Budda - Om Overdrive  [schematic]

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Budda - Om Overdrive  [schematic]

Postby Frabbio » 09 Oct 2017, 11:37

I traced this unit a couple years ago, i took some photos at the time but i can't find them anymore.
T1 is a BC547, the Jfet is a J201 and the Opamp is LF353.
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Re: Budda Om Overdrive

Postby Frabbio » 09 Oct 2017, 13:50

I found the photos, there is a mod i did after tracing the pedal, adding a RC filter by cutting a trace and upping the stock 2.2uF filter capacitor.

In the hand drawn schematic part names are as in the pedal.
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Re: Budda Om Overdrive

Postby roseblood11 » 09 Oct 2017, 16:55

Have you built a clone based on that schematic?
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Re: Budda Om Overdrive

Postby Frabbio » 09 Oct 2017, 17:24

No I haven't, but it's a good sounding overdrive, i remember i did some mods also on the eq of the pedal to make it more full sounding.
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Re: Budda Om Overdrive

Postby dv8r601 » 10 Oct 2017, 23:12

Thanks for this.
Ill try and whip it up and see if it works as is.
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Re: Budda Om Overdrive

Postby JRombold » 26 Dec 2017, 23:24

Thanks for the great work on this. I had a couple questions about the caps on the board as compared to the schematic. C9, C10 and C11 mainly in comparison from board to schematic. Reason I ask Is I built this and the voice of the drive is killer but over is really bright and noisy. C10 schematic shows a 2.2uf on the board it looks like a standard cap. C11 I can't find on the schematic (could be me....I am blind as a bat). C9 on the schematic shows 2.2uf on the board is 5.6n. C6 on the board I am guessing is 1uf but c6 on the schematic is the 5.6n
Thanks for any help on this.
Sorry if this is a ridiculous question.
Thanks again for all the great work!
Dirty

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Re: Budda Om Overdrive

Postby Frabbio » 27 Dec 2017, 03:44

The hand written schematic in the second post shows the component name as in the pedal!

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Re: Budda Om Overdrive

Postby Manfred » 28 Dec 2017, 19:31

I would very much appreciate it if you could measure the voltages at the transistor pins and give us the read values.
Which gain class has the BC547 A, B, or C?
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Re: Budda Om Overdrive

Postby Frabbio » 28 Dec 2017, 20:51

I am sorry but i don't have the pedal anymore. IIRC the transistor was a Bc547C.

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Re: Budda Om Overdrive

Postby Manfred » 31 Dec 2017, 17:32

Frabbio wrote:I am sorry but i don't have the pedal anymore. IIRC the transistor was a Bc547C.


Thanks, I found the read values on this website:
http://runoffgroove.com/mayqueen.html
The OM overdrive is derived from the May Queen overdrive.

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Re: Budda - Om Overdrive

Postby dv8r601 » 15 Jan 2018, 18:03

Well I KNEW I'd seen this odd arrangement somewhere. Its a Escobedo punch in the face betwixt the two opamp stages. Well Lo and behold its a damn near exact copy of the wonderful Carl Martin Crush Zone Image
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Re: Budda - Om Overdrive

Postby Manfred » 15 Jan 2018, 23:09

Haha, I am hettin old, I do believe it. :?
I totaly completely forgot, I did trace the Martin Crushzone on my own. :shock:
http://freestompboxes.org/viewtopic.php?f=7&t=28021&hilit=crush+zone
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Re: Budda - Om Overdrive

Postby Manfred » 15 Jan 2018, 23:19

Manfred wrote:Haha, I am hettin old, I do believe it. :?
I totaly completely forgot, I did trace the Martin Crushzone on my own. :shock:
http://freestompboxes.org/viewtopic.php?f=7&t=28021&hilit=crush+zone


The edit buttom did not work once again :evil:
I meant mean of course:
Haha, I am getting old, I do believe it. :?
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Re: Budda - Om Overdrive

Postby Manfred » 15 Jan 2018, 23:30

I give up ,a further write error. :slap:
I should think about to use the preview function. :scratch:
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Re: Budda - Om Overdrive

Postby Frank_NH » 16 Jan 2018, 16:59

I thought the Crushzone sounded pretty good, as does this. Too bad Budda didn't add something interesting to the design like 3 band EQ, rather than just producing a straight clone.
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Re: Budda - Om Overdrive

Postby dv8r601 » 16 Jan 2018, 19:34

I built a crush zone off Tagboardfx a while back and noticed the input cap at 220pf was WAY smaller than anything I've ever used so I swapped it out for a 8.2nf and it was slamming. Then put a hot 2n5485 in the fet socket and its been on my board ever since. Now knowing what the om is I wonder if their compressor is a clone as its quite weird as well
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