Anyone know why the bias resistors for the lamp driver are different from the univibe/other clones? The 47k and 100k are swapped it seems. I want to add an offset bias mod and I’m not sure what’s the best way to do it.
Cheers!
Voodoo Lab - Micro Vibe [schematic]
After thinking this thru I’m guessing this is due to a 9V circuit vs 15-24V?jlo wrote:Anyone know why the bias resistors for the lamp driver are different from the univibe/other clones? The 47k and 100k are swapped it seems. I want to add an offset bias mod and I’m not sure what’s the best way to do it.
Cheers!
Are other op amps a candidate? OPA2604? I tried the TL072 and there is an improvement in noise floor and fidelity.
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andregarcia57
- Cap Cooler
which Photocell model works best in this circuit?
thanks
thanks
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FuzzMonkey
- Breadboard Brother
From my research, you want LDRs with the largest range in terms of light and dark resistance i.e. 5649 on this datasheet. How fast they respond is also important. The faster, the better.
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CheapPedalCollector
- Resistor Ronker
How fast the light bulb responds is also key to a good vibe. LED's don't really do it that great as the intensity curve is also different.
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FuzzMonkey
- Breadboard Brother
The thermogenic properties of the filament are indeed a key part of a good vibe.CheapPedalCollector wrote: ↑25 Apr 2022, 22:32 How fast the light bulb responds is also key to a good vibe. LED's don't really do it that great as the intensity curve is also different.
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andregarcia57
- Cap Cooler
00:00 - 00:37 (5649)FuzzMonkey wrote: ↑24 Apr 2022, 10:02From my research, you want LDRs with the largest range in terms of light and dark resistance i.e. 5649 on this datasheet. How fast they respond is also important. The faster, the better.
00:38 - end (5528)
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andregarcia57
- Cap Cooler
hello guys!
for offset adjustment like univibe, 250k trimpot instead of R28 and R29?
thanks
for offset adjustment like univibe, 250k trimpot instead of R28 and R29?
thanks
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FuzzMonkey
- Breadboard Brother
Yes.
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andregarcia57
- Cap Cooler
hello everyone 
Regarding the JRC062D, what is the best replacement for it in terms of sound quality?
TL072 NE5532 TL082 OPA2604 or some other indication.
remembering that the current is not a problem for me, as I always use an adapter for all my pedals.
thanks!
Regarding the JRC062D, what is the best replacement for it in terms of sound quality?
TL072 NE5532 TL082 OPA2604 or some other indication.
remembering that the current is not a problem for me, as I always use an adapter for all my pedals.
thanks!
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nooneknows
- Resistor Ronker
since I've found that my microvibe works way better with a buffer in front (that's why I'm using a Boss as a first pedal) I was mumbling....
what if I put a simple Jfet buffer in place of the first 22K R ? I mean, a common 1 M to grounfd to the gate, Drain at 9V, 10K at source and from the source the 22K R
opinions are welcome
what if I put a simple Jfet buffer in place of the first 22K R ? I mean, a common 1 M to grounfd to the gate, Drain at 9V, 10K at source and from the source the 22K R
opinions are welcome
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mauman
- Resistor Ronker
TL062 is an equivalent low-power JFET input op amp, same specs with lower offset current and bias current than the JRC062. You could also use any of the others you mentioned; the TL0x2 have similar specs, the 5532 has a lower input Z and much higher bias current, the OPA2604 has higher specs. I sincerely doubt you'll be able to hear a difference in the sound of any of these in this pedal.andregarcia57 wrote: ↑13 Oct 2023, 10:35 hello everyone
Regarding the JRC062D, what is the best replacement for it in terms of sound quality?
TL072 NE5532 TL082 OPA2604 or some other indication.
remembering that the current is not a problem for me, as I always use an adapter for all my pedals.
thanks!