Volume and tone controls in front of V1?

[Leif H]

I found an amp an amp schematic below. The tone stack and volume are in front of V1.

I realize that this is intended as a power amplifier for phono / receiver etc.. but would this not be passive tone control, just as on your guitar?

Why would it be designed with the tone stack placed there, and would this not work better inserted between the plate of V1, with a coupling capacitor just in front of it, and the screen of V2?

http://www.r-type.org/articles/5-10-b1.jpg

[Dave H]

Is that the Mullard 5-10?

The tone stack was designed to be driven by a preamp. If it's placed after V1 it would be it's inside the power amp's negative feedback loop.

[Jazz P Bass]

Plus, if you read the circuit description itself:
"The EF86 is coupled directly to the phase splitter to reduce the phase shift at low frequencies. A CR network (C1, R1) shunting the anode load produces an advance in phase which increases the stability of the amplifier at high frequencies."

A coupling capacitor between V1 & V2 will invert the signal.
Here is the complete page: the amplifier is a Mullard 5-10: Mullard 5-10. Ten Watt Amplifier

[Leif H]

DaveH, yes the mullard 5-10

Jazz, thanks, I was wondering if something like this would be a good convert for a guitar amp. I think the best thing would be to gut and redo something vox or 18watt ish with it keeping the output section close to stock.

[Dave H]

...I think the best thing would be to gut and redo something vox or 18watt ish with it keeping the output section close to stock.

This one sounds good.

[Leif H]

This one sounds good.

[ATTACH=CONFIG]31186[/ATTACH]

Looks nice and simple, is that foot switch a fat switch? Front end looks like normal channel of an AC10/15/30 is that a Matchless Lightning?

[Jazz P Bass]

Yeah, it does look nice.

[Dave H]

Looks nice and simple, is that foot switch a fat switch? Front end looks like normal channel of an AC10/15/30 is that a Matchless Lightning?

It's just a lead boost switch. It's the normal channel of the Watkins Dominator/Marshall 18W. I used the footswitch at home when I had a different tone control, one that worked by bridging across the vol pot (like the 5E3 etc.) but they don't work too well when you can only set the vol to 1. I used the LO input and low gain on the footswitch so I could turn the vol pot up to give the tone control something to work with. It doesn't matter now because the tone and vol are independent.

[J M Fahey]

Also see that in the original Hi Fi amp, they were forced to use very high values for pots (2M) and Bass turnover resistor (1M5) precisely to make life easier for anything driving it.