Pass Labs INT-25 Vs. Sugden A21SE (and which one did I choose?)

[@edelweisskoenig]

I returned to this video as my interest for the Sugden A21 returned and I have to say, no I wasn't waiting for your decision. I was absolutely happy with you describing the pros and cons of each amplifier and talking about all the other little details. What a wonderful calm lecture about HiFi gear. Thank you so much.

[@PearlAcoustics]

Thank you. Very kind, so glad you found it useful.

[@stimpy1226]

This is the way an audio reviewer should compare similar audio components. I just joined your channel and I am absolutely loving what you have to say and how you express your feelings about each of these wonderful amplifiers. I know Nelson Pass via email communications and thought that I'd be biased because of my relationship with him but you are so centered in your thinking and listening abilities that I really appreciate this kind of "shootout". You are an honest arbiter that I can enjoy listening and relating to. Keep up the great work!

[@PearlAcoustics]

Thank you. You’re very kind. I’ll do my best.

[@kaybhee6]

@@PearlAcoustics,,,,kool hairstyle,,, just like mine...

[@PearlAcoustics]

@@kaybhee6 😀

[@davidstein9129]

I really liked your post. Yes, this gentleman is a first-class audio reviewer. I agree, he is centered in his reasoning and is a fabulous communicator. He has a wonderful speaking voice too. I could listen to him speak all day. Mostly, I love his videos because he literally sits down to talk to us...his listeners..and he treats us with respect He is here to inform us..not to yell or lecture us. He and Tarun AKA, 'The British Audiophile' are the best of the best audio reviewers on KZbin IMHO. Both are first-class individuals with a quiet confidence. I really appreciate what both of these men do.. the time they spend preparing and what they've done for our hobby in general. They've elevated the discussion about the audio components that they review.

[@Unpreeeedictable]

Another wonderful video Harley. You’re a natural in front of the camera. It makes no sense but there’s something that’s just ‘right’ about British gear pairing with British gear. But we also can’t ignore the significant price difference. At least in the U.K., the Sugden is a relative bargain compared with the Pass Labs. I’m a Pass Labs owner (XA30.5 amplifier) but wholeheartedly support your conclusion.

[@PearlAcoustics]

Dear David, you’re very kind. The XA.30.8 is a fabulous amplifier. Wise choice. The price is indeed very different and will be important to some.

[@KevinBower-gy5be]

Lovely video. I'd also add that the A21SE is hand-built in Yorkshire by a small family firm with only a handful of employees. That's important to me personally - as is the fact that they have their own service departmant who will get me out of trouble should a fault develop. Not that they ever seem to ...

[@PearlAcoustics]

Hi Kevin, thank you for your kind appreciation, I am glad you enjoyed it. Indeed, small scale manufacturing with a very personal and comprehensive support system is very important for me too. However, I think PassLabs are very similar in that point, but obviously in the US.

[@David-jm8wt]

Very interesting and a well presented comparison between the two amplifiers. I have a Sugden A21SE. I would like to comment upon the input sensitivity of this amplifier, which is not an ideal match for the 2v RMS output of most digital sources. I have a small listening room and even with output of my Qutest DAC set to the lowest 1v RMS setting the volume control only requires to be around 9 O'clock for maximum level. Adding the Rothwell attenuators to the source end, the maximum volume control position increases to between 11 and 12, which I find ideal, and has no detectable effect to the sound quality. I did try the A21 amplifier before the A21 SE. Interestingly the A21 SE has an input sensitivity of 110 mv while the input sensitivity of the A21 is 170 mv allowing the volume control to have noticeable wider range. Both amplifiers are extremely good value. I went for the larger output of the A21 to future proof my speaker choice. One attribute I particularly like about the A21 SE is that musical climaxes throw full weight with minimum compression and still excellent separation.

[@PearlAcoustics]

Thank you for your kind words and excellent addition to the debate.

[@philiptparry]

Hi David, how much attenuation did you choose?

[@David-jm8wt]

Hi Philip. On my A21 SE with no attenuation the optimum listening level the volume control was 9-10 O'clock, with 10 db attenuation it was 11-12 O'clock and with 20db attenuation it was 2-3 O'clock. I decided that 10 db was about right as this allowed more headroom for the amplifier. Rothwell attenuators are directional and available in 2 types, Type 1 for fitting at the amplifier input and type 2 are for fitting at the source component output. I chose type 2 as there was more room behind my DAC than my Amplifier to accommodate the additional length of the connections. They are completely undetectactable in use.

[@damonsbest]

Thanks for doing this comparison on your speakers for the owners out there. I agree with others that your very natural in front of the camera. It’s a pleasure to watch. I’d love to see this sort of videos more, from yourself or others in the industry. Keep up the great work.

[@PearlAcoustics]

Thanks Damon. Your comment is much appreciated

[@danielgeiger7739]

Thanks for this great comparison and the service you provide to the PearlAudio/Sibelius customers. I had not even heard of Sugden until now. Just got the XA25 and not running out to get a new amp. But good info to have.

[@PearlAcoustics]

Hi Daniel, thanks for you very kind comments. Please, please do not run out and buy another amplifier, the XA-25 is a great amplifier and deserves its place in your set up!

[@torarnekvaly7753]

Wonderful comparison of two fantastic amps. I have their power amps, Pass XA25 and Sugen FPA-4. I can confirm that the Sugden is hissing and humming, and is slightly smoother than the Pass. But the Pass is way more powerful, even though they both are rated at 25 watts.

[@PearlAcoustics]

Thank you Tor. We’re completely aligned. I love the FP-4 too!

[@dougg1075]

I thought pure class A is more powerful. How is that? I’m learning

[@PearlAcoustics]

@@dougg1075 hi Doug. If measured correctly. Power in RMS is power, ie it does not matter if it is Class A or A/B, D etc. Although some amplifiers can deliver more power for very short bursts, and seem ‘more powerful’ than their average number. It’s complex, but depends more in the honesty of the measurements.

[@tonydeniro284]

The sugden has 30 watts

[@ALWH1314]

I have a pair Passlab x150 and pre amp for almost thirty years and still loving them. Passlab also provides excellent services, I can call them and speak with an experienced live person for advise and they are happy to take my old amp for maintenance just like taking car to dealership. Love to have an INT25 but the problem is I have no excuse to let go my faithful X150. It’s a perfect mate to my B&W 805D4. Passlab sound is transparent, neutral and colorless, to me it harvests speakers and music source better than any other brands.

