Univox U305R ... May Have Been Played By Elvis!

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Actually, I'm really interested in how this turns out, now that you're replacing the caps. I wonder how significant the tonal change will be.
 

capnjuan

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Default said:
Actually, I'm really interested in how this turns out, now that you're replacing the caps. I wonder how significant the tonal change will be.
It's going to be week before the new ones get here ... it's such an oddball design; if you look back in this thread ... I've never seen another schematic with electrolytics in the phase inverter ... If i can find something within range, I'm going to bypass the dud and fire it up again. I'd like to know something about what it sounded like before too ... and if there's anything else out of whack. All of the coupling/blocking caps will be Mallory 150s, Sprague and Illinois ... whoever has the spec values for the other electrolytics. The amp passes a signal ... nasty ... but it passes one. It was running when I bought it and again when I found the footswitch. One of the reverb pots wasn't working correctly although I've hosed a fair amount of crud out of them ... I have replacements but I'm hoping the originals are okay. It came fitted with Sylvania 7591s but I have a pair of matched/used TungSols ... expecting something like the Guild Maverick Lead; cleanish, sparkly, 6L6-style sound.
 

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IIRC, all of the 7591's were sylvania made and rebranded, but I'm unable to remember where I read that.
 

capnjuan

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Default said:
IIRC, all of the 7591's were sylvania made and rebranded, but I'm unable to remember where I read that.
I think I read the same thing ... but here's hoping ... I have a matched pair of NOS Sylvania JAN 6V6s that ... well ... they might last forever. But if they do, they'll do it without ever once sounding sweet and pleasant. Let's hope the made they made the 7591s on a different machine! J
 

capnjuan

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PhillySteve said:
Sheesh Juan, you ought to try lookin' at the 7591s before you post ... or get some of that Memory-Aide ... :p :wink:
:oops: They are Sylvanias ... bought in July/August in the midst of my tube-O-thon ... confused them w/ the 7408s which are TungSols. :mrgreen:
 

capnjuan

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Progress Pics: ... almost done ... whew! The pic below top L to R, shows the blown oil-filled cap, the space and leads sticking up, and, at a different angle, the leads turned down into hooks. Along the bottom L to R, the replacement cap's leads bent under the hooks, trimmed and snugged, and soldered on the right:

capfix.jpg



Repeat steps above another 17 times ... two more to go, far left, small, lavender cylinders:

chassisfullend.jpg


Waiting on the two small caps and two more Mallories (the yellow ones) that turned out to be the wrong value. The cabinet has been cleaned with TSP and got a coat of Nu-Finish; automotive, silicon-based cleaner like Turtle Wax. Then it all goes back in the cabinet, reverb can it its bag, re-mount / connect 15" speaker, tube it up, and power it up ... see what all the fuss is with 7591s!

My calls to Tom Petty's NY agent are not getting returned ... I guess it was that drink I spilled on the Tom last time I was on his plane or maybe barfing on his rug in Malibu ... or this thread ... who knows.
 
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