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Old 17th October 2012, 09:14 PM   #41
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aren't the heyboer trannys like arround 5k on primarys? isn't that kinda low for el84s?
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Old 17th October 2012, 09:24 PM   #42
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GE Black-plate 6V6GT test - YouTube

Total sleeper man xD I want get to upgraded output tranny too I'm just not totally sure if the Heyboer 50w with 2 el34s would like the plate resistance of 4 6v6gt or the 4 JJ6v6 Might be worth a try though them Heyboers pop up on ebay for pretty good deals a Mercury Magnetics would no doubt be killer but I'm sure, they are pretty pricey though figures though they are meaty for sure more Iron and just built better than the cheapo Chinese trannys
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Old 17th October 2012, 09:26 PM   #43
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that's just for my output tranny my power tranny is a beast for a cheap tranny lol
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Old 18th October 2012, 01:58 PM   #44
shanx is offline shanx  Canada
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But for that cheap I think I'll install plugs and try the Edcor, as a learning experiment if nothing else.
Just catching up on your thread here. With the audio grade output transformer, compared to the Peavey stock, Keriwana is right in mentioning that the OT response has a big part to play on the amp's overall sound. Just a few suggestions in how to approach this: The Edcor will probably have very little roll-off up to 20kHz and you may find the amp sounds brighter. If you want to adjust for this, you may want to look at a zobel network, or perhaps adjusting cap and resistance values on the NFB ''presence'' circuit back through to the PI.
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Old 24th October 2012, 08:33 PM   #45
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Originally Posted by shanx View Post
I was wondering about Classic Tone series by Magnetic Components..maybe somebody has used them?
Based on the manufacturer code in the part number, they might have made the original Peavey transformer.
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Old 24th October 2012, 08:35 PM   #46
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Originally Posted by JRGuitarGuy View Post
aren't the heyboer trannys like arround 5k on primarys? isn't that kinda low for el84s?
Depends on how many EL84's. Suppsedly the MM for the Classic 50 with 4 EL84's in PP is 4K. So is the Edcor I ordered.
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Old 24th October 2012, 08:38 PM   #47
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Originally Posted by shanx View Post
With the audio grade output transformer, compared to the Peavey stock ...The Edcor will probably have very little roll-off up to 20kHz and you may find the amp sounds brighter. If you want to adjust for this, you may want to look at a zobel network, or perhaps adjusting cap and resistance values on the NFB ''presence'' circuit back through to the PI.
Yes, if I need to voice the output I'd rather do it before the transformer.
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Old 24th October 2012, 08:55 PM   #48
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I got the first bunch of parts from Peavey. I really don't like these teensie pots with teensie shafts, but they do leave room to add switches or pots to the panel. And the problems everyone had with the small split and fluted shafts getting bent and then the knobs falling off or they try to bend the shaft-halfs by inserting a knife into the slot and braking off a half-shaft tab...Peavey has definitely improved the new replacement knobs! These have an internal white plastic insert with its own springy split. So I'm going to do like the Blue Guitar dude did, and make some inserts from steel shim to glue into the pot shaft slots converting them from split to solid fluted so they have some strength, then I'll order more of the new-style Peavey knobs instead of jamming in teflon tape or paper. Now I need to order more of the new style replacement knobs.

I find if I'm careful I can work on both sides of most of the main preamp and control circuit board without disconnecting the ribbon cables. I've heard of so many people with cracked ribbon cables I'm considering just replacing them with suple new ones on principle as a preventive measure, though mine seem fine if a bit stiff.

Getting a larger full-size 3-spring reverb tank with longer decay and the same input and output impedances was looking difficult, so I even considered paralleling different tanks with impedances to end up about the same, or duplicating the drive circuit or changing the resistors at the recovery circuit. But the simple solution was to order one from Accutronics in Korea directly. They answered my email the next day, and it looks like I'm getting an electrically exact replacement with my physical preferences.

I got a LOT of tweed tolex that matches the Peavey covering, for a better price than thru Peavey. The replacement handle arrived without the chrome mount ends; I wish they'd have mentioned that when I made my phone order.

The circuit board mounts on the old broken volume pot came out very easily with de-soldering wick.

Last edited by cyclecamper; 24th October 2012 at 09:00 PM.
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Old 30th October 2012, 11:33 PM   #49
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Yesterday I found a Peavey Classic 100 at Guitar Center, which is the more sensible way to upgrade my classic 50 for more clean headroom. But someone else bought it before I could. Another will come along when I have the cash to spend.. It's the same circuit, same boards, except it has 2 of the output boards, so it has 8 EL84's instead of 4 (and a bigger power transformer and output transformer). And I'll keep the 50 also. I wish I'd bought two of the upgrade reverb tanks; the shipping from Korea would have been about the same.
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Old 31st October 2012, 12:06 AM   #50
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Cyclecamper - you might get a kick out of this.....One off guitar amp 2
Bob
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