Vintage Newcomb G-12 amp

Discussion in 'Amp Central Station' started by pchilson, Jan 1, 2009.

  1. pchilson

    pchilson Friend of Leo's

    Age:
    61
    Aug 23, 2007
    Arkansas
    Hi,

    I have a shot at one of these but the guy is very unresponsive in replying to my emails asking for more photos and/or information. There doesn't seem to be much info to be found on the model, one review on HC.
    Anyone know of this amp and can add any thoughts?
    I don't have the opporutunity to see it in person at this time. If he still has it I may take a run at it next week.

    These are the pics he has posted of it. You can see why I've requested better closeup shots...
     

    Attached Files:

  2. pchilson

    pchilson Friend of Leo's

    Age:
    61
    Aug 23, 2007
    Arkansas
    No one has ever seen one of these?
    From what I've been able to piece together it has 2x6V6, 1x12AX7 and an unknown rectifier. Guess I'll have to see if I can go get a look. The guy hasn't even indicated if it is in working condition.
     
  3. guitarsavant

    guitarsavant NEW MEMBER!

    1
    Dec 2, 2008
    San Angelo Texas
    Try google. There is a web site that specializes in the Newcombs. They even bought out all the parts when the company went out of business and are recommended by the prvious owner of the company. I'll try and see if I still have the link but I'm not sure if I saved it. Seems like it was pretty easy to find from google.:)
     
  4. pchilson

    pchilson Friend of Leo's

    Age:
    61
    Aug 23, 2007
    Arkansas
    guitarsavant, I've been all over the web looking for info on this amp model. Precious few hits on Newcomb at all. There is one short review of this model on HC. I have not been able to locate any site resembling the one you are talking about. Would be great if you can find the link.

    I'm going to look at the amp today. Who knows what it turns out to be. All I've got is these teeny, far off shots of it. The guy literally responds to emails about once a week and then forgets what your questions were... I'll know this evening what it is.
     
  5. muchxs

    muchxs Doctor of Teleocity

    Aug 14, 2004
    New England
    Bring cash, bring good checks! :lol: Once it's yours you can study it at your leisure.

    It blows my mind the way so many of us live in virtual reality, it's all about the YouTube clips and the HC reviews. There ain't nuthin' like the real thing, baby! :lol:
     
  6. pchilson

    pchilson Friend of Leo's

    Age:
    61
    Aug 23, 2007
    Arkansas
    Oh, I have the cash and I have the time. The unit is not real local to me, thats why I asked the guy to take some decent closeup pics and give a bit more indepth description before I commit to the road trip. In this case I just have to make the trip because the guy just does not respond.

    It blows my mind that people post their items for sale and you have to pull their teeth to get them to actually respond to you. :neutral:
     
  7. pchilson

    pchilson Friend of Leo's

    Age:
    61
    Aug 23, 2007
    Arkansas
    muchxs, you seem to be very knowledgeable in these matters. Have you any experience with Newcomb? Ever had/worked on any?
     
  8. pchilson

    pchilson Friend of Leo's

    Age:
    61
    Aug 23, 2007
    Arkansas
    If I buy it I'll post up some good closeup pics inside and out.
     
  9. muchxs

    muchxs Doctor of Teleocity

    Aug 14, 2004
    New England
    I've got a couple old Newcomb P.A. amps. Yes, worked on them. Any of the old point to point stuff is the same old story, they're 50 year old amps so expect to do a cap job. It's a minor miracle that these work at all by now. If the one you're looking at is functional grab it but expect to do some work.

    Your little Newcomb is interesting. Those little Champ style amps are less common than the P.A. amps. A lot of the P.A. amps survived because they were expensive to begin with, they went into churches, bowling alleys, venues like that.

    Price-wise I'd be all smiles if I got that little amp for around $100. I wouldn't sell it for that if it were mine, then again if it were mine it would be 100% with fresh caps, a thorough going-over and a grounded AC cord.
     
  10. pchilson

    pchilson Friend of Leo's

    Age:
    61
    Aug 23, 2007
    Arkansas
    Thanks, I'll report back this evening.
     
  11. pchilson

    pchilson Friend of Leo's

    Age:
    61
    Aug 23, 2007
    Arkansas
    I bought the amp today

    It needs some work before its ready to play. There is no schematic with it. It was attached to the bottom plate of the chassis but that plate is missing. The amp is not in complete original condition. I suspect the OT has been changed at some point. The tubes are most likely not original, the speaker has been changed to one of the wrong ohm value. All other parts look like factory. No cap job has been done.
    All the caps are color banded caps. I need some guidance on figuring out the capacitor values. I'm also expecting to replace the output transformer as per the mismatch with the speaker stated above but I don't know how to test it for good or bad. Any help on that would be appreciated as well.

