In need of help with an old 60's Gibson Titan Medalist guitar amp.

[tube-a-lou]

Yeah he did make a good point.I'm sure I'll have more than its value sunk into it by the time its all done. I think I still want to go forward with it. I just absolutely love vintage gear and really want to bring it to life especially since its a fairly rare piece. I think it will be at least worth it to me. I do appreciate that advice, however!!


I think whoaru99 is looking into a PT for me, so I'll wait and see what he finds out. Otherwise, I'll probably check in to Heybour. I didn't know they were the original makers of those! Thanks tube-a-lou!
Were the prices fairly reasonable?

Yes they are, a lot better the Mercury.

 

[ehc68]

I’ll try to get a hold of them Monday. Thanks again guys!

 

[ehc68]

My email response from Heybour...
“Eric, Ok, got it. our in house number HTS-4846, is TF-135 P.
Be $135 for a single pc set up and run. this has some kind of foot bracket on it. Not sure if we have those or what was used back when we made this before.
specs
primary 0-120
secondary HV 380-55-0-380
fil 3.15-0-3.15 “

 

[ehc68]

specs
primary 0-120
secondary HV 380-55-0-380
fil 3.15-0-3.15

Are these specs ok? They seemed a little different from the schematic.

 

[drew_t]

Different how? I can't make out what the schematic says.

 

[ehc68]

Different how? I can't make out what the schematic says.

I was looking at a different schematic. I’m at work and don’t have access to it at the moment. Here’s a shot that looks a little clearer....but not much.

 

[whoaru99]

Might want to confirm the 380-0-380 spec with them. That is hot compared to the 330-0-330 shown on the schematic.

 

[ehc68]

Ok, will do

 

[ehc68]

Ok, so Heyboer got back with me. Should I trust the schematic or go with the 380-0-380?
Here’s his reply:
“Eric, I do believe this was what we got from one that was sent in here for us to copy. was back in the 80s. I can make a copy of the card and adjust turns to lower the HV to 330-0-330 if you want. will just give it a -1 suffix for a modified version. let me know, thanks, Phil”

 

[whoaru99]

If the transformer was 760V CT but actually undersized (current-wise) for the load, there could be enough sag for the voltage to be something around 660V CT in operation. But, that's a fair bit of sag. Maybe that's why the transformer is shot?


Mmmm, tough call.

Wonder if Heyboer's 380-0-380 is loaded or unloaded (although loaded is customary).

 

[ehc68]

Wonder if Heyboer's 380-0-380 is loaded or unloaded (although loaded is customary).

I’ll ask about that.

 

[drew_t]

You ought to post on some of the more guitar amp-focused web forums; you'll have a better chance of finding someone who either owns, owned, or has serviced one of these Gibson amps at some point.

 

[ehc68]

You ought to post on some of the more guitar amp-focused web forums; you'll have a better chance of finding someone who either owns, owned, or has serviced one of these Gibson amps at some point

Great idea! I'll give that a shot.

 

[ehc68]

So the specs according to the schematic are....
Primary 0-120
Secondary HV 330-46-0-330
Fil 3.15-0-3.15
660V CT

Am I reading that correctly?

Here is an easier to read schematic...

 

[ehc68]

Well, those specs from Heyboer were unloaded. Here’s what we said.
“Eric, No , that is a no load test voltage with 120 in.. under load , around 365-370. Easy enough to change turns if you want it a bit lower.
When your 135 was made was design at that time yet 115-117 wall ? If we use 117 as primary , no load is then 372/372 . We have that with a lot of these older designs and have to tweek a bit to reflect same voltage as original design intended. A lot of these old Fender PTs on file , we have original and then some modified versions as well.
thanks, Phil”

 

[ehc68]

So I’m thinking having him modify the PT to reflect the schematic (to 330) would be the way to go.?

 

[ehc68]

Can not upgrading an old PT to the current line voltages eventually fry it?

 

[whoaru99]

Can not upgrading an old PT to the current line voltages eventually fry it?

No, they change the windings ratio and stuff to adapt it.

And, yeah, I would shoot for having 330V loaded with 120V nominal supply.

 

[ehc68]

330-55-0-330? or is that 55V spec that he gave me too high as well? Should that voltage instead be 46V?

 

[whoaru99]

If we are going to presume the schematic is correct, what do the numbers say?

If we are going to presume the schematic is incorrect then it's anybody's guess and probably could just as well roll the dice with their reproduction transformer. That is, unless you are going to sit on it until you find someone with the same amp that can and will provide complete assurance of measured voltages.