BLACK FOREST High Gain Preamp - Based on the Bogner Uberschall

[J0K3RX]

CALM DOWN JIM!!!!!!!!...... deep breaths, ..........deep..................deep.................................breathe slowly......in................................out............................in.........................in.................in..................in.................BANG!!!!!...

I understand the frustration of  getting 'nearly there' with home grown stuff!...been there, and will be again no doubt.

I'm pretty sure if you started a thread with that  offer ( with full schemo  and ask that answers be directed/ linked to this thread of course (put a link to here ).

that some of the more knowledgable EE guys would jump on it ....everyone loves a freebie right!......plus everyone gets a fully working schemo....WIN WIN...


btw i live in the congo  

Rob,

Actually, that was kinda calming until I got to the BANG!!!!!! and then I was double pissed cause it tricked me

Good idea... I didn't want to start a "unauthorized contest" in here and get into trouble! But, yeah I could do that!

Congo UK? I think they do air drops over that area to the native tribes and savages? I could ship the pedal in with some supplies but if the Silverbacks get hold of it I am not responsible... You might have to dig your prize out of a steaming pile of gorilla sh!t if that's ok?

[ggedamed]

Jim, two questions:
1. Do you have nearby a fluorescent light or some kind of electric engine? I also had  anger management issues until I discovered that my problem was on the desk - a fluorescent lamp that was bought recently.
2. If a Tube Screamer solves your problem, why don't you use a buffered bypass? I wanted to house a pedal in an old pedal case Boss-size and there were lots of wires inside  - I couldn't tame the oscillation that appeared beyond a certain gain level until I put an op amp buffer inside. I lost the true-bypass thingie, but I gained a really nice buffer.

Also, why don't you record the damn noise? A recording is worth 10000 words.

[J0K3RX]

Jim, two questions:
1. Do you have nearby a fluorescent light or some kind of electric engine? I also had  anger management issues until I discovered that my problem was on the desk - a fluorescent lamp that was bought recently.
2. If a Tube Screamer solves your problem, why don't you use a buffered bypass? I wanted to house a pedal in an old pedal case Boss-size and there were lots of wires inside  - I couldn't tame the oscillation that appeared beyond a certain gain level until I put an op amp buffer inside. I lost the true-bypass thingie, but I gained a really nice buffer.

Also, why don't you record the damn noise? A recording is worth 10000 words.

Ok here's the damn noise... around :59 I switch on the DIY tube screamer (has true bypass) so I have the TS on very low settings but you can still hear how the hum is almost if not all gone.. Then later on I switch the TS back off (you can hear the click) and you can hear the hum again. Also I roll my vol pot on the guitar up and down a few times in the recording so you can hear the hum fade in and out.

http://dl.dropbox.com/u/11178619/New%20Preamps/ENGL_HUM.mp3

No motors, no fluorescent lighting, no electric tooth brushes, vibrators etc..  

Also, built a couple buffers and neither one worked, and by that I mean they didn't eliminate the hum? Don't really understand that either since one of the buffers I built was the TS buffer? I built them on small pieces of perf board.

Edit: almost forgot, I also made a klon buffer, sounded real good but no cure for the hum either...

[stormbringer79]

Oh. Btw, i would recommend posting the issue att ssguitar.com, Roly and JmFahey over there got some serious experience and knowledge,

[ggedamed]

For the buffer magic to happen, the buffer must come first thing after the input jack. Did you put it, by any chance, after the bypass switch?

[J0K3RX]

For the buffer magic to happen, the buffer must come first thing after the input jack. Did you put it, by any chance, after the bypass switch?

Nope, it's first thing after the jack... I don't even have a stomp switch wired into this at this point.

When I use my retail TS7 I can just leave it in bypass and it does the same thing only the tube screamer part of the circuit is bypassed since the retail has buffered bypass. I think when the TS7 is in bypass it's going through both the input and the output buffer if I am not mistaken and only bypassing the TS circuit, then into the preamp?

