A comment going back to post #659 by thomaschan. The Lamizator SRPP circuit is essentially passive I/V with a 90 ohm I/V resistor (R1), and a tube preamplifier (SRPP) to provide voltage gain to return the DAC output to line level.
When the 90 ohm I/V resistor is substituted, gain is reduced -13 dB compared to the 420 ohm resistor. If you have a preamp (tube or solid state) that can provide that level of gain, you should be able to use the lower I/V resistor value. THD from the DAC itself will decrease from 0.01% to about 0.007%. The decoupling caps (C3/C4) will likely need to be increased in value.
When the 90 ohm I/V resistor is substituted, gain is reduced -13 dB compared to the 420 ohm resistor. If you have a preamp (tube or solid state) that can provide that level of gain, you should be able to use the lower I/V resistor value. THD from the DAC itself will decrease from 0.01% to about 0.007%. The decoupling caps (C3/C4) will likely need to be increased in value.
Hardware: RPi Zero W | Allo Kali | ProtoDAC TDA1387 X8 | PGA2311 | Icepower 500ASP | Harbeth SHL5
Software: Moode 8.3.3
Source: Win 10 NAS
Software: Moode 8.3.3
Source: Win 10 NAS
