'72 JMP 1987 Lead: what PT is this?

[Mattececco]

Hi folks.
I just purchased a '72 lead 1987 that seems to have the PT changed.
I couldn't find what kind of PT is that, even searching the code stamped on the sticker. What do you think about it? And why is it not aligned with other components?
I'm interested in finding a proper Drake 1202 164 from the right era, but I bet it could take years.

I spent 3900€ for the half stack, with a 1960 4x12 loaded with t1221 102/3 greenback. I'm not able to compare it with the crazy prices I see out there.

Thanks for any help
Matteo

 

[God of Thunder]

Hi Matteo! Do you have any photos?

 

[Mattececco]

I just found out how to compress images

 

[neikeel]

Sorry, no idea what that PT is. Where do you live as it is probably a local product to you.
What are the voltages from it?

 

[Mattececco]

I l

Sorry, no idea what that PT is. Where do you live as it is probably a local product to you.
What are the voltages from it?

I live in Italy. The seller said he took this amp from the first possessor, who lived in the same town, and that he didn't know about this fixing.
I don't know how to measure the voltages, could you please tell me how to do it?

 

[Matthews Guitars]

That's a big honking transformer! Bet it'd source enough power for a 200 watt amplifier.

The important question is, what are its output voltages in circuit?

 

[Mattececco]

I don't know. I will have it measured in a few days from a technician

 

[GIBSON67]

How does it sound?

 

[Mattececco]

It's my first vintage marshall, so i can't make a comparison. I tried it with a V30 loaded hiwatt 4x12 cab. It sounds quite dark. Tomorrow I'll have it checked by a technician. We'll see

 

[Central Scrutinizer]

@Mattececco welcome to the forum.

Congratulations on your half stack purchase.

Hope you get it sorted out.

 

[Mattececco]

The amp has been tested and the circuit seems to be in good status. Only a diode has been changed to follow the tension coming from the new PT

 

[Mattececco]

The amp seems to run well. The multimeter sees 477 on the PT and 476 on the OT. The technician says the bias had properly set, in order not to overcharge power tubes. He measured values from 20 to 25 on the tubes. It is still visible the sign left from the original PT burning. What do you think?

I'll be looking for a new old Drake but I bet it'll take a while

 

[79 2203]

My 69 Super Bass recently arrived here in Australia from Merate Italy and also has a black replacement PT

 

[playloud]

My 69 Super Bass recently arrived here in Australia from Merate Italy and also has a black replacement PT

The end bell on yours has a distinctive shape. This Italian site - shared by @Spanngitter in another thread - has some similar ones pictured (note the JTM45 PT in particular): https://shop.piemme-elektra.it/Categories/126

The OEM manufacturer for at least some of these appears to be Inmadout (in the UK?): http://www.inmadout.com/T-power.asp Note that the spec sheets are in Italian. TT in Germany also carry their stuff.

The amp seems to run well. The multimeter sees 477 on the PT and 476 on the OT. The technician says the bias had properly set, in order not to overcharge power tubes. He measured values from 20 to 25 on the tubes. It is still visible the sign left from the original PT burning. What do you think?

I'll be looking for a new old Drake but I bet it'll take a while

That B+ is on the high side (closer to the later 1202-324 PTs, I think?), but it should sound good all the same. More headroom than a typical 50W.

How does it sound with the T1221s?

The endbells on your PT also look like those used by Inmadout, e.g. this one: http://www.inmadout.com/download/pdf/TA34M52.pdf

Edit: after finding a thread over at the Amp Garage, it looks like at least one of the people behind Inmadout is Italian and now has his own website: http://www.savinoluce.it/index.php/inductances.html Perhaps he would be a good person to ask?

 

[Mattececco]

Wow thank you! That's some useful news. I will send some emails and we'll see. The amp is ok. There is quite an amount of overdrive setting volume at 9 with an hb. At noon is randy rhoad's territory. Now I'm playing in with the V30 loaded Hiwatt 4x12 (odd modern hiwatt combination, don't know if it is original) Tomorrow I'll take it in my apartment where the t1221 are, but I cannot play it at proper volumes.