember reading that Pass Labs is just now seeing some amps form 30 years ago come in for the first time for capacitor replacements. After owning maybe 15 different brands of amplifiers and integrated amps over 30 years I will forever be with a Pass Labs amp.

If I can be honest I did not think the INT-250 would bring a huge change to the sound but it brings the Dynaudio Heritage performance to where they should be. It maxes them out and makes them sound fully as they were designed to. The INT-25 did great with them but you can tell when doing side by sides that the INT-250 does its magic with more inefficient speakers and the 25 does its magic with easier to drive speakers (just as Pass Labs tells us).

As I listened to track after track, I was appreciating the bigger sound, even at low volumes, that the INT-250 was delivering. The 250 in my system is a bit of a warmer leaning amp vs the 25 and the 25 is not an amp I would ever call bright, thin or analytical. With that said the 250 is not a “warm gooey” amp. It is in no way veiled or muffled, nor is it dark. It is…well…to me…just about right. It truly is a sound one must hear and get dissolved into for a while to truly appreciate. It’s one of those things you would miss if it were gone but it took several days for me to fully appreciate what it was doing for my speakers, my music and the room. I even had to reposition my speakers to balance the sound to where it was as cohesive as before. When I did this, the top end opened up some more and I had the sparkle back while still retaining the fullness and deep bass when called upon.

Even so, the INT-25 is still crazy good and magical. I still have a bond with it. It does it’s own thing very well and while music is a little thinner with the 25 vs the 250 with my speakers, it is airier and has a bit more top end energy. Silky sweet with some sparkle is how I would explain it. The 250 is more about muscle, bass and the mid-range and has a very welcoming sound and a smooth textured top end.

The INT-250 is “Fluid”

The INT-250 was even more musical and fluid than the 25 with the Dynaudio’s, bringing an ease and flow that was not fully there before. Imagine a water hose that is brand new and lets the water flow freely without kinks or bends. There is no resistance to that flow. This is the INT-250. Music flows like there is not one thing restricting it and this means the music expands from your speakers in a way that may surprise you at first listen. The sounds just expand into the room with ease, an effortless liquid flow with a rich golden hue that never leans to the syrupy side but also will never ever fatigue you, even if you listened for 10 hours. Just not possible here.

I would say the 250 has the “House Sound” most associate with Pass Labs. Rich, smooth, organic, huge soundstage that invites you inside of it while giving you a real human performance. The midrange is where the magic lie, and the Pass Labs products do the mids very very well, up with the best of them. The INT-25 may stray a bit from that house sound, but not by too much. Both have the overall same character it is just that the 250 is powering the Dynaudios to where they need to be to bring their full performance. In a larger room this would be night and day and the 25 wouldn’t be able to flesh these speakers out correctly. The INT-250 is truly a special match for the Heritage Specials in a mid to large room. A perfect match if you will. The 25 is a perfect beautiful match in a smaller room.

After a few days with the 250 as my main amp….

The INT-25 Goes Back In. 

This is when I clearly noticed the differences, and they are just that, differences. The INT-250 is clearly powering the Heritage Specials to their full potential with more realism, warmth, depth and bass and can go to loud levels with ease. The INT-25 does sound somewhat sweeter though it is ever so slightly less warm and slightly thinner and smaller. It’s more airy yet the INT-250 is more spacious offering a bigger soundstage and a smoother sound. Some may say the INT-250 leans more towards honey where the INT-25 leans more towards transparency. Yes, the 25 is more transparent here because there is less bass energy, therefore we hear more of the upper mids and treble. It’s a trade off really and for me in my smaller 12X18 space I do prefer the bigger, more effortless sound of the INT-250 with most of the music I listen to. But I have to be honest, I prefer the 25 with some music as that sparkle it has is so nice at times, and sounds a bit more lively all while staying sweet.

I could happily live with either though, as long as I never went to a larger room. The problem though is that I have now heard the INT-250 and I admit, it would be something I would truly miss after having here for the last 10 days. The music shrinks a bit with the INT-25 but only because these speakers love the extra power and current. With my Heresy IV both amps sound fantastic but the INT-25 has a great synergy with the Klipsch and would be my daily driver with those.

