I'm using a stock 70 with a diode replacement for the selenium rectifier.
I would like to run them at there full potential.
BTW, I had no problem biasing (1.56) worn (not bad) RCA 6L6GC's.
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tubes4hifi wrote:yes, those are caps, typically 1uF
they are also commonly used in the PAS3 model, not just the X
Sal wrote:To tell the difference the PAS-3 and PAS-3x, the PAS-3X tone controls has a rotation of approx 200 degrees vs 260 degrees of a PAS-3. If the rotation of the tone controls match the volume control, you have a PAS-3.
Sal wrote:On another note, I have a ST-70 with 6L6 tubes installed. I replaced the 5AR4 tube with a 5R4 tube that lowered the B+ a little and I was able to adjust the bias without a problem. I would bias the 6L6 tubes to 1.4 volts, that is what I did in my amp and it sounds fine to my ears.
Westy56 wrote:Are these the caps? (yellow arrows)
I could not feel any detent in the controls.
GP49 wrote:There were no OFFICIAL sub-models of the FM-3, though internal changes were made according to what parts were available at the time of production (brands of capacitors, for instance). However there are quite a number of FM-1 mono tuners which were upgraded with the FMX-3 multiplex stereo kit and the optional faceplate/knobs which were sold by Dynaco, changing the FM-1's appearance (brass/brown front plate and knobs) to that of the FM-3. The easy way to tell is to see if the volume knob push/pulls for stereo/mono switching. In factory trim, that was only found on the FM-3, though it is always possible that an owner bought the FM-3 volume control with its attached slide switch and retrofitted it to an FM-1/FMX-3.