Neurocyton Preamp (Greer Soma 63)

MichaelW

Well-known member
Build Rating
5.00 star(s)
This my second time building this project.

First time was a few months ago, and it worked when I fired it up. I can't remember exactly what I was trying to do or fix but it became a casualty of the "Mike Wong Rework Syndrome". I killed the board. As I recall I pulled a socket AND pulled a trace on that one.

Troubleshooting and rework is definitely a set of skills that I am sorely lacking in. On the plus side most of my builds fire right up first time.

But THIS one worked without issue (although I did try to kill my switch relay...sigh.....dropped a pair of pliers on it......left a gash but fortunately it was only cosmetic)

Anyway, I'm a bit split on the Greer pedals I've built. I really love my Mach 1 (Lightspeed) it's become my favorite low gain overdrive.
I did not care too much for the Southern Belle (Southland). This one I'm 50-50 on so far.

I biased it according to the original specs that @PedalPCB posted somewhere. It's definitely got some cool sounds but it also definitely sounds nothing like a 63 Brownface Deluxe, which is what it's supposed to emulate. (no surprise there....)

With the gain on the higher side it starts to get spitty and gatey, so that might be right up someone else's alley. But to me the best sounds I was getting was with the gain dialed pretty low, around 9-10 o'clock, where it sounds a bit more amp-like. It could be a biasing issue, and I probably should play around with it some more although with 4 JFET's to bias it gets a bit confusing.

I've read some reviews of this pedal comparing it to the Benson Preamp. So I pulled out my Son of Ben and compared them side by side. I don't think they sound too much alike except in that they are both JFET based overdrives. The Benson is a smoother and more compressed overdrive whereas the Soma 63 is more gated and choppy.

It's actually much closer to the Chop Shop, so if you like the Chop Shop you can think of this pedal as in that same vein but with more eq control with the bass, treble and presence controls. There is a pretty cool quality to the pedal that's hard to describe with words but it sounds "big". Like in a 3D kind of way. But it's also not too bassy. I can see this pedal cutting through the a mix or a band situation really well.

When I was experimenting with the relay switching boards, I got two of them (in case I messed one up) so I used the spare one I had on hand in this build since it was going in a 125B. I'm trying not to fall in love too much with relay switching....but it's pretty darn sweet. But it also adds cost and complexity to the build and is pretty much impossible to fit into a 1590B.

Cool pedal for sure even if it may not be a sound I would reach for first. Smooth build, and the board is laid out really well as usual.

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I've definitely pulled the "rework syndrome" move, though I didn't rebuild it as I wasn't in love with the pro 10 green as evidenced by the reworking and fatal malpractice.
 
Nice build. Love this pedal, though I've never really heard the amp it's supposed to emulate. I leave my gain right around 12 o clock, bass and presence on 1 and treble around 11
 
Nice build. Love this pedal, though I've never really heard the amp it's supposed to emulate. I leave my gain right around 12 o clock, bass and presence on 1 and treble around 11
How did you bias it? Did you follow the voltages of the original or tweak it by ear?
 
Do you mean how loud does it get?
Loudness is a subjective concept.
Yes. What level?
For example: If 10mV is applied to the input, how much is the output? (if the potentiometers are at 12 o'clock)?
Enough for Professional Audio Line Input? Or do you need an amp?
 
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Loudness is a subjective concept.
Yes. What level?
For example: If 10mV is applied to the input, how much is the output? (if the potentiometers are at 12 o'clock)?
Enough for Professional Audio Line Input? Or do you need an amp?
Yes, I think there's enough level for it to be used as a true pre-amp although I have not tried it this way.
 
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