• WANTED: Happy members who like to discuss audio and other topics related to our interest. Desire to learn and share knowledge of science required as is 20 years of participation in forums (not all true). Come here to have fun, be ready to be teased and not take online life too seriously. We now measure and review equipment for free! Click here for details.

Adcom GFA-535 ii listening review or: Never meet your heroes

77Bacon

Member
Joined
Mar 3, 2021
Messages
6
Likes
2
So, this is is sort of a listening review followed by a couple questions because I’m new to mid-fi gear. If you can help out with the questions I’d appreciate it.

I recently picked up a GFA-535ii off the Bay and did some critical listening for about 4 hours last night. Until last night, I was planning to complete it with a GFP-565 or maybe a GFP-710 but now I don’t think so.

My setup is what for most of you is likely a 2nd or 3rd system. Its in an apartment I live in during the week due to a long-term work assignment away from home. It consists of a Onkyo A-9010 integrated amp, a vintage Sansui TU-717 tuner and a pair of Revel M105 speakers that I’ve been running for about 4 months, so I’m sure they are broken in. Music source is provided by an iPhone and the little Apple D/A converter dongle running on a long RCA patch cord to the RCA inputs on the 9010. Music is all stuff you can listen to in an apartment! Current favorite is vocals and piano stuff.

WOQIu4f.jpg


The Revels are set at ear level and I have found they make a really good sound stage. They sound the best pulled out from the back wall about 2-3 feet and seem to open up more the further out they are. I have a mini DSP that I wanted to incorporate into this setup, so the plan was to take advantage of the processor loops on the vintage Adcom stuff and go that way.

I’ve read all the usual stuff about preamplifiers and how important they are, and the “straight wire with gain”. Well I thought I had that beat to no end, because I just ran the RCA feeds from my iPhone right into the back of the Adcom. No preamplifier at all, literally just a wire. I was expecting something at least as nice as my Onkyo A-9010 but no.

I ran my listening tests with the tone controls bypassed on the 9010. Don’t get me wrong the 535 was dead quiet to my ears and powerful. Sounded good for a stereo. But compared to the 9010, the 535 sound was soft with a much flatter sound stage. There was a sort of radio sound to vocals and piano that removed some of the enchantment. It tended to make most music sound similar and in recordings with a lot of texture, the fine details that bring amazement with ‘how did they think this up or mix this’ impressions were not there. Not a lot of magic happening. Here is some of what I listened to and the differences:

At Last by Etta James. On the 535 it just sounded like an old song on the 9010 you could really get an idea of what made her great like you could listen through and past the age of the recording. Not fun on the 535.

Someone to watch over by Linda Ronstadt. The 535 impressed me as sort of smooth in that details were not pushed hard, but this softness and lack of detail removed the delight in really getting into these vocals. Sexy on the 9010 if not stunning thinking this is a female vocalist from the “old days”

Crazy by Daniela Andrade. This song is magic on the 9010 between the strumming guitar, and when she starts to sing its so close miked and the sounds are so well defined and separated the impression is she’s maybe performing in the room and these are the monitors, like a live performance at a bar. No magic on the 535 just sounds great.

Time to say goodbye by Bocelli. On the 535 it sounds like a cliché on the 9010 all the texture is there and can give you goosebumps.

Wave by Beck. This is the perfect song to shows the loss of texture, space and fine detail on the 535. On the 9010 you can just get lost in this song and wonder how it was put together and what decisions were made and there is none of this fascination with the 535, just good sound.

I hate you, I love you (featuring Olivia Obrien) explicit: Sounds great on the 535, but on the 9010 everything is so distinct and separated it sounds like there are different speakers for the piano, the vocals, and the percussion.

Don’t know why by Norah Jones. Sounds great on the 535 but on the 9010 there’s complete separation of everything and the piano just glows.

Caribbean Blue by Enya. Like Wave by Beck another recording that shows how the 535 just obscures the fine texture that for me on the 9010 captures my attention and makes me look for the source and just wonder how it was put together.

Stay with me by Miki Kuroki. On the 9010 this showcases a production of extremely high quality and you find yourself listening harder to pick up details and delighting when you find them, on the 535 just sounds fine.

I read through the specifications for both amplifiers and don’t see what would drive the great texture and open sound of the 9010 over the 535. I’m mildly amused to find I’ve turned into one of the people that can hear differences between amplifiers. Until I experienced it firsthand it’s just something I read about and wondered if its real or just conceit.

