I recently tried the Orchard Audio Starkrimson Stereo 2.0 and I thought it was a fantastic amp.  It drove my Magnepan LRS+ very well.  I'm no expert at describing audio gear but the clarity, texture, mids and bass were well done.

GaN amps are not unlike other amps and each manufacturer has a slightly different interpretation and the resulting sound can be quite different.  I have a customer who just did an Atmasphere vs. AGD test.  Both amps are great.  He liked the AGD better because it sounded more like a stereotypical MOSFET design which is quite tubey sounding.  His system needed a more musical amp and he looking to move away from Leben.  If his system was more musical, the opposite result might have been the case and the drier Atmasphere amp could be a better fit.  

I personally have tested Peachtree vs AGD and again, the Peachtree is brighter and more sterile.  It doesn't make it bad, just different and needed to be paired with different speakers.  

There is never an objective "best" amp.  It is what is best for your taste in your system.  

Not sure of your budget but Aavik is one of the best names for SQ.

Pricey of course. 

Some rave about the NAD. Not heard it. 

Have heard Orchard, Peachtree, LSA, Atmasphere, Aavik, Bel Canto.

But all with different rooms/speakers etc. 

I proposed to do a shootout with the top names in class D

but the field is still growing so it would be a task.

I have had 3 GAN amps. Just re-bought the PeachTree GAN400 yesterday.

The best GAN amp I have had was the PeachTree GAN1 that was mentioned above, however, mine was modded by Ric Shultz at Tweak Audio. TheGAN1 went from an OK amp to almost the best system (not just amp). Something so good I sold $15K worth of gear. I sold the following

- Benchmark AHB2 monos

- Lumin X1 DAC/ steamer

- moved my Benchmark LA4 preamp to another system since it could not be used anymore with the GAN1

Maybe more gear, I cannot remember (too much work today).

The GAN1 was not better than the above gear but it was as good with the KEF LS50 Meta. The GAN1 was stronger on the bass and the AHB2 was a bit sharper sounding but the detail level was the same. STOCK GAN1 was nowhere sonically close to this.

The second best GAN1 I have owned is the Peachtree GAN400. The GAN1 is a PIA to use and it cannot have analog sources and adding a sub is very difficult. I needed my tuners back in after listening to streaming on the GAN1 for some time. I purchased the Holo Serene preamp and paired it with the PeachTree GAN400 and a Schitt Yggi+ Less is More DAC. So all of those pieces vs the single modded GAN1. The modded GAN1 was still better than the separates, but the weak link was the GAN400, the other gear is rather amazing. I tried that gear with my CODA #16 and wow.

The GAN400 though allowed me to add my tuners and KEF KC62 sub. This was with the hard to drive Magnepan LRS+ in a small room.

I was not planning to buy the GAN400 again after I recently sold it. But the amps I really want to get for the LRS+ system are more costly that I want to pay today. So I got the GAN400 as a temp measure. The only negative I have with the GAN400 in this system is a slight bit of hardness on the top end. Nothing fatiguing or annoying, just that it is the weak link in this system. If I did not have the need for my analog tuners I would have stayed with the modded GAN1 and sold the KEF KC62 sub. The GAN1 still puts out some good bass minus the sub.

The third GAN amp I had was the LSA Voyager 350. It was also modded by Ric and it then became an much better sounding amp. Overall it was not as strong on bass and felt a little lighter in sound compared to the GAN1 and GAN400 from PeachTree. I would have not considered it for the LRS+.

If my other office gear was not so good I would not sweat using the PeachTree GAn400 with this office system. Though the low price ($1200), low cost of the LRS+ speaker, and the almost excellent sound of the amp are good reasons to just stick with the GAN400.

I should add that the modded GAN1 was very good with the amazing Yamaha NS5000 speakers but only when the volume was turned up higher than expected. That made me think the amp was underpowered for the speakers or the room was too big.

AGD is decent a little rolled off at the top. 
The type of transistors just a gimmick. If you want the best stuff for the money I like Modwright. Unlimited budget Audionet.

I am using a pair of AGD Tempo (bi-amping). I compared the AGD's to the Atmasphere monos and to a Pass XA-25. 

