BLACK FOREST High Gain Preamp - Based on the Bogner Uberschall

[JebemMajke]

Well it worked last night. And in the mean time I've tried to put it in a box, but the holes didn;t match. So did it caveman style
And oh yeah, only mid pot is dead.

[J0K3RX]

Well it worked last night. And in the mean time I've tried to put it in a box, but the holes didn;t match. So did it caveman style
And oh yeah, only mid pot is dead.

Can you verify before I pull all of my pubes out, roll them up and smoke them!?

[JebemMajke]

Mid pot did the beeep. Any way I've placed 10k a pot for mids and it's more than enough. As far as I'm concerned. 2sk117 is my choice for q1. The beep issue is mids maxed + lots of gain. My advice here is to use 100k c pot for gain. Ive tried B and A and rev log would work so much better. And to add 1k-2k resistor between gain pot and that 4.5 volts ( since it's not touching the ground, but that middle line, which is 4.5 i'f i remember correctly ). And oh yeah, 100k pot for treble is enough as well. Maybe even 500k for bass. Sweep does most of the work here.

Perhaps this pedal would be better with bandaxall tonestack.

[jymaze]

Hey, I finished my Petruccifier (based on a Mk IIc+, including a simulation of the 5 band eq set on a big V shape) yesterday and it works, but intolerable fizz on the top... I have to do some tone shaping for sure.

But the thing that struck me is that it is so quiet! No hum, just the normal white noise you get at max gain. And it is not even boxed. And I used a messy vero board too. I used 2N5457 (5 stages of them).

[JebemMajke]

My E3 died  it has octave up all the time and it's LoFi
I think the pots are responsible for LoFi. But octave up .... Any idea?

[pakrat]

I guess I would start with diodes and transistors, but what do I know. I built the Krank and it is definitely not right.... no sustain and crackly distortion. I just looked over everything and even double checked all values and it's all good. You have a working Krank built with no part substitutions?

[J0K3RX]

My E3 is still chuggin along... not sure whats up with that?? I did something once and got an octave up on-top of the regular signal but I can't remember what it was that I did??

pakrat... 6.5v on the 4.5v trace is not good.. I sent you PM.. double check that. Something is causing the voltage to be too high there.

To be honest, I am having more consistently good outcome making my own designs over these Russian ones... I have to remember they use Russian transistors and such.. not sure they make the transition to J201 very well... And with so many fakes floating around who the f@#k knows what yer gonna get?? Not sure about the 2SK117's.. I have never used any of those...

[J0K3RX]

For the Krank you guys may want to comb over this thread! He seems to have messed a lot with the Krank and had good results...
http://www.diystompboxes.com/smfforum/index.php?topic=89399.0

[J0K3RX]

Hey, I finished my Petruccifier (based on a Mk IIc+, including a simulation of the 5 band eq set on a big V shape) yesterday and it works, but intolerable fizz on the top... I have to do some tone shaping for sure.

But the thing that struck me is that it is so quiet! No hum, just the normal white noise you get at max gain. And it is not even boxed. And I used a messy vero board too. I used 2N5457 (5 stages of them).

Damn-it man!! I want me a Petruccifier!

[JebemMajke]

I guess I would start with diodes and transistors, but what do I know. I built the Krank and it is definitely not right.... no sustain and crackly distortion. I just looked over everything and even double checked all values and it's all good. You have a working Krank built with no part substitutions?

Well 2sk117 is  q1. And 10k pot for mids. But everything else ( bs170's for mosfets ). Did you use that 470k trim to find the sweet spot?

[JebemMajke]

Used krank as preamp ( into return of fender solidstate amp ) ... killer
Ps a friend of mine ( owver of that fender ) loved Krank and BF4.

[pakrat]

Replaced R8 to 2k and R14 to 3k and it's much better. Still getting 4.6v on the 4.5v rail so I'm going to R24 now. Sound is good, a little noisy and seems to be a bit unstable, in that the signal jumps in volume a little. Definitely on the right track though......

[pakrat]

Swapped R24 for a 33k to lower to 4.5v but only got to 5v. Sounded like crap so I went back to 24k. Somehouw in all of this I got 2 broken joints for my pots during debugging.... fixed 'em and it's working! I am using J201 and 2n7000 as per the layout and it sounds great. The only changes I made were R8 to 2k and R14 to 3k and that got it working for me. Thanks for the input guys 

[pakrat]

@Cap Is your layout verified Riccardo?

[J0K3RX]

@Cap Is your layout verified Riccardo?

+1

Looks like he built it but never heard anything after that??

Maybe I will etch it and try it... Somebody has to, might as well be me, right?

[deadastronaut]

right i have a spare breadboard at long last......

which schemo of these beasts to try first?...

one for good chunk, but good for flowing lead too, and chord definition...recommendations ?

[J0K3RX]

right i have a spare breadboard at long last......

which schemo of these beasts to try first?...

one for good chunk, but good for flowing lead too, and chord definition...recommendations ?

I really like the E3 Engl and it needs some lovin...

[deadastronaut]

hi jim:

funny i have that schemo on my desktop...

i'll try that then before anything else creeps onto my breadboard ...cheers man.

so j201/2n7000x3/ 2n5458x2



oh bollox, i haven't any 2n5458's....guess i'll have to sub em..

[jymaze]

Still voicing the Petruccifier. It sounds very good through an amp, but it is as a preamp direct to the PC with a cab sim (I tried an Engl 4x12, have to try some other ones) that it really gets there.
Actually as a preamp it sounds totally awesomely brutal and chunky . It is prefect for hyper defined palm mutes, never had a sound that defined for that actually, it is like surgical precision. Marshall-type sound appears super bloated and messy compared to it.

I would like it to sound as good as a pedal so I have to add some switched voicing option to it. I probably have to have the option to switch off some of the insane scoop I put in the post eq since a clean deluxe reverb is pretty scooped to start with and the scoop is not even in the same spot which ends up causing a sound that is starting to sound hollow.

[J0K3RX]

Still voicing the Petruccifier. It sounds very good through an amp, but it is as a preamp direct to the PC with a cab sim (I tried an Engl 4x12, have to try some other ones) that it really gets there.
Actually as a preamp it sounds totally awesomely brutal and chunky . It is prefect for hyper defined palm mutes, never had a sound that defined for that actually, it is like surgical precision. Marshall-type sound appears super bloated and messy compared to it.

I would like it to sound as good as a pedal so I have to add some switched voicing option to it. I probably have to have the option to switch off some of the insane scoop I put in the post eq since a clean deluxe reverb is pretty scooped to start with and the scoop is not even in the same spot which ends up causing a sound that is starting to sound hollow.

I want Petruccifier!!!  You make work NOW!