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Asher Guitars WD Music Products Amplified Parts Mod Kits DIY Nordstarnd Pickups Warmoth.com
Asher Guitars WD Music Products Amplified Parts Mod Kits DIY Nordstarnd Pickups Warmoth.com

NAD - 1966 Ampeg GS-12R

Discussion in 'Glowing Bottle Tube Amp Forum' started by -Hawk-, Sep 21, 2017.

  1. -Hawk-

    -Hawk- Tele-Afflicted

    Oct 14, 2015
    IL, USA
    Made a thread asking some questions about this amp not too long and want to thank all of those that responded for their help. It almost convinced me to pass on the amp, but I decided I should at least go talk to the guy, play it, and make an offer if I wanted it.

    The story is the guy bought it in 1981 as part of a package deal. He was buying an old cream Les Paul Custom and the seller offered to throw in the amp for an extra $50. At some point he had a 3-prong added. It mostly sat unplayed since it didn't really match his preference for heavy rock/metal tones.

    Best guess is that it's a 1966 based on tube layout.

    It was listed for $400, which seemed like a reasonable price to me. Reverb sales go from about that range up to the $700's. I did get a chance to check it out as thoroughly as possible without taking it apart and got to play it. Probably a healthy dose of mojo dust clouding my brain here, but it sounded freaking great. Trem was nice. Reverb was lush and wonderful. Full sounding tone that really pulled my strings. So, getting to the point - I really wanted.

    Explained to the guy that I loved it, but also that it was at best a player grade amp and I was going to have to invest a few hundred into it to get it into giggable condition. Offered him $300 for it, along with the opportunity to wait and see if he could get a better price from someone else. Apparently he hasn't even got another inquiry in the few weeks it was for sale. He said that he felt it should be played and if I was planning on gigging it he'd sell it for that price. So, I feel like I got a great deal!

    Placing some calls today to check on a cap job. Going to try to find someone with Ampeg experience. I'd love to do it myself and feel like I'd have the ability to do it with a little help, but nobody around here to show me.

    I need to get a toothbrush and some goo-gone to see if I can clean it up a bit. I've heard the diamond covering is a pain to clean.

    Fliptops.com has a period correct handle that I'll be picking up. Likely will replace the speaker with a C Rex I have to avoid damaging the one that's in there. No clue if it's original. I may explore replacing the tolex, but no hurry there.

    Again, thanks everyone that helped with my research. This is my first vintage anything and I'm pretty excited.

    Some pics!

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  2. Kerberos

    Kerberos Tele-Meister

    Age:
    67
    359
    Nov 27, 2016
    Long Island
    How cool! Bet it sounds great! Enjoy, make some noise!
     
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  3. theprofessor

    theprofessor Tele-Afflicted

    Aug 8, 2016
    Chattanooga, TN
    That sounds like a fantastic deal to me! Congratulations!
     
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  4. AlabamaOutlaw

    AlabamaOutlaw Tele-Meister

    411
    Feb 20, 2011
    Alabama
    That's one wicked cool amp and total score in my book!! Enjoy!!
     
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  5. jimytheassassin

    jimytheassassin TDPRI Member

    Age:
    39
    28
    Apr 29, 2016
    Oneida, NY
    First, Congrats! It looks pretty damn good for a 50 year old amp. :) I love these old Ampegs and have a couple here in my arsenal right now. 1965 Rocket II, and 1967 Gemini II.

    On yours a cap job is right where you should start, so kudos there. The "cap can" looks to me to be a replacement, and also to have been siliconed instead of mounted more correctly on a cap can mounting insulator. The three prong plug is a bonus, but it will be interesting to see what work was done on the inside previously (for the tech that works on this). It's safe to say, updating the electrolytic caps are a good idea anyways since you say this hasn't been played in a long time (seeing yours, chances are good they've already been replaced once). Find a tech who will do only the work necessary, and not one that will gut it unnecessarily. Have them keep aside what's replaced.

    The gap between the chassis and the cabinet is normal and easy to correct. Pull the back panel off, and push the bottom of the chassis forward. You may need to lift carefully with the other hand, from underneath at the front while you push. I suppose before this you could check and make sure the chassis mount screws are seated. They were usually screwed in at an angle, on the top lip of the chassis, under the cabinet top
     
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  6. Anode100

    Anode100 Friend of Leo's

    May 9, 2014
    Behind my beard.
    Nice!

    Looks like a great slice of vintage goodness!
     
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  7. Bob M

    Bob M Tele-Holic

    652
    May 11, 2011
    North of Boston
    Great score. I've got a '66 Jet and a '65 Reverberocket 2. They'll hang in there with a Fender BF DR or PR.
     
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  8. -Hawk-

    -Hawk- Tele-Afflicted

    Oct 14, 2015
    IL, USA
    Thanks all!

    They are cool, aren't they? What is even cooler is that they are out there selling for a fraction of what Fenders from that era do. I'm sure there's a good reason for that, but in terms of sound I have to say it's got something really nice going on.

