D*A*M - Germanium Pre-Amplifier B-13 BOOST

[beedotman]

Yo!

Here's one of the latest D*A*M custom one off - B-13 BOOST.
It was drawn based only on one gut shot, so there's few unconfirmed component values, but I think it could be prettey much OK and should work fine.
It's slightly modified D*A*M red rooster with added switchable output capacitor (F.A.C rotary switch).
It's sports rare White Jacket Mullard OC81D - PNP germanium transistor, so it has positive ground.
Standard for rangemaster bias string 470K/68K was changed and it could be 470K/56K (56K for sure, as seen on gut shot).
Bias resistor on emitter could be 3k9 or something close to it for correct transistor bias.
Values of caps on F.A.C switch are also not confirmed, but more or less should be ok.



Enjoy!
b.man

[sinner]

Something wrong here, circuit board have no V+ connected

[phibes]

Boost and Filter labels are swapped too. I was wondering why it wasn't making sense in my head schemo wise.

I like your guys drawings a lot but you should start adding a schematic with em when ya draw it out. Would make it easier to spot stuff.

[sinner]

I like your guys drawings a lot but you should start adding a schematic with em when ya draw it out. Would make it easier to spot stuff.

I was thinking to do that, you know, A4 printable friendly sized, with schemo, but I'm waiting for final DIYLC v3, not all schemo symbols are in it

[phibes]

Check out good ol Express Schematic. It's free, everything's in there and you can modify everything to your liking.

Good plan on the printer friendly part. I print to pdf from express schematic at standard size so it makes for a smooth vector print across all different printers.

[beedotman]

Something wrong here, circuit board have no V+ connected

Boost and Filter labels are swapped too. I was wondering why it wasn't making sense in my head schemo wise.

I like your guys drawings a lot but you should start adding a schematic with em when ya draw it out. Would make it easier to spot stuff.

Thanks for correction guys!
Hope now it's OK.

[beedotman]

Schematics is very good idea, will drawn it later today and post here.

[beedotman]

Here's schematic.
I think I dont like ExpressSCH...

[Bill_Mountain]

So elegant in its simplicity.

[Dr Tony Balls]

But why do a cap blend at the input and a FAC control at the out? Both do the same thing....you might as well have FAC/FAC or Filter/Filter. I have been putting FAC style control at the front of my rangemasters but leaving the output cap stock.

[beedotman]

But why do a cap blend at the input and a FAC control at the out? Both do the same thing....you might as well have FAC/FAC or Filter/Filter. I have been putting FAC style control at the front of my rangemasters but leaving the output cap stock.

Who knows... Pedal owner wrote on D*A*M forum that F.A.C switch changes are very subtle... Personally I don't like input cap blend via pot. Switchable capacitors on input works better IMO.

[Bill_Mountain]

But why do a cap blend at the input and a FAC control at the out? Both do the same thing....you might as well have FAC/FAC or Filter/Filter. I have been putting FAC style control at the front of my rangemasters but leaving the output cap stock.

I thought I posted this earlier but I must not have hit submit or something. Anyways…

I quite like the use of two different filter topologies in this design. Also, I can totally see a need for controlling bass in and out of the circuit.

I’m not a D.A.M. fan boy (or even a guitarist) but something about this design strikes me as fun and inviting.