BLACK FOREST High Gain Preamp - Based on the Bogner Uberschall

[chromesphere]

Fixed the error on the BOM and tidied it up a bit.  Also, double checked the values again, BOM is accurate to use.
Cheers,
Paul

[J0K3RX]

Fixed the error on the BOM and tidied it up a bit.  Also, double checked the values again, BOM is accurate to use.
Cheers,
Paul

Now if somebody would double/triple check the layout against the schematic for errors it will be almost a 100% guarantee of working! I sometimes overlook the obvious so best to have another set of eyes QA it!

Edit: Paul, great youtube channel!!

[J0K3RX]

Hi guys!
First of all  J0K3RX thank you so much for this amazing pedal.I'm talking about the black forest which i'm trying to finish.
I used it in front of my amp (not the best way..i know) and this pedal comes to life when the volume pass 12 o'Clock or even better at 1 o'Clock.Compared to bypass  it's VERY loud!
When the volume is lower than the halfway it's sounds muddy and fuzzy.Any thoughts?
You wrote that you removed one resistor 470k from the volume pot as it was more quiter.Does this has something to do?
thanks!

Sorry Michael80, overlooked your post. Not sure why it gets muddy/fuzzy lower than half way? If you are using the presence control get rid of it, causes problems with the tone stack...  if you want to try the 470k resistor or another value just attach it to lug 3 on the volume pot back to the board. Another thing is it may not be biased quite right? When you bias make sure you have the gain maxed.

Another thing you can try is a buffer circuit after output? Maybe something like SHO?
http://www.diystompboxes.com/smfforum/index.php?topic=96322.0;prev_next=next

[chromesphere]

I can verify, you know, a rangemaster, but this layout is intense.  I checked over 70% of it before my brain exploded.  This is what i found.  May or may not be correct, or maybe you have modified the circuit.  Sometimes i thought prehaps i was looking at the wrong schematic, things didnt add up:

15k on J201 source should be 1.5k
2n2 (c12) connected incorrectly.  Connected to ground on pcb layout, connected to +9v on layout.
edit: R13 on the schematic is connected to the 4.5v rail but isnt on the layout
Anyway, lets start with that.  I'm going to lie down. :|

Paul

[J0K3RX]

Thanks Paul the source resistor was 1.5k it's just hard to see the dot so I made it 1k5...  Brain exploded   And no, I have not modified the circuit except for using the J201, 2N5458/59 and the sweep pot.

Corrected, I hope! If it passes inspection I will upload transfer... I will etch it this weekend anyway and be the guinea pig I already have a working one without the pots on-board so no big dealeo... By the way, I uploaded this pic right over the top of the other one so the pic a few pages back is corrected also.


~ Jim

[chromesphere]

Cool Jim.  There could actually have been more errors.  I just totally lost track of where i was (in more ways then one) when i was going through the circuit.

Ill check it again if you want?  Was i on the right track (apart from the 1.5k resistor) with my last post?

Paul

[bluesdevil]

Thanks for checking it out, Paul.
I just etched this today! A few carefully placed drill holes on the traces should do the trick, though.
 Looking forward to getting this built up..... hurry up parts order!!!

[J0K3RX]

Updated transfer.. Sorry Bill! 
http://dl.dropbox.com/u/11178619/New%20Preamps/E3%20Transfer.pdf

[meffcio]

Well, I got used to checking schematics, so I'll do it when I get home, ok?

[Michael80]

Hi guys!
First of all  J0K3RX thank you so much for this amazing pedal.I'm talking about the black forest which i'm trying to finish.
I used it in front of my amp (not the best way..i know) and this pedal comes to life when the volume pass 12 o'Clock or even better at 1 o'Clock.Compared to bypass  it's VERY loud!
When the volume is lower than the halfway it's sounds muddy and fuzzy.Any thoughts?
You wrote that you removed one resistor 470k from the volume pot as it was more quiter.Does this has something to do?
thanks!

Sorry Michael80, overlooked your post. Not sure why it gets muddy/fuzzy lower than half way? If you are using the presence control get rid of it, causes problems with the tone stack...  if you want to try the 470k resistor or another value just attach it to lug 3 on the volume pot back to the board. Another thing is it may not be biased quite right? When you bias make sure you have the gain maxed.

