I was working on a panning circuit and needed an overdrive circuit in it, I came up with a versatile unit that warranted further exploration.
Added an amp style tone stack, using some dumble/ac30 -like values. I really like the range of tone control in this thing.
It has a few oddities that make it a little hard to build, but they give it a unique tone and very wide range of use.
1. npn Ge trans.
2. special dualgang 22k pot that controls gain and clipping simultaneously.
By scraping the trace of the pot section that sweeps the diode clipping in and out to totally remove the diodes from circuit on the 'clean' side, an unusually wide range of clean to clipped is available. The clean side is very clean, while it will clip almost as hard as a Rat or DS1 on the clipped side. It cleans up extremely well from the guitar volume also. Good touch reaction, especially when A/B tested against Ts 808s and MXR dist + etc.
I have not built any of the jfet based designs, I am curious how this one stacks up against some the Tremblay and other creations. I would like to send a prototype to someone who has some of the other jfet od/ dists to compare.
I am also inviting anyone to build it, I will even send a specially prepped 22k dual pot since it is critical to the design, and I have made the mod pretty easy to do in my shop. Not sure where to find good npn ge trans tho, I lucked into a few at my local surplus shop.
I got a chance to hear it played by hot Nashville band, Emerson Drive this past weekend. Guitarist Danick Dupelle played it for 4 songs in soundcheck and really liked it.
(http://img.photobucket.com/albums/v311/joegagan/pontiacs/decadev2.gif)
welcome back, Joe!!
8)
(http://img.photobucket.com/albums/v437/latronax/viersich150.jpg)
Hi Joe,
That looks great and good that you got to hear it like that at "stage" volumes !
I'd love to build one and perhaps lay it out on vero board, if that is OK with you ?
I'd be happy to cover any costs for the dual ganged pot too.
PM me for my details,
Cheers,
Marty.
Good to see you back, Joe!!
Regan
Yes, I did have to add an input cap, I forgot to add it to the drawing ( thanks Ton)
I used a 2.2 uf.
Marty, Email me at joegagan@hotmail.com with your address.
Danick was using a custom b bender tele > big pedalboard with an aphex optical compressor, a Wayhuge Green rhino, Boss Bluesdriver, a TS9 and some other stuff into a Badcat 20 watt head driving a DRz 2 12 cab loaded with a Celestion blue and something else. Sounded awesome!
thanks for the flower pics Ton!
I don't have flowers, but some FFs from my 'garden'
(http://img.photobucket.com/albums/v311/joegagan/r.jpg)
Sound samples ?
Hey Joe,
Good to see you back. :D
Still butchering your tele in the driveway? (http://www.zebox.com/joegagan/) :lol:
That is really a cool looking circuit. I would love to try it out but as usual I'm up to my wazoo (wherever that is) with other stuff.
Doug
I'ts great to have you drop by Joe !!!
I was commenting to myself: "That looks like a Joe Gagan"...then I read it !!!
A very interesting [convoluted' schematic !! Almost too hard to comment on...I'll try.
The dual ganged 22k looks to reduce diode clipping and .. other stuff ... I'll have to go back and see this again !!!
Yupp..SLick Design !! I don't see many dual ganged pot applications...that's what made me look to read the Signature on the schematic.
Joe - I want to have a crack at this. Can you explain how the dual gang pot is modded ? I guess that you break the track on only one of the pots close to the ccw lug ?
Where'd you get them knobs ???
Molded ?
Hey Joe!
What you doing with that fuzz in your hand?
Joe! It's great to see you back! I still can't get enough of the Skyripper and Dino fuzz pedals, at least one of them is always first in my effects chain.
I'll have to try that new design.
Thanks for sharing!
Ry
Joe: Long time (since you ran off to become a booteek pedal mogul 8) --good to see you around!
That circuit looks seriously interesting. What is the thinking for the second mosfet?
Ben
Doug, Hi, no I am not using drills and strumming attachments on guitars this year.
