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Salas DCG3 preamp (line & headphone)
Salas DCG3 preamp (line & headphone)
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Old Yesterday, 03:02 AM   #5101
Salas is offline Salas  Greece
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Salas DCG3 preamp (line & headphone)
Better equalize the tail current between channels via different value R3. Lower in this case to come up. And maybe replace that particular LSK170 with that break out tendency if it keeps doing it no matter what.
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Old Yesterday, 03:15 AM   #5102
hpasternack is offline hpasternack
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I agree. The left channel stubbornly refuses to oscillate. I'm thinking there may be an outright defect in a component. I'd say the odds are close to 100% if I build up another of these boards I won't see this problem again.

I tried to look for oscillation in the regulator, but didn't find anything conclusive. The 13MHz tends to pollute everything once it starts, so it's hard to determine the source. Between the regs and the signal circuitry there's a heck of a lot of gain on that breadboard.
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Old Yesterday, 03:26 AM   #5103
Salas is offline Salas  Greece
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Salas DCG3 preamp (line & headphone)
Sounds like a plan.
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Old Yesterday, 05:52 AM   #5104
hpasternack is offline hpasternack
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I cut the gate traces right next to the input devices and installed 100 Ohm 0805 SMD resistors. I was surprised as heck that this made the oscillation much worse. It seems like I can can damp it out entirely by the judicious application of my finger.

I think the problem is my layout. I think there's capacitive coupling from the output stage to the gate of J2 and that's the issue. I might be able to disconnect the suspect trace tomorrow. We'll see.

This is great entertainment. Much more fun than politics.
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Old Yesterday, 06:15 AM   #5105
Salas is offline Salas  Greece
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You will solve it no doubt. Nice to know you enjoy debugging.
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Old Yesterday, 05:23 PM   #5106
nikosokey is offline nikosokey  Greece
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Μy DCG3 comes slowly....
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Titan 2000 ,Cressendo Millenium 2000, P3A ,VSSA ΤΟ3 ,B1 Buffer ,Golmund Mimesis 9.2 Clone , Dispre 2 - JFET, DCB1,D-Reflector, BibFet, Buffalo II,ES9018K2M, Arduino LDR Volume, AK4490 Discrete Mirand Audio,SSHV2, 6V6 Salas Preamp. USSA-5.

Last edited by nikosokey; Yesterday at 05:29 PM.
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Old Yesterday, 05:27 PM   #5107
Salas is offline Salas  Greece
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Slow post?
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Old Yesterday, 05:32 PM   #5108
nikosokey is offline nikosokey  Greece
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Oh yes my friend. But i setup the other stuff box-Psu orientation.... etc.... until come the boards from Mike.
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Titan 2000 ,Cressendo Millenium 2000, P3A ,VSSA ΤΟ3 ,B1 Buffer ,Golmund Mimesis 9.2 Clone , Dispre 2 - JFET, DCB1,D-Reflector, BibFet, Buffalo II,ES9018K2M, Arduino LDR Volume, AK4490 Discrete Mirand Audio,SSHV2, 6V6 Salas Preamp. USSA-5.

Last edited by nikosokey; Yesterday at 05:46 PM.
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