GUSTARD DAC-R26 Balanced Decoder R2R+1Bit Dual Native Decoding Music Bridge

[Jake2]

Some preliminary observations re the LB after getting it working late this evening (I followed all the advice above - one output on, sleep mode, can disconnect GPS antenna once synced). So far used it only with my best cable the Harmonic Tech, foil taped BNC junction at R26 end.
- The LB responds to & scales well with quality, clean power - I was using a topping P50 low noise PS plugged into a stock power cable into unfiltered power board - the LB sounded good enough, but it took a big jump in dynamics and scale when I switched the stock cable to the Flux-50 style IEC filter + good AliX power cable plugged into my Puritan PSM156 with Groundmaster dedicated earth. What I normally use to power the OCK-2.
- the LB’s midrange has a particularly full body, natural tonality and smoothness - really nice. With my revealing speakers than can lean edgy to my ears this is more pleasing than the internal clock which has just a hint of edginess by comparison, voices not quite as palpable. LB’s bass is warm, full and flowing. Soundstage a little more layered than the internal clock.

Pretty impressive for less than 200 quid!

Am heading away for the weekend so will leave it on, ticking away in case there’s burn in…

 

[Jake2]

Since this is now a tweaking and modding thread, my favorite sandbox, I want to make some comments on Rod's (@rodthebod ) carbon/brass isolation footers he spoke about several weeks ago. I ordered several sets and Rod kindly sent them right out, and one night earlier this week I put a set of three beneath my 45 SET amp, turned it on, and walked away to tend to some other things. This is an amp I've recently installed, along with a temporary set of little Klipsch RP600m speakers to get me by until I build a proper pair. I'd been enjoying the new amp but not so crazy about the limitations of the speakers.
Two hours later I sat down, having completely forgotten I'd installed the isolaters, put in Leonard Cohen's You Want It Darker, and did one of those pull your head back in surprise moves because I couldn't believe how transparent, present, and dimensional the music sounded. It's a great recording but still, I didn't expect such a rapid burn in of new tubes and caps I'd installed! I played through some Martin Wasilewski, Many Katche, Melanie Gardot, Kit Downes, Julian Lage.....just kept listening because it was sounding so good! To my surprise and bedazzlement, my sweet little amp and these mediocre speakers had somehow woken up in 24 hours, wow! Imaging was fantastic, soundstage wide and deep, the music was crisp and clean.
I got up off the couch and went over to turn the amp off which requires a crouch and a reach to the back of the amp (until I mod this too), and it was then that I remembered I'd installed the isolators. Holy crap. Most honest kind of testing in my book, when you're sitting there for two hours asking yourself what the hell happened to your system.

I'm sending on a couple sets to Camrector today, and I understand Jake also has some heading his way. I don't know what those guys will think, but I'm honestly still pretty shocked that thes unassuming little feet are having such a remarkable impact on my system.

Rod isn't paying me any royalties, and I hope I'm not overwhelming him by posting this if he gets a bunch of PMs, but I just have to say this is a no brainer in our world of BS overhyped tweaks. This had an effect on par with the FMC mod, probably greater. Thanks Rod!

Goodness that is a glowing testimonial. My anticipation is building - now if the postman would actually deliver them - the first set has gone AWOL, hopefully just taken a long detour - but Rod kindly has sent another.

 

[Johnjc1]

Some preliminary observations re the LB after getting it working late this evening (I followed all the advice above - one output on, sleep mode, can disconnect GPS antenna once synced). So far used it only with my best cable the Harmonic Tech, foil taped BNC junction at R26 end.
- The LB responds to & scales well with quality, clean power - I was using a topping P50 low noise PS plugged into a stock power cable into unfiltered power board - the LB sounded good enough, but it took a big jump in dynamics and scale when I switched the stock cable to the Flux-50 style IEC filter + good AliX power cable plugged into my Puritan PSM156 with Groundmaster dedicated earth. What I normally use to power the OCK-2.
- the LB’s midrange has a particularly full body, natural tonality and smoothness - really nice. With my revealing speakers than can lean edgy to my ears this is more pleasing than the internal clock which has just a hint of edginess by comparison, voices not quite as palpable. LB’s bass is warm, full and flowing. Soundstage a little more layered than the internal clock.

