Rocktek ODR-1 Overdrive

All about modern commercial stompbox circuits from Electro Harmonix over MXR, Boss and Ibanez into the nineties.
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blackboarcult
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Post by blackboarcult »

Hadn't gotten around to post this one yet.
Another cheapo, yet not awful-sounding one.
The circuit does not seem to stray too far from your standard OD. It has a fairly flat freq response but a limited drive range.
I'll get around to modding it at some point, but the bastard crapped on me shortly after reassembling it and I couldn't be bothered to reopen it.

Trace double-but-not-triple-checked. Pinch of salt, etc.

Have a nice one!
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Aromatic_Brush_6769
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Post by Aromatic_Brush_6769 »

Do you know what c21 does? Or the stock value? Mine has that missing for some reason

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blackboarcult
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Post by blackboarcult »

I think it has something to do with the LED, but I don't remember exactly. I'd have to open it again when I come back from holidays

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Aromatic_Brush_6769
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Post by Aromatic_Brush_6769 »

blackboarcult wrote: 28 Jun 2023, 23:02 I think it has something to do with the LED, but I don't remember exactly. I'd have to open it again when I come back from holidays
Ah fair, honestly I should be glad it's missing then since I got it for free because the guy who had it thought it was busted but the led was just dim lol. Threw a really bright purple on in and it's bright enough now

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guiddruid
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Post by guiddruid »

C3/C6 and C15/C4 look odd. The smaller capacitor dominates in each case & makes the larger capacitor redundant.

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Manfred
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Post by Manfred »

guiddruid wrote: 15 Jul 2023, 21:51 C3/C6 and C15/C4 look odd. The smaller capacitor dominates in each case & makes the larger capacitor redundant.
I agree with you.
I would replace these electrolytic capacitors C3 and C4 with a jumper wire, these are a source of failure due to aging over the years.
I guess that C21 is used for LED popping suppression.
To be sure it would be necessary to trace this part of the circuit.

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Post by guiddruid »

Looking at the pcb a bit more, looks like the weird looking cap may be due to switching circuit not being included in the schematic.

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Post by LeftPerspective2673 »

guiddruid wrote: 16 Jul 2023, 10:38 Looking at the pcb a bit more, looks like the weird looking cap may be due to switching circuit not being included in the schematic.
That'd explain why mine cuts the sound for a second when I turn it on, it's missing that capacitor. I wonder if it went bad, someone took it out and then left it out because it still worked

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