[@PearlAcoustics]

Absolutely Alex. Simply no need to replace what you have. In my private office I have a QUAD 405 from the 1970’s. It’s a similar story to PassLabs. If something works fine and the company gives excellent customer service, then why change?

[@JeandeMauleon]

Very well !! i had a Pass Labs INT 30 and choosing the H.P is very very important with it. It was very nice with Klipsch Cornwall III.

[@PearlAcoustics]

Thanks for sharing your observations

[@Drackleyrva]

Excellent review, Harley! I've been looking around for a review like this. I just bought my first class A amplifier---the Sugden A21 Signature. I got a good deal on it since the dealer was willing to sell me his demo (in the states). I absolutely love it!!! Wow---the soundstage is spot on and the richness and warmness is addictive. I'm not sure if there's a big difference in the sound from the Signature as compared to the SE. I did upgrade the power cord but didn't hear much of a difference. BUT, the iFi Nova power cord has noise reduction properties so I'm not sure if it will reduce any hiss. I haven't tried that experiment. But I will say that I don't need to go pass the 10 o'clock position for loudness!! I've tried the amp with Tekton Lore Reference (>95db efficient) and Dynaudio Special 40s (around 87db) and the A21 had no issues with power. Thank you!

[@PearlAcoustics]

Thank you. Much appreciated. Glad you are happy with your Sugden, it’s a fine piece of kit.

[@johnt8710]

This was a very useful comparison. Thank you.

[@PearlAcoustics]

You’re welcome

[@ianlock4552]

Great comparison video. I was in the market for an integrated class A amp last year and considered both of these options. In the end I cam across a Luxman 590AXII, less than 6 months old, for about the same price as a new Sugden. The Luxman has even more features than the Sugden, including a fairly handy phono stage (although I don't use it anymore) and weighs more than the Pass. I still remain interested in comparisons with the Sugden and Pass so found your video very interesting. Other reviewers have said the Pass is a little warmer in sound and the Luxman is more neutral. I have never found anyone compare the Luxman to the Sugden.

[@PearlAcoustics]

Thanks for your comment. Enjoy your Luxman

[@richardelliott8352]

I used to work with an interior decorator who used luxman as her second choice line when the big high end very expensive line she always used was not appropriate. That gave them tremendous credibility in my eyes, as she was very capable.

[@henrykpycha1637]

Thank you for a nice review. I had the Sugden amplifier and I had the Musical Fidelity class A amplifier. I sold both and made my own class A tube amplifier with 300b tubes. And finally I am satisfied. I agree with your opinion about Sugden but I was looking for linearity of sound. Thank you again

[@PearlAcoustics]

Thank you for your kind words. There’s nothing to beat the satisfaction of building one’s own amplifier. Especially if it ends up sounding how you want an amplifier to sound. Congratulations

[@jonathansturm4163]

It seems paradoxical to me to refer to either of these amplifiers as "expensive". In 1972 a close friend purchased the A21 and it has been in continuous use ever since. I have no idea what it cost back then but today you can purchase an A21 for $AU5,000. That's $AU100 per annum, or less than the cost of a cup of coffee in a café per week.

[@PearlAcoustics]

Hi Jonathan. I am absolutely with you on this. The initial outlay can be seen as large (especially when trying to justify it to someone not emotionally involved in the purchase). But as my father always said, expensive tools always work out the cheapest in the long run.

[@budgetaudiophilelife-long5461]

🤗👍JONATHAN,I CALL THIS A C.B.A. …cost/ benefit,analysis 😁💚💚💚

[@ianmedium]

This can be applied to most things but can also have exceptions. I collect vintage watches and the excuse to lay out large sums on say a Rolex is that fifty years from now whilst cheaper watches will have fallen by the roadside the Rolex will still be going strong frankly is trot! If well looked after ( and the Rolex has to be equally well looked after!) even the most humble quartz or mechanical watch approaching fifty will still work well, keep time well and look good. My humble vintage Timex watches work just as well today as my similar age Air King does. I bet a much cheaper Rotel or Marantz will still be working well fifty years from now, especially with modern caps! But it is true to buy the best you can afford still just for owner pride and feeling, everything is emotion after all and I do think psychologically it makes a difference, though I love both and admire my little four quid Timex still looking great and working well after fifty years the Rolex still feels a little more special knowing the parts are of higher quality even though practically I know from fact and experience that does not matter!

[@PearlAcoustics]

@@ianmedium thanks for the analogy.

[@budgetaudiophilelife-long5461]

@@ianmedium 🤗👍THANKS IAN ,YOU MAKE EXCELLENT POINTS AND when I wore watches , I experienced this as well 😎💚💚💚

[@stillastillsfan]

Luxman 590AXII? I’m a tube guy Luxman LX-38 Ultimate but I considered at one time the two class A amps you reviewed and the Luxman.

[@davidstein9129]

I really enjoy your videos. I learn so much from you..even on repeated views. Thanks so much. Cheers, David-

[@PearlAcoustics]

Thanks for the feedback David, it’s very motivating! Best wishes from Belgium

[@davidstein9129]

You're most welcome. Please keep up the good work. I was able to get a nice discount on a gently used Pass Labs XA-25 PowerAmplifier. In fact It was nearly 65% off list price. I will pair it with a Pass Preamplifier and a well regarded pair of tower speakers from Qln of Sweden. I'm hoping this will be a pleasant sounding combination. 🙏 Fingers crossed. All these products are from audio manufacturers who produce their products in small batches. My Pass Preamplifier sounds magical with my Qln speakers. I suspect the new Pass Power Amplifier will too. Kind Regards from The United States, David-

[@PearlAcoustics]

@@davidstein9129 👍

[@DKBoerner]

Very sophisticated review. It answered a lot of questions I had about Class A. Great show and thanks a lot!

[@PearlAcoustics]

You’re very welcome!

[@summerforever6736]

Good for a space heater

[@neophonics6433]

Thank you for your honest comparison review. Sugdens across the board have the sound stage right as you concluded for the Sugden A21SE Signature Pure Class 'A' Integrated Amplifier.

[@PearlAcoustics]

Thank you.

[@MM-ls3vu]

I had the Sugden amplifier and decided to sell it. I'm still in love with my tube amps for more natural sound, details and 3d presentation. Currently, driving my 87dB speakers by Yaqin MS-2A3 class A 2x14W! The sound is fantastic.