While the 250 brings much more heft. body, dynamics, volume and oomph to the Heritage Specials the 25 brings delicacy, air and sweetness. The 250 can drive these 85db speakers to higher levels with more authority and if you like it loud, or listen to rock, metal or EDM then the 250 would be your cup of tea without question. If you prefer small jazz trios, acoustic, or vocals and you are in a smaller room you may appreciate what the 25 brings to the table. Both amps can sing beautifully.

The INT-25 can bring small vocal performances into my room with a 3D magic that is wide open and sweet. The INT-250 can bring a concert into my space with ease, or those small vocal presentations just as well, but with more warmth and vocal realism.

After a few more days I understood fully what the INT-250 did for the extra cash it demands. The INT-250 brought with it…

A bigger soundstage.

Nicer imaging but still sweet and natural rather than etched.

A Smoother more ethereal sound.

Bigger, fuller voices.

That gorgeous blue meter.

It is a bit more 3 dimensional.

Effortless ease at any volume.

Seismic bass when called upon.

Unlimited capabilities. Will drive ANY speaker to its full potential.

Going back and forth between the amps, and really NOT wanting the 250 to best my oh so sweet INT-25 it was getting harder and harder to not want to keep the INT-250.

Listening Notes

One track that fully made me realize what I had here was “Romano” by Savage Rose.

WOW… when the vocals come in, the voice is so real, it is truly a remarkable thing to behold. Compared to the INT-25 the voice is fuller, bigger, fluid and even more real. When the music kicks in you can almost feel the bass energy throughout the room but it is tight, tuneful and doesn’t bloat at all. Sure, the speakers help here but as a combo they are truly remarkable. The INT-25 presents this track in a way with more sweetness and sparkle and transparency but also less bass weight, so it sounds smaller, thinner.

Listening to “Cordelia” from Lost Horizons took me to another world with the INT-250 and the Dynaudios and what a world it was. I was surrounded by such a beautiful sound, and the soundstage width was amazing as was the depth. I felt surrounded by the music, and in turn, felt the emotion of it as well. When the sound kicked in it jarred me as the INT-250 has a way of doing that…from quiet to loud is like…BAM! It’s amazing.

Both amps excel with the mids though, and both present amazing presentations of the music. Even so, the INT-250 is the most refined amp I have ever heard. There is literally zero noise, and music does emerge from blackness. It’s quite special for the price I paid, really.

Listening to Nina Simone and “New World Coming” which was released recently with darkDARK I was truly blown away, literally. When the bass kicks at the 46 second mark it pressurized my entire room and my my speakers sound like they were 20 feet tall providing a wall of sound that was NOT coming from them. Ninas voice was full, detailed and right in the center. I did not have this same experience with the INT-25 as it just did not have that Bass kick of the 250.


So which is the better amp?

It all comes down to the speakers you own as one could be better for some speakers than the other. That INT-25 is a special piece and all Class A at its rated power. If you have speakers that are 87db efficient or better, the 25 is more than enough as long as your room isn’t huge. If you have speakers that are 87 or below, like mine and/or have a large room or just like it powerful and loud and never offensive, the 250 is worth its weight in literal gold.

The truth is, and this is honest as I have no skin in the game here, nor do I make a cent on my recommendations here… I have never heard integrated amps sound as glorious as these two Pass Labs offerings. Ever.

They are truly special indeed but the reward for best integrated I have ever heard? That now goes to the INT-250 as it does all of what it does while keeping an iron grip on the speakers. I’d rate the INT-25 2nd and the Vinnie Rossi L2i SE in 3rd for my sound preferences. If I never heard these Pass pieces the Rossi would have stayed #1 as it is also a very special musical masterpiece and it gives a presentation many may prefer to the warmer fuller Pass Labs sound.

There is never a hint of bass bloat or puffiness here. No sloppy sound. The bass is there yet the sound remains clear as a bell, even at high or low volumes. It does amazing things lat night when listening low.

The Decision…

I have a choice to make. Keep my 25 and be happy as I was before or keep the 250 and know that I have the best I can get for my speakers and space and heck, any future space that may be larger. The 250 can power any speaker, to any level. It can do so with a smoothness and 100% glare free sound even into the ear busting sound pressure level categories. It’s a beast of an amp, American made with a great company and a legendary and well loved designer behind it. Pass amps are some of the most reliable you can buy. The 250 is a better match to my 85db speakers without question.