I think the 535 sounds good and that’s it. I have to agree with the Stereophile review by Corey Greenberg, the 535 is a no. Its disappointing because Adcom stuff is something I’ve wanted to try for some time.

So I know this was long but I’ve got 2 questions that hopefully you guys and gals can help me out with:
  • Do you think that me running my RCA feed directly into the back of the 535 with NO preamplifier, somehow degraded the sound? And that it would somehow sound better with a matching Adcom preamplifier due to some reason involving impedances or what the amp was expecting at its inputs? But I can’t imagine how adding a preamp to the 535 would be electronically cleaner than literally a straight wire with no electronics in the path whatsoever.

  • What’s the step up from the Onkyo A-9010, a Marantz? I’d still like to find something with a processor loop so I can play with my MiniDSP, but I’m having second thoughts on that plus no modern amps come with processor loops. Also I’m aware of tubes, tube rolling, tube sound don’t want to get into that yet.
Thanks,

Bacon
 
Last edited:

IowAudio

Member
Forum Donor
Joined
Oct 23, 2019
Messages
85
Likes
102
Location
Iowa
I was the same way with the Sony SS-M7A speakers. Wanted a pair since I was a kid. Finally got a set and liked my budget Sony CS5 more.... Kinda the same when I spent $700 on the Emotiva PT-100 preamp and A300 amp. They didn't sound any better than my $100 used Marantz SR4021 and miniDSP HD just more powerful. I got to listen to a Adcom 5400 not to long ago that was for sale buy a local. It did sound good but wasn't going to be an improvement over my Marantz so I passed. Also a lot of Adcom gear is getting pretty old and I'm not interested in repairs. It doesn't surprise me you weren't blown away. Your iphone may not be enough. Try using your misiDSP as a preamp and control gain in Windows. If you decide to keep the Adcom you will need a preamp of some sort. Could also be something wrong with the Adcom.
 

b1daly

Active Member
Forum Donor
Joined
Dec 15, 2018
Messages
210
Likes
346
So, this is is sort of a listening review followed by a couple questions because I’m new to mid-fi gear. If you can help out with the questions I’d appreciate it.

I recently picked up a GFA-535ii off the Bay and did some critical listening for about 4 hours last night. Until last night, I was planning to complete it with a GFP-565 or maybe a GFP-710 but now I don’t think so.

My setup is what for most of you is likely a 2nd or 3rd system. Its in an apartment I live in during the week due to a long-term work assignment away from home. It consists of a Onkyo A-9010 integrated amp, a vintage Sansui TU-717 tuner and a pair of Revel M105 speakers that I’ve been running for about 4 months, so I’m sure they are broken in. Music source is provided by an iPhone and the little Apple D/A converter dongle running on a long RCA patch cord to the RCA inputs on the 9010. Music is all stuff you can listen to in an apartment! Current favorite is vocals and piano stuff.

WOQIu4f.jpg


The Revels are set at ear level and I have found they make a really good sound stage. They sound the best pulled out from the back wall about 2-3 feet and seem to open up more the further out they are. I have a mini DSP that I wanted to incorporate into this setup, so the plan was to take advantage of the processor loops on the vintage Adcom stuff and go that way.

I’ve read all the usual stuff about preamplifiers and how important they are, and the “straight wire with gain”. Well I thought I had that beat to no end, because I just ran the RCA feeds from my iPhone right into the back of the Adcom. No preamplifier at all, literally just a wire. I was expecting something at least as nice as my Onkyo A-9010 but no.

I ran my listening tests with the tone controls bypassed on the 9010. Don’t get me wrong the 535 was dead quiet to my ears and powerful. Sounded good for a stereo. But compared to the 9010, the 535 sound was soft with a much flatter sound stage. There was a sort of radio sound to vocals and piano that removed some of the enchantment. It tended to make most music sound similar and in recordings with a lot of texture, the fine details that bring amazement with ‘how did they think this up or mix this’ impressions were not there. Not a lot of magic happening. Here is some of what I listened to and the differences:

At Last by Etta James. On the 535 it just sounded like an old song on the 9010 you could really get an idea of what made her great like you could listen through and past the age of the recording. Not fun on the 535.