[@morespinach9832]

What speakers?

[@robertfournier7050]

My introduction to a Sugden 25a I think that's the model was in a shop being a small repair. We listened to it over and over and we're hoping that the owner would be delighted in that we found the problem in the amplifier's preamplifier section.

[@crtgamer2355]

To remedy the gain being too sensitive on an integrated amp, I decrease the volume of the source using the VU meter on my connected cassette deck with record engaged. I usually aim for just over the 0dB mark.

[@crtgamer2355]

Sorry, I should have said I use my cassette decks VU meter as a reference to decrease the volume of the source.

[@CT99999]

Great content, thanks for all the valuable info!! Note for other viewers: 1.5x speed is a regular speaking pace.

[@PearlAcoustics]

Thanks very much. Love the tip too 😉

[@Unicorn-ST]

Harley, you always catch my interest, even when you are talking in this video about 2 integrated amps that are out of my scope. I love how you do the videos and it’s a pleasure to watch and listen to you. Recently I bought a second hand new integrated amp, a Musical Fidelity X-T100 than I match with my Kef C55… I now is a modest gear, but in my case, the MF has done the Kef got a new life, they sound better than ever and I am enjoying a lot with them. It would be really magical to test some speakers like the Sibelius

[@PearlAcoustics]

Thank you Vincente, I am so pleased my videos connect with you. Very kind feedback. With regards budgets, when I review something I never make excuses for price. The piece of equipment either sounds good, or it doesn’t. It is either well made, or it isn’t. There were decades when I could not afford even moderately priced equipment, so (like you) I bought classic secondhand gear that had ‘gone out of fashion’ and then I kept it. The joy older, well looked after equipment can bring is endless. I hope one day you get to hear our loudspeakers too. We are opening listening rooms around the world, to enable just that. Best wishes, Harley

[@thomasfi1275]

The input sensitivity of the Sugden is 110mV. That’s the only reason why it play loud at low volume knob position.

[@BlueCliff72]

I've been waiting for more info about the INT-25 / Sibelius combo! And I've been hesitant about the INT-25 price tag if I'm quite honest 😅 Thank you for taking the time to make this video! In the meantime, I'll investigate some Sugden amps and keep saving up

[@PearlAcoustics]

You’re welcome

[@TheCharlesAtoz]

We missed your reviews Harley, and you! Nicely done A/B between these stalwart integrated amps, I'd keep them as well.

[@PearlAcoustics]

Thanks Charles. I have been very busy recently, with sound recordings and many other things, but I plan to make many more from now on.

[@TheCharlesAtoz]

@@PearlAcoustics I'd like to meet you and hang out in your new sound digs. If anything, YT can bring people together! I've learned a lot from your channel, and enjoyed your process.

[@PearlAcoustics]

@@TheCharlesAtoz you’re always welcome! Just contact us to arrange.

[@robmoores6078]

If you want more magic Harley, try the A21a Signature. There is something about that amp that is truly special and in my view the sweet spot in the Integrated range. I've owned the IA4, SE and ANV-50 and there's something about the way the A21a presents music that is incredibly involving. Great video - wonderfully informative.

[@torarnekvaly7753]

I found the A21a (non signature) very soft and lacked resolution.

[@PearlAcoustics]

Thank you Rob, very generous comment. I’ll ask my Sugden distributor to lend me one.

[@paulgrooveside2803]

@officialPearlAcoustics0you are a scammer, everyone please ignore.

[@PearlAcoustics]

@@paulgrooveside2803 thanks Paul! We’re trying to stop this… but it’s not easy

[@franckraymond6245]

​@@paulgrooveside2803 auriez vous l'amabilité de développer s'il vous plaît 🙏

[@paulshepherd-smith1875]

Nice one Harley. Fantastic review. Have listened to the Pass Labs NT-60 (big brother) before and it was excellent. I really value your insights and opinions. Keep up the great work.

[@PearlAcoustics]

Thank you Paul, you’re very kind

[@dannysegers4347]

So much passion and thought in all your video for the MUSIC 👏👍 I’m loving It ❗️❗️♥️🙏

[@PearlAcoustics]

Thanks Danny!

[@jeromemeyers7079]

Thanks Harley! That was really interesting. I think I may have been your first customer to pair the INT-25 with the Sibelius? In any case, it makes perfect sense why the Sugden would win out, at half the price and sounding almost the same as you say. Nevertheless, I love the INT-25 - you didn't mention it, but the optical volume dial continues to be a pleasure to use. However, I find the INT-25 remote to be nice looking, sure, but the IR signal just doesn't work all that well. It's just as well, because I pretty much only use it for volume, and in general I'd rather use the dial for the feel of it.

[@PearlAcoustics]

Thank you Jerome, very kind. Indeed, you were one of the first that I know of. I am pleased you mentioned the volume control, it’s very nice indeed. I should have focused on it a bit more. Thanks fir bringing it up

[@hermanchigrin6360]

I don’t know if this was suggested in the numerous comments. I would like to make a suggestion for you to try the Lavardin integrated. IS or IT, both good. It is a worthy candidate and can be purchased used around 2000 euro. If I was closer by, I would certainly lend mine.

[@PearlAcoustics]

Thanks for the suggestion.

[@Ricky-cl5bu]

Brilliant review, I too have about 5 different amps valve class a class ab naim alchemist etc love changing them about 😊

[@PearlAcoustics]

Thank you!

[@derranstokes8760]

Harley, I only discovered your channel yesterday and have been binge-watching.Thank you for such an informative and entertaining video.

[@PearlAcoustics]

You’re very welcome!

[@neps4th]

I wish you expounded more on the soundstage such as depth. Also what about image focus such as a female vocal with good accompanying instruments like piano and such.

[@PearlAcoustics]

Good point. Honestly, the image focus and tonality was very similar. The Pass was a little more neutral, accurate. But it was a very subtle difference. I thought I talked about depth. They both performed roughly the same. I hope this helps?

[@BSabbath]

Thank you for the wonderful comparison. I am currently using Sugden A21SE with Heresey IV and Epicon 2. Dreaming about buying Int25. The price is too high for me. This video will help me to take the right decision hopefully.

