Grommes LJ5 output transformer - needed help

[hugh811]

Hi everyone,

I need your help to restore a pair of Grommes little jewel (LJ 5) tube amplifiers. These are mono block tube amp, use 2 * 6V6 (so i think that it is push pull). One unit is all original, but the other one has a non-original output transformer.

I would like to restore it with the original output transformer. I have searched the info about that but nothing is mentioned on the Internet. If you have any clue to clarify the issue, please help. Did Grommes produce their own OPT or they used OPT from other producers of that era, like Philco? I saw a very similar NOS Philco OPT on ebay, it was designed for tube radio. Just wonder if it is the same OPT installed on Grommes LJ amplifiers.

Thank you for your help.

 

[hugh811]

Here is the picture on ebay


.

 

[knockbill]

Post the numbers on the original OPT if possible,,, EIA codes may be on it, and help ID the maker/tx...

 

[hugh811]

I will post original picture this evening. Thank you Knockbill

 

[hugh811]

Here is the original OPT. It is numbered with
T0 - 10B
637709

Any clue will be helpful !

 

[knockbill]

Central Coil is 637xxx, don't know anything about them, but that's the EIA code...See if that Philco is also 637...

 

[Tom Bavis]

You want a transformer for push-pull 6V6s, which will be about 10K primary with 4, 8, and 16 Ohm secondary. The only source for the original part is a junk Grommes chassis. Your best bet for a (new) similar looking one may be a guitar amp replacement. But there may be a number of similar parts around from other amps (maybe a few in my basement). Mounting screw spacing is the first thing to know..

That Philco is NOT close - the 511 had an interstage transformer and an output choke for a high-imprdance speaker​

 

[primosounds]

Here is the picture on ebay


.View attachment 1056817


View attachment 1056819

You can not go by appearances. You must know the specifications of the output transformer so you can match the replacement. Heyboer is a transformer manufacturer that can make a replacement that is the same as the original specs. They may already have the data on file.

 

[knockbill]

You want a transformer for push-pull 6V6s, which will be about 10K primary with 4, 8, and 16 Ohm secondary. The only source for the original part is a junk Grommes chassis. Your best bet for a (new) similar looking one may be a guitar amp replacement. But there may be a number of similar parts around from other amps (maybe a few in my basement). Mounting screw spacing is the first thing to know..​

New Sensor makes a PP OPT (8.5 / 8R, IIRC) that will work, and they are pretty cheap,,, they actually look like the ones on the LJ... I tried a pair of them on a Maggy 175,,, but finally found originals and used em for guitar amps...
When you replace OPTs you will need to dial in the FB to match the new ones....​

 

[knockbill]

Here's a pic of the NSC OPT...

 

[hugh811]

I thank you all for your help. A junk Grommes chasis would be my first choice. After - market transformers follow, but it means I have to buy a pair. They are mono blocks. The hunt for grommes part/repair chasis has began