Someone to watch over by Linda Ronstadt. The 535 impressed me as sort of smooth in that details were not pushed hard, but this softness and lack of detail removed the delight in really getting into these vocals. Sexy on the 9010 if not stunning thinking this is a female vocalist from the “old days”

Crazy by Daniela Andrade. This song is magic on the 9010 between the strumming guitar, and when she starts to sing its so close miked and the sounds are so well defined and separated the impression is she’s maybe performing in the room and these are the monitors, like a live performance at a bar. No magic on the 535 just sounds great.

Time to say goodbye by Bocelli. On the 535 it sounds like a cliché on the 9010 all the texture is there and can give you goosebumps.

Wave by Beck. This is the perfect song to shows the loss of texture, space and fine detail on the 535. On the 9010 you can just get lost in this song and wonder how it was put together and what decisions were made and there is none of this fascination with the 535, just good sound.

I hate you, I love you (featuring Olivia Obrien) explicit: Sounds great on the 535, but on the 9010 everything is so distinct and separated it sounds like there are different speakers for the piano, the vocals, and the percussion.

Don’t know why by Norah Jones. Sounds great on the 535 but on the 9010 there’s complete separation of everything and the piano just glows.

Caribbean Blue by Enya. Like Wave by Beck another recording that shows how the 535 just obscures the fine texture that for me on the 9010 captures my attention and makes me look for the source and just wonder how it was put together.

Stay with me by Miki Kuroki. On the 9010 this showcases a production of extremely high quality and you find yourself listening harder to pick up details and delighting when you find them, on the 535 just sounds fine.

I read through the specifications for both amplifiers and don’t see what would drive the great texture and open sound of the 9010 over the 535. I’m mildly amused to find I’ve turned into one of the people that can hear differences between amplifiers. Until I experienced it firsthand it’s just something I read about and wondered if its real or just conceit.

I think the 535 sounds good and that’s it. I have to agree with the Stereophile review by Corey Greenberg, the 535 is a no. Its disappointing because Adcom stuff is something I’ve wanted to try for some time.

So I know this was long but I’ve got 2 questions that hopefully you guys and gals can help me out with:
  • Do you think that me running my RCA feed directly into the back of the 535 with NO preamplifier, somehow degraded the sound? And that it would somehow sound better with a matching Adcom preamplifier due to some reason involving impedances or what the amp was expecting at its inputs? But I can’t imagine how adding a preamp to the 535 would be electronically cleaner than literally a straight wire with no electronics in the path whatsoever.

  • What’s the step up from the Onkyo A-9010, a Marantz? I’d still like to find something with a processor loop so I can play with my MiniDSP, but I’m having second thoughts on that plus no modern amps come with processor loops. Also I’m aware of tubes, tube rolling, tube sound don’t want to get into that yet.
Thanks,

Bacon

There are several reasons that could explain your experience:

- the adcom is old and not performing to spec
- sighted testing, no matter how much you think you can be objective, you can't, at the very least you must match level precisely and have a quick way to make the switch to compare sounds, the perceptual difference that various psychological bias can impart is huge (and it doesn't alway go the way you 'expect')
- there might be some kind of signal processing going on in your A-9010 you missed
- you have the left right speakers switched on one amp
- polarity of one speaker switched
- I think it's unlikely running your iphone to the adcom is responsible for any sound degradation, however having a real volume control has a profound impact on subject experience of how an amp sounds, again you must carefully equalize levels to compare

FWIW, it is unlikely you will find an amp that 'sounds better' than your Onkyo. If you are happy with features and power there is no reason to switch.
 

SIY

Master Contributor
Technical Expert
Joined
Apr 6, 2018
Messages
7,413
Likes
16,336
Location
Alfred, NY
There are several reasons that could explain your experience:

- the adcom is old and not performing to spec
- sighted testing, no matter how much you think you can be objective, you can't, at the very least you must match level precisely and have a quick way to make the switch to compare sounds, the perceptual difference that various psychological bias can impart is huge (and it doesn't alway go the way you 'expect')
- there might be some kind of signal processing going on in your A-9010 you missed
- you have the left right speakers switched on one amp
- polarity of one speaker switched
- I think it's unlikely running your iphone to the adcom is responsible for any sound degradation, however having a real volume control has a profound impact on subject experience of how an amp sounds, again you must carefully equalize levels to compare

FWIW, it is unlikely you will find an amp that 'sounds better' than your Onkyo. If you are happy with features and power there is no reason to switch.
This.

One other point, though- if the OP is using the iPhone, he may want to check the file formats. iTunes, for example, seems to use a lossy compression. It's not night and day different than uncompressed, but it's not totally transparent, either.
 
