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 Post subject: Newcomb Amplifier / Ultra Tone 1C3
PostPosted: Jul Mon 23, 2018 9:00 am 
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Joined: Mar Mon 26, 2018 7:20 am
Posts: 7
I have recently aquired a film amplifier, name on it is Newcomb Amplifier / Ultra Tone.
It for sure needs tons of work, but it has a great patina.
Valve line up is on the left - 5y3 rectifier - Plug in module of 3 10μF caps, two 6L6 tubes ( outputs ) then 3 x 6J7 tubes ( pre amps ).
These numbers are printed on the valve bases.
It has a tone control (left), channel - 2 (mike 2), channel - 1 (phono/mike - 1).
This is an American origin amplifier I.E. -120V.
Still got many original components in it.
Does anybody have a circuit diagram
Or maybe something simuliar ?


thanks for your help .
dmxtothemax.live.com.au


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 Post subject: Re: Newcomb Amplifier / Ultra Tone 1C3
PostPosted: Jul Mon 23, 2018 5:08 pm 
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Location: alameda,CA
Newcomb primarily made stuff for schools and auditoriums. They aren't super high end but more or less built like tanks and fairly basic. Basic enough to where you could just replace the caps and be fine. Values should be marked on everything inside so just replace like with like. You can't get the multi-section electrolytics anymore so just replace each section with individual capacitors. It should make a nice, reliable machine when done.


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 Post subject: Re: Newcomb Amplifier / Ultra Tone 1C3
PostPosted: Jul Mon 23, 2018 5:22 pm 
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Location: Mountains of Mourne. Ireland.
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https://www.ebay.com/sch/i.html?_from=R ... Complete=1

You might have to wing it without a schematic... :)

Greg.


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 Post subject: Re: Newcomb Amplifier / Ultra Tone 1C3
PostPosted: Jul Mon 23, 2018 6:18 pm 
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Location: Fernandina Beach, FL
Sure that the outputs are 6L6? They appear to be 6V6 unless amplifier in the picture has the wrong output tubes.

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Don


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 Post subject: Re: Newcomb Amplifier / Ultra Tone 1C3
PostPosted: Jul Tue 24, 2018 10:53 pm 
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Joined: Jan Thu 01, 1970 1:00 am
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Location: Boston, MA USA
I don't think a 5Y3 rectifier will run 6L6s. So if the 5Y3 is correct then the output tubes are probably 6V6s as Don says.

-David


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 Post subject: Re: Newcomb Amplifier / Ultra Tone 1C3
PostPosted: Jul Wed 25, 2018 4:54 am 
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Location: Thornhill, Ontario, Canada
dberman51 wrote:
I don't think a 5Y3 rectifier will run 6L6s. So if the 5Y3 is correct then the output tubes are probably 6V6s as Don says. David
Agree, PT looks small, too... so, 6V6s. Should be an easy fix. Check the transformers before committing to serious restoration work (PT: winding continuity, no short to core/ground, no-heating when powered up with all tubes out, no-load voltages correct. Then, with 5Y3 out: check it heats tubes OK), OPT: continuity in both halves of the primary and no short to core/ground.) Of course, replace all electrolytics before any B+ is applied, also all wax paper caps (don't keep any!) with film caps.
Good luck,
Cheers,
Roger

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Roger Jones,
Thornhill, Ontario
Ontario Vintage Radio Assoc. http://www.ovra.ca


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 Post subject: Re: Newcomb Amplifier / Ultra Tone 1C3
PostPosted: Jul Wed 25, 2018 9:12 am 
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Joined: Mar Mon 26, 2018 7:20 am
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that picture does show the actual unit involved.
Many of the tubes in it are wrong as you have already picked up
it has 6L6's in it, but 6V6's are correct
they are on order now.
And the rectifier in it was 5Y4 not the correct 5Y3
result burned out 5v winding as 5Y4 uses 3A not the 2A a 5Y3 uses
But I think I can find a 5V tranny somewhere
Because the other windings seem ok

the pots missing on one of the inputs and the wires are off the tone control
there are other wiring just hanging under neith the chassis
A circuit would speed things up a heap
But I suppose I could wing it using simulair circuits
so something similair would also help.
thanks


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 Post subject: Re: Newcomb Amplifier / Ultra Tone 1C3
PostPosted: Jul Wed 25, 2018 8:30 pm 
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Joined: Jan Thu 01, 1970 1:00 am
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Location: Boston, MA USA
Are you really sure you want to put so much effort and $$$ into a common 10 watt PA amplifier? There are lots of amplifiers around of higher quality in better condition.

-David


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 Post subject: Re: Newcomb Amplifier / Ultra Tone 1C3
PostPosted: Jul Fri 27, 2018 4:10 am 
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Location: Thornhill, Ontario, Canada
dberman51 wrote:
Are you really sure you want to put so much effort and $$$ into a common 10 watt PA amplifier? There are lots of amplifiers around of higher quality in better condition. David
Agree. There are better amplifiers to spend time on.
Cheers,
Roger

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Roger Jones,
Thornhill, Ontario
Ontario Vintage Radio Assoc. http://www.ovra.ca


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 Post subject: Re: Newcomb Amplifier / Ultra Tone 1C3
PostPosted: Aug Mon 06, 2018 7:57 am 
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Joined: Mar Mon 26, 2018 7:20 am
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I like the patina of some of these old amps,
Happy to spend the time and money on them,
Keeps me out of mischeif.
mostly !


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 Post subject: Re: Newcomb Amplifier / Ultra Tone 1C3
PostPosted: Aug Tue 07, 2018 2:57 am 
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Location: Tucson, Arizona U.S.A.
The photo doesn't show any 6J7 tubes either. Does your unit have wires for the top caps? If not, those tubes are wrong too.

A 5Y4 won't burn out the transformer because the filament current is 2A, not 3. Unless the socket was rewired, it won't do anything at all since the pin connections are different. Perhaps you mean 5U4?

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Jim Mueller


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