Sometimes life is good!!
My sweety calls me on the phone yesterday from a garage sale,
AND
Hun> " Hun? Im at this garage sale and theres one of those amplifer thingies like you have in the garage here,, It has Tubes and its heavy, Want It?? "
Me> " Whats it look like? How Much?? Does it have speakers?? "
Hun> "The garage sale guys laughing at me because I can barely lift it to flip it over to see in the back. He says $5.00 he will take $5.00 "
Me> " Can you describe it a little more? "
>Hun " Its black, It has handles on it, lots of knobs and It has tubes, Should I bring it home?? I offered him $3.00 But he is insisting on $5.00 "
>Me " YES, Buy It "
Hours later, My Gal is home(power garage saler)
Hey, You can get that heavy thing outta the trunk of my Pt Cruiser, I lugged it here!!
Oh My,
A 1971 maybe 1972 UNIVOX U1511 150W Head Only ! Sadly, The Quad of 6550's are missing
But, Still has All the original 12AX7's as well as the 12AU7's And a 6AN8 ALL Mullards.
Has Me thinking, I have a couple nice quads of el34's here, The 6550's are fairly expensive, How Hard can it be to Mod it for el34s?,
I found SOME info Here on the Amp History UNIVOX
1511 - same as 1011 except with 4 6550 and 150W output.
OK the 1011 uses 6L6's
1010/1011 (1) ($605) - separate w/ 10 tubes, 105 W, 2 channels, 4 inputs, bright and normal for each channel, volume for each channel , bass, middle and treble shared on both. presence, reverb, tremolo speed and intensity, variable impedence (8/16ohm) and a cabinet w/ 8 10" Univox Special Design speakers. Volume for channel one also had "Pull HB", a brightness/boost selector. Also has a 2-4-6 ohm switch on the back, as well as 4 separate speaker outputs, and two foot switch inputs. The handles are located on top of the head. The 1010 came with the 1011 (amp) and the 2080 (cab).
Any Advice would be helpful.
Gene
My sweety calls me on the phone yesterday from a garage sale,
AND
Hun> " Hun? Im at this garage sale and theres one of those amplifer thingies like you have in the garage here,, It has Tubes and its heavy, Want It?? "
Me> " Whats it look like? How Much?? Does it have speakers?? "
Hun> "The garage sale guys laughing at me because I can barely lift it to flip it over to see in the back. He says $5.00 he will take $5.00 "
Me> " Can you describe it a little more? "
>Hun " Its black, It has handles on it, lots of knobs and It has tubes, Should I bring it home?? I offered him $3.00 But he is insisting on $5.00 "
>Me " YES, Buy It "
Hours later, My Gal is home(power garage saler)
Hey, You can get that heavy thing outta the trunk of my Pt Cruiser, I lugged it here!!
Oh My,
A 1971 maybe 1972 UNIVOX U1511 150W Head Only ! Sadly, The Quad of 6550's are missing
But, Still has All the original 12AX7's as well as the 12AU7's And a 6AN8 ALL Mullards.Has Me thinking, I have a couple nice quads of el34's here, The 6550's are fairly expensive, How Hard can it be to Mod it for el34s?,
I found SOME info Here on the Amp History UNIVOX
1511 - same as 1011 except with 4 6550 and 150W output.
OK the 1011 uses 6L6's
1010/1011 (1) ($605) - separate w/ 10 tubes, 105 W, 2 channels, 4 inputs, bright and normal for each channel, volume for each channel , bass, middle and treble shared on both. presence, reverb, tremolo speed and intensity, variable impedence (8/16ohm) and a cabinet w/ 8 10" Univox Special Design speakers. Volume for channel one also had "Pull HB", a brightness/boost selector. Also has a 2-4-6 ohm switch on the back, as well as 4 separate speaker outputs, and two foot switch inputs. The handles are located on top of the head. The 1010 came with the 1011 (amp) and the 2080 (cab).
Any Advice would be helpful.
Gene
No advice, just a comment. Whenever I ask my wife to describe something the very first word out of her mouth is the color of the thing regardless of what it is.
Last fall when she was looking to get a new car I asked her what kinds she was interested in. Her answer- "A blue one with a camel interior."
Last fall when she was looking to get a new car I asked her what kinds she was interested in. Her answer- "A blue one with a camel interior."
Sherman said:No advice, just a comment. Whenever I ask my wife to describe something the very first word out of her mouth is the color of the thing regardless of what it is.
Last fall when she was looking to get a new car I asked her what kinds she was interested in. Her answer- "A blue one with a camel interior."
Oh, and she forgot to tell you that it has one or two humps?
The Butcher
Sherman said:No advice, just a comment. Whenever I ask my wife to describe something the very first word out of her mouth is the color of the thing regardless of what it is.
Last fall when she was looking to get a new car I asked her what kinds she was interested in. Her answer- "A blue one with a camel interior."
HAHAHA,
Mine just read the post,, She thinks im picking on her but laughing!!
Gene
A quad of 6550s for 150W would be either class B ultralinear with tons of feedback or very high plate voltages.
In both cases I would not replace them with EL34s. They would sound awful (for deeper class B operation because of reduced max plate dissipation) or just c**p out (for too high voltage, maybe on the screen).