I did that for a concert last year where I headlined a little blues fest in my neighborhood. I set 3 guitars in a semi-circle on stands, each one run through it's own loop of fuzzes and delays etc. Then into a mixer to a guitar amp ( the sound coming out of the mains in the theatre was orchestrally massive but in a Zappa-esque sort of way). The 3 guitars were tuned to a I, IV, V progression, the drill was used to play a blues progression by a friend while I rode the faders, mutilated the FX and played leads on my regular guitar over the top. It was a fun show, but it was a little awkward for a regular blues crowd. They forgave me later when we reverted to 'regular' music. I have it on DVD tho!
Porhas, sound samples will be later, my studio time is alloted to other projects right now.
Ry, thanks for the compliment. Your comments about the skyripper immediately following 9 - 11 are still with me to this day.
Petemoore - those knobs are regular bakelite knobs scultped with a dremel etc, (using a dustmask of course) then painted. Each knob has approx 30-40 minutes of work invested. Interesting thing about the gain knob - this pedal has extreme versatility but I didn't want any switches except the bypass. 5 knobs is still a lot , but the 3 knob tone section is a joy.
Ben, the circuit was nice with just the first two stages, but since I am a gain junkie I wanted to a add a third stage to regain some balls lost in the tone stack. Sure enough, when I tried the 3rd stage, the distortion smoothed out and the whole thing sounded better to my ears.
torchy, I did a diagram to detail it out. see below
I am using omeg pots, they are easy to open and reclose without damage. Unfortunately, I do not know where they can be bought in this country without purchasing large quantities, I had to place a $1k minimum order to buy omegs.
The reason for the dual gang is to get more control with one knob. As the gain goes up, the diodes are sweeping into play more and more as well. This obviously sounds different than simply raising the gain and letting diodes clip fully. As mentioned, by completely disconnecting the diodes (via the modded trace), there is none of that hint of fizz that would exist if it was left in circuit. Of course, this could be done with a switch and an extra pot, but I think this is more elegant.
(http://img.photobucket.com/albums/v311/joegagan/decadepotdiagram.gif)
'bout time brotherjoe,
i think i'll put on my "rocks" LP and listen to 'back in the saddle again' and drink a beer post haste in giving you a warm welcome back
:D :twisted: :D :twisted: :D :twisted: :wink: :!:
call me bro,
- tom pollock
Wow thanks Joe ;)
AC127s on order ...
QuoteStill butchering your tele in the driveway?
Looks more like surgery to me... :wink:
Welcome back to the forum Joe. I was wondering what happened to you. 8)
Good to hear from you, Joe. Another interesting design!
Sonny
Welcome back Joey G! Glad to see one of my pedal building idols back in action...you had a big hand in getting me into this hobby. Gotta blame someone, right? ;)
Phillip
Pretty much as predicted, eh?
Joe, Indirectly or directly [in my case] had a primary role in getting someone interested in building stompboxes, discussing circuits...
:D Thank You Sir !!!
Joe certainly has given the DIY community some food for thought over the years. I've been enjoying his Tone Dog circuit for some time and best of all, Joe is sending me the pots to build up a Decade prototype. I hope more folks get involved and make this potentially VERY useful pedal. I've got my breadboard ready willing and able.
Tone Dog?
2 cents more from me:
add a pulldown-resistor to the "left" of the input cap (e.g. 4M7),
against switch-poppin`...
:wink:
Tone Dog:
(http://axiseffects.home.att.net/misc/tonedog.gif)
Phillip
lemme add a pulldown on that one, too... :)
correct again.
I had been getting away without pulldown resistors on my earlier pedals, but I took the Decade Proto to a blues jam downtown last night and noticed a pretty bad switch pop, funny you mention this the same day I decided to add one.
The good news is that the pedal sounded great through a Laney AC30 type amp. Nice breakup while retaining chord clarity. Another guitarist in the audience noticed how clean it got when I turned the guitar volume down, and said that it was a great replacement for a Ts type pedal (I had the gain about 80% up).
