Input audio transformers

Status
This old topic is closed. If you want to reopen this topic, contact a moderator using the "Report Post" button.

Diaultra

Member
2017-08-20 6:13 pm
Dear Group

I have an analog tube compressor that came with 2 Edcor XSM 600/600 input transformers.
The wiring is as follows:

INPUT > PRI : Pin 1=(+) / Pin 2=(C.T.) / Pin 3=(-)
OUTPUT > SEC : Pin 5=(+) / Pin 6=(C.T.) to Attack Wiper / Pin 8=(-)

I don't like really the sound of the Edcor. As I find in vintage transformers a nice low end sound, I am trying to implement 2 very old trafos I have that sound lovely. They have 9 pin and the ohmmeter reads:

Pin • / Pin 2 = 27
Pin 3 / Pin 4 = 29.4
Pin 5 / Pin 6 = 11.5
Pin 7 / Pin 8 = 31.8
Pin 8 / Pin 9 = 34.1

A model of the same transformer I found on the internet states in the label:

Output TF 1A 13
FREQ (.2 - 4.0) KC

Pin • / Pin 2 = 0.15 K 0MA
Pin 3 / Pin 4 = 0.15 K 0MA
Pin 5 / Pin 6 = 0.15 K 50MA
Pin 7 / Pin 9 = 0.6 K 0MA
Pin 8 = C.T.

My transformers do not have that label printed in it. Information is practically non existent on the net.

What I tried?

1)
INPUT / PRI

Pin •= (+)
Pin 2 + Pin 3 linked
Pin 4= (-)

OUTPUT / SEC

Pin 5 = (+)
Pin 6 + Pin 7 linked
Pin 8 = C.T. to Attack Wiper
Pin 9 = (-)

Result: Total Low End Loss.


2)
INPUT / SEC

Pin 5 = (+)
Pin 6 + Pin 7 linked
Pin 8 = C.T. Floating
Pin 9 = (-)

OUTPUT / PRI

Pin • = (+)
Pin 2 = (-)
Pin 3 = Attack Wiper
Pin 4= Floating

Results: Good, but with Output gain loss. Is necessary then to set the Compressor Level to the max. +8dB and the threshold to infinite to have slightly -1dB GR.

Any thoughs?

Thanks in advance!
 
Last edited:
Status
This old topic is closed. If you want to reopen this topic, contact a moderator using the "Report Post" button.