• WARNING: Tube/Valve amplifiers use potentially LETHAL HIGH VOLTAGES.
    Building, troubleshooting and testing of these amplifiers should only be
    performed by someone who is thoroughly familiar with
    the safety precautions around high voltages.

James Transformer BS

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yes I think that's correct, the b connects to your psu, and the s is indeed screen, try both the 3k5 and 5k and see which you prefer, also try reversing the b going to the tube and the 3k5 to your psu and see which you prefer, its optimised the correct way for capacitance, but you may or may not prefer t'other way around, won't do any harm
 
Geek said:


I thought this was going to be a rant thread :D


that was my first thought too regarding the title.

I hope it's ok to ask but if I have an output tranny which I know is for an EL34 in PP and I know the B+, UL taps, and plate taps. but I don't know which is 0, 4, 8, 16... how could I check that? my DMM cannot measure any resistance in the speaker side.
 
pmillett said:
The guess above is correct.

There's a datasheet here:

http://euphoniaaudio.netfirms.com/ea/nfoscomm/catalog/pdf/6113-25K.pdf

Assuming this is the one...

Pete


Thanks Pete, I looked all over for that.


JojoD818 said:



that was my first thought too regarding the title.

I hope it's ok to ask but if I have an output tranny which I know is for an EL34 in PP and I know the B+, UL taps, and plate taps. but I don't know which is 0, 4, 8, 16... how could I check that? my DMM cannot measure any resistance in the speaker side.

I think you could hook up a resistor across the primaries and then measure different resistances on the secondaries.
 
JojoD818 said:



I hope it's ok to ask but if I have an output tranny which I know is for an EL34 in PP and I know the B+, UL taps, and plate taps. but I don't know which is 0, 4, 8, 16... how could I check that? my DMM cannot measure any resistance in the speaker side.

CAREFULLY apply a high AC voltage (100V through a Variac would be ideal, but 220V mains will work) to the primary, then measure voltages at the secondary. No loading needed.
 
Hi JojoD

I think you could also apply a (small) voltage to the primary and measure the secondary. The highest reading would be for the 16 ohms, the lowest for the 4 ohm...

Or juist build an amp and try to find out which is which listening to the amp...would make a nice blind test, I think :D

Erik
 
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