[posmaster]

My 2 (probably useless) pfennig

It really sounds like a ground loop from the sample MP3 and the description of it getting louder as you turn down your volume.

If you're shunting noise to the guitar output ground, and then it's somehow munging it's way into the Black Forest's ground that *could* explain it, as well as why the 18K resistor was helping...

That being said I hope this gets sorted for you.

[J0K3RX]

My 2 (probably useless) pfennig

It really sounds like a ground loop from the sample MP3 and the description of it getting louder as you turn down your volume.

If you're shunting noise to the guitar output ground, and then it's somehow munging it's way into the Black Forest's ground that *could* explain it, as well as why the 18K resistor was helping...

That being said I hope this gets sorted for you.

It's isolated, no? What could it be looping with? If I use it all by itself (with no other pedals) and running from battery I still get hum...  I am open to that idea but I just don't see what it could be in a loop with? Maybe the Line 6 USB interface that I am running into the computer with? But then again it does it on my mosvalve power amp also...? And again none of my other pedals do this hooked up the same way??? I am also getting my mains power from a APC XS 1500 which has regulated smooth AC power, no spikes, no dips just clean power. Tried plugging the 1spot directly into the wall to see if it might be the UPS system but still does the same crap... Even tried it in different rooms of my house and the hum follows... The only other thing is the metal plate in my skull and if I take that out my brains will spill out all over the carpet and my wife hates when I spill my brain on her nice berber carpet! 

[caspercody]

Do you have a battery power amp? Trying to see if you can hook this up with nothing plugged into a AC outlet (computer, amp...)

[posmaster]

My 2 (probably useless) pfennig

It really sounds like a ground loop from the sample MP3 and the description of it getting louder as you turn down your volume.

If you're shunting noise to the guitar output ground, and then it's somehow munging it's way into the Black Forest's ground that *could* explain it, as well as why the 18K resistor was helping...

That being said I hope this gets sorted for you.

It's isolated, no? What could it be looping with? If I use it all by itself (with no other pedals) and running from battery I still get hum...  I am open to that idea but I just don't see what it could be in a loop with? Maybe the Line 6 USB interface that I am running into the computer with? But then again it does it on my mosvalve power amp also...? And again none of my other pedals do this hooked up the same way??? I am also getting my mains power from a APC XS 1500 which has regulated smooth AC power, no spikes, no dips just clean power. Tried plugging the 1spot directly into the wall to see if it might be the UPS system but still does the same crap... Even tried it in different rooms of my house and the hum follows... The only other thing is the metal plate in my skull and if I take that out my brains will spill out all over the carpet and my wife hates when I spill my brain on her nice berber carpet!  

Yeah - that's why I wasn't sure it was a ground loop - but that's really what it sounded like in teh sample . The old "guitar+cable as noise antenna" deali-o... and maybe ground loop isn't the exact right phrase...

I'm still a rank amateur at this pedal-building thing, but coming from 20+ years of wiring and re-wiring guitars that's what jumped out at me from the sample

*and please take anything that sounds like something super-obvious with the intention of wanting of getting this working, my clumsiness in expressing things graciously, and not a slight on your skills :-)

[jymaze]

I agree, according to your recording Jok3rx, it sounds like mains hum to me. Could be shielding, could be a ground loop, could be nearby equipment...

[J0K3RX]

I agree, according to your recording Jok3rx, it sounds like mains hum to me. Could be shielding, could be a ground loop, could be nearby equipment...

And I agree... But, nothing else (pedals) I have do this..? And, it doesn't explain the few others that have built this and described the same noise.. unless we all have noisy mains and ground loops...

Actually this is mild compared to when I first built it! I have brought the noise down some... It was unbearable in the beginning!

[J0K3RX]

*and please take anything that sounds like something super-obvious with the intention of wanting of getting this working, my clumsiness in expressing things graciously, and not a slight on your skills :-)

No man, it's all good! Any ideas welcome!!

[ggedamed]

With all the respect, this Sherlock Holmes/Hercule Poirot type collective analysis is very entertaining to me  .