If I keep the 250 I would have to sell my beloved 25 to help fund it (and that would be sad). After all of that I would be looking at about a $2800 out of pocket to upgrade to the 250. Is that $2800 worth it for the beauty, the sound, the peace of mind and knowing that it can’t get better for me and my tastes?

Yes but at the same time, the INT-25 is just so sweet. A beauty in and of itself.

As I was trying to decide on what will be my last integrated amp to go with speakers I will never sell (and yes I am serious) I listened to a track by Lightning Hopkins… “You Just Gotta Miss Me” and I listened to it four times. Twice with each amp.

The INT-25 had a sharper attack but less weight. This made the song sound a bit thinner and not as large, smaller. It sounded so sweet and had that glorious top end, and provided more excitement with body and guts to the mids but the bottom octaves were light. With the INT-250 the sound grew about 30%, meaning it sounded so much larger, even at the same decibel levels. It was more polished, bigger soundstage but a more relaxed top end, but just slight. There was less excitement but more foundation to the sound. The bass was the star of the show again and gave more life and guts to the track.

This track made my decision easier for me.

I then listened to Sinead OConner “Bewitched, Bothered and Bewildered” from her “Am I not Your Girl” album. I have never heard this track sound this good. Her voice was big, full, and standing in front of me. On lesser systems (some that cost more) this album sounded thin and boring and was hard to listen to. With the 250 it was full of life and offered a crazy real lifelike in the room performance.

Sure, it could get better if I wanted to go up the chain with Pass Labs but man, this is beautiful stuff right here. The INT-250 was truly flexing its muscle.

Don’t know what you got till its gone…

I know that when you sell or return something you know you love then you will always miss it. You will regret it deeply. I have sold audio gear or camera in the past that I adored but I needed the funds for something more important at those times in life. I always look back and say “I wish I never sold that piece”. One of those was the QLN Prestige 3 speakers which are up there with these Heritage Specials in their “Specialness”.

I would 100% have that regret if I sent back the 250 as I would miss the huge bass performance increase alone, and then the bigger sound, more real midrange and vocals, the supreme musicality and the way it just sucks me into the emotion of the music even more than the INT-25 did, which I did not feel was possible.

Which is more expensive in the long run? Regret or $3000?

I have had amps in here I have not written about as while they were fantastic, they didn’t speak to me. I will not name names but they were in the same price brackets as the INT-25 and the INT-250. I have heard some big name brands and exotic brands. I even had some lower end gear in here looking for the same performance in a much lower cost package. I will say none of them came close to these two Pass Labs pieces for me, my room, my speakers and my tastes.

The INT-250 is indeed the finest integrated amplifier I have ever heard in my life for my tastes, and it is important I say this as not all have the same tastes! (I have not heard all integrated amps of course, so take that for what it is), and the INT-25 is up there in the top 3. It’s built to last forever, made in the USA by passionate music lovers and with superb customer service if the need ever came up. It’s big blue meter is gorgeous yet simple and it’s not an amp that brags with bling. It delivers the goods in sound and real musical performance. It doesn’t want to be the king of one thing as it is a master of all. A master of music reproduction where it matters, by speaking to your soul and bringing you the emotion of the music.

I’m keeping it. It makes my speakers shine in a system that has been 30 years in the making. I feel blessed. Well….let me back up. If Pass releases an update to the INT-250 in a few years, depending on what it is…who knows. : ) If it were matte black, with that big blue meter and brought 30 watts of Class A…I may be tempted. Of course there is always the dream. The $85k Xs300 amps and $38k XS preamp. Ouch! Nahh, I am more than happy where I am.

I can highly recommend Mark at Reno HiFi if you are ever looking for any Pass Labs gear. Yes his website looks like it is from 1992 but you will get the best service, best price and a home demo period if you want or need that, I mean, what is not to like about THAT? He also may have deals on demos, as he does often. That is the only way I was able to get into this INT-250 and while it was a demo, it was just like brand new out of the box. Not all will be fans of Pass Labs as we all have different ears and likes when it comes to audio but if you like fluidity, warmth, texture, and a big welcoming soundstage that sounds like music, these are well worth a look. They do speak to the heart more than the brain. With music, that’s how it should be.

Thanks to all for reading this, I hope you enjoyed it as much as I enjoyed writing it.