Both the Pass and the Atmasphere's are darker than the AGD's in my system (Bakert Rhythm pre and Fyne F1-8 speakers). The AGD's are smooth, detailed, and balanced - again in my system and to my ears. If you have speakers that are a little bright you might prefer the Atmasphere monos which are also excellent.

@yyzsantabarbara 

Always appreciate your thorough assessments. I have a Voyager and love it. I also have a Ric Schultz EVS 1200 and love it too

The amps I want to hear is the Daniel Hertz Maria "amps". It is like the PeachTree GAN1, but maybe not GAN. It also has an A2D convertor for analog sources. I also believe a sub is easy to hook up to it. No remote control though.

I am looking for forward to what the future will bring with Peachtree GAN1 like pieces. Eliminating so many items makes sense to me in many ways other than just cost.

BTW - when I owned the LSA Voyager 350 it was with the older KEF LS50 and the Thiel CS3.7. I forgot I had not upgraded to LS50 Meta yet. I sold the Voyager because my CODA #8 that I owned at that time was stronger on the bass for the hard to drive Thiel CS3.7. Wish I had not sold the CODA #8, it is perfect for the LRS+.

As I post this comment, I am listening to some Earth, Wind, and Fire on the LRS+ and PeachTree GAN1 and each time I hear this MODDED "amp" I am shocked at how good it sounds. Just beautiful.

Thank you for all of the responses so far. 

@verdantaudio I agree there is no objective best amp. I’m asking about peoples’ preferences and the reasons they landed there. I am not hoping to get a unified alignment on this thread, but get broad knowledge about what’s available and how they differ. Which AGD amps did you compare to the Atma - were they the Audion? Would you characterize them as rolled off on top, or just sweet? My brother has the Audion, though he lives too far for me to be able to try them in my system to compare. 

@jeffseight To my knowledge, Aavik uses Purifi, not GaN. I agree they are some of the best Class D, and I have a high affinity for them. I own Borresen 02 as we speak. 

@markmuse Interesting to hear that you find the Tempo to be less dark than the Atma as others comment that the Audion are darker than the Atma. This is helpful to understand what might be gained by moving up to the Tempo. I’d be curious to hear of anyone who has compared the AGD Audion to their higher offerings and share their impressions. I personally have heard the Atma monos at shows and have found them to be brighter / more detailed than many non-GaN solid state amps. I’m guessing that Ralph voices the monos to be more like his OTLs, of which I have owned two (MA-1 and S-30). 

@yyzsantabarbara Thanks for the impressions between the GAN1 and GAN400. I wasn’t aware Ric Schultz was offering mods. I’ll look into that as well  

Keep the comments rolling, it’s all helpful!

@blisshifi 

If I remember a conversation with Alberto correctly the Tempo is simply a stereo version of the Audion, probably with a common but beefier power supply. I have two of them to use as mono blocks that also bi-amp. 

If the Audion's and Tempo's are rolled off in the HF, I might now be able to hear it. I can't hear anything over 10k. But I think there was a model upgrade in the Audion at some point. Maybe wrong, but if so that might account for different perceptions.

I don't think Rick Shultz is modding GaN amps anymore. I had an LSA Voyager I was going to send to him, but he said he wasn't doing it any more. That was a year or two ago.

You might contact Alberto at AGD. He replies to emails to his site.

Aavik uses the Pascal modules. I currently have Hypex based Ncore NC400 monos with a BAT VK-40 preamp, I would like to upgrade to either the new Hypex Nilai 500 or the Aavik I-280. Very difficult to find comparisons. 

Technics Grand Class Integrated Amp

@markmuse Thanks for the details. 

@greg_f Thanks for the correction on Aavik. Are Pascal modules a GaN design or no? I didn’t think they were. They sound great regardless. 

@blisshifi No problems, the Pascal modules (UMAC) don't use GaN technology, one of their features that makes them different to Hypex, Pufiri, IcePower and the rest of the classD designs is that they use a sinusoidal waveform instead of the more widely used triangular waveform to produce the PWM so theoretically the output filter design is easier and should produce less RF noise. That's the theory.

You say they sound great, I have never heard any Aavik amplifier in real life, it will be very useful to know how they compare to a good AB integrated like the Gryphon, VItus, Pass Labs, T+A, etc. Any pointers?

