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About jkchrome

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  1. Hi guys, I just got a circa 1964 GA-100 Bass amp. Serial number starts with a 4, and I haven't gotten in to find other codes yet but that seems about right for the year. Pretty cool, all stock, and it's a piggyback that has a compartment in the cab for storing the head. Head has a tan painted metal enclosure, and uses 7591s with a single 15. Less than 100 made that year (or any year) so kind of rare. Just wondering if anyone has a pic of the BACK of the head cabinet, looks like it may have had a back cover but that is missing now. Thanks in advance. If there is interest I'll post pics
  2. Hi, As I said in the original posting, belonged to a friend of mine that used to use it when he had a band a long time back. He had some bills to deal with and called me. So it's not a "yard sale find" or pawnshop prize, just something that came available at a time when I fortunately had the money to get it.
  3. Hi,pics up now. Thanks for the interest.
  4. Pics, one to show where there are NO screw holes for a trapeze, and one of a top view. Note the original case, too. Thanks for the interest.
  5. Hi, I recently acquired a 1965 ES125tdc/tcd and it has a Firebird-style vibrola with the lyre cover and plastic handle (not a sideways vibrola). Belonged to a friend of mine that has had it for over 20 years but obviously not the original owner. At first I thought it was an add-on BUT then I looked down by the strap button and no screw holes from a trapeze (the Lyre vibrola has the bracket folded over and screwed into the top). So, either it was special-ordered like that or Gibson put out a one-off or a small number of them as I can't find another like it. Anyone else seen one? Serial nu
  6. Hi, Thanks for all suggestions. I had my amp tech (very experienced) look at it and he discovered that all the preamp tubes are wired for 12ax7 and driver is probably a 12AU7 or 12AT7. He thinks it may have had the preamp tube sockets rewired from what would have been 6EU7 tubes. The amp has definitely seen some modification from stock. Anyway, it's cool and now I can actually stick something in and run it, and not blow the 6eu7 tubes that I bought based on the one schematic I did find.
  7. Hi everyone, Well, since I started the post I contacted Gibson support (sent a schematic for a different amp), contacted Groove Tubes as suggested(got a reply, no schematic), contacted Skip Simmons who has worked on other oddball Gibson amps for me (his suggestion was to have someone that knows look at the pin wiring to determine tubes, and that's a good idea so I'm having that done now by my regular amp tech that has been working on amps for about 40 years). Meanwhile, if anybody has an 8 tube version like mine, I'd love to hear from you. And I will post the results of getting it looked at
  8. Thanks. It's possible that a schematic for this model doesn't exist , they apparently made around 300 or so of this reverb/non-trem model , only for one year, and not the same amp as the earlier GA77 or the later, oil can ones)), and I even have a schematic with GA77RV on it but a slightly different tube setup. I'm hoping that mine isn't the only one out there with 8 tubes. Maybe someone out there will recollect seeing one.
  9. Thanks. I'll try that. So far I think that I have the first three right, 6EU7, and the inverter, 12AU7, 6l6 pair and GZ34. But, the mystery is what tube is in between the last 6EU7 and the 12AU7. If I knew that I'd be at least able to get started. I'm hoping somebody out there can fill in this gap. Apparently Gibson put out two variations (at least) of this short-lived amp. Seems like mine must be the less common one. The amp does not look like it's been modified. I actually have a GA77RV schematic that I found BUT with only 7 tubes. pretty frustrating. Worst part is that I owned th
  10. HI I have a 1961(?not sure of year) tweed GA-77RV (has reverb, no tremelo). I bought it years ago and am finally getting around to trying to get it running. Unfortunately I don't have a tube chart and the only schematic (downloaded online) for this model I have found shows 7 tubes, but my amp calls for 8 (five small tubes, two power, one rectifier, and the power and rectifier are octal sockets, pretty sure this had 6L6 power tubes and maybe a 5AR4 but just guessing). The older GA77 is of course a different amp. When I got it, some tubes were missing so I need to figure out at least the pro
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