USB Regen from Uptone Audio

[DaveF]

I only had a very very quick scan through the Whatbestforum thread John. To be honest the bickering there was kinda off putting. One thing I noticed was these tones he was seeing at 4 or 12 KHz,(cant remember exactly) seemed to be way below -100dbf. That's pretty tiny. Gonna have to take more time to read back through the history and what jitterbug is all about. Nice to see a few people having a go at some measurements though.

[jkeny]

I only had a very very quick scan through the Whatbestforum thread John. To be honest the bickering there was kinda off putting. One thing I noticed was these tones he was seeing at 4 or 12 KHz,(cant remember exactly) seemed to be way below -100dbf. That's pretty tiny. Gonna have to take more time to read back through the history and what jitterbug is all about. Nice to see a few people having a go at some measurements though.

Dave, I would forget about the Jitterbug - it's a far less interesting device, comprising of some passive filters on the VBus & chokes on the USB data lines, AFAIK
The Regen is a far more interesting device

If you want to see measurements that try to characterise the Regen device, itself, then look at JohnW's measurements on PFM
If you want to see fairly stock measurements on the Regen + Explorer DAC which have little chance of seeing anything, then look at Amir's measurements. Let's bring Amir's plots over here so people know what's being spoken of:

This one shows the reduction in noise floor on the output of the Explorer DAC when using the Regens cleaner 5V supply to the Explorer DAC


This one shows the analogue output from the DAC when the input signal is a J-test (which is a 12KHz sine wave overlaid with some other low amplitude square wave @ a frequency not specified by Amir - is the default 250Hz?)


My interpretation of the tones @8KHz & 16Khz are that they are the result of the 125uS timing of the USB microframes used in USB 2 high speed communication (125uS = 8KHz). Amir's interpretation was that they are jitter from the test. The only way to check which is correct is to do the measurement again with something like a 11Khz jitter J-test or with any tone which is not a fraction of 8Khz.

I find Amir's tests fine for what they are - a very crude look at the output of one DAC used with the Regen without much care or thought put into how the Regen device is purported to work & what the possible ways to measure this on the analogue output of a DAC might be. Instead he works on the premise of - if it can be heard, it must be measureable on the DAC's analogue outputs (which is fine) & then uses fairly crude, stock measurements to check this.

And here's where we arrive at the great divide - we all know we have heard improvements that are not measureable on the analogue outputs of DACs - it's going to take some new thinking to find out what it is in the analogue waveform that is changing but it will come in time, I'm sure!

What I found most disappointing was Amir (who is one of the more open-minded objectivists) making this categorical statement based on his measurements:

"For my money, I think a rock from the garden put on top of my DAC may do better than either one of these devices. For the price of Regen, you can buy 10 high-res downloads and I am confident that would bring more happiness to your music life than this device."

His listening report "I then tested the Regen. Once again, comparison is hard and next to impossible due to multi-second switching. On first insertion, I thought I heard an improvement. I went back and forth and the tables turned and no Regen sounded better . In other words, the differences imagined or real, are well within placebo range."

[tony]

Would concur with John's view on Amir. It seems like he just wanted to make a big noise statement and get attention.
Will see does he manage to devalue regens in the process.

[mick]

Had been following this thread with interest and took a chance.
My Regen arrived this morning. I have a tri-linear ps with a custom built audio pc ( thanks Nige ).
I use a JKDAC32. I connected the Regen and it was plug and play with no problems.
It will not be going back. It certainly improved the overall sound quality of my system.
Sound staging was improved wider,deeper, higher with more air around voices and instruments.
Bass was a little deeper and more detailed.
Detail was improved throughout the frequencies. The sound was also sweeter.
All in all a well worthwhile purchase.

[jkeny]

Would concur with John's view on Amir. It seems like he just wanted to make a big noise statement and get attention.
Will see does he manage to devalue regens in the process.

Yea, compare & contrast his lax attitude to audibility checking of the Regen to his campaign on high-res audio where he used multiple blind tests to "prove" he could hear a difference.

Had been following this thread with interest and took a chance.
My Regen arrived this morning. I have a tri-linear ps with a custom built audio pc ( thanks Nige ).
I use a JKDAC32. I connected the Regen and it was plug and play with no problems.
It will not be going back. It certainly improved the overall sound quality of my system.
Sound staging was improved wider,deeper, higher with more air around voices and instruments.
Bass was a little deeper and more detailed.
Detail was improved throughout the frequencies. The sound was also sweeter.
All in all a well worthwhile purchase.

Yep, this seems to be the consensus opinion - it seems to me as if the edges of auditory objects are better defined. It's hard to know what is the underlying mechanism that might give rise to this but one theory I have is that there is some low level, underlying, noise modulation which is being removed or improved by the Regen. This will not show up in the stock tests run by Amir & others. Without carefully focussed testing, this will difficult to reveal, but then there are many with more expertise in testing than me who might have something to say?

I guess there is also variability in the quality of the USB signal reaching the DAC without the Regen as to whether the improvement wrought by the Regen is noticeable or not? There are many other variables too but this would seem to be one of the main ones.

[mick]

Yep, this seems to be the consensus opinion - it seems to me as if the edges of auditory objects are better defined. It's hard to know what is the underlying mechanism that might give rise to this but one theory I have is that there is some low level, underlying, noise modulation which is being removed or improved by the Regen. This will not show up in the stock tests run by Amir & others. Without carefully focussed testing, this will difficult to reveal, but then there are many with more expertise in testing than me who might have something to say?

