tjlee Posted February 27, 2008 Share Posted February 27, 2008 I've owned my Gibson Thor bass amp since about 1970. I seriously need to rebuild it, as it's lost most of its power. I have two options. First, does anyone truly know if this amp was a real fifty watter? Second, does anyone know if there's a way to tame the bite of the treble response? It's very harsh, almost like having the bright switch pulled up on my Marshall, which makes the tone sound off even for my guitars, not to mention basses. This amp has been modded heavily, with balanced outs for recording, a pre amp out and power amp in for stage work, extension speaker jack (it then runs at two ohms), and two fx loops (parallel and series). I wouldn't think that it's output would suffer from such things, but then, who knows? Any thoughts? I'm thankful. Link to comment Share on other sites More sharing options...
gunny Posted January 21, 2009 Share Posted January 21, 2009 I know the previous question is a year old. I just picked up a Thor tube combo from Craigslist. I've been aware of this amp model for years and thought I'd pick one up one day. I repair amps in my spare time (40 yrs experience). I only had to to minor work to bring the Thor back to full performance. The bias was a little high so I changed a resistor to bring bias in line. The AC polarity switch was shot and I installed a SPST toggle in its place. There was a steady low level buzz. To cure that I installed a 0.022 uF capacitor on BOTH Line to ground and Neutral to ground sides of the power transformer primary. Bingo! buzz gone. It already had a 3 wire grounded cord installed. I measured output at a full 50 Watts RMS. That answers the question for the previous thread. The speakers in mine are nothing special by today's standards for bass, but they perform just fine. No farting out. I'm very pleased with my acquisition. Any tube amp is capable of being restored to original conditon. Link to comment Share on other sites More sharing options...
thorny Posted January 25, 2009 Share Posted January 25, 2009 Gunny, I just got a Thor in for repair, and I was asked what kind of speakers are in it. I confess, I can't figure out how to get to the speakers. The back is sealed and tolexed over. There are no screws on the back or the side. I thought to remove the front panel and pry on teh grill cloth frame that it may "pop" off and the speakers would be front loaded. But I pry and it has not popped off yet, and I am concerned that I might damage it. Did the front grill cloth panel just pop off, revealing front loaded speakers? or is there some trick I don't yet know? The guy wants the amp to sound better for guitar, so that I am looking into that. Right now I don't think it sounds particularly good for guitar or bass really. I thought I would look into the speakers. I just can't get to them. Link to comment Share on other sites More sharing options...
raven1844 Posted February 25, 2009 Share Posted February 25, 2009 I just bought a Gibson Thor Amp. All tube, 50 watts, 2x10 combo. Once it's here, I'll plug the Thunderbird into it and give it a spin. I'll post some pics as well as my "review". I don't expect much from the amp, but I figured it would be a great conversation piece to go along with my Thunderbird. Looking at the specs on it, it looks very simple. Can't wait for it to arrive! Does anyone else here know any of the history of these amps? Link to comment Share on other sites More sharing options...
TJLeebassplayer Posted March 3, 2009 Share Posted March 3, 2009 Thanks for the info. I'll try your ideas with the capacitors, as I'm also getting some hum in it. Mine has an aftermarket master volume installed, so I'm looking forward to having the fifty watts back and hearing what it can really do with it all. Thanks again for all your help. Link to comment Share on other sites More sharing options...
raven1844 Posted March 7, 2009 Share Posted March 7, 2009 Thorny - Were you able to figure out how to get the grill off? Mine just arrived today and I had a heck of a time with it. After I nearly ruined the grill cloth, I figured out there are three nuts inside the head area you need to loosen. Then the gril slides up - the bottom having been sitting in a slot at the bottom of the cab. It's a PITA to get the head out of the cab as well! And whoever made mine, sure loved staples! Wow - it was loaded with them! When I put the head back in after adding a speaker out jack and a preamp out through the input jack #2, I put the screws back in minus the grill. Then I just used some velcro from a pedal board to hold the grill like on modern amps. Link to comment Share on other sites More sharing options...
raven1844 Posted March 7, 2009 Share Posted March 7, 2009 Here's a link to my photobucket where I'll be uploading pics of my THOR as I work on it etc... THOR Photos Link to comment Share on other sites More sharing options...
raven1844 Posted April 18, 2009 Share Posted April 18, 2009 More 411... Link to comment Share on other sites More sharing options...
gunny Posted May 11, 2009 Share Posted May 11, 2009 I had a posting over in the amps sections from earlier this year. Is the amp really a 50 Watt unit - absolutely! I measured the output into a dummy load and got a full 50 Watts with no distortion. I had to change out one speaker because it was previously torn and badly repaired. I used an old one from a Fender Super Reverb, ie a guitar speaker - not a bass speaker - however it works fine in this amp. I would never attempt to gig with this because the power is too low for that. Off topic - I just serviced a GA-5T Skylark for a friend. I love these vintage Gibson tube amps because they are so well made and sound great...real keepers! That amp was rated 12.5 Watts and it also delivers the goods....like a Fender VibroChamp but with more power and a bigger speaker. On the Thor, I found the settings (for electric bass) of Treble and Bass at approx 3 o'clock to be just fine for me. Not too boomy and not too hissy at those settings. I play 'clean and deep' with no distortion or effects. Link to comment Share on other sites More sharing options...
GibGuy Posted September 28, 2016 Share Posted September 28, 2016 I know I am reviving an oldy here but have a Gibson thor g-7 solid state that powers on and then throws the internal breaker...any thought on why? Link to comment Share on other sites More sharing options...
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