OP
7

77Bacon

Member
Joined
Mar 3, 2021
Messages
6
Likes
2
There are several reasons that could explain your experience:

- the adcom is old and not performing to spec
- sighted testing, no matter how much you think you can be objective, you can't, at the very least you must match level precisely and have a quick way to make the switch to compare sounds, the perceptual difference that various psychological bias can impart is huge (and it doesn't alway go the way you 'expect')
- there might be some kind of signal processing going on in your A-9010 you missed
- you have the left right speakers switched on one amp
- polarity of one speaker switched
- I think it's unlikely running your iphone to the adcom is responsible for any sound degradation, however having a real volume control has a profound impact on subject experience of how an amp sounds, again you must carefully equalize levels to compare

FWIW, it is unlikely you will find an amp that 'sounds better' than your Onkyo. If you are happy with features and power there is no reason to switch.

The Adcom may indeed be old and not performing due to that alone. I can omit testing bias and basic connection errors, unless the bias works in reverse too because I was expecting the Adcom to sound at least as good. I also had the 9010 set in bypass mode (tone controls). I thought running with no preamp at all would be ideal in terms of reduction of degradation of the signal, but the Adcom just did not bring any sense of wonder to the program material. What was reduced to me was the execution of fine details and just the sort of smoothness and sense of space to the sound. I mean it was clearly, for a critical listener anyway, a step backwards and it was pretty clear after several songs.

What started me on the sound quality topic wasn't even an amplifier. I was jonesing for a vintage tuner and when I had my two besties in front of me, a Sansui TU-717 and a Yamaha T-2 there was a big difference. The 717 was easily the better of the two, same issues like separation, sense of space, soundstage but at a level where my wife could agree the 717 was better after only some time listening.

I'm also thinking the differences might be the result of the system that is the amp plus the speakers connected. I understand that amps will change their responses based on the connected load and maybe the Adcom does not pair well with the Revels.
 
Last edited:
OP
7

77Bacon

Member
Joined
Mar 3, 2021
Messages
6
Likes
2
This.

One other point, though- if the OP is using the iPhone, he may want to check the file formats. iTunes, for example, seems to use a lossy compression. It's not night and day different than uncompressed, but it's not totally transparent, either.

I'm not familiar with digital formats, but I'm using Amazon HD as the app on the Iphone. On that topic, I've tried to tell the difference between the standard formats and the HD versions and cannot.
 
OP
7

77Bacon

Member
Joined
Mar 3, 2021
Messages
6
Likes
2
So as a side bar to this topic I picked up a Proton A-1150 and spent several hours listening to that last night, run directly by the Iphone as before, same favorite recordings and Revel 105. This amp absolutely killed the Adcom in terms of SQ and seemed like a warmer sound than the 9010, its seemed like it was controlling bass better at any volume. It also seemed to have much better channel separation than the 9010 which had me spending all morning looking up crosstalk specifications on both. I am really not sure if there was any difference to the 9010 in terms of the space or soundstage, but in some parts it sounded ever so slightly not smooth, so I ordered a pair of the speaker protection relays and will replace those, their 30 year old contacts might be dirty and adding some distortion. It was definitely a different sound again than the 9010 I have to spend more time listening to it to know if its a keeper. The giant VU meters are a bonus!
 
OP
7

77Bacon

Member
Joined
Mar 3, 2021
Messages
6
Likes
2
Next up was ran the phone into a Schiit Loki, then to the amp. That also sounded good and it was nice to be able to adjust the sound.
 
OP
7

77Bacon

Member
Joined
Mar 3, 2021
Messages
6
Likes
2
After that I bought a Schiit Asgard 3 and ran that without the Loki. The Asgard arguably dulled the sound with its warmth and smoothness. It still sounded good, it was dead quiet but it really pulled a lot of magic from everything but vocals. Piano especially lost most of the air around the tones that would make my hairs stand up with the A-9010. Vocals never sounded smoother but fine details were gone. The Asgard just seemed to pull my system firmly down from mid-fi to to low-fi. Maybe with a less resolving speaker this wouldn’t be noticed. Anyway after about an hour with it the first night and three the second I put it on EBay.

I would really like to opine that it’s unfortunate the current state of measurements can’t seem to capture any of this. I’m certain that the Asgard had a dynamic slowness to it that softened any kind of attack it might otherwise have.
 

