ProtoDAC TDA1387 X8 project

[hifinet]

Before I add the Lampizator tube output, I had been using the ProtoDAC with 90 ohm resistor. Sound quality was OK. However the SRPP tube output makes a huge improvement. Especially when I use separate power supply for the DAC and the Pi.

As for the Pi +5V decoupling capacitor, I am using 220uF Nichicon MUSE. I haven't got a chance to try different value yet but I will. At the moment, I am planning on a better power supply for the B+. Looks like a lot of tuning is needed for this streamer.

Will you be building one as well? Love to hear from others.

Yes, I would like to try the SRPP with a 6021 medium mu dual triode subminiature tube. This cascode JFET buffer should also be tested.

That buffer, is that in conjunction with the tube output device or in place of ? Where in the chain ProtoDAC-xxx-xxx would you place it ?

I am thinking of using the JFET buffer instead of the SRPP. In my experience, buffers always improve sound quality. There is no additional distortion, and adds the ability to drive any load. An SRPP+ circuit (kind of an SRPP plus cathode follower), that can drive lower impedences, might perform better than the SRPP. If you are going to the trouble of using tubes, with high voltage and heater supplies, it makes sense to use a tube buffer.