It could very well a combination of causes.
Jim, try to disconnect the shield on one of the cable patches that go into/out of the pedal and see if it does anything.

[J0K3RX]

With all the respect, this Sherlock Holmes/Hercule Poirot type collective analysis is very entertaining to me  .

It could very well a combination of causes.
Jim, try to disconnect the shield on one of the cable patches that go into/out of the pedal and see if it does anything.

Well, I am glad you are getting entertained by all of this At least I am accomplishing something then...

I may be onto something... standby

[fretzburner]

I'm getting myself an AMT R1 to compare this side by side and check if the hum on my build is comparable to the original.The last time i tested this compared to real boogie amp was very good.Both same hum content(amp and Engl build).Hope that R1 will arrive sooner.

[J0K3RX]

I'm getting myself an AMT R1 to compare this side by side and check if the hum on my build is comparable to the original.The last time i tested this compared to real boogie amp was very good.Both same hum content(amp and Engl build).Hope that R1 will arrive sooner.

My AMT pedals are very quiet... I would say the P1 has the highest gain of the bunch since it has 6 gain stages... All of my pedals are quiet, except for the ENGL and Black Forest. Then again none of my other pedal have as much gain as these 2. Probably a 50k gain pot would bring them down to the gain level of the others... Would probably cure all noise problems also since mine clear up 100% noise wise when I turn the gain back about half way on the pedal...

[pakrat]

Jim, don't even joke about cutting gain from these things........

[J0K3RX]

Jim, don't even joke about cutting gain from these things........

Here are my thoughts for whatever they are worth... Get a great tone, good amount of gain but not too much, then slap a tube screamer in front of it, end of story! Been doing it for years and I can always seem to get a killer heavy sound and very tight with very little noise! I am not the only person that thinks this way... Many hard rock, metal, death metal, prog metal players etc do this. Even if they have a preamp/amp that have a bat sh!t crazy ton of gain they will dail the gain back on the preamp and "jack it up" with a tube screamer or close variant! Just adds the magic ingredient plain and simple!

Here is a great example of this! Take note of the gain settings on both


And here is what it sounds like. Pretty massive and heavy in my opinion!
http://dl.dropbox.com/u/11178619/Preamps/AMTCRATE.mp3

This is a "small" rig that Ola Englund threw together (that is him playing by the way) using an AMT P1 with the gain dialed way back, a Maxon OD808 with the level cranked all the way and the drive all the way off, then running into a Crate Powerblock (basically a stereo power amp with EQ) with the gain on 2 or 3 then running into a 1X12 cab and mic. I know the Powerblock is a full on stereo preamp/power amp but I do the same setup with my mosvalve and the P1 and get the same sound and same amount of gain... I can also run direct and get roughly the same sound and same amount of gain... It doesn't get any more simple than this!

So, what I am purposing is that we build these preamps with built in/on-board Tube Screamer/OD pedals... Fairly small circuit and you don't even have to have a tone pot.. If you know where you like the tone setting on the TS (like I do) then you never really change it unless you have a really bright or really dark sounding guitar. In that case then you can have the tone on a small trim pot inside the enclosure. All in all, with this you can reach that aggressive, massive "over the top" brutal high gain sound with very little hum or noise. Then if you want a crunch sound or clean sound there are any number of things you can do with switching to obtain these as well... This is just a "tried and true" winning combination that just can not be and has not been beaten in my opinion! Thoughts?

[pakrat]

Man, you gotta love Ola, he's the king of getting heavy tones out of just about any setup. As you know Jim, I am a fan of tube screamers and use one in all of my rigs. They just add the perfect amount of extra drive I need, so it sounds like a good plan to me. My Randall doesn't have TONS of gain, but with a TS in front and a PQ3 in the loop it's downright brutal! Add in the fact that I can blend a tiny bit of clean channel in over the red channel and it destroys small villages.
Ordering E3 parts now to finally get back into this thread. Thanks again for sharing!