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OK folks why do I not have tremolo? The roach is flashing ,and changes speed with the control. It just doesn't work. It's a 76 Vibrolux Reverb. I recapped it ,and new tubes. I've tried about all I can think of. Checked voltages ,and most are within tolerance except where I changed the balance pot to bias ,and didn't change the 47k plate resistors on V6 ,and V5 pin 1 is high at 400+ ,and pin 6 is 207. With no input I can hear the tremolo tick ,and it changes went I change the speed control . I replaced the roach with no change. I disconnected the power/red wire to the reverb just in case something was drawing the power down. I disconnected the roach from the 10 meg ,and 100K resistors ,and voltage was the same. Replaced the tube also. Checked all the capacitors,and resistors in the trem circuit. I'm out of ideas. Attached is the closest thing to the original circuit I can find.
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V5 pin 7 & 8 voltages please. -
If the light is flashing, then the problem is on the audio side of the circuit. Bad photocell, bad wires to the depth pot. bad depth pot, bad ground on the depth pot circuit, etc.Comment
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Thanks for the schematic Jazz. That's what I meant to post. Pin 8 is 18v with trem off ,and 0 with it on. Pin 7 is 207v.Originally posted by Jazz P Bass View PostComment
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Here's a dumb question. Is the flashing part suppose to be toward the controls , or the rear panel ?Comment
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The neon lamp connects to the two resistors that are closest to the rear panel.Originally posted by gtrplayr1976 View Post
Because the tubing is often open on both ends, I don't know that only one side flashes or not.Comment
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That's what I thought Bill. I'll check this when I get home. I'm wondering if someone before me put it in backwards. someone had definitely been in it. The new ones have a white dot on one end.Originally posted by 52 Bill View Post
Is that suppose to be the neon lamp side ?Comment
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Use your ohm meter and see what readings you get across the two leads on each side of the bug. The neon lamp side will read as wide open, while the photocell side will probably read a few megohms.Originally posted by gtrplayr1976 View PostComment
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Ok Bill. I'll do that. I'm thinking it may have been installed backwards at this point ,but I may be wrong.Comment
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I don't think it can flash if installed wrong
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Originally posted by Enzo
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Maybe it's the high voltage arcing across the Cds cell.Originally posted by g-one View PostI don't think it can flash if installed wrong.Comment
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From what you have told me it was installed backwards. The photocell side was installed toward the back.Originally posted by 52 Bill View PostComment
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Well someone in fact did have the roach reversed. Flipped it around ,and she's good to go. Thanks for steering me in the right direction Bill !Comment
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Well so much for that theoryOriginally posted by g-one View PostI don't think it can flash if installed wrong.
, like they say, never assume!
Thanks 52Bill for the explanation.Originally posted by Enzo
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I was joking, I assume that it was flashing when the original one was installed.Originally posted by g-one View PostWell so much for that theory, like they say, never assume!
Thanks 52Bill for the explanation.Comment
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