Different first project..... Pedal mod

I was, on recommendation from the very helpful members of this board, going to make a 2 ch. green pre my first project. Problem is that I won't have the cash for a while, sadly. I was hoping to get it done for a an album i'm recording, but it just won't happen.

I'd really like, down the line, to build an la2a and/or an 1176, but for now, I was trying out my electro harmonix black finger as an insert on vocals. It's a opto compressor with lamp/led modes, variable input and output gain, compression (threshold?) and normal/squash modes (ratio?).

It's got promise for helping the vocal sound, but it breaks up very easily. I'm wondering if theres anything I can do so that it doesnt distort the signal like a guitar amp might.

Perhaps someone has a schematic for this unit.... I've been scouring the web and have found only one that I can't even make out, hand drawn and all.

If someone has one, perhaps someone might also have an idea for cleaning up the gain stages, and perhaps controlling the breakup from the tubes?

Sadly it's the only hardware compressor I've got, and it has, if anything, shown me how nice hardware compression can sound on vocals during tracking...... my eyes are finally starting to open up from the dark ages of my only hardware/signal chain being macke mic pre's, and possibly it's god awful (for most things) eq.

Anyway, thought maybe someone has modded one of these, or maybe at least gotten inside theirs before.

I opened mine up and discovered a few things, with a bit of applied knowledge gained from the board, but I'm still trying to learn better how exactly one might 'decode' a pcb or a schematic and figure the use of the components, and what they're doing to the signal.

Anyway,

any help much appreciated,

Billy

have you tried asking at

http://www.diystompboxes.com/smfforum/

that's a cool forum, I'm definitely going register and put a post up over there..... I guess to boil down all of my thoughts (sorry for the lengthy explanation up there), I'm after more of an LA2A sound, and I know that this little pedal is no la2a, nor is it even a leveling amp, i don't think, but maybe someone here would better know the workings of an la2a, and possibly how to get a little la2a out of this little piece of stompbox. It's definitely no t4b in there, but it is an ldr setup.

Maybe the folks over there have some good ideas...... sorry if the whole stompbox thing isnt pertinent over here.

billy

I guess the old Black Finger is defin. around, may have seen it sometime, but you're talking about the newer one, right ?

I think the new Black Finger is an awesome comp. I have no desire to try to mod mine. But, I use it primarily for bass. It is a stompbox, designed for instrument input - low level, high impedence. So, I would guess that a line level signal would be a bit of a slam.

Are you turning the input gain on the BF all the way down?

~ Charlie

billy

Don't be sorry.

The link was given as maybe a better place to ask about the schematic. I think I saw something called the La2 lite at Aron's in a thread. Aron's is one of the better effect sites.

You might find a cool vocal effect with the EH I think people here would be interested.

I do think some people at this forum build DIY effects.

One of the valves in the BF is apparently for gain reduction whilst the other is for amplification.

You could try a 12AT7 or 12AU7 in place of the 12AX7 which controls general amplification. Just a suggestion.

Was the original BF not designed to deliberately cause distortion?

[quote author="rodabod"]
Was the original BF not designed to deliberately cause distortion?[/quote]
IIRIC it was some really primitive compressor/sustainer. That's just based on description/schematic - never tried one.

Sick weird graphic... :wink: Why wasn't that used on the reissue ? :green:

Billy, I sent a PM last night containing the Blackfinger circuit which still seems to be in my outbox????so I'll post it here.
Stephen

[quote author="StephenGiles"]Billy, I sent a PM last night containing the Blackfinger circuit which still seems to be in my outbox????so I'll post it here.
Stephen[/quote]

The old or the new BF ? If it's the new one, then unsurprisingly: yes, me too please. ( chickennerdpig(at)hetnet(dot)nl )

Thanks !

[quote author="enthalpystudios"]that's a cool forum, I'm definitely going register and put a post up over there..... I guess to boil down all of my thoughts (sorry for the lengthy explanation up there), I'm after more of an LA2A sound, and I know that this little pedal is no la2a, nor is it even a leveling amp, i don't think, but maybe someone here would better know the workings of an la2a, and possibly how to get a little la2a out of this little piece of stompbox. It's definitely no t4b in there, but it is an ldr setup.

Maybe the folks over there have some good ideas...... sorry if the whole stompbox thing isnt pertinent over here.

billy[/quote]

hey, there is a great design called the La lite over there....

look for a posting by a guy named Johan:

here is the link to find some interesting stuff.

www.aronnelson.com/gallery

[quote author="clintrubber"]
IIRIC it was some really primitive compressor/sustainer. That's just based on description/schematic - never tried one.[/quote]

I remember it being described as "a fickle finger of fuzz" in a magazine. Istill have the review somewhere.