[@PearlAcoustics]

Thank you for your very kind comment. Enjoy the Sugden for as long as you can hold off the urge for the INT25 ;-)

[@hailtothevictorz]

Thanks so much for the video, Harley. I've been waiting for your review of the Sugden amp and I purchased one myself this year. It's actually the same price here in the U.S. I payed $4000 with a custom color faceplate. Five months for the build and shipping. What a bargain! I'm so glad they play well together with your Sibelius speakers, also on my shortlist for purchase. Every time you have a new video, it's a treat.

[@PearlAcoustics]

Why thank you Tim. You’re very kind. I am so glad your happy with the Sugden. It’s amazing that you got it for such a great price, and with a faceplate colour of your choice! I am sure you won’t be disappointed when you hear it playing through a pair of our loudspeakers. 😉

[@frostycanada6404]

Hello Harley, I truly enjoyed this comparison review. I owned and loved my A21 MKII and in 2021 I moved over to a their ANV50. You might want to give the ANV50 a try as it might close the gap between your A21 and INT-25. My only complain with my Sugden and I’m nitpicking is the input selector switch that is not totally silent (you get bleed through from the adjacent input) if both are in use. The remote can be twitchy / sensitive in operation from time to time. Thank you, Brian

[@PearlAcoustics]

Hi, thanks for your kind comments. I have an ANV50 and love it. I will do a review on it one day. I do agree with you, on the bleed through…. Something Nelson would never allow! Best wishes Harley

[@frostycanada6404]

@@PearlAcoustics I would really love to hear your insights on the ANV50. I’m not sure how my ANV50 actually works (technically) but Patrick Miller of Sugden says it’s not a digital amp and that it’s pure class A. Note: I think this was Tony Miller last design before passing away in 2021. Take care, Brian

[@dmcmaster3544]

@@PearlAcoustics Hi Harley, do you feel the ANV50 has that same sound stage as you noted in the A21 SE? Which of the two would you choose if you could only have one?

[@revelry1969]

What about the Rega Aethos? I think this one seems to be universally loved. May be nice to update this video. Sugden website seems to be down….

[@PearlAcoustics]

Indeed, I have a Rega Aethos amplifier in our listening room. It’s very nice, beautifully made and very attractive. It performs very well too!

[@ianrylands3880]

Great review, I was looking at the Sugden myself about 6 months ago but I settled on a Norma Audio Revo 140 class A/B dual mono block integrated. The build quality is up there with the pass labs and the sound is very natural and non fatiguing. Even though there are reviews online I have yet to see a you tube channel cover the Norma. I would love to see you review this.

[@PearlAcoustics]

Thanks Ian, glad to hear you are happy with the Norma. I will add it to my list 😉

[@ianrylands3880]

Thanks Harley I am very very happy with it. It weighs in at 55lbs so it’s another heavy one like the pass labs

[@gryphongryph]

Yes Norma would be interesting to get an opinion on, also the Swedish MoonRiver int 404 reference would maybe be a good match.

[@ianrylands3880]

I’ve won something?

[@markcarrington8565]

@@ianrylands3880 it’s just morons trying to scam.

[@DeAudiofilosyLocos]

Wonderful video Harley 😊. Thanks for taking the time!

[@PearlAcoustics]

Thanks! Very kind.

[@RedRiverMud]

Wonderful review! Thanks.

[@PearlAcoustics]

Thank you. You’re very welcome

[@Ian-nc4im]

Good video sir! I've had both the A21SE Signature and the INT-25. The INT-25 is still with me. The volume control, the ability to mute, the soundstage and the inner detail to me is what made the INT-25 a keeper. The Sugden is fantastic with an external Parasound phono pre-amp, but the gain coming from my Naim ND5-XS2 was too much and if the volume went past 10 o'clock you were in ear bleed territory. I'm only streaming these days or playing music from my NAS. I absolutely loved my A21 btw, and the price difference is not chump change. Speakers are Klipsch Cornwall IV's and the Pass mates beautifully with them.

[@maconpatton]

Sounds like Steve Gutenberg talking here!

[@robertm8518]

Very nice review! Thank you!

[@PearlAcoustics]

Thanks Robert.

[@MrBonger88]

Great comparison. Thank you

[@PearlAcoustics]

You’re welcome. Glad you enjoyed it

[@stephenfleschler9682]

Despite the higher power, have you heard or compared the Westminster Labs REI monoblack amps which are not what is considered "pure" Class A but a sliding bias Class A design.

[@PearlAcoustics]

Hi Stephen, thanks for your comment and question. No I have not heard the Westminster Labs REI monoblocks. I have just been reading about them, they sound very intriguing. Do you own a pair?

[@stephenfleschler9682]

@@PearlAcoustics Yes, after 50 years of only using various tube amps, such as Audio Research Classic 60, EAR 890 (Class A), various superior monoblocks (boutique), these amps are my last amps as they have zero negatives. It's not that I don't like my big monoblocks but they heat the room, require output tubes that wear out and occasionally draw too much current and fail, are not perfectly feedback adjusted for my speaker's and take 30 minutes to stabilize (warm-up). I keep my Reis on all the time and are ready to listen to. Now my neighbor bought a pair (he also of the tube only variety in a $400,000 system after owning half a dozen tube amps in the past six years-none of which I liked because he thought he need Conrad Johnson amps for simple music and higher powered PS Audio amps for orchestral and rock). The only person I know who complained about them was that they were not "pure" Class A due to their sliding bias; however, they are always in Class A at all output levels. The poster never heard the amps and said to get "pure" Class A Rivieras or Sugden amps. From his comments, another tube user is planning to hear and purchase the REIs and listed a dozen other Class A solid state amps.

[@stephenfleschler9682]

@@PearlAcoustics Yes, I purchased a pair to replace my large tube monoblocks custom built which sound excellent but require 30 minute warm-up (I keep the REIs on always), heat the room 3-4 degrees, are not perfectly matched with global feedback despite 4 position adjustment (no problem with solid state amp), output tubes need replacement and occasionally draw too much current and cause voltage regulation to fail. I have owned about a dozen tube amps for 50+ years including Dynaco IIIs and highly modified Stereo 70s, Audio Research Classic 60 and EAR 890 (Class A). My neighbor has a $400,000+ audio system. He has owned/used half a dozen tube amps in the past 6 years. He had a Conrad Johnson for simpler music and higher powered PS Audio amps for rock and orchestral. Nothing sounded like my system. Two weeks ago after hearing mine and installing a pair in his system, he purchased them. I have never experienced (I've attended and heard 1000s of show setups and dozens of high end home and store setups) the complete neutrality yet dense sound like tube amps from a solid state amp. Maybe big and hot Krells but not Pass Labs type Class A. These are small, very powerful, relatively cool amps whether they are deemed "pure" Class A or sliding bias Class A, they have Class A power at all output volumes. Maybe it's also due to their minimal parts, wiring design, a throwback to 50+ year old minimalist designs but using the latest tech and highest quality parts. I saw some massive new amps which have incredible number of parts. Boggles my mind how so many parts and wiring of these behemoth amps could sound good. They are relatively expensive but they are worth the price.

