Throbak Overdrive Boost comparison w original Overdriver circuit

[mordechai]

I've just bought (2nd hand) the very nice Throbak Overdrive Boost...excellent sounding circuit.  But I'm a little puzzled about a few of its features.

1. The pre-gain switch...does this just switch between two different input caps?

2. The diodes -- In comparing them to the original Colorsound Overdriver schems I've looked at, I don't know where these would factor into the circuit.  Where would they be inserted, and how would they affect the tone?

3. Are there significant differences in electro used as the bypass caps to compensate for the use of lower-gain transistors?

[ODwan]

Hi Mord,
can you post some detailed gutshots? I would also be interested in voltage readings of the transistors.
Greetings,
Timo

[Ben N]

Oh, yes. I've been wondering what's going on in there (especially with the Ge) for a while now. I'll have an order of gutshots, as well, thanks.

[mordechai]

I am unfortunately nowhere near the pedal now (it's with relatives in another country) but I think it's the older one -- here's a gut shot from the we:

http://files.effectsdatabase.com/gear/pics/throbak_overdrive-boost_003.jpg

[Ben N]

Is that other country perchance this one?

That shot unfortunately does not give one much to work from. Can't identify the components, and can't see the traces.