Hum and tube glowing red on my Foreplay ll

[hron61]

I see that cap now, i thought it was a type of resistor. Just used to seeing a standard shaped cap.
I'll reflow that one also as i only checked for a loose connection on it earlier.
I'm curious now about the sweet or sweetest whispers, since i dont have my original paperwork from when i purchased the foreplay, i'll research it further for external indentifiers of each. I'll post a seperate thread for that info.

[hron61]

The 3 power supply caps arrived today and got them installed.
Will power up tomrw and check voltages and resistance and if all goes well i'll fire it up and see if anything changes and report back. I'll order that .1uf cap that I overlooked asap too.

[hron61]

The 0.1uF capacitor is located between the right-hand volume control and the adjacent B tube socket - I apologize, I was working from the circuit diagram instead of the physical layout (too lazy to go downstairs and pull out the manual ...).

For the volume control, I was just thinking it might have a bad ground connection or  switch contact. There were two different volume control switches over the years, called "Sweet Whispers" and the later "Sweetest Whispers" - I think you have the first one?

Your voltages are only 7% low, well within normal tolerances.

I'm pretty sure i have the Sweet Whispers. I bought the fp in 2003 but i do remember the manual said rev2. All my paperwork and manuals were lost back in 2004
I found an old post that said the Sweetest Whispers were used in Foreplay lll.

Btw, would you have replacement recommendation for the 0.1 cap? I've been searching and so many choices and i just want to make sure i get a correct replacement. Much appreciated.

[Paul Joppa]

The 0.1uF cap should be rated for at least 100 volts. (The original is "400v, metal film"s. It, along with the two resistors to which it is connected, raises the filament power bias voltage to around 45-50 volts. It is NOT in the audio circuit, so nothing critical. It is unlikely to be a problem unless it is incompletely soldered, so re-soldering it probably sufficient. It and the two resistors are all crammed into the pin 9 solder lug of the B tube - it's a tight fit, which is a risk factor in making good solder joints.

[Paul Birkeland]

Btw, would you have replacement recommendation for the 0.1 cap?

Leave the one you have in place.  Those things are extremely long lived.

[hron61]

Thanks for the info on what the 0.1 cap is for.
And solid advice from both of you about it, thanks for that.

It is very tight in there and i do have continuity in the connections of it and the solder doesnt look cold, so i'll just let it be. Dont want to create an issue if its not an issue.