Drawmer S3 Compressor Out Transformer Help

[AudioIngenia]

A compressor Drawmer S3 with an output transformer in bad condition (an open wire) has arrived on my workbench.
Unfortunately, the manufacturer Drawmer is out of stock.
The output stage is a tube 12BHT.
Any suggestions to replace this transformer?
Thanks

 

[AudioIngenia]

The output section is somewhat similar to this drawing. There are about 200 volts at the center point of the transformer.

 

[gyraf]

Are any feedback-windings used?

If not, just go with a 4:1 or so.. try what you have at hand in that range..?

/Jakob E.

 

[CJ]

make sure the transformer can handle about 20 ma,

#37 wire will handle 20 ma easily, but you need a lot of turns, which means a bigger core to make it all fit,

what is plate to plate resistance? no spec for that as those tubes were used single ended, 5 k is about the SE resistance,

so figure 10 to 20 k for push pull,

if you run ten times inductive reactance for good bass, then you want a pri z of about 100 K, which means pri ind = 100k/(2 pi freq)

use 20 hz, L = 100,000/(6.28 x 20 hz) = about 800 Henries pri ind.

measure the core stack of the transformer, i bet it is about 5/8" or 3/4",  so try to find something with a 3/4" stack and 800 Henries pri ind.

 

[AudioIngenia]

A local vendor has a pair of Lundahl LL1689 in stock
Can it be valid here?

 

[Evertide]

A local vendor has a pair of Lundahl LL1689 in stock
Can it be valid here?

What is the prim resistance from the 6107 in the S3 ?

When new in stock ?


The LL 1689-PP has 2x 655 Ohm @ 50 mA max...

If , than 2 new out...

 

[AudioIngenia]

The guys at Drawmer have provided me with an original transformer forgotten in the warehouse.
I consider this issue solved. Thank you very much to all.
And very grateful to Drawmer for solving the problem.

 

[Whoops]

If you don't need the broken transformer just send it to CJ for some of his adventures