I recently did a week's test with the Orchard Audio Starkrimson amp with upgraded caps and power supply ($3500 retail).  

I really liked it !  The headline is speed and microdynamics as if to reveal notes and timing in the music that were probably hidden with previous amplifiers.  

Tonally neutral and overtly smooth, there is no warmth yet it's clean enough not to matter.  Midrange presence and transparency are a bit lacking compared to other amplifiers in its class but these are minor issues.  

I totally competent powerful amp in a very friendly package.  

I should also say that I am looking for very high performing GaN amplifiers to perform against some of the best / most high-end units out there, like the T+A A 3000 HV amplifier (which I own along with the T+A PS 3000 HV power supply), Audionet amps as @pennfootball71 mentions, or other Class D leaders like Aavik or Bel Canto Black. High bandwidth, control, transparency, and resolution are all important, but just as important is a completely organic, natural presentation with the proper use of harmonics and lifelike presence/immediacy and dynamics.

@greg_f I unfortunately haven't AB/ed Aavik against other amplifiers with the same speakers in the same room to be able to comment. I would say that Aavik 580 series is a cleaner sound, but still incredibly musical, than my reference T+A HV stack. The T+A has richer harmonics and a tad less control in the lows (Aavik is known for its insane damping factor and that is a large contributor to making Borresen speakers sing the way they do). My T+A is more natural, a bit less clinical, but at the expense of not being as lightning fast as the Aavik. Keep in mind that this was the same set of speakers, but in different rooms (I brought mine back to Next Level Hifi to compare) and different cables (Synergistic Research Galileo SX in my room vs their Ansuz DTC-2 loom). Gryphon has richer harmonics still over T+A, and I prefer T+A, which is why I became a dealer for them. Pass generally has less rich harmonics than Gryphon or T+A but has a warmer character to them. Vitus, I've only heard once, with Estelon Extreme at AXPONA this year, and though I've heard a few Estelon, I'm not familiar enough with what the amp was doing vs what the speakers were doing. In that room, it was a very burly, natural sound, but not as immediate and transparent as Aavik / Borresen combos I've heard time and time again.

@blisshifi Thank you for taking the time to form such a detailed reply, it is exactly what I was looking for. I have been using Class D amplifiers for almost 20 years and the technology keeps on improving, IMO they are the future of amplification. It seems like the Achilles heel of the Class D amplifiers (the top end) is becoming less of an issue with the latest generation. Of course regardless of the topology used, the design of the amplifier is the most critical factor. My speakers (Vienna acoustics Mahler) require the amp to have good grip of the bass units and be fast otherwise they can sound lazy, so they work well with class D amplifiers. 

Even though GaN transistors were not designed for the HiFi industry, they could suit class D topology since they are switching much faster (decreasing dead time, easier filter design, etc) but again it all depends in the implementation of the amplifier, you can't say because an amplifier uses GaN transistors is better than one that uses MOSFETs or bipolars, we need to talk about specific amplifiers.

@markmuse -  I got my modded Gan1 back from Ric less than a month ago, so he is still doing them.  Best to call him 9r send him an email to be sure.

I had a D-Sonic Class D using Pascal module (new about 4 years ago) it was powerful, but it was not as resolving on top as the GAN amps I had afterwards.

I also had a NAD M22 V2 which is also Class D and I returned it since it was not as good to my ears as the similarly priced Benchmark AHB2.

As stated by Greg_f above......it is implentation that determines the final sound.  All Ganfet amps sound different and not necesarilly better than Mosfet based amps (Purifi and Hypex).  Modded high power Purifi amps (VTV even has a tubed buffer version for more 3d liquid sound) sound outrageous.  All class D amps will sound much better with mods.  Recently I have done more mods to the LSA Voyager that are also applicable to the Peachtree GAN 400 (they use the same amplifier module).  Modded Purifi, Peachtree, LSA and Orchard all sound really really good.  Just tonight I finished my first modded Hypex Nilai stereo amp......pics are now online......Yes, I am still doing mods....and mod all the above.  More info and pics will be added in the next couple of days.  I have done a couple more mods to the Peachtree Gan 1/VTV amps since yyzsantabarbara got his and will be trying another mod to the unit I have here now. 

