Foreplay II Volume Full Blast

[Ekapol]

I built my Foreplay ll many years ago with Anticipation upgrade, Sweetest Whispers and Auricaps. Been using Plinius 8200 MKII for simplicity of their remote control being able to dial in the volume to be just right. Last week I felt like really missing the sound from my Foreplay. Hooked it up through A/V processor return input to use the integrated amp just for their power section.

To my amaze, the Foreplay went for the full blast with lots of full woofer movements at times. Do I have short circuit somewhere in my volume pots? I couldn't locate the manual anymore. What might be the locations I should point my ohm/voltage meter to? Any pointers of how I should get started would be most appreciated. Really look forward to have my Foreplay back to working condition.

Thank you,
Ekapol

[Paul Birkeland]

It could well be a solder joint on the enameled magnet wire provided for the kit.  That stuff can be a PITA to solder.  Did both channels exhibit this behavior?

[Doc B.]

If the preamp has been sitting in storage for a long time I would be inclined to look for wires touching that shouldn't be touching. Wires often get pushed around when the preamp gets moved or taken out of the base. One possibility is that input signal at the selector switch is being allowed to bypass the volume switch on one side because of a wiring short and the signal is going directly into the input triode without attenuation. Start looking around the volume and selector switches.

Another simple possibility is that the knob on one side has rotated out of position on the switch shaft and is actually set at "all the way up" when it points to "all the way down".

[Ekapol]

Thank you very much. I will start looking at them this weekend.

Would I be able to tell by taking some measurements before having it full blast? Want to take a proactive step before finding it out from my speakers screaming 

Cheers guys,
Ekapol

[Paul Birkeland]

If you have a phone with a headphone jack and an 1/8" TRS to RCA cable, you can play a 60Hz tone into one of the inputs and measure the AC voltage at the outputs.  If the volume controls aren't working well, you'll see something like ~5V or so of AC at the jacks.  If they are working, then the volume pots will vary the output voltage.

[Ekapol]

Thank you very much Paul. This sounds great. I'll give it a try.