MichaelW
Well-known member
- Build Rating
So I meant to post this in the Mailbox thread yesterday but never got around to it. So I may was well post it here as it's related
@Chuck D. Bones organized a group buy of MP38A NPN Germanium transistors from our favorite Ebay seller in Ukraine.
These are great sounding Russian trannies and Chuck did all the heavy lifting of testing a bunch of them and making sure everyone in the group buy got a nice range of HFE's and leakage examples.
And.....since I was the first one to PayPal him he sent me a bonus! This board is a @Chuck D. Bones and @cooder project that pre-dated my joining the forum so totally was not on my radar. It's based on a Bjorn Juhl circuit called the "Emerald Green Distortion" but with some of Chuck's tweaks and Cooder's board layout. Chuck was even kind enough to send me a relay and PIC for the board!
Here's the original thread for this circuit.
I'm not exactly sure how it went from "Emerald Green" to "Ruby Blue" hahaha but it's an awesome sounding overdrive.
I wouldn't exactly say it's a "distortion" but rather a great Juhls drive pedal with that signature "chewy" overdrive. (there's that word again)
Being the HUGE BJFE fan that I am, I had to build it immediately, so that's what I did.
I used a randomly picked MP38A from the batch I just got from Chuck. It measured around 107 HFE and I didn't bother with leakage numbers as I don't think this circuit is dependent on that. I also used CMPF4393's since I didn't have any 2N5952's. This circuit also has @cooder 's favorite value 3u3 film caps that are impossible to find.....he must have a huge stash......
. After a quick check with Chuck I subbed a tantalum 3u3.
Chuck gave me some target voltages for Q1 and Q2 but I haven't even bothered to check since the pedal sounds so good!
Digging around in the interwebz about this pedal, apparently it was designed to emulate a Vox AC15 2x10 combo. This was surprising because I had already fired it up and was jamming it and researching at the same time and it didn't sound anything like an AC15. Then I found Chuck's original breadboard post and read about the settings to get the VOX type sound. At certain settings it definitely cops a bit of that "pushed/cranked" Vox vibe.
Another great project from Celestial Engineering and Big Noise Amplification!
If there's enough interest maybe we can get @Chuck D. Bones and @cooder to share the Gerber's and I'll order some of these boards to share with the forum.
I goofed the drilling and drilled the status LED on the wrong side.....duh......
For the demo, I used my "favorite guitar of the week". My Epiphone SG Special.
I'm so glad that @Coda talked me into buying this......hahahahaha (yes, that's my story and I'm sticking with it).
To be honest I was a little underwhelmed when I first got it, hot on the heels of the superb Tokai SG. Those are just on a complete 'nuther level of build quality and excellence. But I think 90% of the "underwhelmed-ness" was the pickups and the other 10% was the set up and my typically anal tweaking, polishing and little things that I do to my guitars. The Music City Bridge made a big difference in the sustain and the bone nut also is one of those "little things" that add up to something greater than the sum of its parts. Right now, with these pickups, it's just what I reach for most days when I play. Just fits me so well. I can even overlook the skinny neck profile hahah.
@mjh36 had asked about the neck dive. My guitar is SUPER light. I haven't weighed it but it's got to be under 6lbs. I usually don't notice neck dive because I always play sitting down, but I actually tested this guitar with a strap and the neck dive is pretty pronounced with a regular Fender strap. I'd need to use a wider leather strap I think to tame it. Or......but a full size Maestro vibrola on it. (hmmmmm.....the wheels are turning......heh)
@Chuck D. Bones organized a group buy of MP38A NPN Germanium transistors from our favorite Ebay seller in Ukraine.
These are great sounding Russian trannies and Chuck did all the heavy lifting of testing a bunch of them and making sure everyone in the group buy got a nice range of HFE's and leakage examples.
And.....since I was the first one to PayPal him he sent me a bonus! This board is a @Chuck D. Bones and @cooder project that pre-dated my joining the forum so totally was not on my radar. It's based on a Bjorn Juhl circuit called the "Emerald Green Distortion" but with some of Chuck's tweaks and Cooder's board layout. Chuck was even kind enough to send me a relay and PIC for the board!
Here's the original thread for this circuit.
I'm not exactly sure how it went from "Emerald Green" to "Ruby Blue" hahaha but it's an awesome sounding overdrive.
I wouldn't exactly say it's a "distortion" but rather a great Juhls drive pedal with that signature "chewy" overdrive. (there's that word again
)Being the HUGE BJFE fan that I am, I had to build it immediately, so that's what I did.
I used a randomly picked MP38A from the batch I just got from Chuck. It measured around 107 HFE and I didn't bother with leakage numbers as I don't think this circuit is dependent on that. I also used CMPF4393's since I didn't have any 2N5952's. This circuit also has @cooder 's favorite value 3u3 film caps that are impossible to find.....he must have a huge stash......
. After a quick check with Chuck I subbed a tantalum 3u3.Chuck gave me some target voltages for Q1 and Q2 but I haven't even bothered to check since the pedal sounds so good!
Digging around in the interwebz about this pedal, apparently it was designed to emulate a Vox AC15 2x10 combo. This was surprising because I had already fired it up and was jamming it and researching at the same time and it didn't sound anything like an AC15. Then I found Chuck's original breadboard post and read about the settings to get the VOX type sound. At certain settings it definitely cops a bit of that "pushed/cranked" Vox vibe.
Another great project from Celestial Engineering and Big Noise Amplification!
If there's enough interest maybe we can get @Chuck D. Bones and @cooder to share the Gerber's and I'll order some of these boards to share with the forum.
I goofed the drilling and drilled the status LED on the wrong side.....duh......
For the demo, I used my "favorite guitar of the week"
. My Epiphone SG Special.I'm so glad that @Coda talked me into buying this......hahahahaha (yes, that's my story and I'm sticking with it).
To be honest I was a little underwhelmed when I first got it, hot on the heels of the superb Tokai SG. Those are just on a complete 'nuther level of build quality and excellence. But I think 90% of the "underwhelmed-ness" was the pickups and the other 10% was the set up and my typically anal tweaking, polishing and little things that I do to my guitars. The Music City Bridge made a big difference in the sustain and the bone nut also is one of those "little things" that add up to something greater than the sum of its parts. Right now, with these pickups, it's just what I reach for most days when I play. Just fits me so well. I can even overlook the skinny neck profile hahah.
@mjh36 had asked about the neck dive. My guitar is SUPER light. I haven't weighed it but it's got to be under 6lbs. I usually don't notice neck dive because I always play sitting down, but I actually tested this guitar with a strap and the neck dive is pretty pronounced with a regular Fender strap. I'd need to use a wider leather strap I think to tame it. Or......but a full size Maestro vibrola on it. (hmmmmm.....the wheels are turning......heh)