@ricevs

It is impressive how much more performance is gained by implementing tweaks.

Which amp among the ones you modify is your favorite (no matter class)?

Do you modify other classes amps?

Do you replace PCB track connections with point to point connections, and internal wiring with better quality?

Where would you place your favorite modified amp in comparison to higher tier amps (no matter class)?

Thanks

I own the Peachtree GaN 400......Absolutely love the way it takes a signal and makes it sound "live". I’m using an Audio- GD ...HE1-XLR SE as a Tubed pre with an Audio Mirror Toubadour IV- SE DAC and Borresen X-3 speakers.To me this is as good as it gets.I’ve been to many shows and rarely do I experience anything this Musical a "you are there" sound. I am "inside" the music. An experience I’ve never felt in 40 years of Audio.I also own the Aavik U-150 Pascal class D. Totally different sound. ...But the MC phono pre and built in DAC is world class. I personally don’t forsee ever going back to My KT-88 and 845 Tube amps....The Decware I’m keeping ’cause it’s fun with my High- Efficiency speakers ( Klipsch / Texkton/ JBL.....I'm a firm believer in " System Synergy"....and there's only one way to achieve that....Try lot's of different gear. I've been with Alberto and his gear is Awsome also. Best of luck to you.

Which AGD amps did you compare to the Atma - were they the Audion? Would you characterize them as rolled off on top, or just sweet?

@blisshifi If you look at the comments comparing the Atma-Sphere amps to the AGD, you'll see that they contradict each other- some say one is sweeter or darker and the other the other 'way around. FWIW the Atma-Sphere has bandwidth well past 30KHz, so of someone says it sounds 'darker' or the like, its not because of frequency response- its due to how the amps in comparison make distortion.

@atmasphere I noticed that, and FWIW, hearing your amps between AXPONA ’22 and FLAX ’23, I thought they were anything but rolled off. Maybe since you’re now on this thread, could I ask you to share how you voiced your GaN monos, especially in comparison to your OTLs? Did you attempt to preserve the same level of openness and bandwidth to your other amps (albeit making it easier to drive speakers with)? How would you compare the sonics of your GaN amps to your OTLs? As you know, I was very fond of the MA-1, and later on the S-30 that I had you fully upgrade.

@mbmi Do I understand you right that you prefer the Peachtree to the Aavik? Also you are comparing an integrated (the Aavik U-150) to a power amp with a separate preamp. Is there any way to bypass the preamp section of the Aavik and use your Audio_GD with it? Thanks.

@ricevs I am not familiar with your modifications, the same question as Tjag above, can you describe your modifications and how each one effects the sound of the amplifier? Which amp is your favourite for modding?

@greg_f Here’s a link to Ric’s amp mods that will give you some basic info if you haven’t already seen it, but I’m sure Ric will add more meat on the bone here.  FWIW.

Maybe since you’re now on this thread, could I ask you to share how you voiced your GaN monos, especially in comparison to your OTLs? Did you attempt to preserve the same level of openness and bandwidth to your other amps (albeit making it easier to drive speakers with)? How would you compare the sonics of your GaN amps to your OTLs?

@blisshifi We did not 'voice' either our OTLs or the class D. Most of the work on the amps during R&D was to eliminate noise. We lucked out in that once we had that bit sorted, the things that cause distortion in our circuit tended to cause lower ordered harmonics, much like a tube amp, but at a lower level. I prefer the class Ds to our OTLs, once they have broken in. They are more neutral but easy to listen to; when comparing side by side the big difference most people comment on is the class D seems a bit easier to hear into the rear of the sound stage; they are more 'focused' if that makes sense. 

@soix  thanks but I can't see a link.

@greg_f Ah crap.  Sorry man — here it is…

http://tweakaudio.com/EVS-2/Mods_to_digital_and_Class_D_amp.html
 

Thanks Soix, I will have a look. I sometimes modify equipment myself but I would not mess about with the circuit topology. Normally I would clean up the mains if needed, sometimes upgrade passive components to better ones (but one has to be very careful, better components in most cases are just unnecessary), perhaps better op-amps and definitely would pay attention to noise especially RF. Unfortunately it is not an easy or even fruitful task, one needs proper test equipment which most moders don't have access to, I am not implying that Ric doesn't know what he is doing! Anyway I diverted...

