Modded MT15/MT50

[masa_boozer]

Hi, I saw this thread and implemented the output transformer replacement myself.

The OT I replaced is for a JTM45 (push-pull 50W primary 6.6K ohms).
It is part number AGOT-01J and is handmade in Japan by Athens Electric Co.

As mentioned, the only work involved was soldering in 6 places and drilling new holes to mount the OT to the chassis.
The job took about 60 minutes, most of which was drilling!

I used a blind nut to mount the OT to the chassis.

I had to correct the wiring on the primary side because the OT to be replaced and the original wiring color were different...

Original OT primary wiring
B+:RED P1:BRN P2:BLU

And the bias was adjusted to 30.


As for the results... i'm very happy with them!

I don't have a measuring device so I don't know the exact output.
I don't care about the output watts because that was very loud right from the start!

Haven't played it loud yet, but I'm already happy with it!

 

[Goran Lorencin]

Hi, I saw this thread and implemented the output transformer replacement myself.

The OT I replaced is for a JTM45 (push-pull 50W primary 6.6K ohms).
It is part number AGOT-01J and is handmade in Japan by Athens Electric Co.

As mentioned, the only work involved was soldering in 6 places and drilling new holes to mount the OT to the chassis.
The job took about 60 minutes, most of which was drilling!

I used a blind nut to mount the OT to the chassis.

I had to correct the wiring on the primary side because the OT to be replaced and the original wiring color were different...

Original OT primary wiring
B+:RED P1:BRN P2:BLU

And the bias was adjusted to 30.


As for the results... i'm very happy with them!

I don't have a measuring device so I don't know the exact output.
I don't care about the output watts because that was very loud right from the start!

Haven't played it loud yet, but I'm already happy with it!

Nice job What kind of speaker do you use the amp with?

I must say the amp is pretty loud as is if you ask me.

 

[masa_boozer]

Nice job What kind of speaker do you use the amp with?

I must say the amp is pretty loud as is if you ask me.

Thanks!

I am using a GENZ-BENZ 212cab with one speaker replaced with a vintage30.
The other is a speaker (GBE1240-V75) taken out of GENZ-BENZ in a box made by a friend.

 

[masa_boozer]

I would like to post a picture but can't upload a local file?

 

[Goran Lorencin]

I would like to post a picture but can't upload a local file?

You can use Flicker, that’s how I did it. Or any other similar “service”.

 

[masa_boozer]

You can use Flicker, that’s how I did it. Or any other similar “service”.

Thank you very much for your kind help.

 

[masa_boozer]

https://flic.kr/p/2ngPQxq

https://flic.kr/p/2ngMnPx

https://flic.kr/p/2ngMbNC

https://flic.kr/p/2ngFQgb

 

[Goran Lorencin]

Looking strong, would be nice to hear a sound or two to better understand what happened there

Now all that is left is to replace the ugly original knobs with something like this or any other unique style that you identify with and you're on to something beautiful my man.

https://flic.kr/p/2ngTxPD

 

[Goran Lorencin]

Thank you very much for your kind help.

You're welcome. In our parts we say "more heads know more" ... I am glad to have helped, the guys here have also helped me a lot and that"s what a good forum should look like, isn't it.

 

[masa_boozer]

Looking strong, would be nice to hear a sound or two to better understand what happened there

Now all that is left is to replace the ugly original knobs with something like this or any other unique style that you identify with and you're on to something beautiful my man.

https://flic.kr/p/2ngTxPD

If I get a chance to get louder, I'll record it!

That knob swap is so cool!

I replaced mine with an aluminum knob like this one, but it didn't look good...
So I'm considering a knob like the one you are using!


https://www.amazon.co.jp/gp/product/B09LTR6MGC/ref=ppx_yo_dt_b_asin_title_o05_s00?ie=UTF8&psc=1

 

[masa_boozer]

You're welcome. In our parts we say "more heads know more" ... I am glad to have helped, the guys here have also helped me a lot and that"s what a good forum should look like, isn't it.

You're right, this forum here has been a real help!

I hope my posts help someone that way.

 

[Goran Lorencin]

When are the sample sounds coming? I'm eager to hear it