Hoffman Amplifiers Tube Amplifier Forum
Amp Stuff => Tube Amp Building - Tweaks - Repairs => Topic started by: plexi50 on October 20, 2023, 08:39:27 am
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Here's another amp that i cant find any images of.It says Supro Chicago 51. Yes the Spookie Field Coil Speaker!
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Where does it say Supro? Look up Valco Chicago 51 instead. Valco made Supro amps, but also other brands as well.
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Supro
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Ok im seeing it now. Looks like someone removed the original cloth that covered the amp and were seeing bare stained wood i think. Thats why there are no black vertical lines running across the cabinet, speaker area.
I found this video! Lucky! &t=37s
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Here's another amp that i cant find any images of.It says Supro Chicago 51. Yes the Spookie Field Coil Speaker!
That's not a field coil speaker.
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Here's another amp that i cant find any images of.It says Supro Chicago 51. Yes the Spookie Field Coil Speaker!
That's not a field coil speaker.
Yeah your right. I got ahead of myself when i saw the transformer mounted on the speaker.
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It's the OT
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Valco put "Chicago 51" on many amps of that era. Its not really a model number - its where they were made. 51 was the postal code for Chicago before zip codes.
I think that amp is a transition model from the amps with a 6SL7 input, commonly call Comet and Spectator.
I suspect this National 1210 might be the closest schematic, as it has a 12V preamp tube and a tone control. https://el34world.com/charts/Schematics/files/Valco/Valco_1958national1210.jpg (https://el34world.com/charts/Schematics/files/Valco/Valco_1958national1210.jpg)
Valco made basically the same amps under the names Valco, Supro, National, Gretsch, Oahu and others during that period. I have one labelled "Loney" which was a large music store and school in Chicago.
Very cool amp - Champ like, but different enough.
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Nice amp!
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I suspect this National 1210 might be the closest schematic, as it has a 12V preamp tube and a tone control. https://el34world.com/charts/Schematics/files/Valco/Valco_1958national1210.jpg (https://el34world.com/charts/Schematics/files/Valco/Valco_1958national1210.jpg)
That tone control wiring looks wrong to me.
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Valco put "Chicago 51" on many amps of that era. Its not really a model number - its where they were made.
You also find that text on toolboxes.
And there was a mass-murder "The Chicago 51". "51 women murdered, 0 answers"
One innernet punter claims zone 51 became ZIP 60651, which sounds plausible. Today that is here:
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And there was a mass-murder "The Chicago 51". "51 women murdered, 0 answers"
The guy who made it was a gangster from Chicago who obviously went by the nickname of ‘Chicago’ - and he had a thing about the number 51.
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Catalog: https://jedistar.com/valco-2/
The zone 51 location may be this place. Certainly right vintage and form. See how you can call the bricklayers and set it up as 1, 2, or 3 shops or whutever.
4700 W. Walton St., Chicago 51, Ill
Another stray hit gave 2717 N Normandy which is newer, very 1947 (note twin pipe columns), and may be where VALCo moved to in the 1960s.
2717 N Normandy Ave, Chicago, IL 60707
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That tone control wiring looks wrong to me
I've seen that tone control on some other Valco schematics - have tried it and found that it does little or nothing, and changed it to a known single knob control.
The gangster 51 stuff is chilling.
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was a gangster from Chicago
I had a side gig working at the 4-watt shop. The owner would give me a wad of cash, and order sheet, his ford truck and I'd make the run from Grayslake IL to a zip code just East of PRR's map, back the truck up to a red brick with loading dock, hand over the cash, they'd load me up with CB's, Antennas...Got my orders from the Navy for my final school, Art offered me $22k, (I was getting $5k Gov-pay), the truck and I'd run the store, he was mafia, didn't like being told no :icon_biggrin:
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That tone control wiring looks wrong to me
I've seen that tone control on some other Valco schematics - have tried it and found that it does little or nothing, and changed it to a known single knob control.
Turning that tone pot all the way down mutes the signal. I suspect the schematic is wrong and probably should look more like this...