[@Kobryner1]

Dear Harley, you've made my day. Having Sugden A21 Signature sine 3 years and being sure that I shall not need ANY other integrated amp in my lifetime, I kept konsidering how would they match with Sibelius speakers. (I did exchange quite a few emails with Ajay..) It seems that my intuition was correct. Now I shall work on finding customers for my current speakers so that I could replace them with Your products. Greetings from Warsaw

[@PearlAcoustics]

🙏

[@jeffkalina7727]

Well done sir! Thank you. I started with the XA25 and ended with the INT25. I did have a Sugden trial for a day. It did not convey the "something special" I felt with the Pass. Nothing wrong at all and much less $ so I was tempted. I found a 2 month old INT25 for $5400 which retained 95% of the 3 year warranty. I have heard extremely wide sound stages from other brands-Naim comes to mind. Did not really notice that difference in my short Sugden session. I did recall finding the knob action to feel cheap though. Bottom line-buy the one with a factory closest to you!

[@BlueCliff72]

Hello! Quick question if you don't mind-were all these amps paired with the Sibelius Speakers or another type of loudspeaker? Thanks

[@PearlAcoustics]

Hi Jeff, at $5400, you got an absolute bargain. The great thing about the INT-25 is it’s superb build quality. +!it’s input stage is more compatible with modern, high output input devices. Enjoy!

[@PearlAcoustics]

Hi, no problem. For this video, I only compared them with our Sibelius loudspeakers. Although I have heard the INT-25 through Magico’s too.

[@budgetaudiophilelife-long5461]

🤗👍😎 GREAT TO HEAR FROM YOU HARLEY AND HOPE THAT ALL IS WELL 🤗 It’s GREAT that you don’t have to make that choice and can ENJOY THEM BOTH FOR YEARS TO COME 😁💚💚💚

[@PearlAcoustics]

Thanks! Indeed, I am one of the very lucky ones!

[@violin-schwerin]

great video! have you heard croft acoustics gear? love that very much. would be interested to hear linear tube audio stuff (if only because of their different technical approach to otl) however it's really rare in Europe

[@PearlAcoustics]

Thanks for your kind comment. I would love to hear Croft products too.

[@hongsam123]

Thanks to your opinion, I decided to buy Sugden a21 se signature!

[@PearlAcoustics]

Ok. Thanks for sharing. I hope you enjoy it as much as I do. Best wishes H

[@gino3286]

Hi thank you very much for this extremely fascinating review Speaking of high quality solid state integrated amps my memory goes to a Yba Integre the version with two mains transformers I think it is a class AB design but it sounded very musical I don't know the current production kind regards Gino

[@PearlAcoustics]

Thanks Gino! I have never heard the Yba Integre, isn’t it incredible just how many amazing pieces of gear there is out there? There must be some that fell through the cracks of obscurity…

[@gino3286]

@@PearlAcoustics Hi thank you for the very kind reply I know the Sugden very well it is famous in the Hifi world Great choice Tubes are also nice but their bass is less convincing Kind regards gino

[@hoobsgroove]

if you try short out the RCA inputs! in the a21 that might get rid of the humming and hissing.

[@PearlAcoustics]

Thanks for the suggestion

[@Buddythunder1]

I have the IA-4, which is a better price match to the Pass. I love it, refined and powerful.

[@PearlAcoustics]

Hi, see my comment in your earlier post. Enjoy your your IA-4!

[@jannek27]

7:40 zou ik u mogen vragen welke stroomkabel u gebruikt op de Sugden? Verder vind ik dit een fantastische versterker die mijn Tannoy TD 8 zeer mooi aanstuurt.

[@PearlAcoustics]

I just use the standard cables supplied with the amplifiers.

[@daviddarmanin2188]

Great review as always 👍🏾

[@PearlAcoustics]

Thank you!

[@dougg1075]

Enjoying your videos very much. Keep it up

[@PearlAcoustics]

Thanks Doug. Very kind

[@burakharley272]

Hello. I couldn't quite understand what you said because my English is bad. Prefer sugden between two amplifiers? And the sound stage and price were effective in this. Did I get right?

[@PearlAcoustics]

Yes that’s about it.

[@philipgardiner2003]

Great! Toughts on driving the SF Maxima Amator's with the Sugden A21SE?

[@PearlAcoustics]

I see absolutely no issue here. The SF’s are roughly the same effies our Sibelius loudspeakers

[@philipgardiner2003]

Cool. Thx. One Q, would the Decware Mystery be a good match to drive for Sibelius loudspeakers?

[@PearlAcoustics]

@@philipgardiner2003 absolutely! I not heard it but all reports are good. I see no reason why not

[@jasonme3557]

I guess it begs the question, is one wrong with ether one. Its odd today I am going to demo the Sugden.

[@PearlAcoustics]

They are cloth extremely good at doing what they were designed for. Enjoy your demo

[@lmikek]

Great video. Now the question is. We are in 2022 the environmental issues are also to be considered. Is there any class AB that is very close to the sugden magic??

[@PearlAcoustics]

Thank you for your kind comment. If you are using the Sugden in The winter, no problem environmentally 😉. But yes there are some, that are good but none sounding ‘the same’ that I know of. I have heard that VTV amplifier with the Purify module is very similar. I will be reviewing this quite soon.

