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SANITY CHECK: CB30 clone

Started by kdmr, March 21, 2018, 12:38:23 AM

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kdmr

cloning a CB30 and I've built a few in the past but damned if this thing isn't getting under my skin. I want to believe i've got shoddy transistors but I can't find my documented working voltages. Losing signal strength at the Q1D/Q2S junction. The circuit passes signal through but i know what its supposed to sound like and this aint it. 2N5457, 12v Meanwell switching supply.
Pin voltages (DSG):
Q1: 8.08 / 2.28 / 0
Q2: 12 / 8.08 / 4.09
Q3: 7.91 / 2.34 / 0
Q4: 12 / 7.91 / 4.05
Q5: 12 / 9.58 / 2.88

Obviously the drains on Q1/Q3 are well above the target, but I'm assuming this is due to running at 12v which I haven't had issues with in the past. Running at 9v gives about 6v on the Q1/Q3 drains. Anyone have working voltages that I can use to cross reference?

stringsthings

Quote from: kdmr on March 21, 2018, 12:38:23 AM

Q5: 12 / 9.58 / 2.88


I believe that Q5 is set up as a buffer and that the voltage on the gate should be close to 1/2 * supply voltage.
Closer to 6.0V for a 12.0V supply voltage.  If someone knows more, please chime in.
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