UPDATE April 11th 2021: 

Something has happened with this system since I wrote the review. I am not sure what it is, maybe the 250 was such a lightly used demo it was not broken in yet, or who knows but the sound has become much more open, sweeter and is now as sweet as the INT-25 was but even smoother. It has become more expansive, and enveloping. I find it hard to stop listening anytime I power it up. It’s also become more transparent. Wow, this was already my top integrated but it has gotten even better. I am so happy with this piece, and it will join my Heritage Specials as an end game part of my system.

Also, I was going to skip a vinyl system, but have decided to add one by the end of the year, and will choose a Pass phono stage as well. I think this amp will do very well with a good vinyl system in place. I own hundreds of albums, so why not?

My all time favorite integrated amps that left lasting memories for me (or in the case of Pass, what I still own):

Pass labs INT-25 and 250 – I already said it all above! USA Made.

Vinnie Rossi L2i SE – The most expensive integrated I have ever owned, and it was a beautiful piece in looks and sound. Compared to pass it is a little more dry, more detailed, more linear and without the all out romance of the Pass Labs bloom and glow. It still has sone of this due to the 300B tubes but it lacks the fuller body of the Pass Amps. Technically it is the superior amp but all depends on your tastes. Made in the USA.

Luxman 590 AXII – Sweet, a little leaner than the Pass Labs with more detail so this is more for those who crave sharpness and detail over warmth and liquidity. Class A 30 watts but what it lacks in body compared to pass it makes up for in sweetness and dynamics. Made in Japan.

Line Magnetic 219ia – Class A All Tube 845 Beast. Runs crazy HOT, can heat a room. Sounds sublime but lots of tube maintenance that gets costly over time. I have seen a couple of these blow from bad tubes since I reviewed one years ago, so reliability may not be as good as the Amps above. Even so, for me this is the best I have seen from the Made in China Amps.


  1. Dear Steve,
    I purchased the Pass Int 250 9 months ago which replaced the Burmester 011-956 pair.Pass Labe is more Organic,Richness on Meddle/High Frequency and Bass is more present.Absolutly better than German Tank.

  2. Great review Steve. Just curious. What cables were used for the INT 25 and INT 250? Thanks and I can already feel the need for the Pass Labs. It’ll be tricky since I recently purchased a Synthesis A100 integrated amp and Audio Note E/lexus signature speakers. Where there’s a will, there’s gotta be a way.

  3. Fantastic review. Thank You. I have to choice between Pass INT-60 and Luxman LX-590AXII. Pass is big, heavy and warm. Luxman has phono and hedphone amp. Does the Pass is a much better choice than Luxman considering the sound qualty? The room has 190 square ft.
    BTW: I have a McIntosh MA1200 (in burning process) and Musical Fidelity Ams 35i dual mono class A (I love it). For me Ams35i sounds better. Loudspeakers: Sonus Faber Auditor M (fantastic) but perhaps in the future …

    • Lovely speakers! Love those Auditor M’s. For those the Luxman will be a bit more open and sweeter. The Pass a bit warmer and fuller. Both will provide “magic”!

  4. Hi Steeve! You transmit real passion and communicate clear thoughts and descriptions. Thank you for your great « work »! We have similar sound and music taste, so it is really interesting to follow your reviews… I’m looking for a power amp to connect to a new DAC (Weiss 502 or Meitner MA3) and my Dynaudio Confidence 20 that are quiet similar to the Heritage, probably more accurate I guess… I loved the soind I heard in your video evwn if it was on my iPHone! I have an opportunity for a used but almost new Pass XA25, but I’m not sure I’ll have the « authority », bass control, air and 3D I am looking for… What would be your Pass Lab amp recommandation for a great match? 25W classe A would be OK or I should upgrade and be patient?

    • The Dynaudio’s like power and its really depends on the room size. Small room, ok. Medium to large you will want more power. I would look at the Pass Labs INT 60 as it will sound better than one of those DACs going into an amp alone.

  5. Hi Steve…thank you for yet another thoroughly enjoyable review. Not only do I learn about wonderful stereo gear, but I’ve also added some new songs to my playlists!

    I’m currently searching for an amplifier for a dedicated 2-channel system that will be in a large room and will feature either 1980’s Klipsch La Scala or Heresy speakers. Main sources will be vinyl, streaming and CD/SACD. I’m looking at a number of options, but never considered Pass Labs attainable. This review as well ad your review of your INT-25 are trying to change my mind!

