Ampeg Jet: any lover?

Discussion in 'Ampage Area' started by stiv, Mar 9, 2017.

  1. stiv

    stiv Country Gent

    Sep 12, 2014
    Florence, Italy
    Hello,
    I've been offered a '61 Ampeg Jet J12-D. The amp it's in good conditions, doesn't have the original 12" speaker but a '70s jensen replacement, otherwise it looks pretty original (apart from the leather handle). It even has original GE tubes.
    I'm looking for some low wattage amp to play small gigs or use for studio recordings, that could be cranked for some gutsy overdrive on tap while at decent volumes (I already have an early 80's champ which it's just 5w that sounds good but it's not really enough for me...) to hold his own on a small club.
    I was originally looking for something like a Princeton Reverb or a Deluxe Reverb (although it's 22w, the J12-D it's 15w and it makes a lot of difference), but this Ampeg seems like a good deal.
    Any of you guys plays/have/have had some vintage Ampeg? This one doesn't have a reverb, but it comes with a vibrato (kind of different from the fender ones though, as it doesn't have speed control...).
    I'd really love to hear what you guys think. I've always had pretty good reviews about vintage Ampegs (Jets and Reverbrockets, although it was more for the clean sound than the cranked up sound..), but never owned one so I couldn't tell... Could you compare the J12-D to some kind of Fenderish sound?

    Thanks.
     
  2. Andy Fortune

    Andy Fortune Gretschie

    269
    May 24, 2016
    Corning, NY
    Great amp, but make sure you locate and price out those 6BK11 preamp tubes before you commit. Personally, I love the 6SL7 octal preamp Ampegs the best.
     
  3. hcsterg

    hcsterg Country Gent

    Feb 13, 2012
    France
    Here's my experience, stiv :

    I had for repair an Ampeg JET J12-D from the early 60s.
    Tubes = 2x6BK11 original from Sylvania and 2X7591S from JJ.
    Spkr = replacement Eminence, unknown, ceramic, similar to a Legend 1218 in size.

    The output transformer was blown.
    The JJtubes were blown too - and I suspect them to hold some responsibilities in the damage of the transformer.
    I replaced the output transformer with a Hammond replacement for Fender Deluxe Reverb.
    I removed the NFB loop, finding that the amp sounded better without it (more gain, smoother crunch, more compression).
    I replaced the PSU circuit (capacitors, diodes, resistors) and the 7591 cathode bias and grid feed circuits.

    This amp sounds killer, his major interest is to be played from light overdrive to fully cranked, more than played clean, where nonetheless he gives a good sound too. The tremolo is excellent, even if it tends to throb / thump when the amp is at high settings.

    So where's the 1st problem ? The JJ 7591S power tubes = they are not reliable.

    We changed 3 times the tubes in less than one year, every set died from interelectrode leaks or shorts.
    Even when reducing a bit the idle current (which was somewhat hot, even for the 60s) there was no improvement in reliability : it is a matter of tube quality manufacture and sorting at JJ, the amp circuit hadn't any responsibility anymore.

    It's not the 1st time that I notice quality problems on JJ 6L6GC 6CA7§EL34 7591 power tubes. So be prepared to have some issues with the 7591S from JJ... Unless you opt for another brand, if you can find that rare reference model.

    And where's the 2nd problem ? The JJ 7591S vs. the magnet of the loudspeaker = there's a magnetic interaction which provoke hum, due to the big size of the (non original) speaker magnet and its closeness to the JJ 7591, which appears to be very magnetic sensitive... I had to make a magnetic screen to attenuate that hum, not eradicate it.

    I suppose that the original speaker was probably an AlNiCo one, with a much smaller and compact magnet, so thers was no magnetic influence originally.

    In conclusion : carefully restored, with a good set of tubes (avoid 7591S JJ if possible) and the suitable speaker (AlNiCo with small magnet), this amplifier is a very interesting alternative to the usual Fender Princeton Reverb.

    (And there's also a lot of small cool vintage amps made in Italy from the 60s ;), I hope to snag one, one day maybe...)

    A+!
     
    Sid Nitzerglobin and stiv like this.
  4. Andy Fortune

    Andy Fortune Gretschie

    269
    May 24, 2016
    Corning, NY
    +1 on bad experience with JJ7591s. The new Tung Sol 7591As have been very good for me, though, and much truer to the originals.
     
  5. wildeman

    wildeman Gretschified

    May 10, 2015
    norcal
    '61 is pretty early for 7591 tubes, it should have 6V6s that early i believe. Every Ampeg i've had was a great amp, no dogs out of like 7 amps. Good high quality American amps. That amp will do what you want well, its 56 years old though so it may need some love.
     
    stiv likes this.
  6. wabash slim

    wabash slim Gretschified

    Age:
    70
    Feb 10, 2010
    lafayette in
    I've had two Ampeg flip tops, a B-15 and a B-18X. Both excellent amps. I've used a couple of Jets and they were great. If I was in the market for one, I'd look for a Jet with Reverb, tho. Ampeg's reverb is even better than Fender.
     