RayDunzl

Grand Contributor
Central Scrutinizer
Joined
Mar 9, 2016
Messages
11,613
Likes
12,484
Location
Riverview FL
I would really like to opine that it’s unfortunate the current state of measurements can’t seem to capture any of this.

You have measurements?
 

CMOT

Active Member
Joined
Feb 21, 2021
Messages
147
Likes
112
Well I always wanted a Marantz 8b. Someone gifted me one. I think it sounds great! (not accurate always, but great). So at least one hero holds its own. On the other hand, a Krell amp that was running to spec never sounded better than a variety of more pedestrian amps I compared it against.
 

CMOT

Active Member
Joined
Feb 21, 2021
Messages
147
Likes
112
There shouldn't be that noticeable of a difference between solid state amps.
I am close friends with someone who does psychoacoustic testing for a living. We once did double blind listening for a set of solid state amps back in the 1990s. All decent quality - adcom b&k etc. volume matched, multiple trials etc. some were indistinguishable but some were statistically different (subjectively worse or better than the main group - sometimes obviously so). So SOMETHING is different across solid state amps.
 

ahofer

Major Contributor
Forum Donor
Joined
Jun 3, 2019
Messages
1,892
Likes
3,271
Location
New York City
I am close friends with someone who does psychoacoustic testing for a living. We once did double blind listening for a set of solid state amps back in the 1990s. All decent quality - adcom b&k etc. volume matched, multiple trials etc. some were indistinguishable but some were statistically different (subjectively worse or better than the main group - sometimes obviously so). So SOMETHING is different across solid state amps.

I take it you didn’t document this experiment? Because there‘s a paucity of documented tests replicating your results. If you heard a difference under properly controlled circumstances it was likely obvious in the measurements (e.g. huge variance in impedance matching, frequency response, distortion or output).
 

SIY

Master Contributor
Technical Expert
Joined
Apr 6, 2018
Messages
7,413
Likes
16,336
Location
Alfred, NY
After that I bought a Schiit Asgard 3 and ran that without the Loki. The Asgard arguably dulled the sound with its warmth and smoothness. It still sounded good, it was dead quiet but it really pulled a lot of magic from everything but vocals. Piano especially lost most of the air around the tones that would make my hairs stand up with the A-9010. Vocals never sounded smoother but fine details were gone. The Asgard just seemed to pull my system firmly down from mid-fi to to low-fi. Maybe with a less resolving speaker this wouldn’t be noticed. Anyway after about an hour with it the first night and three the second I put it on EBay.

I would really like to opine that it’s unfortunate the current state of measurements can’t seem to capture any of this. I’m certain that the Asgard had a dynamic slowness to it that softened any kind of attack it might otherwise have.

Presumably, no basic controls? If there were, could you please describe the level-matching and double-blinding process?
 

Midwest Blade

Senior Member
Joined
May 8, 2019
Messages
302
Likes
388
Have you had the Adcom serviced? Dealing with old used equipment, you may be dealing with an actual drop in performance.

I have not seen actual measurements for either the 9010 or the 535 so making this comparison is somewhat incomplete.

Envious of your Revel 105's, great speakers.
 

tmtomh

Major Contributor
Joined
Aug 14, 2018
Messages
1,323
Likes
3,865
@77Bacon , a belated welcome to ASR! I was really interested to read your post as from the summer of 1991 until May of 2020, I used only Adcom power amps in my stereo setup, and my amp was a 535 (1st gen, not the ii) for the first 3/4 of that time. I also used an Onkyo 9010 for a few years in my secondary system.

I would echo @b1daly 's, @Midwest Blade 's, and others comments above about the likely various factors. Within that, I would note a couple of factors.

First, based on Amir's testing the iPhone/dongle combo, while sonically just fine, puts out about 1V of power as opposed to the more standard 2V put out by desktop/non-portable line-level source components. The lack of a preamp stage in the Adcom might have no sonic impact (and even a sonic benefit) with a 2V input, but it's possible that a 1V input could sound better with preamplification in the chain.

Similarly, I wonder about the output impedance of the iPhone dongle, which is less than 1 Ohm - excellent for a device designed to feed headphones, but as far as I know orders of magnitude lower than a typical non-portable source component. I'm not saying this is bad or a problem, but significant differences in output and input impedance can affect sonics. Similarly, an integrated amp whose input is a preamp could present a very different intput impedance to sources than a power amp (and different brands/models of power amps by themselves have widely varying input impedances).