I am using the Peachtree Gan400 for my Magnepan speakers. I have several pairs and they are very good match for the LRS+ , 1.7 or the 3.6s. I have tried different amps from CJ , MCormack , VTL and others but the Gan400 has not disappointed.

The Peachtree GaN400 is $2000.....another $500 gets you a mod that transforms it into an even better power amp.....same with all of the amps mentioned below.

I have modded the LSA Voyager amp (same amp module as in the Peachtree Gan400), different versions of the Purifi amp sold by VTV, the Orchard Starkrimson amp, the Peachtree GaN 1, the VTV D300 and just now finished my first Hypex Nilai stereo amp. These amps are all fantastic with mods. I did not A/B them directly as I had them at different times and with different setups.....but all sound amazing. I personally am into the digital input amps and have a modded VTV D300 here as my reference.....at it is seriously special. I am going to be sending my own modded amp off for review.....stay tuned.

Now for the elephant in the room. Every time Ralph claims that the only thing that matters is a particular distortion type then I have to come in and tell the truth. Send me 4 pairs of Atmasphere class D amps. I will leave one pair stock. The second one I will do my usual mod to. The third one I will add silver WBT jacks, silver plated OFC wire, zippy sounding caps for the output filter, etc. The fourth amp I will use rolled off jacks, wires, caps, etc. The stock amp will sound really good. My modified amp will sound much, much better. The silvered amp will sound forward and zippy and the other amp will sound rolled off and dull. Anyone can hear this without using blind tests.....but even double blind tests will show the same results. The four amps will measure exactly the same!!!!!.....but sound way, way different from each other!!!!! This is the truth.....everything matters. I am not saying the stock amp is not a great amp.....nor am I saying that distortion artifacts don’t alter sound. But this one size fits everyone thing is the same as what ASR does. They say that as long as the amp has low enough distortion then it is inaudible. Ralph says that as long as an amp has a "certain type" of distortion then it is inaudible. Total popycock...total malarkey....he he....I like these silly words. I have been doing listening tests and A/Bs for over 45 years. This (everything makes a difference) has ALL WAYS been there. Please do not listen to anyone (including me).....listen to the gear and decide what is real with your own ears on your own system......THIS IS TRUTH!

I'm a Schill for Orchard Audio.

'Nuff said !

Folks, just so you know, if you are going to be successful with a class D product, one thing it has to do is meet EU Directives for radiation, so it can obtain the CE mark for use in Europe. In the US, you have to meet FCC part 15.

But its more than that. If the class D circuit makes noise, which will be in the form of RF energy due to parasitics in the design, this noise can leak into the AC line as well as being radiated to other components in the system. Both digital and analog gear can be quite sensitive to this sort of noise. It might blot out certain FM stations on your tuner and generate noise on the AM dial. GANFETs in particular are insanely fast and can switch at some amazing speeds. Just before release of our class D we were concerned about the devices running warmer than we thought they ought to- we found that there was a tiny bit of noise coming from the comparator chip, causing the outputs to switch at 60MHz!

When you change out parts in the output filter or elsewhere in the design, the change can result in parasitic noise due to extra inductance that is introduced. An example is the lead inside a capacitor, which can and is a different length depending on the part used.

For this reason the product needs to be tested for RF and AC line radiation. Failing to do this means that the probability of noise introduced through modification is very high!

Any class D designer will tell you this.

They will also tell you that any such modifications voids the warranty.

@ricevs 's comment about distortion is simply false and this has been known for 90 years in the audio world 😀 (ref.: see Radiotron Designer's Handbook. 3rd edition). Perhaps he could get out there and show us all how its done by designing and building his own design from the ground up.

Ralph,  

I have been modding class d amps since 2005.  No one has ever heard birdies or AM signals or whatever.  I can clearly see the harmonics on my scope riding on the 400-500K waveform.....What I do does not increase the noise and as I just said, NO one has ever had a problem...........The modified Wima caps I use have super low inductance (5mm long).   The real issue here is that the mods I do work (make the amp sound better and that my customers all agree on this) and it goes against your "philosophy".   You don't believe that fuses, wires, jacks, etc. into infinity make any sonic difference.  Fine, go to ASR and join the bunch there.  But for those of us that listen....we know different.  WE EXPERIENCE TRUTH with our ears. 

