GaN amps: Peachtree or LSA Voyager?

@markmuse 

LSA doesn't talk much in their literature about lowering distortion instead mainly focusing on the advantages of GaN.  San Francisco Audio Society liked the amp, Audio Science Review did not.  It will be interesting to read your impressions. 

question - in your view, what accounts for some amps having noticeably better soundstaging and imaging capabilities than others? be it solid state vs solid state, solid state vs tube, class a or ab versus class d types

most would say tube amps have the most expansive imaging, better at achieving ’holography’ and perceived image depth so to speak... while class a or ab amps can be all over the map in their spatial capabilites (some better one are quite good in this respect, while others are poor), and often, amps using class d modules really tend to flatten the soundstage and locate instruments/performers relatively poorly

curious to get your take on this...

@jjss49

My theory is the the way various amps make distortion has a lot to do with it. I used to think it was how well the amplifier was able to get phase relationships right and I still think there’s something to that, but by no means is it the only thing! One thing that seems to have a bit of correlation is the decay in harmonics as the order of the harmonic is increased. It needs to be on an exponential curve. Another thing that I feel needs more research is the role that the 2nd and 3rd harmonics play in allowing the ear to make out the detail required to reproduce the soundstage correctly. This relates to my first sentence in this paragraph. If the amplifier isn’t devoid of distortion but the 2nd or 3rd is too low, apparently that can prevent the amp sounding 3D.

IME the class of operation has little to do with how well the amp is able to winnow out soundstage depth and detail.

Frank gives a lot of credit to both the differential balanced design and the Exicon power mosfet output transistors...so hopefully Ralph can shed some light on why this might be some kind of secret sauce??

@snapsc

"Balanced Differential Design" Is a registered trademark of Atma-Sphere FWIW.

What happens in a differential circuit is even ordered harmonics are cancelled in the load of the output of that circuit. If differential throughout, cancellation occurs throughout too. This means that distortion is compounded less from stage to stage throughout the design.

This results in the 3rd harmonic being the primary distortion component which is very effective at masking higher orders in the harmonic spectra if its strong enough. Since there is less compounding of distortion in a fully differential circuit, the higher ordered harmonics decrease at a faster rate as the order is increased compared to a single-ended circuit. This means it will be smoother than the single-ended circuit, since the ear assigns tonality to all forms of distortion and the higher orders are assigned ’harsh and bright’. SET fans will comment about how smooth their amps sound, but it can get even smoother and with more detail bringing you closer to the music.

Mathematically speaking the non-linearity associated with this type of decay is called a ’cubic non-linearity’ as opposed to the quadratic non-linearity seen in a single-ended circuit. Probably more than you really needed to know; we’ve been relying on this method of controlling distortion in our amps for decades on now. Our class D does not use this method so much; it relies instead on having enough Gain Bandwidth Product that is feedback is properly supported at higher frequencies and so it able to control higher ordered harmonic generation that way instead.

Whatever the distortion signature actually is, that is the 'sonic signature' in amps that audiophiles talk about.

@markmuse, Thank you so much for doing this comparison.  I cannot wait to hear how the Voyager v AVA 225’s goes.

The 225’s have been of great interest to me for a long time.

I own the Voyager and loved it in used with my previous speakers.  But have not had access to it since receiving new, much better speakers recently.
 

Will have the Voyager back in about 10 days and am anxious to compare it to the two amps I’ve been using lately.  The new speakers are quite remarkable for their ability to pass thru what is ahead of them an thus will reveal the Voyager’s traits more than my old speakers could.

@rc22 what are your new speakers? I bought a Pair of Fyne F1-8 a couple of months ago and I am loving them. They very easy to drive - 6 ohm minimum impedence. Every amp I have tried with them has done well, but of course some are more satisfying than others. The 225s are great. Will have the Voyager tomorrow.

@markmuse Audiovector R3 Arrete’.  They are 8 ohm and 90.5 sensitive.  A  friend of mine was just over and he liked them very much.  He has a big room and really enjoys his Fyne 704’s.

The R3’s are the company’s smallest floorstander and happen to be an  ideal size for my dedicated room.  

I for one am seriously looking forward to pairing the new class D Atma-sphere monos with my Tannoy Stirling GR's.....ye MF'in ha!