Thanks to those who have volunteered to build it, I will get to modding those pots tomorrow and get them in the mail.
Howdy Chaps,I've nearly finished building my one but cut the trace in the pot at the wrong end so I'm going into the shop later to get another and hopefully I'll cut it at the proper end.I put sockets in to try the J201's and also I'm able to switch in a 2N7000 mosfet at the first stage after building the multiface with them and liking the sound.I also put in a extra chain of GE diodes to switch between.I'll have some photos up of the circuit unboxed by the end of this day or in about 8 or so hours.
Also the cutting of traces is an old trick for guitar tone controls to lift the signal from the control,but cut at the high end, and get a slight boost and similar,kind of, to the tone lift switch in tube amp tone controls to lift ground.Hats off to Mr Gagan for such lateral thinking and I'm looking forward to hearing this one.
Hey Joe, good to hear from you. Are you still double neckin?
Well I just fired mine up and I do like it very much and the addition of germanium diodes is a plus for a slightly smoother sound at full bore.My 2N7000 isn't working so I'll have to go in and figure that out but apart from that its a very nice classic kinda distortion overdrive.I haven't subbed in the J201's either so I'll go and fix the 2N7000 and see what happens then box it all up before subbing the J201's in.Oh,and I used an AC 130 which happened to be lying about and came up with an hfe of 140 in a regular DMM test so it may be super leaker but it works.
Cheers Joe!
Anyone else built one of these yet? I am waiting on some parts and I will get one going.
I got mine up and going. I haven't spent much time with it but it can get a little too compressed with the clipping diodes when cranked up. It may be worth while to put a diode lift switch. I want to experiment with some other clippers as well.
One thing I caught on the pic of the dual gang pot is that pin 1 and 3 need to be reversed for the diode lift. The schematic is correct but the picture of the pot has the wires reversed. I did try J201's as well and may slightly favor those over the 102's. I will be spending more time with this tomorrow to get a better feel for it.
I've got mine to the debug stage without any luck yet. I think I might know where I went wrong, though. Did you connect the Drain of the FETs to the 1M resistor that runs to the wiper of each 25k trimmer. The schematic makes it look like that point is connected and I'm having trouble believing that it is for some reason.
Thanks!
Ry
Hi Joe!
great to hear from yoe again!
I still think the Skyripper is the best fuzz ever.
The guys in the band don`t always agree though :wink:
Greetings,Ed
QuoteDid you connect the Drain of the FETs to the 1M resistor that runs to the wiper of each 25k trimmer.
Yes I did. Mine fired right up but was a little gated at first it ended up being a ground point that wasn't soldered.
Has anyone worked up a stripboard layout for this circuit?
Head
QuoteHas anyone worked up a stripboard layout for this circuit?
I have one that drew up but I haven't tried it out. I ended up using pad per hole board so it wouldn't get too big. I just have my vero layout drawn out on paper so far.
Dana and Ry both detected the same error form opposite ends.
The pot diagram is correct ( don't reverse ground end as Dana suggests), the error is that the wiper of the right side half of dual gang should be hooked to the top lug, not the grounded side. This also addresses Ry's concern.
updated drawing on the way.
(http://img.photobucket.com/albums/v311/joegagan/pontiacs/decadev2.gif)
I think I have it working, but I want to address one issue I'm having before I post a build report (because it may not be working the way it should). This is really odd, but the pedal does not pass a signal (bypassed or otherwise) in channel 1 of either of my amps. Both amps are Fender. One is a '64 Princeton, the other is a '79 Vibrosonic Reverb. Both amps work with the pedal going into channel 2. Both amps also work fine with just the guitar or any other pedal plugged into channel 1 using the same cords as with the Decade.
What the heck is going on? The Decade works fine going into my Pod with the same cords as well.
Any ideas?
No DC blocking cap in the input of channel(s) 1?
Looking at copies of both schematics, the only difference is that channel 1 has a 1M resistor hanging off of it going to ground, channel 2 does not. There is no DC blocking cap on either.