Firstwatt F1J
- Thread starter Tea-Bag
- Start date
General description This output shield is made especially for the MIRAND Audio AK4490 USB Audio DAC, but it can be used for all dacs’s having a voltage output, preferable differential out. The module is completely discrete and all stages runs in Class A. All outputs are Singleended class A equal to the frontend opamp on TSSA V2/V4/V8 control board Key specifications Supply voltage : +/-15VDC DC offset: <20mV dc Single ended and balanced output. Gain from balanced input to output : +6dB Input impedance : 3.24Kohm per diff input Discrete SSR for transparent mute circuit. Size (WxLxH): 71x110x20mm (With molex connector)
can you play [email protected] file, an measure with DMM set to Vac what you have between XLR pins 2 and 3 of DAC output?
so no guesses, you will get rms reading
logically, no connection to preamp, DAC being standalone
so no guesses, you will get rms reading
logically, no connection to preamp, DAC being standalone
ok
3V96rms from your source
+8db from Iron Pumpkin, which is 2.51V/V
means you have 9V94rms alowable to crank your F1 to full power
original F1 is having gain of 14db, which is tad above 4V/V .......... precisely 5V/V
declared power of [email protected] is 8V94rms ............ that means - you have plenty of gain at disposal
feel free to start with Iron Pumpkin set to 0db gain ........ amp needs 8V94/(5V/V) = 1V78rms at input, for full blast
3V96rms from your source
+8db from Iron Pumpkin, which is 2.51V/V
means you have 9V94rms alowable to crank your F1 to full power
original F1 is having gain of 14db, which is tad above 4V/V .......... precisely 5V/V
declared power of [email protected] is 8V94rms ............ that means - you have plenty of gain at disposal
feel free to start with Iron Pumpkin set to 0db gain ........ amp needs 8V94/(5V/V) = 1V78rms at input, for full blast
whichever
just take two close pairs and use them for amp, one pair per channel - positions Q1 and Q2
