EH - Soulpreacher [schematic]

[modman]

Here are guts of the original

[modman]

schematic

[trad3mark]

Hey all,

Searched for this, but there doesn't seem to be a thread. Apologies if there is!! Just wondering if anyone has one of these or has built one? I'm looking at building a compressor with the parts that i have and this one seems mighty nice. The schematic is all over the web, and there's two drawings of it:

Drawing 1:
http://www.montagar.com/~patj/soulprch.gif

Drawing 2:
http://www.schematics.ca/modules/PDdownloads/singlefile.php?cid=67&lid=473

It looks pretty simple, and from listening to it and trying it out in the shop, it seems like a nice straightforward one to go for. From working through it to make a vero out of, i've noticed one or two things so far that maybe people can shed some light on?

First up, the voltage biasing. I ran a sim of this in Yenka, and it was grand. Thing is though, if i'm trying to make a small vero, there's easier way to bias 9v to getting +9v and +4.5v. I don't see any problem with using an easier method, right?
Secondly, if you look at the input stage, where the switching for True bypass is, there's a buffer before. Is this really necessary? (without getting into the debate of "are buffers necessary at all?")

won't get a chance to breadboard this for a bit, but if it sounds as awesome as the originals looked (http://farm4.static.flickr.com/3053/2803538353_6b00cd2c09.jpg?v=0) then i'm sold.

tm

[mictester]

First up, the voltage biasing. I ran a sim of this in Yenka, and it was grand. Thing is though, if i'm trying to make a small vero, there's easier way to bias 9v to getting +9v and +4.5v. I don't see any problem with using an easier method, right?

Secondly, if you look at the input stage, where the switching for True bypass is, there's a buffer before. Is this really necessary? (without getting into the debate of "are buffers necessary at all?")

tm

First - Electro Harmonix never wasted any components - there's a reason for the use of every part! The reason for the more complicated biasing circuit is that it will have lower noise than a simple resistor voltage divider and can use a lower value capacitor for the 4.5 Volt rail.

The buffer is a good idea before the compressor stage - it isolates the gain reduction circuit from the preceding device (whether a guitar or another effects unit). You could put your bypass switching before the buffer if you really want, but I find it's good to have that buffer to provide a known, low output impedance, which is similar to the output impedance of the compressor itself, so there's no loading change when it's switched in or out.

[dajm]

here's a link to a pcb layout over at diystompboxes.com that may be of use, I don't know if it's verified.

pcb - http://www.aronnelson.com/gallery/main. ... P.gif.html

layout - http://www.aronnelson.com/gallery/main. ... T.gif.html

[borislavgajic]

how you miss this......search...?

viewtopic.php?f=19&t=2937&p=32630&hilit=soulpreacher#p32630

I made one 5 years ago

borislav

[Bernardduur]

Theads should be merged!

Anyone has any info on the 3080 version of the SP???? I have one in my Big Muff Deluxe and it sounds really flat; everything is squised

[lolbou]

Theads should be merged!

Done!

[borislavgajic]

Theads should be merged!

Anyone has any info on the 3080 version of the SP???? I have one in my Big Muff Deluxe and it sounds really flat; everything is squised

that is similar to blackfinger or lowfrequency compressor?
viewtopic.php?f=19&t=2718&hilit=low+frequency+compressor&start=0

or is it like in deluxe octave multiplexer....
http://sites.google.com/site/electrocon ... actory.jpg

boris

[Bernardduur]

This is simplification of the comperssor in the Big Muff Deluxe; a OTA based Soul Preacher

[RnFR]

there are clippers on the output?

[mictester]

there are clippers on the output?

There have to be! They don't clip very much at all - they're there to handle the "overshoot" of the compressor. The compressor has a fairly slow attack, so the initial peaks can get chopped off by the diodes.

[pedalgrinder]

has anyone tried this pedal on a bass curious as to how it would be on bass

[mictester]

has anyone tried this pedal on a bass curious as to how it would be on bass

Yes. It's horrible.

It's pretty bad with a guitar too, but much worse with a bass!

[pedalgrinder]

yeah by looking at it would distort and respond by like shit the type of attenuation and side chain looked average

[Bernardduur]

The OTA version doesn't sound THAT bad on bass....... it gives it a nice squish and a nice expression on the low notes..... just maybe for me too much squish!!!

[pedalgrinder]

wheres the schematic for the ota version i've never seen it any chance you could post it or email it to me. I'd love to see it cheers

[phibes]

wheres the schematic for the ota version i've never seen it any chance you could post it or email it to me. I'd love to see it cheers

Search the forum for the Electro Harmonix Black Finger. I don't know how to link threads.

[pedalgrinder]

hang on thats not a soulpreacher then it is a blackfinger i've seen that one. Different pedal. you said there was a ota version of a soulpreacher or since you wrote it in this thread call EH soulpreacher i assumed thats what you meant. Thanks anyway

[pedalgrinder]

Actually while on the subject of different compressor's that EH made the the low frequency compressor would be a good one also i reckon. Transistor attenuation i've found i like the response and warmth when a transistor attenuates it.