    Excellent- always impressed with the knowledge here! I was wondering about the cap can. I wonder if you can even find a replacement these days or if they'll do it differently. I'm going to venture a guess that if it was replaced, it was done when the cord was installed. He didn't remember the time frame on that, which is understandable considering it was over 35 years ago when he acquired the amp.

    I definitely want the bare minimum done, mainly because I don't want to change the sound.

    I'll try that on the chassis. Seems I've heard they aren't the easiest to get in/out and maybe whoever put in there just didn't have patience to get it right. It's kind of soft, meaning I can push it from the front and it has a little bit of play to it.
     
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  9. Bob M

    Bob M Tele-Holic

    652
    May 11, 2011
    North of Boston
    Be careful with the chassis. They are kind of flimsy.
     
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  10. -Hawk-

    -Hawk- Tele-Afflicted

    Oct 14, 2015
    IL, USA
    Ok I'll keep that in mind - thanks!

    Now to find a bit that fits the screws. I think I have one.
     

  11. WineCaster

    WineCaster Tele-Meister

    379
    Jul 12, 2012
    Oshkosh, Wisconsin
    Cool! I just won one of these on eBay and amp waiting for the seller to ship. Let the good people of the world know any tips or quirks of these amps.
     
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  12. -Hawk-

    -Hawk- Tele-Afflicted

    Oct 14, 2015
    IL, USA
    Nice! One thing I know is that if you turn the Tremolo intensity all the way CW it clicks and there is a wild stutter effect.
     

  13. jimytheassassin

    jimytheassassin TDPRI Member

    Age:
    39
    28
    Apr 29, 2016
    Oneida, NY
    Replacement Cap Cans are still available today. 70/40/40 3 section 450volt caps The wisdom I've gained says however, the volt ratings should be increased on the capacitor, because line voltage has increased in many places and situations since the 1960s. A small change in line voltage supply, can make a bigger difference in B+ voltage being delivered by the capacitors... potentially reaching a tolerance you don't want to exceed. As you mention Fliptops.net, they spec the same replacement value for your amp, but their cap is a few dollars more. I just ordered a replacement for my Gemini II (from www.tubesandmore.com), but got one with increased voltage rating because it was available. In your case, this looks to be the best choice for replacement right now. Otherwise, you would have to compromise somewhere to get the extra voltage headroom, by way of different cap values, or different style capacitors.

    As to they're being affordable..shhhhhh. :)

    oh and to get the chassis out, the trick is to push on the top front (right side then left, rinse repeat) as you receive it out the back. get ready to support the transformer if you do.. I usually grab that and hold it.
     

  14. -Hawk-

    -Hawk- Tele-Afflicted

    Oct 14, 2015
    IL, USA
    Ha! The last part is certainly is a mystery.

    So you think the cap you listed is my best choice of what's available or look for something with a higher volt rating? If the latter, what rating? I appreciate the advice very much.
     
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  15. boredguy6060

    boredguy6060 Friend of Leo's

    Mar 28, 2012
    Sou Cal
    That's a great catch at a crazy good price!
    Bravo
     
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  16. jimytheassassin

    jimytheassassin TDPRI Member

    Age:
    39
    28
    Apr 29, 2016
    Oneida, NY
    A quick search shows this part I listed to be the most compatible. CE is one of the only cap can makers I know of, but I suppose there could be others. Fliptops has theirs made for them, by MIEC. I'll say this about voltage, I really don't know if it's necessary in your amp to worry about this (it was just a passing thought for future Ampegs!). The voltages listed on the schematic for you amp, top out at 356volts, with 117 line volts. Besides that line volts can vary, well so can your internal components. Increase line voltage to 125, and your supply hits 400volts. You're still within tolerances.

    By the way, hopefully you still have a schematic pasted to the back panel. if not, here's a link, one of many on the net, to a schematic http://www.kbapps.com/audio/schematics/tubeamps/ampeg/gs12r.php
     
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  17. -Hawk-

    -Hawk- Tele-Afflicted

    Oct 14, 2015
    IL, USA
    Great info - thanks again! I may source a few of these parts ahead of time to avoid overpaying at the shop.
     
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  18. jimytheassassin

    jimytheassassin TDPRI Member

    Age:
    39
    28
    Apr 29, 2016
    Oneida, NY
    I'll just repeat what i've been told in the past. Look to replace Filter caps (70/40/40 and 20/20 in your amp), Bias supply capacitors (25/25v) and resistor (140ohm 10 Watt), possibly your filter capacitor resistors, and the rectifier diodes for safe measure. A tech can advise you of their condition of course. Any resistor within 20%+/- does not necessarily need to be replaced, but it depends on where it is also (anything in the signal path is probably fine to leave, so long as the amp still sounds good). Fliptops has a kit, minus the resistors and diodes, for $68. So you can ball park where this is going
     
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  19. -Hawk-

    -Hawk- Tele-Afflicted

    Oct 14, 2015
    IL, USA
    Perfect! Ideally I'll get it up and going as soon as possible.
     

  20. slider313

    slider313 Tele-Holic

    Age:
    60
    916
    Jan 6, 2011
    NC
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