[Sedona Sky Sound]

Figured I should start this as a new topic since this has the potential to get ugly fast if i am not careful   . Today I had the unique chance to do an A/B comparison of a high-end Gainclone type chip amp versus the Son of Ampzilla. The SoA was definitely the heavyweight here at 54 lbs versus the lightweight Gainclone which was maybe all of 3 pounds including the external battery pack. The Gainclone was designed/built by a highly respected tube amp/pre-amp designer using top-quality parts. This designer did it strictly to satisfy his own curiosity as to how well a properly designed Gainclone could sound. His basic comment was "this version should be better than most and relatively competitive with the best". Based on the high quality of his other work and my limited exposure to similar commercial chip amps, I would tend to agree.    

The speakers that were used were JBL Corner Horns that were something like 100+ dB efficient. We had also planned to try them with Martin Logan CLSs but quickly scratched that idea after the first test. We started with the SoA just because it was already hooked up. On my test track (Cirque De Soliel - Allegria), the bass was controlled but a little excessive (a function of the room unfortunately). However, the mids were full with lots of layering, the singers voice was crisp and powerful, and snare drums and high-hats had a nice long, natural decay.

We then hooked up the Gainclone and hit play. The first thing that struck me was that the singers voice sounded clearer. OK, that's a good thing, right? Wrong. The reason it sounded clearer was that everything else was gone   . The nice 3 dimensional soundstage of the SoA had been replaced by something totally 2 dimensional. The layered background harmonies that I listen for just were not there. The long natural decay of the high-hats were replaced with a sort of short "clink" sound. I think I now understand what some of the major audio reviewers meant when they wrote "this amp has fantastic clarity and separation" in their chip-amp reviews. Unfortunately, I think they actually meant that as a complement   . For those that happen to be into digital photography, I would say this Gainclone was the audio equivalent of cranking the "un-sharp mask" (that is a sharpening function for those not familiar with Photoshop) about 3 times too much. The primary subject stands out in a halo while everything else is obliterated   . While the bass was relatively controlled and the harmonics were good, they just did not come close to making up for the negatives.    

After hearing so many people praise chip amps as the best thing since sliced bread, I just don't get it. Was it listenable? Yes. Was it good? Not by my measure or anyone else in the room that heard the comparison. I may have thought it was OK IF I had not heard something much better just a few minutes before AND clarity was much more important than soundstage to me. As it was, I probably would not have a problem using one if I could get it for $100 and just needed something to power my computer speakers. However, paying up to $4k for one to use in an audiophile quality system is just beyond me.    

I write this not to start a holey war, but to determine if I missed something. Is there something about high efficiency speakers that chip amps don't like? Is there some other trait that draws people to chip amps that I just did not pick up on? As a dealer, I am always fielding customers' questions regarding what type of amp will work best with their particular system. After asking a few questions, I can usually get a feel for those individuals that will prefer tube over solid state but am pretty clueless as to when I would ever recommend something that uses a chip amp. There are several successful commercial versions (some of which are extremely expensive) and I know they are all the rage in the he DIY community (primarily since they are relatively simple and inexpensive to make) so I can only assume I am missing something. Any thoughts? Thanks.      

Julian

[shokunin]

IMO, it's all going to come down to synergy.  In my opinion, horns and digital amps would not be a good match.  No offense to anyone who uses this combo, but I would think a digital amp would match better to cone speakers who lean towards a bit bass heavy and darker sounding.  The digital amp would liven it up and be a good match.   Of the few digital amps I've heard, many seem to be lean in the midbass and lower midrange which provides a gaping hole in the music spectrum while the opposite is true for "tubey" tube amps.  I classify the SoA definitely on the tubey side.  I suspect you had polar opposites in the sounds of the amp and that the horns liked the warmer sounding SoA or a good tube amp.  They were probably voiced using a tube amp.

Do you know which model of JBL horns it was... I used to work for Harman Speaker Manufacturing, but they were probably designed before Harman acquire JB Lansing.