I think you should get a 90 year old amp and be done with it....since they knew everything about how something sounds 90 years ago.   Living in the past is not living in the now.  You have to come out of your comfort zone to experience anything new.  What is real can be experienced in the NOW.....it is not a philosophy.   

God forbid we should void our warranty!!!!!  Do you know how many people void the warrantee on their brand new Corvette (etc.) and take it to a speed shop to have 2-300 horsepower added, etc?  Tons of people do this because they want better performance.  These guys will spend $20-30K doing these mods....even more.  My mods do the same for $500!

Back when SACDs first came out I made a comment online that my highly modded $200 Sony CD player made the CD layer sound better than playing the SACD layer on the Sony SCD-1 that I had at the time.  This did not sit well with the editor of Positive Feedback....as he had just said SACD was the next coming.  He was also using a stock SCD-1.  Wellllllllll.....he then discovers a local modder (Richard Kern) and realizes that the modded player sounded way better......then he takes it back to be modded two more times and it keeps getting better.. He actually wrote an article in Positive Feedback called "I don't drive stock"....about his experences with modding.  HE WAS OPEN ENOUGH to listen.......Now he knew I was right about the SCD-1 not being very good stock.

Really snarky to add the usual....."Well, if you are so smart then why don't you build your own thing, from the ground up".  Being a skilled designer and being a skilled tweaker are two different things.  Those few that do both bring some seriously great products to the market.  I have been bugging Clayton at Spatial for years to use better parts, wiring and construction.......Finally.....he is doing what I suggested.......many, many years later......he did learn.....some never learn.....some will take their limited knowledge and experience to the grave.   

May you all learn the magnificence of your own being......You are all amazingly beautiful.....Open your hearts and minds and experience the joy and Love that you are........it has always been here....it will always be here.....this very NOW.  LOVE....yourself and everything......EVERY SECOND.

From what I understand, both Ric and Ralph make significant contributions for audiophiles and music lovers all around. As both engineers and designers, it is healthy to have different viewpoints and approaches. In this case, it seems this disagreement is making the thread go off the rails a bit.

Generalized statements are painful. While Ralph may prioritize noise elimination, is it true that he believes it is the only thing that matters? While Ric focuses on improvements to existing architectures, does it mean he doesn't understand distortion or how to do his job without keeping noise away? As system thinkers, you probably share more than you think, but it's obvious you've lost track of common ground with each other. I hope you regain it, at least to agree to disagree in ways that enable each of you to push each other to make even higher performing components. And hopefully, so you don't spite each other on a public forum.

I vote for both of you to have a 5-day hackathon locked in a room somewhere to land on a design together. I bet great things would happen, that is, unless only one of you would come out of the room alive at the end of it!

The reason I went to Ric for mods was I had my Sony SCD-1 modded 20 years ago the way Ric described in his post (by KERN I think). The change in sound was incredible, especially in the SACD layer. I had that player for over 20 years, and it only died earlier this year. Someone bought it from me for the parts. The warranty was the least of my concerns.

Regarding the Magenepan LRS+ and the GAN400. I had this setup in the past and getting the GAN400 delivered either today or tomorrow for the LRS+. It has a bit of hardness to the top that makes it slightly less than fantastic.

I was not aware that Ric does mods on the GAN400 and that the module is the same as the Voyager 350 GAN. He did the mod on my old Voyager 350 GAN so I may consider getting the GAN400 modded if I plan on keeping it. The warranty on the unit I am getting expired already.

Generalized statements are painful. While Ralph may prioritize noise elimination, is it true that he believes it is the only thing that matters?

@blisshifi Of course not! @ricevs apparently has a lot of misconceptions and is putting words in my mouth, making claims that I never made. My position about distortion has been clear for a long time. I've been building class A triode zero feedback OTLs for over 45 years and in amps like that everything you do makes a difference because the amps lack feedback. This is the same as in SETs, of which most also lack feedback.

