madbeanpedals::forum

General => Open Discussion => Topic started by: Willybomb on February 26, 2016, 11:15:40 AM

Title: I need a drive recommendation please
Post by: Willybomb on February 26, 2016, 11:15:40 AM
Gudday all.  I'm looking for a chimey low-medium gain drive in the vein of the English Gent to pair up with a high gainer.

Why not just make an English Gent you say?  Well... I have.  3 times, and none of my builds have worked.  Two I've built from PIF'd PCBs from Coppanchino, and one I built from I\/Iark's vero layout.  The PCBs had an extremely low volume with no dirt in both cases, and the vero just doesn't work.  I've decided that this circuit and I are just not meant to be.

So, any suggestions on a similar thing with minimal parts and controls?
Title: Re: I need a drive recommendation please
Post by: pryde on February 26, 2016, 01:20:43 PM
You could try my subtlety drive pcb. It is oshpark shared so you would have to buy min of 3.
It is a modded rog peppermill. Low/med gain, chimey, and easy to build. Might fit the bill for you.

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Title: Re: I need a drive recommendation please
Post by: jimilee on February 26, 2016, 01:41:17 PM
Did you trouble shoot them? The EM drive is low parts and not too gainy.


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Title: Re: I need a drive recommendation please
Post by: culturejam on February 26, 2016, 01:46:32 PM
Barber LTD is a pretty good circuit for that. There were a few DIY projects floating around for it a while back. I recall Bean did a version waaaaaay back called The Silver Fox (I think) as an etched project.
Title: Re: I need a drive recommendation please
Post by: EBRAddict on February 26, 2016, 01:51:36 PM
Can you post some pics of your build which isn't working? You should hear gain, and you should hear clipping.
Title: Re: I need a drive recommendation please
Post by: Willybomb on February 26, 2016, 02:31:09 PM
Thanks guys, I'm going to check all those out.

Here's the funny thing.  I went and plugged the 2nd coppachino pcb in, and it worked in that it seemed to have volume, and some low level farty distortion.  As I was using an BC549C (and have plenty of those, or did..) , I thought I would switch it around and see if that made a difference.  Annnnd, no.. didn't work at all.  Swapped a new one in around the proper way (reverse to the silkscreen) and was back at the low volume no dirt result.

I have one more Coppachino board to try.  He tells me it's verified.  I'm sure it is, I should try and get hold of the proper 2n5008 I guess.  I have a 2n2222 kicking around.

No proper troubleshooting really beyond "that's all in the right spot and there's no solder bridges".

Laughing at the EM-drive. Five components, 2 pots.  Pretty certain I've got all the parts for it here.
Title: Re: I need a drive recommendation please
Post by: EBRAddict on February 26, 2016, 03:59:01 PM
Start with the DC voltages at the transistor pins. Sounds like something is not biased right.
Title: Re: I need a drive recommendation please
Post by: Willybomb on February 26, 2016, 04:30:36 PM
In regards to the English Gent: Testing the transistor on the PCB:
C: 8.35
B: 0
E: 0

On the vero
C: .01
B: .53
E: .01

Built the EM-Drive off this layout here:
http://johnkvintageguitars.homestead.com/Effects/Fuzz-ODs/Emerson/Em-Drive-with-trimmer.png

Pretty rough and quick build.  Used a 2n2222, 20k trimmer and a 2.2m resistor, only had 500k pots so I shoved a 470k across pins 1 and 3 on both.  Took longer to wire the offboard than it did to find, populate, and solder the vero.  Lots better with a buffer in front, farty fuzz when the gain is maxed, probably better when the guitar volume is down a bit, and still a bit bassy.  Might look at a proper 2meg resistor or lower gain transistor.

What is funny is how well it will do pinch harmonics when the gain is flat out.
Title: Re: I need a drive recommendation please
Post by: EBRAddict on February 26, 2016, 05:56:24 PM
The voltage difference between B to E should be at 0.6V-0.7V or you won't get any current running through a silicon transistor. Are your voltages with or without the transistor in place? You should not be getting 0V at B.
Title: Re: I need a drive recommendation please
Post by: selfdestroyer on February 26, 2016, 06:26:41 PM
I agree with CJ about the Barber LTD and would add a modded bluesbreaker like the JHS Morning glory has always fit the bill for my low gain needs.

Cody
Title: Re: I need a drive recommendation please
Post by: nzCdog on February 26, 2016, 06:44:04 PM
Quote from: selfdestroyer on February 26, 2016, 06:26:41 PM
I agree with CJ about the Barber LTD and would add a modded bluesbreaker like the JHS Morning glory has always fit the bill for my low gain needs.

Cody
I REALLY love my 'barber-esque' Madbean Sparkplug (http://www.madbeanpedals.com/projects/Sparkplug/Sparkplug_rev1.pdf)... I see it's just been discontinued, but the projext doc has an etchable layout
Title: Re: I need a drive recommendation please
Post by: selfdestroyer on February 26, 2016, 06:49:50 PM
Quote from: nzCdog on February 26, 2016, 06:44:04 PM
Quote from: selfdestroyer on February 26, 2016, 06:26:41 PM
I agree with CJ about the Barber LTD and would add a modded bluesbreaker like the JHS Morning glory has always fit the bill for my low gain needs.

Cody
I REALLY love my 'barber-esque' Madbean Sparkplug (http://www.madbeanpedals.com/projects/Sparkplug/Sparkplug_rev1.pdf)... I see it's just been discontinued, but the projext doc has an etchable layout

Also here is that Silverfox layout CJ was talking about:
http://www.madbeanpedals.com/projects/Silverfox/docs/Silverfox_ver3.pdf (http://www.madbeanpedals.com/projects/Silverfox/docs/Silverfox_ver3.pdf)

Cody
Title: Re: I need a drive recommendation please
Post by: playpunk on February 27, 2016, 01:31:00 PM
I love the sparkplug. It is my favorite drive


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Title: Re: I need a drive recommendation please
Post by: Willybomb on February 28, 2016, 01:12:37 PM
QuoteAre your voltages with or without the transistor in place? You should not be getting 0V at B.

That's with the tranny in place and measuring each leg.