DIYstompboxes.com

DIY Stompboxes => Building your own stompbox => Topic started by: cnspedalbuilder on November 07, 2017, 11:39:02 AM

Title: Rickenbacker McGuinn onboard compressor schematic/layout
Post by: cnspedalbuilder on November 07, 2017, 11:39:02 AM
Hi, I was thinking of replacing the rhythm circuit in my Fender Jaguar with an onboard compressor, and I believe something similar was done with the special edition McGuinn Rickenbacker.  Does anyone have the schematic or layout and do you think it can fit in the Jaguar rhythm circuit cavity by someone who is not a layout or wiring ninja?

I found a zombie thread from 2006 with none other than Mark Hammer and RG Keen discussing this, but the schematic is long gone.
Title: Re: Rickenbacker McGuinn onboard compressor schematic/layout
Post by: pinkjimiphoton on November 07, 2017, 12:19:40 PM
last i knew, roger is now using a janglebox.

the guys at rickenbacker are crazy defensive about their intellectual property, (with good reason) and AFAIK, no legit schematic for this has ever been produced.

i suspect from reading about it tho its basically a simplified mxr dynacomp with a few tweaks.

i hope ya find the schematic, i've always wanted to see it. ;)
Title: Re: Rickenbacker McGuinn onboard compressor schematic/layout
Post by: Mark Hammer on November 07, 2017, 12:46:07 PM
This is the original one:

(http://www.cnjradio.net/ricgits/19515.gif)
Title: Re: Rickenbacker McGuinn onboard compressor schematic/layout
Post by: pinkjimiphoton on November 07, 2017, 02:30:17 PM
awesome share, mark!
funny, was just reading an old interview with mcguinn and the guy who designed it said in the sidebar they wouldn't release the info about it or issue it as a standalone.
looks cool, hope the boys at tagboardeffects spot it ;)
they do way better veros than i do ;)
Title: Re: Rickenbacker McGuinn onboard compressor schematic/layout
Post by: PMowdes on November 07, 2017, 03:18:58 PM
Quote from: pinkjimiphoton on November 07, 2017, 02:30:17 PM
awesome share, mark!
funny, was just reading an old interview with mcguinn and the guy who designed it said in the sidebar they wouldn't release the info about it or issue it as a standalone.
looks cool, hope the boys at tagboardeffects spot it ;)
they do way better veros than i do ;)

Jimi, post it in the request section on tagboards (with Marks blessing of course), i'm sure someone will pick it up pretty quick.
Title: Re: Rickenbacker McGuinn onboard compressor schematic/layout
Post by: Mark Hammer on November 07, 2017, 04:11:22 PM
I don't think it was particularly protected.  Can't recall where I got it from, but I got a whole whack of other Ricekenbacker guitar schems from the same place.

You will note a few wrinkles to this largely-Dynacomp-derived circuit:
a) There is no variable compression.  It's fixed at max compression.
b) The part of the circuit that would normally use a 150k resistor and 10uf cap to set the recovery time uses 1M and 2u2, here.
Title: Re: Rickenbacker McGuinn onboard compressor schematic/layout
Post by: Kipper4 on November 07, 2017, 06:19:21 PM
Is it an OTA or comparator chip please?
Title: Re: Rickenbacker McGuinn onboard compressor schematic/layout
Post by: Pedal love on November 07, 2017, 06:37:38 PM
Quote from: Kipper4 on November 07, 2017, 06:19:21 PM
Is it an OTA or comparator chip please?
3080?

Sent from my SM-S327VL using Tapatalk

Title: Re: Rickenbacker McGuinn onboard compressor schematic/layout
Post by: R.G. on November 07, 2017, 06:52:02 PM
It's a 3080. You can make a 13700 work.

I did a layout of a moderately modified onboard compressor from that schematic ... um, 15 years ago? Still in my archives somewhere. I made it to fit the acrylic panel for my Rick 330. Worked.
Title: Re: Rickenbacker McGuinn onboard compressor schematic/layout
Post by: cnspedalbuilder on November 08, 2017, 12:08:05 PM
Thanks everyone. This looks like a pretty complicated setup--rotary switch, 3 tone pots, and 2 jacks! R.G. did you simplify this in your build?
Title: Re: Rickenbacker McGuinn onboard compressor schematic/layout
Post by: Kipper4 on November 08, 2017, 12:29:27 PM
You could easily get rid of the tone section.
I can't remember how those rotary switches work. Don't they link 2 of the outer lugs to the common.
Someone will know or better still have a gif to share.
Figure out the switching links hard wire it.
Do the npn's need to be low gain?
Title: Re: Rickenbacker McGuinn onboard compressor schematic/layout
Post by: Kipper4 on November 08, 2017, 12:43:59 PM
Here we are thanks to my dads old uni.

http://info.ee.surrey.ac.uk/Teaching/Labs/docs/RotarySwitchHowTo.pdf
Title: Re: Rickenbacker McGuinn onboard compressor schematic/layout
Post by: R.G. on November 08, 2017, 03:24:04 PM
Ah. Found it. See:

http://geofex.com/Fx_images/rickcomp1.jpg

http://geofex.com/Fx_images/rickcomp2.jpg

http://geofex.com/Fx_images/rickcomp3.jpg