Just because something was knowledge 90 years ago, like 2+2=4, does not mean its not true today. What is different now, which simply had to be accepted back then, is we know why our ears respond to distortion the way they do. In his comments, Ric conveys that he has not obtained this as part of his knowledge base. He's got a lot of company in that regard- many solid state amplifier designers don't really care what sort of harmonic spectra their amps make.

But some do and not surprisingly their amps get more regard in the audiophile community where people 'follow their ears'. For one to push exactly that sort of philosophy, which I've no problem with at all, since that very thing has kept me in business, that the reason why is being described as poppycock is really a bit astonishing and ironic. You'd think this would be of paramount importance to one who has built his business model 'following one's ears'!

Obviously not all amps are the same. Those with very high feedback amounts will respond less to things like fuseholders, IEC connectors and the like because they have the ability to reject that which is not like the signal. But amplifiers with little or no feedback are very prone to these influences.

Regardless of how much luck one may have had doing mods, class D amplifiers are quite sensitive to layout problems, stray capacitance and parasitic inductance that other amplifier technologies simply are not. It may be that you don't hear any audible artifact from a modified amplifier, but without testing it you really don't know what's actually going on. That's a fact and no amount of remonstration on Ric's part will change that. Integrity requires that sort of testing for noise be conducted, if one is being paid to make changes.

The simple fact is that audio would not exist as a hobby if engineering did not exist. Nothing that we do in the audio world is magic- there is an engineering correlation to everything we hear. But you have to know how the human hearing perceptual rules work to be able to sort out some of the whys.

I find it amusing that someone is trying to denigrate me by lumping me in with the measurement camp. I'm not part of that; what I've found is that correlation I mentioned. Both the subjectivist camp and the measurement camp hate the idea that you can draw a direct line between what we hear in audio circuits and what we can measure in them. Many audiophiles still live their lives according to the myth that we can hear things we can't measure (which was true in the 1980s) as if somehow measurement technology had not marched into the present the same way that every other tech has improved over the last 35 years! Imagine trying to surf the web on an Apple 2 😁

«Both speech and music occupy similar, albeit slightly different frequency ranges. The lowest frequency element of speech is the fundamental frequency, which for a male voice is on the order of 100-125 Hz. (Johnson, 2003). In the human vocal tract, the vibration of the vocal cords for voiced sounds defines the fundamental frequency and its higher-frequency harmonic content and this limits the low-frequency end of the vocal output. There is simply no speech energy below the frequency of the fundamental. In contrast, musical instruments can generate significantly lower frequency with fundamental energy on the order of 40-50 Hz for bass instruments. Figure 1 shows a treble clef showing several musical notes and the frequency of their fundamentals. Middle C (just below the treble clef) is 262 Hz, and a typical male’s fundamental frequency is an octave below that (approximately 125 Hz).

However music, like speech, is slightly more complicated than just a rendition of any frequency components available or audible. In turns out that in music, like speech, it is not the fundamental frequency that defines the “pitch” of the note but the difference between any two successive harmonics. This is called the missing fundamental and explains why one only needs to hear the higher-frequency harmonics to define the pitch, which in some cases is below the bandwidth of the transmitter.»

https://journals.sagepub.com/doi/full/10.1177/1084713812468512

III.
CONCLUSIONS
ß For fundamental frequencies of up to about 1400 Hz,
the pitch of a complex tone is determined by the second
and higher harmonics and not by the fundamental,
whereas beyond this frequency the opposite holds;
this is the case both for tones with harmonics of equal
amplitude and for tones with harmonics of which the
amplitudes fall by 6 dB/oct.
ß For fundamental frequencies
of up to about 700 Hz,
the pitch is determined by the third and higher har-
monics; for frequencies up to about 350 Hz, by the
fourth and higher harmonics.
ß The experimental results strongly suggest that the
pitch of complex tones is based on periodicity rather
than on frequency; it is reasonable
that this also holds
for simple tones.
 

Pitch of complex tones -Plomp- 1967 

Perhaps amplifier designer must be preoccupied by the way their design produce Harmonic spectra... 😊

He’s got a lot of company in that regard- many solid state amplifier designers don’t really care what sort of harmonic spectra their amps make.

