D'Lite grounding and PS questions

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greiswig
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D'Lite grounding and PS questions

Post by greiswig »

Okay, I'm still trying to fix the fizz on OD. I started looking at grounds for issues, and I found at least one ground that is not done according to the Brownnote layout: the ground of the rectifier board is wired where the green arrow shows in the attached picture.

1. Is this likely to cause issues?

The purple arrow shows where Bob-I suggests grounding the first 22uF cap on the dropping string, which again is different from the Brownnote layout. He seems to think this one should go close to the power tubes, instead.

2. Does that seem right or better?


Finally, I notice on some pix that HAD seemed to be using a pair of 200uF caps for the initial filtering, not a pair of 100uf caps.

Is more better?

Thanks, all...
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Bob-I
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Re: D'Lite grounding and PS questions

Post by Bob-I »

Still waiting to hear a clip of that fizz. IMHO grounding is not your issue. I'd suspect HF oscillation.
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jurgen
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Re: D'Lite grounding and PS questions

Post by jurgen »

I used the Brownote layout and my D'lite has virtually no PS noise

I think the 200uf were probably in a 100 Watt amp no?
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greiswig
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Re: D'Lite grounding and PS questions

Post by greiswig »

Bob-I wrote:Still waiting to hear a clip of that fizz. IMHO grounding is not your issue. I'd suspect HF oscillation.
Thanks, Bob...I originally put the clip in another thread that you weighed in on briefly, entitled ""Torn speaker" distortion sound on OD". That thread also outlines my efforts to track down oscillations, etc. I'd appreciate any suggestions you might have.

Would the grounds done as they are currently only be likely to cause 60Hz hum, and not intermodulation distortion, etc.?
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ampdork
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Re: D'Lite grounding and PS questions

Post by ampdork »

George,

I swear I thought I had a picture showing D doing this but it was completely illusion. I honestly have no idea how that happened because I simply know better and this is never done on any amp. That ground should have only the IEC plug grounded there, nothing else at all.
So while not 100% it'as going to help it surely can't hurt.
I was trying to default to Dumbles lead dress wherever possible but that is plain wrong. Sorry again.
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Structo
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Re: D'Lite grounding and PS questions

Post by Structo »

When I initially had built my D'Lite I had the B+ wire from the standby switch running too close to the ac supply wires.
I was picking up some switching type noise in the OD channel specifically.
I re routed the wire from the rect board to the switch and from the switch to the filter board keeping it away from the ac.
No more noise.
Tom

Don't let that smoke out!
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Bob-I
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Re: D'Lite grounding and PS questions

Post by Bob-I »

greiswig wrote:
Bob-I wrote:Still waiting to hear a clip of that fizz. IMHO grounding is not your issue. I'd suspect HF oscillation.
Thanks, Bob...I originally put the clip in another thread that you weighed in on briefly, entitled ""Torn speaker" distortion sound on OD". That thread also outlines my efforts to track down oscillations, etc. I'd appreciate any suggestions you might have.

Would the grounds done as they are currently only be likely to cause 60Hz hum, and not intermodulation distortion, etc.?
What are your settings on that clip? I honestly didn't hear enough to qualify this as a problem. Kinda sounded like the amp was trying to start to overdrive, but didn't quite get there.

Try setting both gain controls at 12 to 1:00, treble to about 11:00, mid and bass to 2:00. Then PLAY some.
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