Another thing you can try is a buffer circuit after output? Maybe something like SHO?
http://www.diystompboxes.com/smfforum/index.php?topic=96322.0;prev_next=next

Thanks for your reply J0K3RX .I don't have the pressence control  installed.
I tried the 470 k but beside the volume drop ,i had the same fuzzy sound until the half way.So i added a 47p cap as a filter to cut some extra highs that caused the problem and now it's much better!!I  will try some different values to find the sweet spot and re bias the trans.Also i will check your buffer idea.very interesting!
Thanks again!

[J0K3RX]

Well, I got used to checking schematics, so I'll do it when I get home, ok?

meffcio, would you be so kind!? Greatly appreciated!! I'm gonna etch it tonight either way so we will see? Other people might benefit... I am working on this format layout with all on-board pots for all of the preamps. A good thing is they are all a lot alike so it's really saving a lot of work not having to completely start over with each one.. I can use the same basic layout format and modify what needs to be changed. There are engl, bogner, krank, soldano, mesa, laboga, vht and diezel vh4 and the diezel is NOT a copy of the diefet! Also, 3 different soldanos and 2 different bogners... Lots o sh!t

[markmcconachie]

I just made a new enclosure for the ubershall

[J0K3RX]

markmcconachie - That looks really good man!! But, as a rule I never use actual brand/manufacturer names on my boxes..even for my own use. but, as long as it's for just your own personal use and not selling I don't see a problem... I am sure the sh!t storm will start shortly

[Michael80]

Ok ...working on the BF pedal for days and finaly i'm getting somewhere. 8)Last thing to do is to find the right resistor combination for R22 & R5 acording to my guitar's pickups and it's done.
But today i discovered another issue!!(the last i hope).
I added a delay pedal to the signal ....guitar--->black forest--->delay--->amp.. and with the BF always on ,everytime i engaged the delay the signal was getting too loud about 6-8db.
Does anybody experienced that before?aAny thoughts?

[J0K3RX]

Ok ...working on the BF pedal for days and finaly i'm getting somewhere. 8)Last thing to do is to find the right resistor combination for R22 & R5 acording to my guitar's pickups and it's done.
But today i discovered another issue!!(the last i hope).
I added a delay pedal to the signal ....guitar--->black forest--->delay--->amp.. and with the BF always on ,everytime i engaged the delay the signal was getting too loud about 6-8db.
Does anybody experienced that before?aAny thoughts?

Well, I can't really say since I have not tried the bf and a delay into the front input of an amp... I'm sure somebody will know but will they respond is the question? What delay is it?

[J0K3RX]

Ok, what I have done now is I have stuck the JSX noise gate between stages 3 and 4 and it is virtually silent when not playing/betwen notes etc.. and best thing is that it doesn't clip or decay the notes at all... Takes a little of the top/high end off.. Probably a nice option for all these high gainers! Total part count = 4 with on/off switch or 4 with on/off switch and control pot...


Also build the cab simulator from another post and it sounds fantasticly real!! puszzle87 (lart) posted it but has since taken his pics down but, mine are still there.. The guy is a genius! Perfect for these pedals.. takes up very little room, no knobs and sounds killer! Just what I was looking for! Just runs parallel with the regular output jack and supplied with +9V, no on/off.. always on but only can tell when you are running out from it. You could probably make it way smaller with SMT!

[deadastronaut]

right now put the whole BF/GATE/SIM  thing up as 1 schematic...

but seriously, i can't wait to try this stuff....when i get my sh#t together.....when....

nice one jim.

btw : just runs parallel to regular out?...are you splitting somewhere?....sorry i need more coffee.

[caspercody]

Can you point me to the JSX noise gate?

[J0K3RX]

right now put the whole BF/GATE/SIM  thing up as 1 schematic...

but seriously, i can't wait to try this stuff....when i get my sh#t together.....when....

nice one jim.

btw : just runs parallel to regular out?...are you splitting somewhere?....sorry i need more coffee.

Just 2 outputs coming from the main output of the preamp...

Here is a really sh!tty sample of the cab sim and the gate... I am switching the gate on and off so you can hear the diff. Excuse the playing, just testing
http://dl.dropbox.com/u/11178619/New%20Preamps/E3_SCS_NG.mp3

Edit: Just fyi - I was sitting as close to the pedal as possible to get as much noise as possible... you can move away from the pedal and the hum isn't so bad!

[J0K3RX]

Can you point me to the JSX noise gate?

Best thing to do is just look up the Peavey JSX schematics, look between the 3rd and 4th stages... or google jsx noise gate. It's also somewhere back in this post in the BF stuff.