Drawmer S3 Compressor Out Transformer Help

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AudioIngenia

Well-known member
Joined
Feb 22, 2017
Messages
68
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


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


 
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.
 
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