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Tube Mic Preamp - which Edcor transformer?

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I am starting to build an all-tube microphone preamp. Planning to use two stages of 12AX7 and one 6922 SRPP output, now I am looking for the input and output transformers. Edcor looks to have what I need, but their web site does not a lot of information. Any suggestions on which Edcor transformer will work better?

Thx.
 
I've never used Edcor transformers. I checked out their web page and looked at their mic input transformers, specifically their 1:8 ratio ones as that's the kind of ratio you need for a tube mic pre.

I note that:

1. Specs do not define the operating level at which measurements are made

2. There is no magnetic screening

3. They are quite inexpensive

I have no proof but I expect these are relatively poor mic transformers. You would probably be better looking at Jensen for example or Lunfdahl or Sowter.

Cheers

ian
 
Originally posted by SY The Edcor plots I saw did specify the level. The left hand axis was marked "dBU." Distortion looked pretty good. [/B]

Yes, they did, but they fail to say whether it is input or output level; I suspect they are output levels. Also all the distortion characteristics look identical. I would very very surprised if a 23 dollar transformer can achieve better than 0.01% distortion at 10Hz at +18dBu output. If it can I'll take a truck load.

Cheers

Ian
 
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