My theory is the the way various amps make distortion has a lot to do with it. I used to think it was how well the amplifier was able to get phase relationships right and I still think there’s something to that, but by no means is it the only thing! One thing that seems to have a bit of correlation is the decay in harmonics as the order of the harmonic is increased. It needs to be on an exponential curve. Another thing that I feel needs more research is the role that the 2nd and 3rd harmonics play in allowing the ear to make out the detail required to reproduce the soundstage correctly. This relates to my first sentence in this paragraph. If the amplifier isn’t devoid of distortion but the 2nd or 3rd is too low, apparently that can prevent the amp sounding 3D.

IME the class of operation has little to do with how well the amp is able to winnow out soundstage depth and detail.

thanks ralph for your thoughts, i tend to agree it is about higher order harmonics in the distortion profile and how these affect the auditory sensation of the decay of notes

@pehare 

That should be an interesting review. I have mad respect for Ralph, though Ive never been in a position to buy his kit. Why not start your own thread?

@pehare A dealer loaned me a pair of the Atma-Sphere GaN monos. They are indeed very nice. Interesting that they have a big toroidal transformer, the only D I have come across that does. I could eventually end ups with a pair. Just wish they had more power. At the time I was still using my KEF Reference 1s which benefit from lots of juice.

@markmuse 

It will be interesting to read your comparison of the Voyager and the Atmasphere Class d monoblocks.  Based on the specs of your speakers...it appears that the Atmasphere could easily drive them to over 104db at a listening position 10' back so I'm not sure more power would really be of much value, especially since the speakers are rated at 90 watts max continuous power handling.

@snapsc 

When I had the Alma-Sphere monos I had not yet acquired the Fynes. The KEF Reference 1s that I was using at the time need a lot more grunt in an amp than the Fynes.

I no longer have the Atma-Spheres here to compare to the LSA. Listening at the moment to the AVA 225 monos on the Fynes (an excellent combination by the way). Going to insert the LSA in a few minutes.

The AVA's will also be an interesting comparison as they have had a lot of good press lately as well.

@rc22 @snapsc @yyzsantabarbara @niodari @lewinskih01 @ricevs    

First impressions, and a qualifier: My comments relate entirely to my system and my sensibilities. Both the AVA 225M and the LSA Voyager GaN 350 are superb amps in my opinion. These are my FIRST impressions:

It is closer than I expected it to be. The LSA seems to have a blacker background, better decay, better rendering of textures, better detail. I think the AVA has slightly better global dynamics but has more of a tendency to break up on dynamic peaks (maybe from switching into AB?). Or maybe it seems that way because the LSA doesn't break up. The LSA has better micro dynamics. Imaging is a little better on the LSA. Both amps are what I would call slightly warm. 

Both the AVA 225M and the LSA Voyager GaN 350 are superb amps, and each is a steal at the retail price. As things stand now I am going with the LSA. I hear nothing negative and lots of positive. But again these are first impressions that might change. If they do I will update this thread. 

Makes sense....what you heard. Van Alstine is not a tweaker....he does not believe that parts or connectors or fuses, damping, etc....make any difference. He uses ordinary wire, connectors, capacitors, resistors, unbypassed power supply caps, transformer mounted with steel hardware, fuses everywhere.......even on the output.. etc. etc. If you tweaked his amps they would sound completely different and way, way, way better. I am not modding his amp....he would not approve and would freak out and anyone with a modded Van Alstine amp woud probably never get help with any issue, etc.

As I have stated....high end audio is all over the place......not so with quarter mile hot rodding.....everyone knows how to make a car go fast........all knowledge is available to anyone......In high end audo....it is a giant mystery for most people. When I tell people to remove binding posts and spades for better sound, etc.....they have no idea what I am talking about. There is no "tweaking bible".....where all the secret sauce is revealed. I am not making one......no one would buy it.....people want to believe the advertising sales pitch.

This is why you have to listen for yourself. Then you will know what is what. I appreciate all serous A/Bs of equipment. Thank you Mark for letting us know what you heard.......My friend used to say "It all comes out in the wash"......meaning, that over time....the truth about things is known.

The truth about the intrinsic beauty of our soul is what is always real...May you bask in the light of your own being.......and radiate it to everyone.

Hi Ric. I’ve been doing this comparison without the tweaks I bought. After I‘m sure I have a handle on the character of the LSA I will add them back. Then I will likely send to you for mod. 

@markmuse I was the first person to have Ric mod my Voyager. It was a noticeable improvement. My preamp did not have an ON/OFF switch nor does the modded Voyager (stock does). So I had some issues when changing cables.

