BLACK FOREST High Gain Preamp - Based on the Bogner Uberschall

[J0K3RX]

pakrat that looks great!

Ok so you guys know this is a WIP right? WIP = Work In Progress...

Don't hate me but I have made a few changes Nothing much on the layout except the position of R6, it's been moved between stages 3 and 4 instead of 2 and 3. The rest of the changes are part values. please examine carefully! The old setup will work 100% these are just what I believe to be improvements to the design. The pads for R6 can easily have a jumper installed then make a couple holes between the 3rd and 4th stage and cut the trace in between. Stick the resistor in the new holes and bend the leads over and solder them to the traces... Bingo Again, some part values have changed! Busy right now or I would itemize them... maybe one of you guys could compare and make the list? very small, maybe 4 or 5 very common parts...

Layout in white so it doesn't kill your printer


board transfer.
http://dl.dropbox.com/u/11178619/BFUltra%20-%20R3.2.pdf

[pakrat]

J0K3RX..... you b@stard lol!

[J0K3RX]

J0K3RX..... you b@stard lol!

Board came out great! You can mod it, I have faith in you!

[pakrat]

Yeah it's no problem... I don't notice too many differences, just a few cap changes and the resistor swap? Also, any reason why c1 abd c22 are both 100uf electros but different voltages? This should run at 9-12v correct?

[J0K3RX]

Yeah it's no problem... I don't notice too many differences, just a few cap changes and the resistor swap? Also, any reason why c1 abd c22 are both 100uf electros but different voltages? This should run at 9-12v correct?

The voltages are just a goof on my part...   I try to keep them all 25v cause I am weird
C1 and C21 should be at least 12v minimum or 25v if you want to run at 18v... If you bias @9v and then run at 18v your biasing my be off @ 18v though? But that's just a guess... Actually you can use 220uF for C1, but I didn't really notice any difference between 100uF and 220uF. 

R6 is now 1k, I had it at 10k which is what the actual tube preamp had but the tube preamp runs @ 300v + so that was not in spec with 9v... It was dropping the voltage at the positive side of C1 to 6.7v which was starving the first two stages. I could bias the to 4.5v but that was not half of the supply voltage. Half would or should have been something like 3.4v which is all out of whack.. Sounded good somehow but just not quite right.

[pakrat]

Ok, that's fine.... I usually get 25v for the size anyway. I'm gonna build it according to the v3.2 layout exactly as you have it, and prob try 9, 12, and 18v just to see. I'll trim to half the working voltage. Thanks again for the work you're putting into this!

[scuzzphut]

I turn my back for five minutes and everything's changed again 

Just kidding  - not had much time lately - concentrating on finishing my lightwah when I get a spare hour.

Are you happy with this now J0k3rx or are you still tinkering ?? I've etched my PCB (the version before the mod, but I'm sure that won't be much of a hardship) and will probably be starting to populate it at the weekend.

[pakrat]

@scuzzphut Even if he says he's finished.... don't believe him 

[J0K3RX]

I turn my back for five minutes and everything's changed again 

Just kidding  - not had much time lately - concentrating on finishing my lightwah when I get a spare hour.

Are you happy with this now J0k3rx or are you still tinkering ?? I've etched my PCB (the version before the mod, but I'm sure that won't be much of a hardship) and will probably be starting to populate it at the weekend.

I think the main backbone of this pedal is done... The rest is just bells and whistles that can be added to the last layout either by changing a few parts or making a small perf board or whatever... There are so many little things that you can do to these pedals and I just want to find the best of the best and to hell with the rest! Some mods like the "Wide" switch can be left off and just keep it set to wide all the time since I think that sounds best anyway. I just want to have 2 toggle switches, 2 foot switches (High and Low Gain) and 6 knobs. One could even leave off the presence knob since I have it all the way up most of the time or you could just make a presence switch. You start going crazy with switches and mods and then you end up with something that doesn't even sound like what you had in the beginning... Then you end up trashing it all and going back to the start Keep it pure and simple and keep the features that you really want.

That being said; In the future I will probably make the tone stack separate from the main board for a couple of reasons. Number 1) Most if not all of these preamps use the same tone stack and if I had a tone stack board I could just use the same TS board for each preamp. Number 2) There would be much less wiring going to the pots since they would be attached directly to the board, less of a mess, looks better, less work and maybe less noise etc. Number 3) I could layout the boards quicker since I wouldn't have to lay out the tone stack every time and the main board would be shorter and easier to work with not having the extra caps, resistors and holes.

This is kinda what I was thinking... The traces and holes for the resistors and caps have not been added yet but you can get the idea from the pic.

[J0K3RX]

@scuzzphut Even if he says he's finished.... don't believe him 

pakrat & scuzzphut are like the two old men in the balcony on The Muppet Show that heckle the performers in the theater....

[pakrat]

I guess I'm Waldorf.......

[haveyouseenhim]

@ jim

Do you happen to know what setup Dimebag had on 'Walk'?  Some say it was a tweaked Randall but others say Krank. If you could emulate that sound you would be a god in my eyes

[J0K3RX]

@ jim

Do you happen to know what setup Dimebag had on 'Walk'?  Some say it was a tweaked Randall but others say Krank. If you could emulate that sound you would be a god in my eyes

Funny you should say that... I just so happen to have a project for that amp or what many believe that amp was...RG100ES solid state? hard to dupe!

[haveyouseenhim]

Yea, thats the one.  by amp project do you mean emulator pedal or the actual amp?

[J0K3RX]

Yea, thats the one.  by amp project do you mean emulator pedal or the actual amp?

preamp... but it is way at the back of my list of too doo's so don't hold your breath Maybe a Krank sooner! I think a lot of the Dime sound was just his style... That dude was insanely good!!!

[pakrat]

Dime used Rg100ht, Rg100es, and the Randall century 200. Plus he had a furman pq3 or pq4 in his loop and an mxr graphic in his chain. I believe he scooped mids all the way out with the graphic and then added them back in with the pq. I actually play through that same setup basically and I can tell you, it sounds brutal! I have a layout of the randall RG100es from JMK but it's unverified.

[pakrat]

Shouldn't it be easy to copy the Rg preamp? It's a solid state amp, so it should just be an exact copy? I think the pre in the head runs at 24v though, so 9v would lose a lot of headroom? I bought a 24v power adapter for that project but the black forest has actually taken over my plans here...... Oh, and you are right J0K3RX, a lot of his tone was from his fingers and his absolute genius! RIP Dime!

[J0K3RX]

Ok, it's time for another update to piss off all of you that etched the last board

Here is a sound sample with and without the noise gate addon. Yes, I said noise gate!

Here are 4 takes and all were recorded without pause so you can hear the difference while I am switching and stopping between takes... Also, I didn't touch my vol on my guitar at all, it was on full for the entire sample so you can hear the noise or lack of noise when I stop playing...

They go in this order:
1) Boost off and noise gate on
2) Boost on and noise gate on
3) Boost on and noise gate off
4) Boost off and noise gate off
http://dl.dropbox.com/u/11178619/Noise%20Gate/Dragon%20Attack%20Noise%20Gate.mp3

If you like this then shoot me a PM and I will send it to ya... It's so simple you will laugh!

[deadastronaut]

noise gate?.... now i'm curious..

simplest is always the best....

[J0K3RX]

noise gate?.... now i'm curious..

simplest is always the best....

Oh ok, twist my arm



I wish this forum would host pics!