    Even if I can make a 25 work it would likely have to be a used/demo unit, so please count me as standing in line if/when you sell yours. If that ship has already sailed, I would appreciate any thoughts you might have in other amps that pair particularly well with the LS.

    Thank you again for sharing your love of excellent music with us! Regardless of anything else, it’s really fun to live vicariously through you!

  6. Great review, thanks. I am looking for an outstanding integrated to pair with my Wilson Audio Sasha DAW’s and my HoloAudio May DAC. The Wilson’s are so superb they unveil everything good and bad. They are incredibly accurate hence why I went with the May Doc which is warm. I’m looking for something smooth and lush to compliment the Wilsons in a smaller room. Note I almost exclusively stream via Qobuz or Tidal. Thoughts on the Passlabs integrated as an option. Mu budget is 15-20. Thanks

    • The INT 60 would be smoother and more lush than the 250. With that said, the 250 is my fave Pass integrated and would power your Saha DAW’s with ease.

  7. Hi Steve,

    Good review as always! As for the Solid State ClassA amps, I would encourage You to try Sugden Masterclass IA-4 integrated amp.

    • I have tried that amp and it is fabulous, especially for the cost. Sudden makes wonderful products, I even owned a phono pre from them at one time.

  8. Steve. This is a great review and I share your asssessment, having the XA30.8 since 3 years. They can drive very difficult speakers very well. Only downside – very heavy. I use it with a DCS Rossini CD/DAC and Wilson Sabrina.

  9. Truly, I had the gut feeling you’d explore this unit after acquiring the INT-25, and I’m so glad you did, and so glad for you, brother. Great move, & great review. Thanks again.

  10. Steve
    Lockdown in England eased today, and I spent 6 hours at my local HiFI dealer auditioning gear. Very interesting…
    Everything was played through Wharfedale Elysian 2 speakers. Phenomenal. £4.8k with the (essential) stands. Never heard a better speaker at any price. The quality and finish are amazing which is the cherry atop the cake. Need a medium/large room though.
    Amps were
    *Roksan blak (a trade-in)
    *Rega Aethos My potential buy
    *Marantz model 30, for comparison
    *Nain supernait 3, for comparison
    *Gato dia-250s npm (a trade-in)

    Well, The Marantz and Gato are class D. All I can say is, class D isn’t coming, it is fully here! In a decade class D will dominate.
    The Roksan surprised me. Very good. The Rega was brilliant, highly musical. Edged the Roksan. Feet tapping, head nodding. The Naim, surprisingly, was a little less bombastic and initially obvious, refined and civilised. Too polite?
    The Marantz is good, class D is now powerful and musical. Not quite as involving and emotional, but close…cheapest here at retail price. A good buy.
    The Gato was a level up from the Marantz, blow for blow with the Rega/Naim. Completely unfazed and unstrained. Easy. Confident and competent.
    I spent an hour with each. The Naim for me. Just. That demure, in this company at least, slightly reticent approach won out eventually. I realised it wasn’t at all fatiguing and did everything with nearly the confidence and control of the Gato or Rega ( at least at sound levels that weren’t, frankly, silly). Touched me the most, made most sense of the music.
    All very good amps. Not a duffer here. The choice between Rega, Gato and Naim would be down to personal choice. The Gato is also a DAC/streamer. The Roksan nearly hangs with them and just edges the Marantz. The star of the show though were the Wharfedale Elysian 2 speakers. Would be good at twice the price. They were the real revelation…I seriously covet them. Thinking to do, wife to placate…

    • Now that you’ve listened to that selection of amplifiers try to audition the Pass Labs. INT-250 with your loudspeaker of choice.
      The authority the INT-250 imposes will raise the performance to a level beyond anything you’ve previously experienced, or perhaps believed the speaker capable of.

      • I reviewed the INT-250 a while ago (right here and you commented on it), and owned it. Replaced it with a Pass Labs XP22 and XA 60.8 and 250.8, which I still have (though not in use at this time, all are in boxes).

  11. Steve – the strongest contender to the Pass INT250 appears to be the recently announced Boulder 866. Any thoughts on it? I believe it costs the same as the 250.

    • Never heard a boulder amp but of course have heard only good things. I am 100% happy with this 250, and have no desire for different, more, or change. If I can get one sent to me, I would love to compare it.

  12. Hi Steve, loved this review on INT250 and very timely as I also recently tested the INT 250 at my dealer here in Singapore. Would you ever consider pairing it with Wilson Audio Sabrina X or Focal Katana 2 speakers??