Congrats on the Voyager.

@markmuse thanks for sharing your first impressions on Voyager vs AVA 225s. This is particularly interesting for me since i still didn't decide to choose Voyager GaN 350 or Orchard monoblocks. Your impresión is fundamental. Just saying roughly, based on the impression that Atmasphere monoblocks left on you, how would you compare them with the Voyager? 

Did you feel any irregularities/distortion, dependencies of the high frequency reproduction on the speaker load? 

@markmuse 

appreciate the initial comparison of AVA225 and LSA Voyager.  You say you didn’t expect the two amps to be so close.  Curious which one you expected to sound better?

First, since I wrote this I discovered a noise problem that might or might not have to do with the LSA, don't know yet. It could be the tubes in my preamp. I will follow up today and post the results. The LSA is second hand, not new. If it is the amp it is going back for sure. I suspect the amp because in my experience tube noise is constant regardless of volume setting. This noise was not apparent at listening levels but at full volume even from my listening position is was very apparent. It was not just hiss, and the left channel was worse. 

@niodari  No problems with the HF. Smooth, clean, and delicate at listening levels.

@rc22  I didn't have expectations that I am aware of. I prefer the looks of the AVA, cute little shoebox size monoblocks. 

Difficult to evaluate amps without including type of pre-amp and its significant influence. I am thinking of combining a Gan Amp with a tube pre but having second thoughts as to some of the comments as to speaker compatibility. May settle on some tried and true combos. But I may have a new room to consider first. 

I'm happy (sort of) to report that the noise problem is my preamp, NOT the Voyager. Now I have to figure out what to do about the pre. Replacing tubes in it is a PITA because I have to pull the unit from the cabinet, disconnect all, and remove the entire housing to get at the tubes.

Recommendations for preamps from those with a Voyager? @yyzsantabarbara 

@jpwarren58 That is my current rig. Rogue RP-7 NOS > Voyager

@markmuse Funny you should ask. My CODA 07x preamp was great with the Voyager. Read up on the CODA 07x. It is a slightly warm and tube fans love it. I am an SS fan but I really like it too.

I am debating selling my complete Livingroom system (which includes the CODA 07x) to buy the active KEF LS60 speaker. I would not need any other gear with this. If I keep that system I would need to get more gear to finish it off, KEF Blade2 or REF 1 speaker, DAC, additional Benchmark AHB2 amp.

I also tried the $799 Topping pre90 preamp with the Voyager and it had volume issues. The Benchmark LA4 (my keeper preamp) sounds like the pre90 but does not have the volume issues of the pre90. However, with the Voyager it maybe too much of a good thing for some folks. Too much detail and maybe too sterile a sound.

I had sold my Voyager before I owned the Schitt Freya+ preamp. That preamp will likely be very good with the Voyager. I say that because I really liked the Benchmark AHB2 | Freya+ | RAAL SR1a headphones. The AHB2 and Voyager (modded) sound very similar. The CODA 07x is better than the Freya+ but it costs more.

@markmuse :

“It is closer than I expected it to be”

The above line is what made me wonder if you specifically had a hunch one of these would sound better than the other.  But I get that you very well may have just not expected any two amps to be this close in performance.

Rest assured I have no angle in my questioning.  Like accusing you of “confirmation bias”, for instance.  You strike me as a seasoned hobbyist who calls it as he hears it after carefully assessing. 

@yyzsantabarbara If you are interested in the KEF Reference 1 I have a pair for sale. Less than a year old in mint condition. Walnut. See US Audio Mart.

Yeah, I had an LA-4. It would be too much of a good thing with the Voyager. It was great with the Rowland 535 monos though. I'm thinking more tubes, but maybe a little less bloomy than my current RP-7. Though I should probably change tubes. That might change the noise as well. The Rogue RP-9 looks interesting, as do some of the ARC reference preamps, and Atma-Sphere MP-3. Am I nuts or what?

@markmuse If you are inclined to go with tubes give the Schitt Freya+ a 15 day home trial. Only thing you have to lose is having more money in your wallet. It is a very quiet tube preamp.

@markmuse 

During your listening test, in addition to your analytical listening did you also do what I like to call musical listening… no analysis, just close your eyes and see which amp is the most musically and emotionally compelling… and with no fatigue from an hour or two of listening  

Its hard to turn off the brain and do this but at the end of the day it’s not the minute detailed differences in the amps that matter, it’s what makes you want to listen rather than do something else. 

