Gustard R26 - different sound signatures in different units

@sls883 Yes I've tried all menu settings on all units. The basic sound signatures didn't change. 

The one I got from Ebay had a very tiny font on the display and it put all options on one page. The other ones had a larger font and put the options spread among two pages -- you scroll down to the second page. I tried updating the firmware on the one with the tiny font but there was no change.

I noticed that the new price on an R26 has dropped a lot from about $1650 to $1450 in the time I've been exploring it. Not sure if this indicates a drop in review quality or excitement in general about the unit.

@audphile1  Yes I made some mistakes, in particular not spending enough time critically evaluating the R26 I got from EBay. But keep in mind the R26 from Amazon is returnable, and I can probably sell the R26 I got from Ebay (I would be honest with them and say it has a bright sound signature, though not objectionable, could be just the thing for a person who likes rock etc.). 

The other issue here is that I plan on having the R26 custom modded by a guy who does amazing work. The base model only has to be "good" but it will be "great" after the mod, I have good reason to hope for. 

Right now the newest R26 is not "good" however, due to the shrill highs. But I'm probably evaluating it too soon. I'll probably refrain from a conclusion before 300 hours of burn-in. Some sources say ladder DACs take a long time to burn-in.

The EBay R26, when driven from a DDC (U18) with an Aurender N100 as the USB source, has some remarkable qualities. Unusually good dynamics and musicality for a DAC in its price range. I evaluated several other DACs this year, including more expensive ones (including a Terminator, a Schiit Yggdrasil and more) and none of them were as musical or dynamic as the EBay R26. 

@alexberger thanks for the tips. sounds wise.

@bigshutterbug I would also like to know what input you used. What you are describing sounds like the USB input on the first R26 I bought. Switching to the I2S or Coax inputs with a U18 DDC was an entirely different sound signature, much more lively and extended, much better dynamics. 

I don't find that the filter settings make much difference for the large differences in sound I've heard between units. This older R26 I bought from EBay is much brighter, no matter the input, than the more recent R26's I've tried. It's much brighter no matter the filter setting. The later R26's through the USB input were dull no matter the filter setting.

@audphile1 I guess you don't like the R26? I think it has some remarkable qualities. Musical and dynamic (the two R26's I have now even though one is much brighter and one has a sibilance problem which may resolve with burn-in). 

The guy who does custom equipment and mods for me is Igor Kuznetsoff of the New Jersey audiophile society. He does a lot of different stuff. I love his sound signature. Very dynamic, incredibly detailed microdynamics, very musically expressive with all the details contributing to the music, not "analytical."

I have power conditioning from him and power cords. I have vibration isolation from him. Other cabling by him. This all sets up the ideal conditions for the R26 to shine with his sound signature. That's the stock R26. It will be enormously improved with his mods. I'm going to get a simple version - will cost around $500 for the mod. The result will probably be something one can't get in a stock DAC for less than $6000. Just throwing a number out there, it all depends on one's taste and preferred signature. I didn't like the PS Audio DirectStream DAC Mk. 1. 

@mofojo It was partly not realizing they sound much better when driving by a U18.

1. Bought R26 from Amazon on strength of its reputation among the New Jersey Audio Society. Drove it via USB. It was really boring sounding. Dull, no high-end extension.
2. Exchanged that one for another from Amazon on the theory it was defective. It was a little better through USB (more extension) but then I discovered I could use the U18 DDC and drive it through the I2S or coax inputs. All of sudden it sounded great.
3. Then, thinking I knew how the R26 sounded, I got interested in saving money and bought a used one from EBay at a large discount. (returning the second R26 to Amazon). This sounded much brighter... much much brighter (either through USB or the DDC). At this point I was also trying other DACs and kind of got tired of audio. Went back to other hobbies and listened from time to time but not critically.
4. Finally started doing critical listening to the third R26 and realized it was far too bright and aggressive on classical music such as piano. Bought another R26 from Amazon. May sell the bright one. I don't think it's broken so to say, but might appeal to rock music lovers or something. This new one from Amazon sounds different than all the other three. It hasn't finished burn-in through, so I'll give it some more time. (Has about 175 hours of music, at quiet levels. Right now has a kind of annoying sibilance region, not well integrated with the midrange.)

Update: I sold the one R26 I had that was too bright for my ears--I explained to the buyer that it sounded great through USB and they went for it. Then I purchased an R26 direct from the Shenzen company in China. It sounds terrific and good tonal balance! My theory was that the ones on Amazon are the returns for defects, but direct from China it should be their best stuff. So I'm happy now.

In the meantime I was trying other headphone amps and discovered that my headphone amp was considerably bright. I didn't realize this because I hadn't compared to other amps in years. This could even be stimulating the ear resonance I have. So I'm in the market for a different headphone amp.