    • Thank you and I am glad you enjoyed it! I would LOVE to do that. Problem is, I can not afford to buy those to try it out! If Wilson or Focal wants to ship me a pair to test, I would love that of course but that is the only way I could do this kind of thing. Thank you.

  13. Love this review on INT250. Would you ever consider pairing it with Wilson Audio Sabrina X or Focal Katana 2??

    • yes, I have the xa30.8 and the Sabrinas, this is a marvellous combination. Note that x30.8 has about 150W at 4Ohm vs the 500 of the Int 250. I am listening loud, but never had a problem. Particularly since Sabrina’s impedance is a nightmare it is a priori not clear what works. Pass Labs certainly do.

  14. Great review Steve.
    I recently also read your review on the Vinnie Rossi. You seemed to really like it as well, what made you sell it?

    • Thanks Simon. I have talked of this in other reviews and in comments. The VR is a gorgeous amp and when you get to this level of integrated amplifiers ALL are going to be glorious yet different. The VR is gorgeous, and offers a sound that is full, sweet, dynamic and clean. I had to sell that amp as when we moved, we sold 80% of our belongings. All furniture, all audio gear, everything as the new location and move took precedent over all of that. To be honest, I got in a but too deep with that piece (over my budget) and it was all on a credit card that I was chipping away at. I had to do that in order for this move to be smooth. So I started from scratch over the last six months and have been slowly building up a system I can truly adore long term and one that can serve as a reference. Thank you.

  15. As I’ve said many times, I’m not about to spend the kind of $’s that you do on your audio equipment, however that doesn’t mean that I don’t enjoy reading about your process. A welcome insight in the era a too much GAS.

  16. Thanks for the very enjoyable HiFi reviews. I appreciate that you report the differences between the 25 and the 250 while recognizing that which sound signature is better depends on listener preferences and of course room size and associated equipment.
    Your reviews also make clear that one can derive enormous enjoyment from HiFi equipment that is relatively modest in cost. An extreme example is the enjoyment I get from streaming my iPhone to a Bluetooth speaker while exercising in my home gym. Everyone can enjoy music.
    Sometimes your equipment upgrades seem to come at head spinning frequency so I would guess you will always be on the hunt for the next even better component. If true, that will be good news for all the readers who really enjoy reading your reviews

    • Thank you and well, not true. YES we can enjoy music with low cost gear. See my report and video on the $699 PS Audio Sprout. I use this in my living room system. But this is a system I have been building for six months. I have all gear I have bought over these months. The Klipsch are staying and are in my living room with the Sprout. My Dynaudio’s will never leave, as I have stated. The Pass is my reference amp, and the 25 and 250 are gorgeous. As I said, this is me, a real guy, building out a real system over many months. I am set for speakers, amp, cables, and am now competing a Lumin U1 mini against my Bluesound Node 2i. The Node will go to my other house (100ft away from my main house) where a smaller system is being set up. I am not swapping gear, just adding to build my main system ; ) That doesn’t mean I will not do more reviews as if something is sent to me to check out, I will happily talk about it. In fact, I do have something on the way soon where I can do that, and I am excited about it. Even so, these audio reviews are never motivated by money as I make nothing if someone buys something I speak of. If someone goes to Reno HiFi and buys a Pass Amp, I do not get a kickback, discount or anything. I am happy to refer people to him as I found through ecperience that he is the real deal, and has amazing service. Same for any dealer I speak of here. It’s a passion project for sure! But one can spend $30 and enjoy music, of course. I am just someone who is and always has been passionate about 2 channel music. Thank You for reading!

      • Just curious if you have done the node to lumin U1 mini comparison yet? I have a bryston bdp-1 that is a little glitchy and trying to figure out if f the lumin is worth when being feed into a Pontus II?



        • The U1 Mini is a nice upgrade to the Bluesound if you listen critically (have your speakers set up in the room correctly). I LOVE mine and have n9t wanted for a new streamer since picking it up, It’s rock solid, never an issue, updates automatically and is well worth the cost if you really enjoy your system!

    • Steve I run my Pass XA 25 with an elekit tube preamp, or schiit saga, or straight in from source. You notice the difference with the elekit tubes complementing the XA25 and filling out and smoothing the sound nicely. I wonder if you’d like to check out a tube preamp with the Pass gear.