Pretty impressive for less than 200 quid!

Am heading away for the weekend so will leave it on, ticking away in case there’s burn in…

Thanks for your update and your experience Jake.

 

[Johnjc1]

Yes Tony (Coherent Systems) gave me some good tips when I decanted the LB inside the R26 from the TAS forum about the LB clock. I believe he was the one who originally recommended the LB for audio with all his experience of using one for many years, but John can clarify that one.

Yes Tony suggested as it performs well and is low costs. He had nothing to gain from the recommendation accept respect.
He has used it for a good few years but prefers other more expensive clocks (between 4 to 5 figures clocks) these days.

 

[Knobstler]

If I recall it right it goes in the same direction as the ‘230V’ embossed print on the fuse holder

Ok that means upwards i guess. I hope your right

 

[camrector]

I found this quote really interesting
"While the Bodnar doesn’t have a super desirable PN plot from memory its about -70dbc @ 1Hz, however from our experience the amount of spur /noise deviation on the plot curve itself has a greater effect on the result imho"

This entire read was from EEV Blog about clocking and linking lab equipment.
When audio was mentioned, the glossed over quotes are
“Audiophiles should read,the classic jitter papers,from1970s..1980s, eg AES AES.ORG by Dr Steve Harris and from Audio Précision AP.COM by Dr Julian Dunn.
So, even at 24..32 bits an ordinary can XO for $10 will give, same sound as these products if a double blind ABX test is made.”
“Any digital audio DAC or SRC is dependent on the input signal for the clocking.
Only an ADC required a clock of exact frequency.”

“Jonpaul's astute observations regarding audio clocks are on the money, having the main oscillators/synthetic etc close to the point of data conversion.”

10mhz isnt some special magically frequency. It’s just the rubidium frequency standard.These clocks ALL add jitter.
Trying to clock a 44.1 or 48 kHz signal with a 10MHz clock, mathematically is not clean. You will need to use methods such as asynchronous rate conversion to multiply the rate down correctl, (Cascading PLLs) invariably resulting in a ‘dirtier’ frequency spectrum of the clock signal. Jitter.
Transmitting a 10mhz signal across however long the BNC cable takes more time than what’s sitting right inside the DAC. That time difference increases jitter.

 

[Johnjc1]

I asked him why it performs well considering it measures badly. His reply
it doesn't measure badly, just not as good as the usual suspects The key here is the lack of spurs on the phase noise plot, it may not be the lowest but its one of the quietest

 

[camrector]

I asked him why it performs well considering it measures badly. His reply
it doesn't measure badly, just not as good as the usual suspects The key here is the lack of spurs on the phase noise plot, it may not be the lowest but its one of the quietest

Where is this plot?

 

[Clivem2]

I wonder whether the R26 and many other DACs have spurs due to their internal clocks so external clocks can end up giving a better sound. There has to be a plausible explanation somewhere,,,,given the femto clock in the R26.

 

[Johnjc1]

I am not going to to ask him to show a plot. If you want to do that feel free. to ask him directly.

 

[camrector]

I am not going to to ask him to show a plot. If you want to do that feel free. to ask him directly.

Who should I ask?

 

[camrector]

I wonder whether the R26 and many other DACs have spurs due to their internal clocks so external clocks can end up giving a better sound. There has to be a plausible explanation somewhere,,,,given the femto clock in the R26.

you would just need to find the actual clock component data sheet.

 

[Clivem2]

you would just need to find the actual clock component data sheet.

Any clues?

 

[Johnjc1]

Tony at Coherent Systems

 

[camrector]

Any clues?

I’ve been digging. No luck
If one of you guys want to pull that sticker off and see if there are any other markings while copper foil wrapping the insides, I’d be grateful!