Gibson Duo Medalist

[davohilts]

Hello,

I've just received a Gibson Duo Medalist with a 12" speaker from a bid on Ebay. It matches my Gibson Hawk and Skylark in that it has the funky bat ear sides and the fake woodgrain top. It came without tubes and apparently had the power supply caps replaced but still has some issues.

I've read reviews on this amp that the tone setup is off and that there is a mod the help get rid of the 'ice pick' treble. Has anyone here done this to a Gibson amp? I love the sound of both my Hawk and Skylark, so according to Gerald Weber this Duo Medalist was a big mistake never hitting the mark. It weighs a tone but i'm not gigging with it so as long as it sounds as good as it looks i'm gonna be a happy camper.

Thanks.

Dave

[Gibson Gear01]

Hi Dave,

 

First, I suggest you outfit your amp with the proper tubes to make sure your amp fires up and works. I have heard a few stock Duo-Medalists and they all sounded a little different. One was definately an ice-pick, and the other was not at all. The Reverb is top-notch, and 7591 power tubes are so under appreciated. The 6eu7 pre-amp tubes are a little hard to find but they are out there. They are very quiet, and are basically internally humbucking.

I am also familiar with the mods to the tone networks that will "open up" the amp so to speak. One note: the Duo Medalist is not the most user-friendly amp when it comes to modding it. It can get very complicated when you open it up and compare it to the schematics. If it's over your head, then we advise you take the amp to a qualified tech for servicing.

[davohilts]

Will do, i've got the tubes on order and should have them by next week or so. I'll post my findings when I can actually play thru the duo.

Thanks for the advice.

Dave

[davohilts]

I finally got the tubes I needed and have spent the holiday break working on the amp.

I replaced the filter caps with proper value caps and solved the hum issue I had after I first brought the amp up to full power. The tremelo works but is weak in my opinion (compared to my Falcon) and the reverb doesn't work at all. I can shake the tank and it gives off a nice jangly sound but it will not work with a guitar plugged in. I have put a dummy load on the amp and ran a signal thru it and can trace the circuit up to the transformer for the reverb and after the reverb and get signal at both ends (from input jack to the final preamp tube which sends the signal to the amp section) but I'm at a loss how to test the reverb transformer.

The transformer has a blue and red wire which connect up to the preamp section and then the shielded wire which connects to the reverb tank input rca connection. I get signal into the tank from the tip of the rca jack but no signal at the output rca jack. How does one check if the transformer is working? I've checked the resistance on the tank input and output and get 170 ohms on each.

If I need to get a new transformer where can I get one?

I had a similar issue with my Falcon and ended up putting in a Fender reverb transformer and Fender reverb tank to solve the issue. This gave me a spare Gibson tank from the Falcon and I've tried that one on my Medalist to see if maybe I had a bad tank but got the same result, no reverb.

Any help would be greatly appreciated!

Dave