Keeley Compressor C4 [gut shot]  [traced]

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Keeley Compressor C4 [gut shot]

Postby Crimson » 31 Mar 2009, 11:59

Hi,
http://www.scribd.com/doc/3522835/Keeley-Compressor
I've already read somewhere that the keeley comp is a modded Dyna comp...i've also found something where the mods was explained (he simple change the value of some caps, adds an IN vol control, and adds the attack pot) but now i can't find it anymore...
Does someone knows the value and the caps that he changes?
And also the trannies that he uses on his pedal...
I know that 2N3904, 2SC1815, 2SC1849, 2N5088 could be used with good results...
So thanks in advantage for your help,

Crim
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Re: Keeley Compressor C4

Postby Crimson » 31 Mar 2009, 13:06

I forgot...
Does he use electrolytic caps for the 1uF polarized, or tantalum caps?
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Re: Keeley Compressor C4

Postby Crimson » 31 Mar 2009, 16:32

Again...
The attack is just a pot that sets the recovery resistor, or works on the value of the 2K trim?
Thanks again...

Crim
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Re: Keeley Compressor C4

Postby lynessmy » 31 Mar 2009, 18:55

5pcs of 0.1uf changed to Panasonic orange droplet.
1uf change to tantalum.

Clipping control is the trimmer in Ross Comp and attack is the resistor connect Q3 and Q4 (transistor numbered from left to right) to the Vp.
Transistor is 2sc1849. :horsey: ready to roll....
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Re: Keeley Compressor C4

Postby Crimson » 31 Mar 2009, 21:08

Are you shure that he keeps the same caps value as the ross comp?
And the "trim" (or clip) pot: is just a 2K pot and you can set the whole range, or is a lower value with an extra "stop resistor" in series?
Just last question on the Attack: do you the value?
Thanks a lot again!
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Re: Keeley Compressor C4

Postby BennyBoop » 02 Apr 2009, 21:47

Anyone got a schematic? perhaps even a layout?
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Re: Keeley Compressor C4

Postby Crimson » 03 Apr 2009, 07:44

BennyBoop wrote:Anyone got a schematic? perhaps even a layout?


It's a ross/dyna comp...
The trick is the quality of the components and I'm pretty sure he changes the values of some caps...
Maybe 1uF tantalum caps instead of the electrolytic made the "magic"...I don't know, i'm looking for some guts or some info from someone who have the pedal......

Crim
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Re: Keeley Compressor C4

Postby Crimson » 05 Apr 2009, 09:34

I found what I was looking for:

Rocket Roll wrote:Build a Ross (project file at http://www.generalguitargadgets.com/dia ... r_comp.pdf) and change the components as follows:

* C2 should be value of 220pF, the parts list lists it as 0.0022uF (2200pF).
* C11 should be value 0.001uF instead of 0.01uF
* C12 should be 0.01uF instead of 0.1uf
* Trim pot is 2k value.

That's about it. Now, whether those mods turn that Ross into a 100% Keeley - I don't know, but I doubt anyone can "upgrade" a Ross compressor design any better than that. And that's speaking from a personal experience, of course.


So, does Keeley clone a standard Ross-comp with good parts, or does he some changes?
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Re: Keeley Compressor C4

Postby vietpham » 28 May 2009, 21:37

Hi all, attached is the guts of the Keeley C4. I've tried to draw as much as I can and though there are still some part missing. It's pretty much the same as a Ross Compressor. Hope this be of little help. This is a double sided circuit. White line is the front, red line is the back trace.

Rgds

V
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Re: Keeley Compressor C4

Postby noelgrassy » 28 May 2009, 22:17

Nice work vietpham. Which parts are missing? The trim pots and such like?

I will chillax until you update this since this is damn near complete.

Thanks,

NG.
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Re: Keeley Compressor C4

Postby schtaf » 29 May 2009, 05:52

+1 on the awesome work! thanks
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Re: Keeley Compressor C4

Postby lynessmy » 29 May 2009, 07:47

noelgrassy wrote:Nice work vietpham. Which parts are missing? The trim pots and such like?

I will chillax until you update this since this is damn near complete.

Thanks,

NG.


I guest the trimmer has been replaced by the CLIPPING knob at the panel.
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Re: Keeley Compressor C4

Postby Crimson » 29 May 2009, 11:49

Really thanks a lot man, very good job!
I've some questions...

- Sustain pot: are you sure is reverse log ? i was sure it's linear...
- trim ( or clip control ): 150k? are you sure? I think it's replacing the 2K trim on std ross comp...but 150k is really a lot.And also i see only two connection instead of 3...is it right?
- two 1K resistors near the trim. are you shure of the value?
- resistor between 9V and the attack pot is 10K ?

Thanks again for your help and your pics...

CriM!
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Re: Keeley Compressor C4 [gut shot]

Postby vietpham » 02 Jun 2009, 01:34

I'm sure w the pot values and type. The trimmer is replaced w 2 1k Resistors so it's like trimmer is set in the middle. The clipping pot is just connected in series before it enter the transistor. This is to reduce the gain before the signal is compresses/ sustained.
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Re: Keeley Compressor C4 [gut shot]

Postby mictester » 04 Jun 2009, 15:17

A massive improvement can be obtained by duplicating the transistor that's connected to the output of the CA3080. The one that's there already (with the equal emitter and collector resistors) can continue to be used just as a phase splitter to feed the two recifier circuits. The additional transistor has its base connected to the base of the existing transistor, and has 10k from emitter to ground and 10k from collector to the supply rail. The output is then taken from the emitter of the additional transistor. This prevents the clipping that can occur at the emitter of the original device due to the action of the rectifier appearing in the output - this is meant to be a "clean" sustainer, after all!

I'll post an amended diagram later...
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Re: Keeley Compressor C4 [gut shot]

Postby gkoerselman » 04 Jun 2009, 16:10

I compared the gutshots against the schematic of the Ross and came up with the following eagle schematic.

If anyone can spot any mistakes, please let me know! If anyone is interested in the eagle file, send me a PM with your e-mail address.

Thanks to vietpham again for the gutshots!
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Re: Keeley Compressor C4 [gut shot]

Postby fosnal1950 » 04 Jun 2009, 16:14

Can't see the schematic ; just : image !!

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Re: Keeley Compressor C4 [gut shot]

Postby sevinisthenumber » 19 Aug 2009, 01:26

so on the tonepad layout.... To put a usable trimmer externally just replace the 2k trimmer with a 2kb pot?
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Re: Keeley Compressor C4 [gut shot]

Postby Scruffie » 19 Aug 2009, 01:33

Yup.
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Re: Keeley Compressor C4 [gut shot]

Postby sevinisthenumber » 20 Aug 2009, 04:14

Were do i place the pre gain knob into the circuit? Use a 100ka pot on the input as a variable resistor?
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