Sick weird graphic... :wink: Why wasn't that used on the reissue ? :green:

Click to expand...

Very strange graphic and name. I wonder if it was considered non politically correct. It sounds like some sort of tropical disease. Heh heh.

Oh no, more fingers...

Wow... thanks for all the replies.... I'm checking out this La2 lite right now. It is indeed the newer valve version.

And yeah, I have it on the insert on my mackie 24/8, and the line level signal indeed slams it. I have the "Pregain" turned all the way down, and I just about have to keep the post gain down as well.

It is designed to distort, and on guitars I like it quite a bit. A bit specific for general use, but great from time to time.

I've used it on vocal recordings before, on a punk/emo type band, where the singer had some kind of Robert Smith meets Joey Ramone type of voice, and It worked really well. Whenever he would yell/scream/sing loudly, it would break up and distort much like a guitar amp.

Very cool effect. But I'm kind of itching to see how it would work out if it didnt distort so much. It is really crunchy.....

Anyway, going to check out this la2 lite site.

The thing is, even turning up the 'Post Gain' seems to introduce distortion. Could two valves be responsible for gain reduction, pregain and postgain? I'm wondering if one or all of those gain stages could use some modification so that they have some more headroom.......


But I'm still working on it, tweaking things around. I wonder if I could rig something up than can bring the low impedance mic level to high impedance 'guitar level,' whatever that is, so that it didnt slam so hard. I suppose that itself might do the trick......


Anyway, thanks for the help and remarks, It's nice to find a place that stimulates my understanding of these things, rather than stimulating my confusion.

Billy

[quote author="enthalpystudios"]The thing is, even turning up the 'Post Gain' seems to introduce distortion. Could two valves be responsible for gain reduction, pregain and postgain? I'm wondering if one or all of those gain stages could use some modification so that they have some more headroom.......
[/quote]

Please skip if you know all this, but soldering some nice little utility box could solve all this:

There are various circuits around for using FX-pedals in mixer-inserts - look for BreakJackAdapter or something like that.
In essence they're simply attenuating the signal to avoid overdriving the pedal & bringing the gain back up after the pedal. That's all.
Some circuits use ganged att & gain so that you can determine the 'correct' setting without net level loss.

I'd make such a utility-box a separate thing (& don't mod the B'Finger), so that you can use all kinds of pedals in inserts.

Bye,

Peter

[quote author="clintrubber"]Oh no, more fingers...
[/quote]

White finger?

They are bloody racists! Only joking :razz:

There are various circuits around for using FX-pedals in mixer-inserts - look for BreakJackAdapter or something like that.
In essence they're simply attenuating the signal to avoid overdriving the pedal & bringing the gain back up after the pedal. That's all.
Some circuits use ganged att & gain so that you can determine the 'correct' setting without net level loss.

Click to expand...

I'm not sure if this would work because the input volume needs to be at a certain level for the gain-reduction (compression) to take place.

I'd check the schematic and see if it is true that only one of the 12AX7s controls general amplification. I would guess that one stage would amplify the signal as soon as it goes in, an the other would be used as make-up gain after the compression.

Well what I'm wondering at this point, and something that I've thought about building before, is that perhaps a reverse 're-amp' type DI would do the trick. I could then just run the line level insert to that and then to the pedal, where, now that I think about it would probably like to go to a standard DI to get a linelevel signal.

Or maybe this is exactly the breakjack adaptor you're talking about?

Could be a pretty useful little box. Anyway, maybe somebody has a schematic for a reamp/reverseDI type box? Or even for just a good 'vanilla' DI?


Kind of thinking out loud I guess....

[quote author="rodabod"][quote author="clintrubber"]Oh no, more fingers...
[/quote]

White finger?

They are bloody racists! Only joking :razz: [/quote]
I'd be surprised if there wouldn't be a Red Finger soon, in one of those Russian wooden boxes of course... (obvious obvious remark Peter...)

[quote author="enthalpystudios"]Or maybe this is exactly the breakjack adaptor you're talking about?
[/quote]
Function is the same, but the official re-amp uses a TX, while those BJA's usually don't... just a simple attenuation (resistive divider) and perhaps a buffer and then to the FX-box and then an opamp for gain.

Well that indeed sounds like the box for me to build ;]

Don't quite have the cash for any fancy trafo's.

I'll have to keep searching on that..... is there any other name it might go by?

and thanks very very much for helping me with some direction/knowledge/etc....

billy