Tone (?) caps in Vox AC4 tremelo circuit

[old tube]

I'm just about to start point to point soldering my first build which is an AC4 clone. I'm building it almost completely from the guts of a 1964 Philips reel to reel. I was able to salvage a good number of in spec. Mustard caps.

My naive question is; are the 3 caps in the tremelo circuit (top right of diagram) only to regulate the 12AX7 or do they play any part in the tone?

I was going to put mustards in there (2 x 0.01uF and a 0.02uF). But if they do not influence tone then I'd rather use something else e.g. new mallory's and save the Mustards for a future Hiwatt clone.

Many thanks

[tubeswell]

My naive question is; are the 3 caps in the tremelo circuit (top right of diagram) only to regulate the 12AX7 or do they play any part in the tone?

The caps in the RC network in the LFO circuit have no effect on the tone in the signal path per se.

But trem does have an effect on your tone.

I would just use any old film caps of an appropriate voltage rating and capacitance in the LFO network. YMMV

[tictac]

Just finished an amp similar to an AC4 and used ceramic disc caps like Fender amps do. They're cheaper, save space, and function perfectly for the job...

my 2 cents...

TT

[echuta13]

I'm with tictac. Just use a sturdy cap. The values you use will affect the amp more than the type of cap you use.

[Firestorm]

Use the highest voltage rating you have. I don't know why, but these caps seem to start leaking current.

[old tube]

Many thanks all for the advice, very helpful.

"Use the highest voltage rating you have. I don't know why, but these caps seem to start leaking current."

Well that rules out the 250V "Tropical Fish" I've got that I'd though of using. I've got some 630V Mallory's, will use them.

[tubeswell]

Many thanks all for the advice, very helpful.

"Use the highest voltage rating you have. I don't know why, but these caps seem to start leaking current."

Well that rules out the 250V "Tropical Fish" I've got that I'd though of using. I've got some 630V Mallory's, will use them.

Wise move - given that the HT voltage supplying the LFO is 270 on the schematic, then 250V wouldn't cut the mustard.

[old tube]

[quote="tubeswell Wise move - given that the HT voltage supplying the LFO is 270 on the schematic, then 250V wouldn't cut the mustard.[/quote]

Indeed!