[JoshK]

I think Julian is referring to chip amps, aka gainclones, not switching amps, aka digital.  Two totally different technologies.

[shokunin]

I think Julian is referring to chip amps, aka gainclones, not switching amps, aka digital.  Two totally different technologies.

Did not know there were completely different.. sorry, I take back my comments on the gainclone matchup.  I listened to a 47labs amp with a sony transport a 47labs shigaraki dac/dumpty ps, etc and the guy who owned it said it was a digital amp... guess i should have looked into it more.

[Jon L]

I don't know.  I think it's almost impossible to discuss "chip amps" in general based on one sample, especially a one-off, unique sample.  

I mean, we don't listen to Son of Ampzilla and think we know what a traditional SS amps sound like in general, right?

One also has to wonder if the battery power supply throws in another variable.  It's extremely difficult to design/implement a battery PS that will give you density of sound and dynamic energy, ESpecially true for amplifiers.  

Perhaps a side-by-side audition with this particular chip amp and other well-knowns will illuminate matters, such as AudioZone, real GainCard, etc.

[Sedona Sky Sound]

Hello Jon L,
I understand your point, but that is exactly what I am trying to figure out. While Chip Amp A might sound a little different than Chip Amp B, it is probably safe to generalize that it will sound and act more like a Chip Amp B then a tube amp. Also, the higher-end of any segment is going to act more alike than not. While I may not be able to generalize all SS amps after just listening to the SoA, I can make a pretty educated guess as to what the high-end SS segment will do. While they may be voiced a little different, I know that I can put a SoA, Pass X250, or Mark Levinson 335 in my system and can be pretty well guaranteed good control of the bass, full but not bloated midrange, incredible dynamics, low THD, non-fatiguing sound, etc.    

While I have not heard a lot of chip amps, I have heard a couple. Unfortunately, each time in the past has been in a system I was unfamiliar with. Looking back, I would say that the general characteristics I mentioned were present in each of these systems but I had always attributed the sound to something else (i.e., bad speaker placement, bad speakers, etc.). This just happened to be my first opportunity to do an A/B comparison. As I alluded to before, I have little doubt that this implementation was equal to of maybe better than a 47 Labs Gaincard with Humptey, so you can pretty much use that as a baseline. Seems like you may have some familiarity in this area so curious if there are products that are multiple times better than the Gaincard. Thanks.

Julian

[Kevin P]

There are a lot of variables and I'd say that you shouldn't draw conclusions based upon a single sample.

[doug s.]

i agree that this one-off amp doesn't seem to be a good comparison.  why not get someone like dusty vawter of cia audio to loan ya a pair of his chip-amp derivatives.  they're not too spendy, at $1k retail/pair, and lotsa folk have good things to say about them.  i have no personal experience w/these types of amps, myself, but yer results don't seem to add up here...

ymmv,

doug s.

[JFT]

Julian, is this the amp you are referring to, or was there some other battery powered amp that I didn't see?

http://wardsweb.org/LSB/11_06_04/sa08.html

[cjr888]

I write this not to start a holey war, but to determine if I missed something. Is there something about high efficiency speakers that chip amps don't like?

I would say in general they prefer high efficiency, but matching them can lead to some odd combinations, and they seem rather sensitive to associated parts.  Know much more about the specific amplifier used or the speakers?

[Sedona Sky Sound]

Hello Fred,
There were actually 3 different chip amps at the get-together (I think 2 were battery and one was powered). One was an actual commercial model, one DIY, and then Lee's "prototype". We used Lee's chip amp for the test since it seemed to be built to a much higher standard than the others. I believe he was using the LM3875 chip and there were pretty much no "stock" parts in the amp. Resistors, diodes, wiring, etc were all "audiophile approved" parts   . I can't remember off-hand the other modifications he did to the design but at the time they all seemed logical and should have helped versus hurt the problem areas in question.  

Your wife was in the room when we were testing, so I am pretty sure she can back-up my impressions between the two amps      

Julian