Second, those Adcom amps are 30+ years old and in my experience almost always have at least some internal components that have degraded or drifted out of spec. It's an open question how much (if at all) replacing the caps and such impacts perceived sound, but it's a plausible factor for sure.

Third, volume-matching is very difficult, and studies have shown that we can detect and respond to volume differences that are pretty small. Worse yet, when volume differences become small, we sometimes don't perceive them as volume differences but rather as differences in things like bass warmth/power, presence, "liveliness," "engagement," and so on.

Finally, it's entirely possible that the two amps do indeed sound different. But even there, the Adcom sounding "flatter" and having a smaller soundstage does not automatically mean it's reproducing sound at lower fidelity than the Onkyo. Deviations from maximum fidelity, specifically low-order harmonic distortion in the midrange and treble, can add a perception of ambience and soundstage size that's not actually on the original recording. I'm not claiming this is definitely the case. My point is only that even though you expected the Adcom to sound better and it didn't, you still could have heard a difference that your brain immediately interpreted as inferior, which is independent of the actual fidelity of each amp.

Don't get me wrong - I myself have heard clear subjective improvements when I swapped out my 535 for a 5400, and then again when I swapped out the 5400 for a Purifi-based Class D amp. And I always enjoyed the Onkyo when I listened to my secondary system. For those of us who don't have the equipment or the time/wherewithal to conduct precise measurements and properly controlled blind tests, my view is that life is short and if the Onkyo sounds better to you, stick with that.

If you are looking for an upgrade that will improve on both the Onkyo and the Adcom, though, then you've basically got to look at the measurements (this is the perfect site for that!) of various amps and roll the dice as to whether such an amp will actually sound better to you if you get it.
 

preload

Major Contributor
Forum Donor
Joined
May 19, 2020
Messages
1,240
Likes
1,401
Location
California
I take it you didn’t document this experiment? Because there‘s a paucity of documented tests replicating your results. If you heard a difference under properly controlled circumstances it was likely obvious in the measurements (e.g. huge variance in impedance matching, frequency response, distortion or output).

Agree. I had a similar reaction. An anonymous internet forum poster's account of a casual experiment performed 30 years ago without any details of the methodology or statistics is meaningless to me.

That is not to say that you can't create conditions that could result in audible differences among power amps. For instance you run level matched volume levels that could drive the lesser power amp into distortion. You could also run high volumes such that the noise floor is audible in quiet passages (thereby being able to differentuate by SNR alone). But neither are what we mean (or care about) when we want to know if amps sound different.

Honestly it's difficult to demonstrate that there are truly 0 audible differences. However what seems to be clear from the available authoritative reports is that any differences in modern ss amps that measure accordingly (FR/distortion/noise/output impedance /etc) are small or are not audible. If you're noticing large immediately noticeable differences between ss amps, my first suspicion is that something was not controlled in the experiment or there was defective equipment (or, and I hate to say this, dishonest reporting.)
 

ahofer

Major Contributor
Forum Donor
Joined
Jun 3, 2019
Messages
1,892
Likes
3,271
Location
New York City
Agree. I had a similar reaction. An anonymous internet forum poster's account of a casual experiment performed 30 years ago without any details of the methodology or statistics is meaningless to me.

That is not to say that you can't create conditions that could result in audible differences among power amps. For instance you run level matched volume levels that could drive the lesser power amp into distortion. You could also run high volumes such that the noise floor is audible in quiet passages (thereby being able to differentuate by SNR alone). But neither are what we mean (or care about) when we want to know if amps sound different.

Honestly it's difficult to demonstrate that there are truly 0 audible differences. However what seems to be clear from the available authoritative reports is that any differences in modern ss amps that measure accordingly (FR/distortion/noise/output impedance /etc) are small or are not audible. If you're noticing large immediately noticeable differences between ss amps, my first suspicion is that something was not controlled in the experiment or there was defective equipment (or, and I hate to say this, dishonest reporting.)

It can also be a difference in the impedance matching, output transformers, etc misbehaving with the speakers, or even other components, to reshape frequency response. But available evidence suggests such a thing would be trivial to measure and therefore anticipate. Also kinda falls outside “well-designed”, but that never stopped some audiophile brands.
 

Wes

Major Contributor
Forum Donor
Joined
Dec 5, 2019
Messages
3,851
Likes
3,607
to echo the above, I'd definitely try a cheap but well regarded pre-amp out
 
Top Bottom