AQVOX DAC - The Modification Thread

I love modification threads. Will follow this with great interest!

Regarding the output caps, I guess it’s ok to remove them as long as the pre integrated amp has caps on the input? Or can you do without completely?

I expect that as long as there isn't any DC from the DAC, then it's not an issue whether the pre has caps or not.

HOWEVER.... I won't be held responsible for anyone blowing their kit up 😂

Yup, will do.

I am trying to reach out to a guy who is selling one in Denmark, but as of yet he is unresponsive.

zleepy are you from that part of the world? Maybe you could do me a favour?

Update:

Being absolutely confident in my ability to carry out all of the modifications i want to without issue, i bought another Aqvox DAC lol...

Cant hurt having a back up, can it?

Anyway, the real reason for picking up a second Aqvox is for comparison. At first, it will be standard (SMPS etc) vs the modded and upgraded version, complete with the new "specially selected" amplifier modules in the BNIB one i bought. These are removable and swappable, so when the second Aqvox DAC get here, i will decide which one i am going to upgrade. The BNIB DAC is black, the used one is Silver. I always wanted a Silver one, so my initial thought is to do that one.

I also had another thought. What if i were to use an O-Core instead of the toroid i usually pick for these things?....I think i may have to find out.

You need a Champagne coloured one now to complete the set!

Fantastic! Very interested in your comparison

Not really surprised myself having heard the benefit of removing SMPS on multiple occasions.

Update:

The DAC has been on and playing since i got back from Alans a couple of days ago, so there's probably about 48ish hours on it now. It went through a bit of a muddy patch last night but by the time i was up this morning it was wide open and singing nicely again.

Being fairly confident that the DAC had now settled down, i decided to put the fuse in that Norman sent me.

Well, well, well!

Being the sceptic i am, i am not expecting anything here. I popped the fuse in and checked the phase arrow was pointing the correct way. I sat back and pressed play on "Hermanos Drive" - Hermanos Gutierres

I am laughing my head off as i type this, but i am stunned. The transient detail has gone through the roof. The little palm mutes on the guitar are lasting longer before decaying to inaudibility. The sound is cleaner, more linear, more open and resolution is improved by this. Soundstage layering is now deeper and the separation is easier to hear. My head has fallen off a little bit here, so i am going to listen to a few more tracks before saying anything else, but yeah....this is ridiculous lol

The fuse is inside the dac, but will only work with side gripping fuse holders like this one :

Norman reckons it sound no different one way round, stunning the other. IT sounds stunning, so i presume it's right...if there is a right. It is AC after all.

Either way...it's not coming out!

And no....no whiskey, yet lol

A few more updates from today:

First on todays agenda was to try out the amplifier modules from the other Aqvox DAC. As you may recall, the modules (red square devices) in the new Aqvox were a pair of newly designed (i believe) hand selected modules. The ones in the silver DAC were the same as i'd heard in my previous Aqvox.



The swap is simple as they are just pins into sockets, so away i went and within seconds i was transported to my old Aqvox's sound. Incredibly insightful, precise, maybe forensic, and a little leaner too, but there it was. I listened to a few tracks and then felt compelled to go back to the new modules for a comparison. It's really odd, the new modules are not as lean sounding, have a bit more LF heft and weight, and appear to make humans sound more human....i was a bit stuck between a rock and a hard place, as the forensic nature of the old modules really put me onto this brand. I love that about it, and while it may be forensic, it was never strident or harsh, just extremely clean.

As i was sat there pondering the pros and cons, the postie arrived.




HE delivered what i deem to be an absolute necessity for hifi...EMI/RFI IEC filter sockets. I put one in straight away, well after a light bit of filing to open the case hole a little.

I went back, plugged it in and there it was....

The new modules in place and the EMI/RFI filter now at work, the Aqvox was somewhere between the two presentations of the amplifier modules. The sound is organic and natural, but its also now a little cleaner and insightful. The DAC is now pulling out strands and sinew of detail but it's far better balanced tonally than with the old modules. It's awesome.

I listened to Fleetwood Mac, Tango in the night, and i was hearing things in the background that i hadn't heard before, or certainly not noticed. So much so that i paused the track because i thought it was something going on next door, or in the other room etc...but it wasn't. I thought I was imagining it, so i plumbed in the Silver DAC and voila!....I was not imagining it at all. The difference the EMI/RFI filter made is quite exceptional.

I am absolutely buzzing at this point.

Then....More GREAT news. My desoldering gun arrived.

I have now tested it and i am 100% confident that i will be going ahead with recapping this DAC. I cannot wait!

Here's my test work on the PCB for the silver dac.

I could do... Hadn't thought to look at what they are.

I think you like making more work for me 😂

Yeah, two traffos mate. The little one providing the 5vdc and 3.3vdc

Big one providing + & - 16vdc