What about a single couple of 6550, and a mod to the impedance selector of the OT? You should save a few bucks... and have a 60/70W. you aren't gonna need 150W for your guitar.
Bye! you're lucky (to have a wife that would carry a heavy dirty tube amp head to home, and to have found a tube head for 5$).
In both cases I would not replace them with EL34s. They would sound awful (for deeper class B operation because of reduced max plate dissipation) or just c**p out (for too high voltage, maybe on the screen).
What about a single couple of 6550, and a mod to the impedance selector of the OT? You should save a few bucks... and have a 60/70W. you aren't gonna need 150W for your guitar.
Bye! you're lucky (to have a wife that would carry a heavy dirty tube amp head to home, and to have found a tube head for 5$).
jlsem said:
I think Im going to head in that Direction, I have a seymour duncan convertable 100w with a quad of el34s, A Homebrew PP 6V6st setup about done. Guess by then I'll be ready for a restore job.
I still have as of yet to put any meters on the Univox to check it out. I do know at this point the output tube sockets will most likely need replaced (less than pretty) And Im sure the caps should be done.
One thing nice( And not so nice) was the layout underneath, Easy socket access/not so nice printed circuit for the rest.
Heres a Peek
An externally hosted image should be here but it was not working when we last tested it.
Funny,, I look at the filament wiring and now wonder why my 6V6 project was picked on LOL.
Gene
After searching for a while, And checking a few forums,
It is the general concensus that the U1511 is basically a beefed up version of the U1011 And notice the photo above shows in fact, It does utilize the same basic circuit board, Though Im certain there were vastly different componet values .
But Me Still wonder about going to EL34's
Only because I have them .
Gene
It is the general concensus that the U1511 is basically a beefed up version of the U1011 And notice the photo above shows in fact, It does utilize the same basic circuit board, Though Im certain there were vastly different componet values .
But Me Still wonder about going to EL34's
Only because I have them .
Gene
If yu pull two tubes, all you do to get the impedance right is use the next lower impedance output - plug the 8 ohm load into the 4 ohm jack. This is done all the time in guitar amps.
I Googled the model and found forums.univox.org I didn't go there, but it has possibilities for you.
I'd stick with all four tubes. Remember, this is a guitar amp, not a stereo. Guitar amps routinely exceed data sheet specs on tubes. We don't expect the tubes to last years, and we are not going for zero distortion.
I Googled the model and found forums.univox.org I didn't go there, but it has possibilities for you.
I'd stick with all four tubes. Remember, this is a guitar amp, not a stereo. Guitar amps routinely exceed data sheet specs on tubes. We don't expect the tubes to last years, and we are not going for zero distortion.
Im Back,
I had actually already signed up at univox.org. I posted there in hopes of finding the actual schematic for the U1511. I had located the U1011 elsewhere.
It appears that I would have better luck taking photos of Bigfoot while camping in central park NY than finding the U1511 schematic.
One fellow Said the following as far as converting to more common less expensive el34's
: Hi Gene,Converting a Marshall with 6550s to EL34s is done by decreasing the bias voltage range of about 10 volts to adjust the bias properly for the EL34. This is done by changing 1 or 2 resistors in the bias circuit. Also, the feedback resistor should be connected to the 8 ohms leg of the output transformer instead of the 4 ohms leg. I think it should be the same in a Univox. Unfortunately, the U1511 schematics doesn't seems to be in the archives. You would have to draw a small schematics of the bias and output section.
A search on this forum revealed a rough draft of part of the output stage.
old post
gene
I had actually already signed up at univox.org. I posted there in hopes of finding the actual schematic for the U1511. I had located the U1011 elsewhere.
It appears that I would have better luck taking photos of Bigfoot while camping in central park NY than finding the U1511 schematic.
One fellow Said the following as far as converting to more common less expensive el34's
: Hi Gene,Converting a Marshall with 6550s to EL34s is done by decreasing the bias voltage range of about 10 volts to adjust the bias properly for the EL34. This is done by changing 1 or 2 resistors in the bias circuit. Also, the feedback resistor should be connected to the 8 ohms leg of the output transformer instead of the 4 ohms leg. I think it should be the same in a Univox. Unfortunately, the U1511 schematics doesn't seems to be in the archives. You would have to draw a small schematics of the bias and output section.
A search on this forum revealed a rough draft of part of the output stage.
old post
gene
Surely the cost of four 6550s is nothing compared to the candlelit dinner for two that you need to pay for as a thank you for your wife's selfless devotion at attempting to knock the seller down from an already silly price to an even sillier one? Oh, and thinking to tell you before someone else leapt in and bought it first. And bringing it home.
It's worth it...
Just think, what's she going to do next time she sees a bargain amplifier? Is she going to think, "he has too many of those ugly brutes already" or is she going to think, "last time I found one of these, we ended up with a romantic evening"?
Glad to hear you found some 6550s.
Just think, what's she going to do next time she sees a bargain amplifier? Is she going to think, "he has too many of those ugly brutes already" or is she going to think, "last time I found one of these, we ended up with a romantic evening"?
Glad to hear you found some 6550s.
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