Valve DAC from Linear Audio volume 13

It's leaving a strong first impression Marcel.

After a while I will play around with some different reconstruction filters, probably a separate low voltage supply for the clock and maybe even a LCLC power supply for -300V. Not sure if any of those things will make a difference.

There is a choke loaded power supply here about to be wired up to go into a preamp. It will suit the ValveDac so perhaps it could be trialled there first.
 
I did, particularly the "for now", which seems to imply that he wants to get it up and running again eventually. In case I misinterpreted that, which of the many PicoScopes has your preference?

For what it's worth, when I get rubbish out of an oscilloscope, it is almost always due to poor contact in the probes. I have five passive probes and none of them are really reliable.
I can highly recommend the 5000 serie with built in function generator and loaded with all kind of analog and digital features.
Ultra reliable, also for the 200Mhz probes.
https://www.picotech.com/download/datasheets/PicoScope5000Series.pdf

There are also PicoScope versions with less features but all very good.
With FRA4PS you can make very reliable bode plots and even turn your picoscope into a VNA.

Hans
 
The thickness of the molybdenum getter layer that is sputtered on the inside of the glass also differs a lot from one brand to the next. I once bought four 85A2's, each from a different brand, and the Pope 85A2 had such a thin getter layer that you could see the electrode structure shine through far more clearly than with any of the others.
 
Amazing

Hi all,

I was wondering if anyone considers building the valve DAC from Linear Audio volume 13 (which is not a solid-state DAC with a valve-based output buffer, but which uses E88CC valves as the actual DAC). If so, I would be very willing to answer any questions about it. If there is more than one person who wants to build it, you can save a considerable amount of money on the main PCB by ordering it together.

Best regards,
Marcel

Edit, 18 August 2020...30 May 2021:.......


Hi this is an amazing approach that you updated the 1rst Message! So a newcomer like me immediately can see the most important parts in the thread. Really thanks for that! Szabolcs
 
We've had two PCB group buys, one for the original version and one for the DSD-only version.

As far as I'm aware acg and SonnyMarrow have their original versions up and running and I have my DSD-only version.

Where are all the others?

This project deserves to be build and really rewards the effort with some amazing sounds.

I have to mention Marcel too - the support he provides to builders of his design is simply amazing and should be seen as a confidence booster to potential builders who might be considering taking on this project.
 
Yes, input is solely I2S at this stage and I would like to get the spdif operating. I've not tried it since everything has been working so it may well just work. Am travelling now so will get back to it next week sometime.

My understanding is that i2s is automatically selected by the dac if the signal is viable which means somehow disabling the i2s to make the other inputs available. Is this right?

ValveDac sounds very good Marcel. Was listening this morning before leaving and was enthralled.
 
We've had two PCB group buys, one for the original version and one for the DSD-only version.

As far as I'm aware acg and SonnyMarrow have their original versions up and running and I have my DSD-only version.

Where are all the others?

This project deserves to be build and really rewards the effort with some amazing sounds.

I have to mention Marcel too - the support he provides to builders of his design is simply amazing and should be seen as a confidence booster to potential builders who might be considering taking on this project.
Ray
As far as I know you also have the DSC2? Is it the latest with onboard X-tal osc.? And how would you rate the valve DAC to the DSC2? To my ears the DSC2 is a very good DAC nothing has surpassed it here, but I have some issues, as there is no such thing as an USB to DSD with more than 2 channels. I need at least 3 ;-(
A number of the No-dacs I experimented with sounded as good, but had(very low level and occasionally noise issues)
So currently I am using a Khadas tone Board that is the closest I can find to the No-DAC performance.
 
Both DSC2 (v2.5.2) and Valve DAC are astonishingly good decoders and better than any chip-based DAC that I have heard (though there are lots I've not heard) - that's using them with HQ Player.

Both use a Beaglebone as HQP NAA (with Pavel's 'Pure' software loaded). The DSC2 has a Twisted Pear Hermes/Cronus reclocker and the Valve DAC has Pavel's reclocker.

To me the Valve DAC just wins out for sound quality, it is richer and more organic sounding, but the DSC2 wins for convenience, there is no adjustment/tweaking required. I can happily listen to either of them though.
 
It's only the original version of Marcel's decoder that has those options and, as per my earlier post, there seem to be only two of those that have been built (other than Marcel's) and then only recently so I doubt there's much informaton to report.

I achieve the modulation for the DSD-only version with HQ Player, which has many options. FWIW I've settled on DSD256 with poly-sinc-ext2 as the filter and AMSDM7 512+fs for the shaper.