  7. stiv

    stiv Country Gent

    Sep 12, 2014
    Florence, Italy
    Wow, now that's a real help..:) Thanks a lot, now I know a lot more about this amp.
    For what the owner said to me, both pre and power tubes are original GE, so I believe the JJS are out of the picture (he even offered me some EH replacement power tubes included on the price).
    About the speaker, I'm pretty sure it's not alnico but due to the fact that the amp still has original tubes I guess it didn't caused much hum over the years.. I never paid much attention to some hum as I always played my amps live, but this low wattages could see a lot of studio so I better pay some attention now as it could be really annoying..
    Btw I'll probably have a try on the amp by Saturday, so I'll find out what amount of hum it's there (I don'think that a vintage amp could be dead Silent anyway).
    As for 60s italian vintage amps, I've already have my due part of Binson, FBT and Lombardi when I couldn't afford to buy a Fender so for the moment I'll look for something else..:D
     
  8. Andy Fortune

    Andy Fortune Gretschie

    269
    May 24, 2016
    Corning, NY
    The J12A is a 6V6 amp, with 6SL7 preamp tubes, but the J12D is definitely 7591s. Don't hold me to it, but I think the first J12Ds came out in '63.
    EH 7591s have survived longer for me than JJs, but the Tung Sols sound more like the real thing, in my experience.
    Don't forget to check the prices on 6BK11s...you could be paying for that amp all over again when you replace them.
     
    stiv likes this.
  9. stiv

    stiv Country Gent

    Sep 12, 2014
    Florence, Italy
    Thanks for the kind advice. I opted for Tung Sol as well in my Hiwatt head, and never sounded better. They're a bit pricey but absolutely worthy.
    Alse the advice on preamp tube will be the first thing I'll check. To be honest, I never changed preamp tubes on any of my amps (vintage or not) unless they were faulty. My Hiwatt and my Lombardi (an old italian amp, similare to Vox but with a better reverb) still have their original Mullards.
     
  10. stiv

    stiv Country Gent

    Sep 12, 2014
    Florence, Italy
    Well thanks. I think this is my main issue at the moment. I always dragged my favourite amps with me on the road nevermind their age, and one of my biggest weakness as a musical instruments owner is that I never particularly paid much attention in taking care of them (and that's bad). I love worn out amps and worn out guitars, anything that has some "I lived a life before you bought me" Mojo.. So reliability plays an important thing on my decision. I've always been lucky enough to be let down very few times on the road by my equipment (not much amps, but a lot of speakers..:D). I've had for a while a 65 Super Reverb but it was a tank (and reconed) that was the oldest amp I owned so buying this Ampeg would be a sort of taking my chances for me.
    I guess I'll give it a try.
     
  11. Gretschtim1

    Gretschtim1 Country Gent

    Dec 4, 2012
    Dundalk, Md
    If you need any parts for that Ampeg get them from Fliptops.
    Great service and they will match the parts to make the amp as original as possible.
    I recently bought a 1965 Gemini 1 amp which I've loved since I was a young teenage.
    It was the first really good amp I ever played through.
    So after all these years I finally found another one in near mint condition.
    It's got the best reverb & tremolo out of any amp I've ever played through - tons better than any Fender amp.
    I bought new filter caps, a NOS tremolo unit and a NOS 7199 driver tube.
    The speaker in this amp is original and so are most of the tubes - stamped Ampeg.
    Fliptops treated me great and was able to get my filter caps back to the original state - the ones that were in the amp had been replaced - they were close but not an exact match.
    The amp sounds great now even with the 52 year old tubes.
    I put some JJ 7591s in it and the amp sounds the same as it did with the original tubes (the JJs gave the amp a little more power which I would expect compared to 52 year old tubes) but otherwise the tone was the same.
    Ampeg guitar tube amps are very gentle on tubes so I guess that's why they last so long and that's a good thing.
    Good luck with your Jet.
    Ampeg guitar amps are very different than any other guitar amps out there.
    They can be super sweet and warm.
    They can also get very bright like surf guitar.
    I've been recording with it lately and I also use the Fender Deluxe at the same time - what a great blend of tones.
     
    Andy Fortune likes this.
  12. Gretschtim1

    Gretschtim1 Country Gent

    Dec 4, 2012
    Dundalk, Md
    The low watt Ampeg combo amps are really quiet if the filter caps are good and the correct ones.
    My Gemini 1 is actually one of my most quiet tube amps - more so than the Vox AC 15 & AC 30, 63 fender Bassman & 65 Fender Deluxe.
     
  13. hcsterg

    hcsterg Country Gent

    Feb 13, 2012
    France
    Thanks stiv ! Vintage Italian amps are indeed good instruments... Do you know a website where I could find more informations about those numerous Italian amps brands ?

    A+!
     
  14. stiv

    stiv Country Gent

    Sep 12, 2014
    Florence, Italy
    I'm not sure you could find everything in a single website... you'll find some sparse infos on the web.
    Btw you could ask me for reference.. ;) Not long ago I was always on a hunt for a good piece of italian gear, you could find many of them on flea markets and buy them for a handful of liras. They still comes up from time to time.
    They all have a unique sound, but all of them lacks of some versatility.
    My main amp it's still a serial no. 0000 that I helped Lombardi (one of the most glorious italian amp brands, just slightly ahead of Binson) develope as a prototype. An all-tube Class A clean machine, that takes any pedal like a dream and has a gorgeous reverb.
    Problem is... it's a 40-80w, and weights a lot.
    That's why I'm in the market for the Ampeg: I'm getting old. The time for Hiwatts, Super Reverbs and AC30s has gone...:D
     
  15. hcsterg

    hcsterg Country Gent

    Feb 13, 2012
    France
    OK, stiv. The few Italian names that come to my mind are : Gemelli, Galanti, Davoli, Wandré, Sound, SuperSound, FAL, Crucianelli, EKO, FarFisa, Geloso, Binson, Meazzi...

    Unfortunately, I can't reach Italian Flea Markets (it's not easy, even when in holidays in Italia - my wife has her family in the Valsesia /Piemonte region), and the French Flea Markets are somewhat poor about that...

    The J12-D is very lightweight (circa 10-12kg at max.) you won't be deceived about that, and yes, like you it's more and more difficult for me to carry those big sounding tube amps - that I still keep, nonetheless !

    A+!
     
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