@snapsc 

It is harder for more analytically inclined or obsessive people. I am not one of them. 

🤣

@markmuse why change preamps? Just install a complete new set of tubes and you should be set for years. Unless you want to do major tube rolling. You decided on your amp by using the current preamp. Changing it will be like a start over and a lot more work.

Looking forward to more amp reports.

Thanks,

aldnorab

@aldnorab  You are right of course. Probably the tubes (not sure yet), but these are not very old. NOS from Brent Jessee. Supposed to be tested and matched. I have the original tubes that I can stick back in to see, but it is such a pain to do: have to disconnect everything, pull the unit from the cabinet, unscrew about a dozen screws to remove the entire housing. 

Re the amp: I'm done for now. Staying with the Voyager. My initial impressions seem to be consistent with ongoing performance, so not much more to say. It is an excellent amp and a bargain at the retail price.

@markmuse 

 I haven’t read this anywhere about the M225s, so I’m wondering, some  amps seem to need an hour of warm up time to sound their best….is that what you found with the M225s?

@snapsc 

Probably true, but I can't confirm. I leave my amps on all the time and did that with the 225M. I will say that the 225M are very efficient... no idea how they accomplished that, but even under a heavy load they barely get warm. The Voyager never gets hot but it gets warmer than the 225M. 

That review about LSA GAN is bad...I'd stay:away:

@nyaudio98 

Really? And what review would that be? If you are addressing me, I already own one and love it. 

@nyaudio98 

If you don't have personal experience then keep 3rd party comments to yourself, or at least link to them. I have had one for 1.5 years+ and LOVE it. The more upgrades to cabling and transport I have done since owning it, the better it gets

I think he meant this one , don't really understand what this may yield referring to sound quality, apparently highs are fine with this amp. I may also confirm that tomorrow 

https://www.audiosciencereview.com/forum/index.php?threads/lsa-voyager-gan-350-review-stereo-amplifier.28115/

It is pretty strange that in this day of measurements, that LSA would allow a product that measures this poorly to hit the market without a few tweaks that would drastically improve its sinaid and other measurements and maybe even the sound.

But, what I really appreciate about ASR is their teardowns...lots of people measure and listen...but that doesn't tell the whole story about safety and reliability.  It looks like the gan350 is a mixed bag:

If you like the sound buy of an amplifier buy it, critics be dammed. 
 

Spreadsheet and graph jockeys drive me crazy. 

In my opinion, reviewers are mostly just one person's opinion and do not really add more than that. A few of them think they are either golden ears or know a lot more than the average bear. You see a few of them post on A'gon too with that attitude.

I get a lot more value from A'gon users posting their impressions of gear. More viewpoints and usually a bit humbler. A lot of opinions on the LSA Voyager on this site

I have the Voyager (supposedly the amp used by the SF Audio Society) to use in warmer months instead of my Line Magnetic LM845 tube amp. I briefly hooked it up when I got it and was impressed, but only listened for a few hours. Maybe I'll hook it up again this weekend to spend some more time with it. However, I also have a condo in AZ and might ship it there to use with a Don Sachs tube pre that I'm not using right now. The speakers are Clearwave Duet 6 standmount speakers that I think will sound great with this combo. We just purchased the condo and will be there in a couple weeks to start setting it up. I picked up a used Cambridge EVO150 all in one to use at first, but I could just use it as a streamer/dac too. We'll see, I like having options.

@yyzsantabarbara I'm also impressed by the LS60 and I'm also thinking of selling all this stuff (the voyager, sachs pre, cambridge) and getting a pair of LS60's instead, but that's another subject. We'll see.

First off ...how can you own a GAN amp from underwood for 18 months.....  When it's only been out a few months. As to reviews..you can't complain of negative reviews..when the positive ones are used by the company. Yes audio science review 

@nyaudio98 

You need to double check how long the Voyager has been available. Much like other of your comments, this too makes no sense

I don't know if they got a bad amp - quality control issue?  However, my Voyager GAN modded by @ricevs sounds freaking awesome across the frequency band.  Highs and mids are pristine and crystalline clear.  Lows are nice.  I don't give a sheet how it measures, it sounds fantastic.

@jaymark 

Thank you for all of your posts on this amp. The discussions you generated led me to this amp, albeit somewhat round about, and I am very happy with it. 

Can you characterize the sonic improvements resulting from Ric's mod? I do have his RF filters.