output ransformer for 6SA7 Headphone amp Help

[colin.hepburn2]

Hi All
Well I’m considering anther Headphone Amp I have a circuit in mind but its OTL which I am not to keen on it uses a 6SN7 the output valve is the 6as7 I want to use a gapped output TX but not sure what I m looking for to match the 6sa7 valve it has to drive Headphone from 32 up to 300 ohms
On the other hand I am secretly thinking of the mother of all headphone amps a 2A3
I may just do this so I am assuming the output TX will be 2.5k or 3k for the 2A3

 

[dsavitsk]

You might try the transformer scheme used in the espressivo amp: http://www.nutshellhifi.com/gary/index.html

It is a good way to match both low and high efficiency headphones. The listed transformers are very expensive, but there are tone of others for as cheap as about $10 that will work well.

 

[tube-lover]

I was prepareed a tube head phone amp.

size was Z11(M6) EI76X50 with 4N wire.
pri was 2.5~3K sec was two winding. 0~30Ohm.

since this OPT will seperate into two chamber for good band width.


THIS IS A SE OPT SINCE I SPECIAL DESIGN IN BALANCE WINDING TO GET BETTER BANDWIDTH & LOW LOSS FOR SMALL SIGNAL. THIS SE OPT ALSO HAD AIR GAP OF IT.

the first chamber
============
pri
sec-----30ohm
pri
sec-----30ohm
pri

sec chamber
=========

pri
sec-----30ohm
pri
sec-----30ohm
pri






every chamber will paralell winding.

after that, if the user like to use 30ohm, sereis connect for the pri & parallel for all the sec of the two chamber will equal to 2.5K:30ohm.


if pri & sec also series connect. Will same as 2.5K:120ohm, since this was I special made & design for AKG K1000.

I will use 6EM7 with 1.1W power output. matching impendance to push for the AKG K1000.

Standard version will Z11(M6 core).

I can supply Nano amorphous core too!!

I can special design different output impendance to different headphone.

thx

thomas