[@johnchapman2197]

Great video - I have a Glen Croft GCI integrated - transvalve amp (mid 90's?) - Ken Kessler said it was a £1500 amp playing like it was £3k but its getting on a bit. Would I be better off with the A21? And what speakers are you using please? RIP Glen Croft by the way - died early November a minor genius and true gent

[@PearlAcoustics]

Hi John, the speakers are our Pearl Acoustics, single driver, Sibelius. It’s hard to comment on your amplifier situation, there are so many variables. If ‘Getting on a bit’ means it’s not performing as it used to, or you think more modern amps might perform better. That could be true. The A21SE, for example, is extremely high quality (sound wise). You can always reach out to us via ‘enquiries @ PearlAcoustics. Com. Best wishes, H

[@Christographer_UK]

Another great video Harley. As a matter of curiosity, what is the larger Sugden amp sitting below the A21 & how does that sound compared to the A21 & the Pass?

[@PearlAcoustics]

Thank you Chris. That’s an ANV-50 anniversary. Very interesting amplifier. A bit more dynamic than the 21se and a bit more neutral. ‘Correct’ but not boring. And it does not run hot, and has components designed to last 100 years!

[@MG-iv8oo]

i will be getting the int-25. i so want to pair them with your speakers but i am not a jazz or classical listener and i (perhaps wrongly) associate your speaker value proposition with jazz/classical. i critically listen to more post punk, alternative, instrumental "complex" music (e.g., radio head, cure, joy division etc). i listen mostly at low volume in a small/medium dedicated listening room. again, i am in love with the concept/idea/vision of your speakers but not sure it is a fit for my taste. please help!

[@PearlAcoustics]

Hi, lovely to hear from you! May I suggest you reach out to us via our website and we can discuss your needs and expectations, we’re not going to try and sell you anything but we might be able to help, or even put you in touch with someone with a pair living near to you. Best wishes, Harley

[@dsm238945]

Harley, thanks for this comparison. I have dreamed of having an INT-25 for a long time. Price and lack of availability for a used one have stopped me. I did purchase the A21SEabout four months ago. It was a dealer demo and I got it for about $3,600 USD. I absolutely love it! I run it through Klipsch La Scala speakers in a moderately large room. It is glorious playing vinyl, SACD or streaming. Now that you have put up this video I can quit wondering if the INT-25 would have been worth saving up and waiting for.

[@PearlAcoustics]

Thank you David. So pleased you’re happy with your Sugden.

[@storm-sf5rj]

i had a Sugden A48 in the late 70's to mid 90's the Orange and Brown one and i loved it but the output transformers blew and when i moved house in 1995 i left it in the old house, i wish i had kept it and got it repaired

[@PearlAcoustics]

Indeed…

[@torarnekvaly7753]

Another difference is that the Pass "can" be turned on all the time, while the Sugden needs to be turned off not in use.

[@PearlAcoustics]

Hi Tor, interesting comment. I am not sure that either should be left on unless you want to heat your listening room. 😉. FYI I often forget to turn my amplifiers off and the next morning I am not aware of any difference in the temperature of either component. Or safety risks.

[@maxcasci7432]

Beautiful really beautiful review I wanted to kindly ask which amplifier is the one on the bottom right (Musical Fidelity)and your respectable judgment on it thank you very much good listening

[@PearlAcoustics]

Thank you very much, you’re very kind. The Musical Fidelity is a M8s. It’s absolutely fantastic… I will be doing a review of it in the coming weeks… it’s a real classic

[@maxcasci7432]

@@PearlAcoustics I thank you and I wish you good work

[@nskiad]

Just out of curiosity, with the sugden powered on , if you go to 9-10 o’clock on the volume with nothing playing, do you hear that hum and hiss as you mentioned? Thanks for the review! It’s awesome!

[@PearlAcoustics]

Thanks for your very kind appreciation. With regards to the Sugden’s hum and hiss, I hope I did not worry you? that’s never going to be an issue, especially when playing music. I only mentioned it because the Pass was absolutely silent, in comparison. So no, sitting in your chair 2-3 meters back, even in the quietest of rooms at 9 or 10 o’clock. You should not hear a thing.

[@nskiad]

@@PearlAcoustics ok thanks! I have the Sugden LA-4 preamp, which I do hear something similar when close to the speaker. Wasn't sure it was normal, but sounds like it is.

[@markhusbands6132]

Love it Harley!!!!

[@PearlAcoustics]

Thank you

[@tonydeniro284]

A sugden a21se paired with Tannoy speakers, pure bliss

[@adrianbeck1654]

I wonder if there is a synergy with your speakers and a Croft amplifier(English and class a from a small family owned company)

[@PearlAcoustics]

Dear Adrian, thank you for your question. Would love to try. I have heard of them but never had the pleasure of auditioning one in my studio.

[@adrianbeck1654]

I used to have a audionote oto,a class a design el34 valve amplifier,I miss it(I love your transmission loudspeaker design,I wonder if you would ever consider a transmission line subwoofer design;because it would Serve a hole in the market,and solve a problem of placement for a lot of us(ie put the subwoofer in our seated listening position and crawl around the floor until we get the best bass definition and extension,that the opposite is true-that is the position for the subwoofer to be placed)which is not possible with your main speakers-wife factor etc.

[@PearlAcoustics]

@@adrianbeck1654 thank you for your kind words. Of course our loudspeakers do not require sub-woofers, as they already go down to 38hz very easily. Many sub-woofers are designed in a reflex type system. But I am not sure if I totally understand your suggested solution.

[@ChicagoRob2]

Going against the grain, here, but after being with the INT-25 for quite a while, I moved on to the Yamaha A-S3200. Call me a blasphemer, but what an amazing piece of audio gear.

[@PearlAcoustics]

No blasphemy possible in the hobby of HiFi 😉 Yamaha make high quality equipment

[@briancampbell7712]

what about a Copland CTA 405...❓

[@PearlAcoustics]

I have never heard these amplifiers. They look very interesting though.

[@BeanieHead1500]

Surprised that you chose the Sug despite the hum/hiss - wouldn't that mean the background sound ultimately would not be as "dark", which is often a quality sought by audiophiles?

[@PearlAcoustics]

You’re absolutely right. It’s just that, luckily, in practice it is so lie, it is inaudible in the listening position and I felt the soundstage width, was more significant.

[@1mctous]

I agree with Harley about too much gain. The volume pot should traverse most of its range before clipping (2-3 o'clock). I also agree that low level steady noise isn't bothersome because the brain quickly filters it out.

[@spvlinn9009]

That will be my choice too even I am in the states. Also I wonder if you will have a chance comparing a21se to Lavardin ITx? That will be very interesting.

