OLC - Dr. Watt - Schematic

Stompboxes circuits published in magazines, books or on DIY electronics websites.
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gkoerselman
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Post by gkoerselman »

Not verified yet but I think it should be without errors.

I found the tone stack non standard so checked and it is the same (except for minor differences in pot values) to the one displayed here: http://hiwatt.org/Schematics/DR_Pre2InputJP.gif. The mu-amp (last stage) is the same (except for minor differences in cap values) to the OLC Orange Peel.

I've attached the eagle schematic file in the zip. Let me know if anyone spots any errors.
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DR-Watt Schematic.png
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DR-Watt.zip
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salocin
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Post by salocin »

Thanks gkoerselman :thumbsup

Product page: http://www.olcircuits.com/olc_drwatt.html

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culturejam
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Post by culturejam »

I have the Slow Century project PDF as well, but I just can't be arsed to trace it right now. :lol:

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madbean
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Post by madbean »

That's a lot of gain!

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DahakaNishoba
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Post by DahakaNishoba »

@gkoerselman the other half of pdfs is actually at home I'll send them asap when i come back

maybe gonna edit a schem for the valve ones soon....good job on this one btw and thank you for the eagle file
The way electronics work in a stompbox is like the way pixels move in a videogame
it's Magic, in Technology

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ZombiCrow
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Post by ZombiCrow »

Hey, zombie thread, but I can't much about this circuit anywhere else. Just finished my build, and everything seems to work correctly except it's quiet at max volume settings, 10+db quieter than unity. I've checked all my component values, checked all the J201 trannies to make sure they're functional, swapped in a few replacements, etc, but it's still quiet as can be. I am going to message OLC as well, but in the past they've been a little difficult to get ahold of, so I wanted to see if anyone else had any experiences or suggestions.

As far as measurements, my J201 trimmers are set at almost exactly 4.5v each, and the last two J201s are at 9v (coming straight off the power, so expected, correct?) and around 4.5 for the J201 going to ground. Not sure where more volume should come from, but I'm also a little bit of a beginner. Never had any kit trouble before, however, so who knows. Thanks for your time, everyone!

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anselm
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Post by anselm »

When everythin looks fine, but do not work properly, dmm might not do the trick.
You shyould try somethin like this:
Image
made one, put the jack into your guitar amp, power your circuit, attach clip to the ground of it. Plug the guitar in, and ask your kid/girlfrend to strum da hell out of it.
Use probe on drains and gates to find the spot of your signal loss. Localize the problem is the first step to fix it.

Bet the issue hides somewere after the tonestack. Start from the end of the circuit.

Have fun.


xqz my engl :wink:

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ZombiCrow
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Post by ZombiCrow »

SOLVED - with the help of the audio probe, I found a crazy-buried missed soldering on a capacitor. This thing sounds pretty cool for bass :) Thanks for the good idea, I wish I hadn't been so buried in the hunting that I missed it!

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anselm
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Post by anselm »

Glad u"r catch the little green bustard))

For somethin little more complicated u can use software osciloscopes. Another simple, but wery, wery usefull tool. I got this one
https://www.zeitnitz.eu/scope_en
needs two wires - probe with simple woltage divider+diode limiter, and 4.5-6.3 mm jack wire for signal generator

Not as good, as the real one, but still hella better then nothin, and pretty handy.

xqz my engl :wink:

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