Sorry, I shouldn't have called it an external crystal oscillator, but a crystal oscillator in a package or something like that.
All good Marcel. The ValveDac sounds great as is so at most I will try a 5v battery power supply and drop off L5 (?? from memory) in terms of clock modifications.
Although not yet directly compared, I have here a Holo May KTE and a Phasure Nos1a, both nice sounding dacs that I like a lot, and once I get the ValveDac into a box I will hook them all up to the preamp and start figuring out where they sit in terms of my enjoyment. Your creation is right up there, perhaps my preferred option at the moment without any controlled listening
based solely on the many highly engaging listening sessions as part of my system.
Although not yet directly compared, I have here a Holo May KTE and a Phasure Nos1a, both nice sounding dacs that I like a lot, and once I get the ValveDac into a box I will hook them all up to the preamp and start figuring out where they sit in terms of my enjoyment. Your creation is right up there, perhaps my preferred option at the moment without any controlled listening
based solely on the many highly engaging listening sessions as part of my system.
Hallo, I’m thinking about selling my board (dsd only + filters) withh all components, completely soldered, with matched tubes, lundahl filters. 1 year passed and project still not finished so, if anyone interested, please msg me. Thanks.
Just finish it, or at least get it working on a breadboard - if you do you'll wonder why you ever thought about selling it.
Around 300€ the board completely populated. Then I have to sell the LL1684 (plus caps for the filter boards) and a septet of 6922 gold. Msg me if interested, tnx.
I've just ordered bits to make a second ValveDac. Am going to build it identically to the first (have managed to actually get all the same parts!) but will experiment with a few different things such as output coupling caps, reconstruction filter, output transformer and power supplies et cetera. I just don't trust myself to make sound quality assessments where I cannot switch between alterations at will so having two dacs on hand is the ideal solution.
This is a great sounding dac that more people should be building.
This is a great sounding dac that more people should be building.
Question to acg, SonnyMarrow and anyone else who has built the original valve DAC: which sigma-delta method has your preference?
I listen mostly to PWM8 but have not spent much time with the PWM4 or Chaos, but they all sound good.
For me, PWM5 and PWM9 are very similar to the point where I'm not sure I could pick them out blind. I've tried using the ABX button but a lot of that is luck. I typically default to PWM9. Chaos was easy for myself and others to pick out, it's very different. It almost sounds as though it's a little more "blunted"? Almost a slight veil.
As far as the filters, I guess I'm deaf because there's no way I could pick any of those out blind haha.
I need to play with ABX now that I have nicer tubes, maybe things will be different now.
Thanks acg and SonnyMarrow! If I ever design a new DAC, I will definitely have to keep the highest PWM mode, but could skip the chaos if needed.
Hi Marcel,
I was wondering if any of the mundorf inductors could used instead of winding one’s own for the DSD circuit. Apparently Mundorf will make some
adjustments upon request. Hificollective “carries” the full range:
https://www.hificollective.co.uk/catalog/components/inductors-coils/mundorf-inductors.html
many of these are available in sizes of 1.80mH, which should be possible to adjust. However, I’m not sure if the rest of the specs would cause problems (size, DCR, etc).
-Raja
I was wondering if any of the mundorf inductors could used instead of winding one’s own for the DSD circuit. Apparently Mundorf will make some
adjustments upon request. Hificollective “carries” the full range:
https://www.hificollective.co.uk/catalog/components/inductors-coils/mundorf-inductors.html
many of these are available in sizes of 1.80mH, which should be possible to adjust. However, I’m not sure if the rest of the specs would cause problems (size, DCR, etc).
-Raja
Hi Raja, I had my inductors custom wound by Don Audio.
https://www.don-audio.com/Custom-Inductor-RM8-Core
The filter PCBs I did for the group buy have the pads for RM8 inductors.
Ray
DC resistance and distortion will be no issue at all with those inductors. The only problems I can imagine are poor suppression of far out of band quantization noise if the parasitic capacitance of the inductor is too high, or hum if you place them too close to a transformer. If you want to try it, go for physically relatively small models, those are likely to have the smallest parasitic capacitance.
Subscribed. Nothing to my ears beats high-rate DSD into SET Tube Amps. Great project, Marcel!
If you ever do, I would 100% want whatever you cook up. The ValveDAC has been nothing short of amazing.
I'm putting together a ValveDAC (DSD version) for someone (using Mirko's board that he was selling a few posts back) and I've just order the passive through hole parts to progress my spare board from the group buy - I may try the CD optimiser with my one using the Sowter trasformers that Raja sent me.
Anyway, for the former build I'll be using a JLSounds I2SoverUSB board (version 3) on the input but I've just had a surprise when I read the documentation - on the isolated side the Mute and DSD-On flags are both 'Lo', the reverse of those flags on the non-isolated header. As the Valve DAC requires those flags to be 'Hi' it looks like I'll have to build a small module with an invertor or, alternatively, an isolator for the 'Hi' flag outputs. I've also dropped JLSounds a mail to see if there's a firmware option too. Anyway, it's a bit of a nuisance especially as anything I have to build will likely need 3.3V power.
Anyway, for the former build I'll be using a JLSounds I2SoverUSB board (version 3) on the input but I've just had a surprise when I read the documentation - on the isolated side the Mute and DSD-On flags are both 'Lo', the reverse of those flags on the non-isolated header. As the Valve DAC requires those flags to be 'Hi' it looks like I'll have to build a small module with an invertor or, alternatively, an isolator for the 'Hi' flag outputs. I've also dropped JLSounds a mail to see if there's a firmware option too. Anyway, it's a bit of a nuisance especially as anything I have to build will likely need 3.3V power.