[@PearlAcoustics]

I don’t know the Lavardin ITx

[@spvlinn9009]

@@PearlAcoustics French thing

[@scottbennett3119]

Very nice review! Now I am wondering why the Pass Labs amp has a narrower stage width presentation. What accounts for the difference?

[@PearlAcoustics]

Hi Scott that’s an extremely interesting question that I would love the answer to. We know we can play with soundstage using DSP technology but I don’t know the physics here. I a am going to see if I can find out. It’s probably something to do with phase shifts, I am guessing.

[@scottbennett3119]

@Pearl Acoustics Great. I can't wait to learn what you find out!

[@qddk9545]

Maybe the finger tapping of the speaker wood fits the Sugden better 🙂 🙂

[@scottbennett3119]

@@qddk9545 Wrong thread...

[@bladerunnern6]

To the Int 25 I would have compared the Sugden IA 4. This is a very nice video anyway!

[@PearlAcoustics]

Thank you. The reason I did not compare the IA4 is because it has more features than the int-25. But you’re not the only one with this remark, so I gave ordered one from Sugden. 😉

[@bladerunnern6]

@@PearlAcoustics Thank you!!

[@gibcoprobe66]

Great review. Surprised you didn't mention the heat aspect. Most of the reviews I have read or seen mention that the Sugden gets really hot, I mean uncomfortable hot... I would think the Pass Lab with those huge heatsink don't warm up as much? Is that your experience?

[@PearlAcoustics]

Hi, interesting question and thanks for your kind comment. I think it’s the A21 that gets very hot but the A21 SE gets fairly hot but only by design. And not really hotter than the Pass. Class A amplifiers will always run hot. But both amplifiers take this into account. Even the A21 has been around since the 1960’s and Sugden has a good reputation for reliability.

[@gibcoprobe66]

@@PearlAcoustics Thanks for the clarification Harley.

[@r423fplip]

I would probably buy the topping pa5 ! Or the la90, if they give it more power and a remote.

[@alfovebraseth]

A guess from me as an engineer, the Pass might use more negative feedback and a push-pull topology which eliminates hum and hiss. The Sugden might use less negative feedback, and it is single ended, which produces a livelier and greater soundstage, and more gain on the volume control. I have the Sugden IA-4 and it's a keeper, I really like it.

[@PearlAcoustics]

Very interesting. This could be it. I wonder if anyone can add to the conversation here?

[@alfovebraseth]

@@PearlAcoustics If you see on the FirstWatt product page, Nelson has both PushPull and SE class A designs, I have built a Pass and it is great. I highly enjoy your reviews, thanks a lot.

[@PearlAcoustics]

@@alfovebraseth indeed, Nelson is an extremely gifted engineer. I always wanted to build some of his designs, and I am sure I will one day. What better way to understand the principles of amplifier architecture

[@ABDULRAHMAN7334]

Thanks for this information. Why do you have one way speakers? you do not believe in 3 way speakers are better?

[@PearlAcoustics]

Hi, we have one way because we believe they have certain advantages. We can produce a loudspeaker that sounds completely natural, has a full frequency range from very low to high, and can transmit incredible detail. Three way speakers are different and can sometimes go louder. Each has its own purpose. The best way to discover this is to hear them for yourself. 😉

[@ramanmanan203]

This was a great video to watch and I am left with some longing.. You see, I am a gear head.. I have the Luxman C900U/M10X separates and Luxman 550AXII, and Luxman 595ASE integrated amplifiers. Also have the Rodgers High Fidelity EHF-200 MKII. Should I stop lusting after the Pass Labs INT-25, I hear nothing other than excellent reviews of PASS lab equip.. My dealer just started to carry the Pass Labs brand.. I am a big sucker for Class A amps..

[@PearlAcoustics]

Hi, thanks for your kind comment. PassLabs equipment is truly excellent and extremely well built. But as you have such good material already, my advice is take your time and only switch, if you are certain. And if you can don’t sell gear to acquire new gear. Not until after you E had the new stuff at home for a month. By then alm should become straightforward

[@ramanmanan203]

@@PearlAcoustics Thank you so much Harley!! and really appreciate your advice on not to sell gear to acquire new ones.. I purchased all the above after careful scrutiny and in home audition.. If at all I'd sell the Luxman D03X CD player, to get the Int 25, cause I am not listening to CDs as much anymore, and it's a recent purchase my dealer let's me swap to a different equipment as long as it is twice as much in price and within a year.. I am new to your videos, and I just love them.. Your calm demeanor and thoughtful words..

[@PearlAcoustics]

@@ramanmanan203 thanks. Very kind

[@Linux_Lucy]

Have U tried a Mains DC Blocker on the Sugden ? ? These will (usually) sort the Transformer HUM .... However, I don't know if it will cure the 'Hissing' ! ? Having recently borrowed a friends A21 'Line' Amp for a month, I will be ordering one in January .... BTW ... I didn't hear any of the Hum / Hissing issues on this 'Model' ! ! ...Could U have a 'rare' Dodgy Sample ? .. Oh, and 'yes', the Lyngdorf 1120 is a Brill bit of Gear. I've had mine about 6 months now. Luv Luv Luv It 😍Another nice, well produced Video. ATB.

[@PearlAcoustics]

Hi, I am not sure a DC splitter will make a difference. I think I must be clear, the hiss and hum is only audible when on high volume and no input signal. So it is not an issue in practice. Glad you like the TDAI

[@BadMonkeyFinger_Audio]

Great video! What a fantastic comparison (I always find comparison vids the most useful). I love these two brands, and was ecstatic to see this as a suggested vid. I'm not surprised at all by what you've stated. I wish I could play in that ballpark, though... My pockets aren't that deep, unfortunately. I currently own an old A48b that has been modified with point to point wiring, increased capacitance, a much better switch, bypassed balance and mono sections, etc etc.. It sounds awesome when warmed up; I'm so curious how an A21 would perform by comparison (I've only heard them in stores, so no direct experience/ comparison so far). Hope to find out one day. If this Sugden A21se beat out the Pass INT25 - even by a touch, it must be seriously impressive.

[@PearlAcoustics]

Thanks, very kind. Our hobby is a strange one, when you compare the A21SE with your ‘old timer’ you might find that it is no better, to your taste. Enjoy the music!

[@iamspyvspy3077]

What happened to your PureAudio ONE ?