I guess there is also variability in the quality of the USB signal reaching the DAC without the Regen as to whether the improvement wrought by the Regen is noticeable or not? There are many other variables too but this would seem to be one of the main ones.

I believe that the quality of the dac,amp and speakers will also play a part in wheather you can hear improvements or not.
The JKDAC32 is exceptional and is more than up to the task. I have a Tom Evans Vibe with the latest upgrade and the Pulse ps. This is feeding a Gamut D200 mk111. At the moment I have Yamaha NS1000.
I would class this set up as being very good.
On the latest Unthanks CD 'Mount the Air' the first track has a faint cymbal on the right of the soundstage and well back in the mix. With the Regen plugged in this cymbal is much further to the right and more audible.
On another track 'Magpie' there are three female voices which are better separated and easier to follow especially the deeper voice.
This is typical of the improved sound quality I have experienced with the Regen.
I do not know why the Regen should make such a difference. There is no power on the cable from the PC to the dac so the Regen doesn't do anything with that which it would on other dacs. Supplying battery power instead of taking power from the PC through the sub cable was one of the big improvements with The JKDAC32.

[jkeny]

I believe that the quality of the dac,amp and speakers will also play a part in wheather you can hear improvements or not.
The JKDAC32 is exceptional and is more than up to the task. I have a Tom Evans Vibe with the latest upgrade and the Pulse ps. This is feeding a Gamut D200 mk111. At the moment I have Yamaha NS1000.
I would class this set up as being very good.
On the latest Unthanks CD 'Mount the Air' the first track has a faint cymbal on the right of the soundstage and well back in the mix. With the Regen plugged in this cymbal is much further to the right and more audible.
On another track 'Magpie' there are three female voices which are better separated and easier to follow especially the deeper voice.
This is typical of the improved sound quality I have experienced with the Regen.
I do not know why the Regen should make such a difference. There is no power on the cable from the PC to the dac so the Regen doesn't do anything with that which it would on other dacs. Supplying battery power instead of taking power from the PC through the sub cable was one of the big improvements with The JKDAC32.

Yep, the playback equipment needs to be of a suitable quality - especially have a low enough noise floor to allow the improvements of these devices to be audible. I've said it for a long while now but I do believe that what we are hearing as improvements in audio for many years now is less about removing distortions, etc & more in the area of psychoacoustics. In other words, we are improving aspects of audio playback which are of importance to our auditory processes but not so easily measured (or not considered particularly important to hearing). For example, the traditional way people think of noise is as an audible background hash & if inaudible then it's of no consequence. Another example - people think of ground loops as something which causes a hum & if not audible then it's of no consequence. Both of these examples are the same kind of literal thinking that pervades a lot of discussions & leads to the ill-informed statement "well if it's night & day difference then it will be easily seen in the measurements". A small difference in audibility of the leading edge of instruments, voices, etc (the sound envelope) can lead to a much greater impact in how we perceive the playback - how much more realistic the playback illusion is.

The literal & linear thinking behind this shows a lack of understanding of auditory processing (the small bits we know about it) & a lack of interest in understanding this. I consider it one of the most fundamental requirements of anybody who is trying to develop audio playback systems that are intended to be listened to - to inform themselves about auditory processing or even take an even slight interest in this area. Unfortunately, most are still focussed on accuracy as it's engineering & it's easier to measure. I'm not demeaning engineering as it's hugely important & how we have arrived at this point but clinging to the accuracy as the criteria is possibly missing what part of this accuracy is of significance to our auditory system & what isn't - what we might be overlooking/underestimating or unaware of.

[sebna]

Maybe I should try it one more time... maybe with one of the well run-in units :) I have heard all the improvements mentioned but also it was bringing brightness and harshness at the top end in my case but at the same time my system is fully SS so I guess more prone to highlighting those issues.

[mick]

Maybe I should try it one more time... maybe with one of the well run-in units :) I have heard all the improvements mentioned but also it was bringing brightness and harshness at the top end in my case but at the same time my system is fully SS so I guess more prone to highlighting those issues.

I don't think that is the cause of the brightness you describe. My amps are solid state and the sound is sweeter. The bass is tighter and deeper which gives a fuller,more rounded sound. Could the Regen be showing up some other problem in the system.

[nige2000]

Maybe I should try it one more time... maybe with one of the well run-in units :) I have heard all the improvements mentioned but also it was bringing brightness and harshness at the top end in my case but at the same time my system is fully SS so I guess more prone to highlighting those issues.

I don't think that is the cause of the brightness you describe. My amps are solid state and the sound is sweeter. The bass is tighter and deeper which gives a fuller,more rounded sound. Could the Regen be showing up some other problem in the system.

A bit of guess work
I Dont have a regen but seb likely has a USB card which will provide a decent enough USB signal it is powered by the teradak linear supply putting a regen on this could be just like washing your jumper twice at it just not get much cleaner
I think Mick is using the usb3 port on the back if the PC so his potential for improvement is much larger

I see two potential areas for Sq loss in the regen at our standard of audio PC mainly power supply but also the additional cabling
Using a cheap smps power supply is kinda like washing your jumper in dirty water
I believe the guys tested a battery powered one at a meet and it was a clear favourite

There are differences in usb cable and the differences are far from small and generally speaking more of it leads to worsining sq

IMO the regen us built for a target market of Mac and desktop and laptop users that will undoubtedly get a large improvement
I'd imagine to get the best out if it it will need some light modding and clean power