Valve DAC from Linear Audio volume 13

[MarcelvdG]

Is this a suitable trimmer capacitor for C7?

https://www.mouser.com/ProductDetail/768-JZ150/

The Multicomp mentioned in one of the PDFs is rated at 200V but seems to be unavailable in the US. My concern is that the Multicomp is rated for 200V, and the one I used is only 100V. I've found a higher-voltage replacement if needed.

100 V should be more than enough, so if it fits on the PCB, it is suitable.

 

[Markw4]

Seems likely I'm the only one here to go to the trouble to compare Cronus with I2SoverUSB. Can only recommend the latter.

 

[SonnyMarrow]

Well my FPGA order was originally expected to arrive in April. Just got an update, it's now expected in October. Going to be a long time before I can get this up and running. Of course the LX45 and LX150 are available, just not the one we all need.

 

[acg]

That's a bummer Sonny.

 

[nautibuoy]

I've been reading through the thread, but can't seem to find a definitive answer. Will the twistedpearaudio amanero/hermes/cronus combo work with the DSD-only version of the DAC?

Yes, it should be fine as long as you sort out the connector pins as per Marcel's post.

 

[SonnyMarrow]

Is the software license to use the LX150 expensive? That might be my only option, or building the DSD-only one I have the PCB for...

 

[nautibuoy]

Seems likely I'm the only one here to go to the trouble to compare Cronus with I2SoverUSB. Can only recommend the latter.

I've tried both, (and others) in various contexts, perceived little (if any, could just be down to a simple inadvertent small change in the volume setting for example) audible difference, and continue to use both.

I'm currently using a BBB/Hermes/Cronus with my DSC2 SDM decoder, a BBB with Pavel's (ppy) isolator/reclocker with my Valve DAC SDM decoder and a JLSounds I2SoverUSB with my Soekris DAM1121 R2R DAC.

Almost forgot, I also have BBB/Acko SO3 isolator/reclocker in my Twisted pear Buffalo 3SE DAC.

 

[rfbrw]

Is the software license to use the LX150 expensive? That might be my only option, or building the DSD-only one I have the PCB for...

When it was available ISE 14.7 was about $2995 and up. It isn't supported on Windows 10.
For Windows 10 there is the free ISE14.7 VM for Windows 10. It runs in a virtual machine and it supports all Spartan 6 devices.

 

[SonnyMarrow]

Wait even the LX150?

 

[MarcelvdG]

So the free ISE14.7 VM also supports the LX150? The free Webpack version of ISE14.6 used to support everything up to and including the LX75.

 

[SonnyMarrow]

Is the LX45 not good enough?

 

[MarcelvdG]

Not for the present design, no. Maybe it would be possible to redesign it to fit into an LX45, but that won't be straightforward and I haven't got the time to try it.

 

[SonnyMarrow]

No worries, I assumed that was the case or it would have been the recommendation. Ordered a LX150.

 

[rfbrw]

So the free ISE14.7 VM also supports the LX150? The free Webpack version of ISE14.6 used to support everything up to and including the LX75.

Yes. 14.7 VM covers all Spartan-6 devices and gets 14.7 on to Windows 10. Only downside is that you no longer have the free standalone programming software or Lab Tools as Xilinx used to call them. Vivado still has it though.

 

[SonnyMarrow]

I'm assuming the LX150 would be compatible?

 

[SonnyMarrow]

Got the Jensen transformers and my input PCBs in today. All that's left is power transformers and the FPGA.

 

[rfbrw]

I'm assuming the LX150 would be compatible?

Should be. Same footprint. Just more resources.

 

[MarcelvdG]

The TE0630 LX150 module should be compatible with the TE0630 LX75 module, but I don't expect the .mcs files to be compatible. (Rfbrw, please correct me if I'm wrong about that, as that would make things simpler.)

That is, you will have to generate your own .mcs file. That involves taking the Verilog files and user constraints file (.ucf), regenerate the filters and FIFOs as described in the README.txt file of version 2.1 and the files FIRandFIFOgeneration.pdf and PlanAheadoptions_10July2016.txt of version 1, run synthesis and implementation and then you will have a new mcs file suitable for the LX150 module.

Appendix A of the TE0630 user manual https://shop.trenz-electronic.de/tr.../TE0630_series/TE0630/documents/UM-TE0630.pdf describes quite clearly how to get the mcs file into the nonvolatile configuration memory of the FPGA module.

By the way, I just saw that the TE0630 LX150 is now out of stock at Trenz, just like the LX75.

 

[SonnyMarrow]

I bought the last LX150. Hopefully I can do all of that once I get the FPGA in hand.

 

[MarcelvdG]

Except for the last step, programming the module, you can do all of it without the module. If you should run into insurmountable problems, I will try to borrow a Windows 10 computer to generate the file and WeTransfer it to you. (It will be too large to post as a zipped attachment.)