What's your budget ?
This combo wouldn't be a bad starting point:
DAC: https://www.minidsp.com/products/minidspkits/curryman-i2s-dac
USB receiver: 384kHz Asynchronous USB to I2S/SPDIF CM6631A PCB - DIYINHK
PS: Classic Reference 78xx power supply linear regulator 3.3V 5V +-12V - DIYINHK (one for +3.3, +5 and one for +/-12V).
Add a case, a pair of small transformers and you're pretty much done.
I'd go with JLSounds, IF you are feeding the DAC with a computer (over USB):
Products - I2S over USB Audio
If you have only S/PDIF Coax for the source, I can't suggest anything within reasonable budget, which is better than the FiiO.
This is certainly within budget. I'd like to keep it under $300.
Would the above combo sound better than say a V90 DAC, ODAC & FIIO?
You say to get two transformers, one for the power for each channel? So I need two of the above dc supply boards then right?
USB in my experience is better, but only when done right.Yeah I am feeding it with SPDIF right now. WOuld the USB sound better? Or does the physical connection to the computer introduce noise into my preamp & amp?
you could just buy this:
SMSL P1 Linear Power Supply two output for the decoder and headphone amp use for M8 V2 VA2 Sanskrit SD 793II SD 192 etc-in Other Batteries from Electrical Equipment & Supplies on Aliexpress.com | Alibaba Group
but that would be no fun
I had RS6000 infinity, that was a long time ago. Are your speakers quite old?