| Built the DDDAC MKII USB audio card, modified it to feed SRPP tube amp line stage - Click HERE for Original Thread |
| wa2ise |
I bought this DDDAC USB to TDA1543 board kit http://www.dddac.de/files/dddac-usb-1543-dac32.pdf
built it (with the low jitter clock module), tested it, and then modified it.
I changed the circuit the TDA1543 analog output feeds. And the reference resistor on the Vref pin, to set it to 1ma. And the output resistors are the equivalent of 220 ohms to a 2.2 Volt source. The analog audio here is approx 200mV. Then I feed that, thru a cap, to a SRPP tube circuit to amplify this to normal line levels.
I built the SRPP circuit using an old preamp chassis that had a small power supply and a pair of 9 pin tube sockets. Used to be a tape head preamp.
Sounds great! :hphones: |
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