"Many audiophiles still live their lives according to the myth that we can hear things we can’t measure (which was true in the 1980s) as if somehow measurement technology had not marched into the present the same way that every other tech has improved over the last 35 years!"

The above statement is the real MYTH....it cannot be proven. The TRUTH is that you cannot measure wire, jacks, resistors, solder, removing unneeded parts, upgrading most parts, etc.......but these things all make a sonic differentce that you can hear. In audio...it is the sound that is real.....not some pretend myth measurement dance.

If Ralph wants to believe that everything you hear can be measured....well let him live in that realiy....nothing wroing with that. But, for those with ears.....we know....we know all cables sound different.....and we know there is no measurement tool that can tell us how they measure (because wires do not measure.....other than capacitance, resistance and inductance......which by themselves do little to tell us how something sounds).

The "more feedback equals less differences in parts" thang that Ralph stated is totally untrue (poppycock!). I mod the Purifi amps that have tons of feedback....way more than Ralphs amps.....and everything I do makes the same sonic difference when done on the ZERO feedack digital amps I mod.  I havae worked on several high feedback solid state class A/B amps over the years.......everything I do can be heard just like any other less feedback amp.

Those with Ralph's amp can do a quick test.....just remove the covers and remove all the hardware on the toroidal transformer.....lift it off the chassis and place a quarter inch thick piece of wood underneath.....put the transformer back down and listen.  This CANNOT be measured.....but it can be heard....by YOU!

The Iconoclast wires by Belden were designed by a very scientific guy. However, they make them in three grades.....regular copper, OFC copper and PCOCC copper........do they sound the same?....(same exact construction, just different pruity of wire)....NO, the more pure wire ones sounds better......Can they measure the difference?.....NADA.

Have a great every moment!

Everyone knows that Ralph is the real deal and gentleman.

’Nuff" said

Many believe you can hear things that you can measure, yet it is proven to be out of the ranges of human hearing.

like what you like, to hell with what others say. Like re soldering makes a difference. Only those that benefit monetarily act like they believe it makes a diff. 

Proposing a "tweak" is not the same as designing an amplifier..

For example i had a better experiment to propose about for sure what cannot be measured BUT could be heard :

Put a 250 gram of quartz on your amplifier...

Put a 250 gram of shungite on your amplifier...

Put the two together now...

You will hear a difference...

I fine tune my S. S. amplifier with these minerals tweaks... Really for the best...

But tweaking is not designing... No more than walking with better crutches are like installing an up to date prosthetic legs or growing a new one ..

And an improvement by design is always better than tweaking a design... So good the tweaks will be ... And they will if you know what you do with your ears...😊

But all of what we can learn from a component  and hearing if  we learn how to modify or tweaks it  are not all  measurable...If we tweak...

But if we design , all that we made MUST BE measurable, by defintion of a good design... And it is better if the designer as atamasphere know about harmonics for sure... And i will trust him precisely because of that...

And he knows that objectivist as subjectivist are deluded focussing on the gear but forgetting about psycho-acoustic basic ...

Just buy a certified good quality amp to start with and no need to take chances on tweaks.  

Just buy a certified good quality amp to start with and no need to tweak. 

You can also buy a cheaper amp and tweak it (void the warranty) and potentially have an amp that sounds a lot better. I have (or had) both great stock amps and tweaked amps. I listen to music a ton of hours each day on both types of amps. 

I already own a Sansui alpha...

It work well out of the box and is not a bad S.S. design at all...

But i "helped it" not because it need it... But because my ears are not yours...And i like experimenting and i could do it anyway...

Our hearing work non linearly , this means that a little well chosen specific  level of " noise" can increase the signals/ noise ratio for MY EARS ... Differently for yours... It is called tweaking for this reason...

Also some design dont need this helping hand, because the amplifier will be immersed in a specific mechanical,electrical and acoustic environment which can be already optimal without need for "help" and each one of our ears structure and internal filters and biases are different...

Audio is the art of trade-off ... There is NO PERFECT DESIGN...There is no perfect environment for all and every component... For example some speakers need some type of room , some amplifier work better with some speakers or dac etc ...

😁

Just buy a certified good quality amp to start with and no need to tweak.