AQVOX DAC - The Modification Thread

I'll try them mate. Thank you.

The thought has crossed my mind, and it's definitely doable, even with the LEDs.

But.....do i want to?

At the moment the DAC is sounding way better tonally with the WEET caps in, but they obviously cannot stay in as I can't get the lid on. The Amtrans are the better caps overall, there is no doubt in my mind about it, but they do sound a little lean. Believe me, the WEET are a good...bloody good for £3 each, but I heard the positives of the Amtrans and I'm not ready to give up on them just yet.

I also know that I have taken them out way too early due to impatience, so they will get another chance. They are high voltage caps and this DAC is putting out very little to stress them, so experience tells me that they may take a serious amount of hours before they calm down.

I am going to give these WEET 100hrs and see what happens, then I'll try the DAC with no caps at all, then the WIMA when they land. In all that time the Amtrans will be burning in with some volts through them. I'll give them all a good listen, and then give the Amtrans another shot.

If there isn't a winner, and the volts on the Amtrans doesn't do it, I'll whack some square WIMA in, put the lid on and flog the digital setup.

The Aqvox is the DAC that's got the closest to dethroning vinyl for me, and it's still 2nd to it...even with a rather underated Kontrapunkt B on the vinyl rig. I drop the needle and it sounds right. Really right. It's never sounded wrong!

I'll move to a single box DAC and streamer and just play the stuff I can't get on vinyl.

You may find the sound to be somewhat direct and possibly thin depending on the how the i/v stage is configured Oli just check the impedance and back emf. ANY mini inductors in the signal pathway after those caps at all?

Interesting discoveries

Vey interesting indeed. I expected removing the output caps to be the silver bullet really. Apparently nothing is ever simple in this hobby!

I have the Aqvox recapping project in the pipeline. It's more for my entertainment than being a serious project. I really like upgrading/modification projects like this.

Very nice to hear all the work you have put into it is starting to pay off! 

The long burn in correlates with an upgrade/recapping I did to my Audiolab 6000CDT. All electrolytics were replaced with Panasonic FM:s along with upgrading the rectifier diodes, some mechanical damping in various places, and adding an AES XLR output. When I listened to it afterwards I really thought I had ruined it. I was actually sure I had made a mistake with some of the components. It was very aggressive and unpleasant sounding. It took at least 100hrs for it to become listenable, and it continued to improve over a long time period. Very happy with it. It was very good before, and even better now.

The end?

Well, it just might be!

The WIMA Black Box caps have arrived, but they are too tall for the casework, so they will not be going in. I was 100% sure they would fit, but the spec sheet i saw Vs what's arrived are two different things. Not surprising as i wasn't sure about the spec sheet when i read it. Therefore, i am calling time on the Cap hunt and continuing without any output caps, mainly because i can't find any i want to use. The lid will be fitted tomorrow and that will be that for now.

After approximately 500 hours of use, the Aqvox is now performing at a level of musical insight and satisfaction that i am REALLY enjoying, and thoroughly impressed by. The upgrades have yielded more detail, more definition, greater transparency and a general overall feeling of being a dac punching well above it's price tag, including the mods. My one question mark is over the LF. The one criticism i have heard levied at the Aqvox is that it can sound a little lightweight. Admittedly, i am one such person who though that. With the modified caps and regs, the Aqvox is now a bass monster. I mean that too. Had i speakers in the full range category, the sound would be extremely dynamic and powerful. And that kind of explains why i am a little concerned. This is a MAJOR 180 shift Vs before. Is that down solely to the upgrades, or is that an effect of not having caps on the output?.

I am told that the only function of the output caps is to capture any stray DC, and that they are not responsible for any frequency filtering etc. Thats fine, and i love the sound it's now making, but you know when you have the urge to just make sure? ...... i have that.

From a personal perspective, i LOVE the balance now. It really does make the music sound alive and palpable, far more so than previously. I will, at some point, check it out, but for now i am going to just enjoy the fruits of my labour.

There is a standard Aqvox coming for a bakeoff in October...so i will report back then.

Mine is 22k

3.3uf

May I borrow your thread Oli?

Following in Olis footsteps I bought an Aqvox DAC. This was already during summer, but it was not until last week I got mine finished. 

I bought it on a whim purely as a fun project when I saw one pop up in Sweden. Got it for cheap and started ordering caps and regulators and parts for the LPSU. 

Long story short and a big thanks to both Alan and Oli for the support, it's now playing in my system. I'm a bit shocked about the performance really. I think this will be in my setup for a very long time. It has everything I need in terms of I/O:s and the sq is stellar. It is no longer just a fun project, it has become a fun but very serious project 

Anyway, since it's so good I'd like to try to squeeze out everything possible, and my attention turned towards the clock. There's two of them, one on the USB input board and one between the upsampler and the DAC. I don't use USB so that will be left as is but what about the DAC clock? To me the crystal oscillator looks very basic and I think there could be room for improvements there.

However, the more I read about this, the less I fancy doing it. Ideally I'd like to swap just the oscillator for a better quality one, but my knowledge about this is virtually zero. What I've been reading so far is that I'm more likely to mess something up rather than gain anything by swapping the oscillator. Reason for that is that the components surrounding the oscillator likely are designed to work with that particular oscillator and it's parameters. 

A "super clock" board installation would most likely require some irreversible surgery. 

I'd like to ask you guys for advice. Should I just leave it be, or could there be further improvements had by messing with the clock?  

Mine is fed with Mutec and cheap Chinese clock with external PS for clock and Mutec. Great step in quality of sound and very simple. Just a case of a couple is AES cables. Thinking I must try a LB clock for comparison.

Also thanks to Oli for putting mine together.