Vintage Epiphone combo

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andresound
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Re: Vintage Epiphone combo

Post by andresound »

martin manning wrote:
andresound wrote:Should I rather use 6L6. Might get a bit more clean headroom.
I doubt it. The only real difference between 5881 and any of the various 6L6's is the power handling capability (max plate dissipation). The socket spacing is surely assuming the small straight-sided 6L6GC envelope, which dates back to 1959.

Good to hear you have the hum solved. What does the ground scheme look like now? Still using the cap can for everything except the last filter?
The 6L6 did seem to add a bit more "oomph" :D .

No Martin, still using can cap for all stages exempt last filter. I had too many ground points. Now I have 2. First stage-output section, PI/reverb and V2 and last section-v1. There is still a "small" bit of 60hz which I will address, when Axial caps arrive.
If it sounds good, it is good! Trust your ears
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martin manning
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Re: Vintage Epiphone combo

Post by martin manning »

I don't understand exactly what you are saying re the two grounds, but IMO all V1 and V2 grounds should go with the input jacks and the last filter, since both sections of both tubes are supplied from that node.
andresound
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Location: Durban South Africa

Re: Vintage Epiphone combo

Post by andresound »

Martin, Sorry for confusion. I Thought I only had 2 grounds (these were the ones I did)... Output section and all others near the input. BUT... Come to think of it, I will have another look at the original grounding that was implemented when built 55 years ago. I would suggest it was a poor design from a grouping point of view.

1. There are 2 "studs" that secure the tag board to the chassis. Both are ground points. V1 cathode ground is secured at the one end.
2. The other side has the cathode bias resistor (200 ohm and cap, 25uf) grounded there. I think the can cap is grounded here too :roll:
3. The last filter stage 10uf cap is grounded on the chassis opposite the input jacks :shock:.

Obviously, this whole grounding scheme must be reworked. I need to be more pedantic in future. Thanks for the input Martin.
If it sounds good, it is good! Trust your ears
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martin manning
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Re: Vintage Epiphone combo

Post by martin manning »

That doesn't sound too bad, actually. With V1 and V2 grounds at the input end and and the others at the power stage cathode, I would think you'd have a pretty quiet result.
andresound
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Joined: Mon Dec 01, 2014 8:48 am
Location: Durban South Africa

Re: Vintage Epiphone combo

Post by andresound »

Just an update. Removed Can cap and went with 2 x 20uf film caps. Hum problem is gone 😀. Thank you everyone for the help 👍.
Time for next project (100w ODS and an 68 bassman 50w head "MOD" project).
If it sounds good, it is good! Trust your ears
kingdanielm
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Joined: Thu Feb 15, 2018 9:09 pm

Re: Vintage Epiphone combo

Post by kingdanielm »

Reviving this thread since I can't stop my internet sleuthing on some of these older Epiphones...

Has anyone ever come across the EA-10 Deluxe before? It's funny that the schematic is everyone online, but I have never come across evidence of an actual EA-10 Deluxe. My guess is that it's a 59-60 model, and like the other 1959 amps, they seem to be incredibly rare.
andresound
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Location: Durban South Africa

Re: Vintage Epiphone combo

Post by andresound »

Remember..mine is a EA-10RV (has reverb). Only 76 made. BTW... been playing this amp a LOT and loving it. Changed the V1 cathode cap down to 10uf 👍
If it sounds good, it is good! Trust your ears
kingdanielm
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Re: Vintage Epiphone combo

Post by kingdanielm »

andresound wrote: Fri Mar 30, 2018 6:46 am Remember..mine is a EA-10RV (has reverb). Only 76 made. BTW... been playing this amp a LOT and loving it. Changed the V1 cathode cap down to 10uf 👍
Right. I'm looking to see if anyone has come across the NON reverb models that preceded yours. Schematics galore, but zero evidence of these amps around. I've never heard anyone talk about them, nor have I ever seen a picture of one anywhere.
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