    I will post details as they come to me or as you ask. Thanks for your help on this one.


    [​IMG]

    Cap color bands - how do I read these?

    [​IMG]

    The tops of the two RCA 6V6GTs - whats the squiggly on the one tube?

    [​IMG]

    Is this some kind of code? only marking on the RCA 6V6s

    [​IMG]
     
  12. pchilson

    pchilson Friend of Leo's

    Age:
    61
    Aug 23, 2007
    Arkansas
    Some more pics

    of the amp.

    PT - only code I can find on it. Is this a manufacture code?

    [​IMG]

    Rear of the chassis

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    Front of the chassis

    [​IMG]

    chassis with the rear panel shroud attached

    [​IMG]
     
  13. pchilson

    pchilson Friend of Leo's

    Age:
    61
    Aug 23, 2007
    Arkansas
    Still more pics

    [​IMG]

    [​IMG]

    [​IMG]

    Someone drilled and installed another jack, its not wired to anything. I suspect they may have had a speaker out wired at one time.
    [​IMG]
     
  14. pchilson

    pchilson Friend of Leo's

    Age:
    61
    Aug 23, 2007
    Arkansas
    I'm figuring on a cap job and possibly OT. I'd like to put in a multi tap so I can have choice of speakers I have on hand.

    This is the lable on the OT thats installed. I can see it doesn't fit the original mounting holes. I have no way of knowing if this is even a correct spec for the amp. How would I test that or know what spec OT the amp should have?
    Anyone recognize the little logo on the left?

    [​IMG]

    [​IMG]
     
  15. eddiewagner

    eddiewagner Poster Extraordinaire

    Age:
    60
    Nov 6, 2005
    ROCK!linghausen/germany
    that is a pretty cool thing. i have no idea about it, but it looks good. if it would be mine, i would bring it to an amptech to take care of business.
     
  16. pchilson

    pchilson Friend of Leo's

    Age:
    61
    Aug 23, 2007
    Arkansas
    Forgot to add the tube compliment in the amp is:

    1 x 5Y3
    1 x 6SF5 (metal)
    1 x 6SC7 (metal)
    2 x 6V6GT

    10 to 12 watt output?
    Single ended or push/pull?
     
  17. muchxs

    muchxs Doctor of Teleocity

    Aug 14, 2004
    New England
    10kCT on your OT indicates push-pull. If the amp works the impedance mismatch didn't harm the OT. Any tweed Deluxe replacement OT will work, some are better than others. That's a matter of taste...

    If I remember correctly those red/red/orange/black caps are .022s unless I misplaced the decimal point. Go .022 @ 400v or 600v. Save the old ones. They're not Sprague "Bumble Bees" but they're still "Bumble Bees". They may leak by now at full operating voltage, used as tone caps in your Telecaster they won't know the difference. The big brown/black/yellows are .1s. That leaves the one odd one, not sure if that last band is brown or red, .01?

    http://www.tpub.com/neets/book2/3g.htm

    You'll want to check that can cap on top of the chassis. 50 year old coupling caps are sometimes in surprisingly good condition. 50 year old electrolytics are more surprising when they're o.k., frequently... they're not.

    That scribble on top of the mica in your tube is a magic marker mark written on there by a worker at RCA around 50 years ago! Almost cave art... :lol:

    Big grey PT... The advanced program is to probe 5Y3 Pin 2 or Pin 8 referenced to ground (whichever one connects to the cap can) and see what your B+ is. BE CAREFUL! I'm going to abbreviate the usual safety warning and just say that if you don't know what your doing don't poke around in there. Judging by size alone I'd say that transformer is adequate, I'd be interested to see what the high voltage actually is. Over 400 volts is generally a bad idea for 6V6s.
     
  18. Jahmbie

    Jahmbie Tele-Afflicted

    Nov 19, 2008
    College Station, TX
    Nice find there! This looks like a very tweed deluxe like amp. I'm with getting it recapped and a multi-tap OT. If you got this for under $200 then the amp gods are smiling on you, my friend.
     
  19. pchilson

    pchilson Friend of Leo's

    Age:
    61
    Aug 23, 2007
    Arkansas
    Thanks guys!
    Took the tubes in today and put them on the tester. All were good except the 6SC7 which had a short. Now to find a replacement and see if the amp works fully.
     
  20. ThermionicScott

    ThermionicScott Poster Extraordinaire

    Age:
    38
    Dec 3, 2005
    SW CR IA US NA PE
    That's a cool amp. The 10KΩ/10W output transformer would be just right if you're running 250V on the plates: http://tdsl.duncanamps.com/show.php?des=6V6GT

    My vote would be to roll with the iron you have, if the speaker is 4Ω. :cool:

    - Scott
     
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