[@PearlAcoustics]

Hi, I am careful not to talk too much about products that are no longer available. My PureAudio One, was sold to a customer who wanted an integrated amplifier that he never had to upgrade. I was hoping to replace it with the power amplifier version, but never managed to find one.

[@wladers39]

Hello Harley. A bit off topic: is it a Pro-Ject CD Box RS2 T CD Transport sitting on the top shelf? If so, how do you find it and what DAC do you use with it, please?

[@Lomitte-zq8fj]

Hello! I have Kef LS50 speakers and a Moon brand 250i amplifier from Simaudio. I would like to upgrade my system with the Sugden A21SE amplifier. Is this a good idea?

[@PearlAcoustics]

Hi, I am struggling with your question as I do not know how your existing system sounds. + your room can have a massive impact. My advice is not to change anything unless you can define clearly what you do not like in your system. (Or unless you just fancy a change)! 😉 The Sugden is very nice, hand built and rather ‘warm’ sounding. Very relaxing to listen to. But I cannot say if for you it will work. Sorry about that!

[@Lomitte-zq8fj]

@@PearlAcoustics Hi, My system sounds pretty good and I'm happy with it. I heard on the internet that the Moon brand from Simaudio was not very good compared to the Sugden brand. I hope I made the right choice on the amplifier. I like your videos😆

[@PearlAcoustics]

@@Lomitte-zq8fj thanks for your kind comment. Enjoy the music.

[@willmac5642]

Love my X150.5 (with Hattor pre)

[@cameronkrause4712]

Well, it was very interesting. I honestly thought you would have gone with the Pass Labs. I am still wondering how you will feel if you use both of those amps for another 6 months. I wonder how these amps perform when one is playing mono albums. But ultimately these amps will benefit from lots of breakin time.

[@PearlAcoustics]

Indeed, another six months might make difference but I have known the Pass for a while now, so I think (for me) the facts remain. Pass is exceptional quality in all its aspects but the little Sugden, for all its faults is very engaging. Maybe a better comparison is the Pass as a Mercedes and the Sugden a Citroen 2cv! 😉

[@cameronkrause4712]

@@PearlAcoustics I must say that I really like the look of the Sugden.

[@markcarrington8565]

@@PearlAcoustics ouch, Harley. I doubt Sugden would thank you for that comparison! Mercedes vs Honda would be my choice. Having owned both I say the Merc edges it on build, whilst the Honda is no slouch in this respect, but the Honda gives you more bang for your buck. Nice review.

[@PearlAcoustics]

@@markcarrington8565 thanks!

[@matzeflamingos]

Thank you Harley! which of the two represents the depth of the stage better?

[@PearlAcoustics]

Good question. To be honest, I couldn’t tell much difference between the two. That was the strange thing. With the Sugden the stage was wider but the depth was more or less the same. That was very unexpected

[@matzeflamingos]

@@PearlAcoustics Thank you

[@dmcmaster3544]

Hi Harley, do you feel the ANV50 has that same sound stage as you noted in the A21 SE? Which of the two would you choose if you could only have one?

[@PearlAcoustics]

Hi, yes, they both have a very similar soundstage. Difficult to answer. But if I could only have one, and it getting warm was not an option, I would go for the A21SE. The ANV-50 is a more modern design and more similar in character to the PassLabs-Int 25. Hope that helps?

[@PerthSoftware]

I had the original Sugden A21 back in the 1960s!

[@xcvbxcvb2179]

Could a RCA attenuator solve the gain issue on the sugden?

[@PearlAcoustics]

Absolutely. But in fact, it’s not really a ‘problem’ I was more making a comment. Attenuators make sense, especially when balancing the inputs if differing source components. But this where I like the addition of devices like the Lyngdorf TDAI, one can make these adjustments totally in the digital domain.

[@geraldgreene5563]

What a great video

[@PearlAcoustics]

Thanks! Glad you enjoyed it.

[@mookie2637]

Well, I've been wrestling with this a little bit. As a convert to Class A/SE (coming from Naim, via a Pass Labs Aleph 3), this is a very real choice for me, speakers being ProAc DB1s in a fairly small room. The Pass is very expensive in the UK (£8K?), and this seems to be a clear view that ultimately the Sugden is just as good if not better. The other contenders in this space are the Colin Wonfor designs, but they are not easy to get hold of, and reviews/dems seems non existent.

[@PearlAcoustics]

Hi, living in the UK, the Sugden is an excellent choice, especially for a small room, due to its wide soundstage

[@richardelliott8352]

tremendously enjoyable to hear a perspective about quality sound that doesn't require some kind of room filling battleship testosterone statement . Since it is all just illusion, I , and my limited budget, prefer a well informed long term buying decision over the all too typical bombastic HI Fi reviewers approach of cubic money and then buy something else when the next best greatest thing come along.

[@carlitomelon4610]

Excellent as always Mr Lovegrove. Of course keeping both gives you the opportunity to demonstrate the Sebelius with either for potential customers. You might look in to installing a different logarithmic potentiometer in the Sugden. I'm sure they'd work with you on that. Then it could be useful all the way up to 11 with less noise maybe? Regards 🎵🎶☺️🎶🎵

[@PearlAcoustics]

Hi Carlito, you make an excellent point. My colleague Ajay feels exactly the same as you and will propose it to Sugden. But Sugden have a massive waiting list for their products so I am not sure how much R&D they want to do right now.

[@carlitomelon4610]

@@PearlAcoustics Well.... I'd take the bull by the horns and replace the pot myself! 🎵🎶😉🎶🎵

[@alistairwilson5344]

Thanks for the great review Harley. Out of interest, how does the Pass Labs int-25 compare with the Quad Artera pre you used when you reviewed the XA25 a while back? I already have an XA25 and am looking for a suitable preamp at the moment. Any thoughts would be greatly appreciated, as it doesn't play well with my current passive preamp.

[@PearlAcoustics]

Thanks Alistair! The XA-25 deserves a pre with ‘punch’. Maybe, reach out to us via email and we can advise you better. Pre-amplifiers are so tricky because there are so many options, depending on your input needs.

[@peterlundin7953]

Have You tried the Rega Aethos Integrated with Your Sibelius Speakers? (It is quite a sleeper) I traded my Sugden A21Se for it to drive my 96dB sesativity Open Baffle speakers!

[@PearlAcoustics]

No I have not... I will check it out. Thanks for the tip!