  17. Great review Steve. I looked at this integrated but I just can’t have an amp that I have to call people to help me move. It’s a beautiful beast of an amp.

  18. Thank you for this review, Steve. I WAITED for it as I am trying to decide on which PL to purchase. Right now I have high efficiency Klipsch Cornwall lll’s and Klipschorns. How do you think the 250 would sound w these older speakers until I can save enough $ to purchase new less efficient? My room is close in size to yours, but I want the flexibility of playing it loud. Plus, I think I’m going to want smaller speakers eventually. Thank you for what you do!

    • Your corns will play louder than you can handle with the INT-25. It’s got grunt, power and OOMPH. It has many more watts than that 25 but you will probably use 5 of those watts to get ear busting levels. What it comes down to for me is sound signature. I loved the 25 with my Heresy IV’s and I think it would be amazing with your Cornwall III’s. The CW III’s are more laid back compared to the IV and I feel the 250 may bring too much of a good thing to those speakers. I can not say I have tried it but I have had the III’s and know their character. The 25 would be amazing. Reno HiFi’s demo option would be great for the 25 and not a huge loss if you didn’t like it. When they get stock of course. : )

  19. Steve, thanks for the timely review of the Pass 250int. It’s timely for me because I ordered a pair of Heritage Specials 5 weeks ago. They proably won’t get here until May or later but a amp upgrade is a distinct possibility based on your 250 review here.
    Btw my demo was with some very expensive Boulder separates (1100 series) 400 watts @4 ohms and it certainly shined with $40k plus separates. I will be looking for a amp only but the xa 30.8 or 250.8 is a possibility. Again thanks for your wonderful review.

    • Thanks Robert. I feel you can not go wrong with any pass product with the Heritage. Hope you get your speakers soon, seems like they are very popular with these wait times!

  20. Fantastic review. What a dream piece. The only thing left now that I am curious about is how either one of these Pass Labs amplifiers would sound with a pair of Harbeth speakers. Not ideal for the rock crowd perhaps, but for those of us who prefer the softer sounds of jazz, classical, solo instruments, acoustic music, I wonder if it indeed is as magical as I imagine it to be. Unless Harbeths have passed through your house in the past and you found them unworthy of a review, perhaps one day you’ll give them a try? Me? Can’t afford them, but dreams are free. Thank you, Steve!

    • I bet they would sound sublime with Harbeth. I have read some things from those who own pass and harbeth and love the combo. I bet an INT-60 would be amazing. I have not had any Harbeth here in my home, but have heard them and I enjoyed them. Lovely and beautiful speakers.

  21. I am a little surprised you bypassed the INT-60. 30 watts of delicious class A bias…I expect you will be tempted soon. I predict you will prefer it to the INT-250.

    That is a lovely system. Enjoy those post-midnight sessions.

    • I thought about it but the 25 has 25 watts of Class A (5 less than the 60), and I preferred the 250 to it in tonality and drive. I was also looking ahead, if I do move this to my other (much) larger room one day, etc. Besides, my 250 never leaves class A in my listening, so I am still listening in all Class A with the 250 99.9% of the time. The 60 would have been more of a sideways move I feel. Finally, the price I was able to get this for made the decision for me.

      • Makes complete sense with the potential move to a bigger room. I am familiar with Sugden amps, a friend has a 21se. Pass is better but costs much more, which is as it should be…

          • What a passionate review! It really got my heart tremble reading those words and inspired me to make the move towards pass labs finally! Currently I am having a Primaluna evo 300 int. with tannoy kensington GR (just got it used), which has very good synergy. But to bring out the full potential of the speaker, I believe pass labs is the way to go. Currently I am tore between the 3 integrated it offers and have been recommended to go with the int-60 by quite a few seasoned pass-Labers. Just wondering from your experience, how do you find int-60 comparing to 25 and 250? Does Int-60 share more similarity with it’s kin or has something different by itself? Would it be your top recommendation to go with the tannoy which has 93db sensitivity? Or int-250 all the way? Your advise is very much appreciated.

          • The INT-25 is amazing, has the most sparkle and air.
            The INT-60 is fuller sounding, warmer. Top end is slightly rolled off.
            The 250 has qualities of the 25 and 250. More air, 3D and with a touch of warmth.

            All keep a similar sound, but also are a bit different.

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