Keeler Designs Push

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Keeler Designs Push

Postby mirosol » 26 Jun 2017, 19:37

So. There was one of these for sale as a defect unit on a local forum. Description said that there is "some bad contacts or something", but the price was realistic. I already knew this one will be gooped, but went ahead anyway. Got it in the mail and ripped it open as soon as i found the time to do so. Sure enough. Massive loads of clear and black goop. The only real issue with the unit was the standard 3PDT stomp, which didn't work properly. Now, i had it open on my desk and... Well. The pedal sounds pretty decent, big and somewhat cool with its high-ish gain. I didn't hear it like it would be a straight up clone of anything i know, so i was somewhat interested. Took my exacto knife, 12V spare iron, bigger knife and a few other tools out. About an hour or two later, i had pile of crap on my desk, but the circuit was finally bare. All it took was some moderate violence and lots of patience. I did break the power supply current limiting resistor, 47p cap at the feedback loop and also did some damage to the power filter cap. Replaced those and ordered suitable pots to replace the original ones (which are quite horrible). Now that the goop is gone, those standard angled pots will fit in there nicely. Did the trace, figured it should work, drew a stripboard layout and built it. Sounds exactly like the original. Well then a gain.. It's very low parts count design. Wasn't exactly what i was expecting. Simple, yet quite cool design. Fat TS clipper stage, followed by a Rat-like "tone" control, which is buffered - this followed by a standard volume control. IMO, this could have gained a lot more respect if it wasn't for the goop. Or the choice of pots. Funniest part is definitely the message left for me..

Anyway, here are the results.

Parts list / BOM:
All resistors standard 1% metal film, 1/4W
R1 1M2
R2 100K
R3 1K
R4 10K
R5 10K
R6 10K
R7 10K
R8 10K
R9 10K
R10 100R

C1 100n/63V poly
C2 330n/63V poly
C3 47p/50V ceramic
C4 6n8/63V poly
C5 1u/63V poly
C6 47u/25V alum. electrolytic
C7 47u/50V alum. electrolytic

Gain B500K
Tone B50K
Volume B100K

OP1 sanded, possibly 4558/072, or some other dual opamp
D1 unmarked Si, possibly 1N4148, could be a zener
D2 3mm Diffused red LED
D3 3mm Diffused red LED
LED 5mm Clear blue

And the photos. And the schematic. And the layout.

Consider all verified.
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For this message the author mirosol has received thanks: 15
bbkassel (26 Jun 2017, 22:21), Chris60601 (03 Jul 2017, 15:15), d312a (27 Jun 2017, 09:35), deltafred (27 Jun 2017, 08:50), dv8r601 (26 Jun 2017, 22:42), FeVeR2112 (27 Jun 2017, 01:01), Intripped (26 Jun 2017, 20:15), Manfred (26 Jun 2017, 21:37), nexion777 (26 Jun 2017, 22:33), storyboardist (27 Jun 2017, 15:24) and 5 more users
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Re: Keeler Designs Push

Postby FeVeR2112 » 27 Jun 2017, 00:59

I find the silkscreen text of "Curious?" pretty funny... Only visible after de-goop... :lol:

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electrosonic (27 Jun 2017, 06:56)
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Re: Keeler Designs Push

Postby dv8r601 » 27 Jun 2017, 07:27

I built this up at work tonight. Easy and very good sounding overdrive with a good bit of gain. I appreciate all your work mirosol, you are a champion among men.
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Re: Keeler Designs Push

Postby Manfred » 27 Jun 2017, 11:35

dv8r601 wrote:I built this up at work tonight. Easy and very good sounding overdrive with a good bit of gain. I appreciate all your work mirosol, you are a champion among men.


Which type of OpAmp did you install?
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Re: Keeler Designs Push

Postby mirosol » 27 Jun 2017, 11:39

I put 4558D in mine. No audible difference between the stripboard and the original unit.
+m

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Re: Keeler Designs Push

Postby dv8r601 » 11 Sep 2017, 17:56

Damn. My bad. I just saw you asked what opamp. I used a rc4558 and a jrc4580. It works great with whatever you put in it.
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Re: Keeler Designs Push

Postby Manfred » 15 Sep 2017, 23:10

I made board layout copy according the schematic and the shots and added the hidden tracks by guess.

PushLayout.JPG

PushComponents.pdf

PushComponentSide.pdf

PushSolderSide.pdf

PushComponentSideMirrored.pdf

PushSolderSideMirrored.pdf
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mirosol (16 Sep 2017, 18:50)
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Re: Keeler Designs Push

Postby Manfred » 18 Sep 2017, 01:43

I made a single sided board version, the conducting paths on the components side were replaced by wire jumpers.
PushLayoutSingleSideVersion.JPG

PushComponentsSingleSide.pdf

PushSolderSingleSide.pdf

PushSolderSingleSideMirrored.pdf
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