ECL86 or parafeed: headphone amp ideas

[indaco]

Hi all,
for my second (serious) headphone amplifier project I've been deciding wheter an OTL in particular with ECL86 tubes (or equivalent) or better a parafeed, though as for my knowledge about OT I am a novice.
The first one I built matches very well with high impedance headphones. This time I'd think for a low impedance one, in particular that can drive a pair of Final Sonorous X headphones of a friend of mine (16 ohm). Since these are expensive and top quality, the amplifier to couple with should be al least of good quality.
Any suggestion in this direction?

 

[jazbo8]

16 Ohms? You would probably want an OPT. BTW, is the pdf copyright material? If so, it must be removed.

 

[indaco]

Yes, the second one seems to me too the possible choice with those headphones.
Sorry. I paid attention now, it must be an abstract from a polish electronic magazine, so it's better to remove...thanks

 

[jazbo8]

Copyright material removed.

 

[hooman]

ecl68????

 

[jazbo8]

Title corrected.

 

[kodabmx]

It doesn't use an ECL86, but it'll work well, it's not expensive, and it's not overly complex.

 

[indaco]

It's an interesting schematic, it seems a kind of push-pull configuration. Can I use other tubes, like E88CC instead?

 

[00940]

With such high quality headphones, have a look to sowter transformers specially made for the job.

As for a schematic, you might have a look here

 

[waltube]

Hi
an alternative way

in attach there is a schematic for a s.e. with EL84 and 6922 in input
Also the HT stabilized circuit.
The performance are fine and with a HT stabilized and well filtered the ripple is more than -80dB so also with a headphone with a high sensibility the noise is very low.
There are two types of feedback that can be used

In attach also the freq. answer with a load of 10 ohm and 600mV on load.
In addition also a THD vs frequency with a good result.

Walter

the pictures

W

 

[kodabmx]

It's an interesting schematic, it seems a kind of push-pull configuration. Can I use other tubes, like E88CC instead?

It is.

You could use ECC99 or 5687 instead of 6N6P, but the you'd need to run several E88CC in parallel to approach the capability of the 6N6P. You could use almost any twin triode instead of 6N3P with a change in bias point (the 240R resistor could be changed to 470R to use 6SN7, etc.) You can even use 6N1P without changes. I just like the 6N3P for some reason.

 

[indaco]

With such high quality headphones, have a look to sowter transformers specially made for the job.

As for a schematic, you might have a look here

Yes, this one is good too. Actually that circuit, similar to the Torpedo amplifier was the first one I took a look. This friend of mine told me there's a vendor here in Italy called Megahertz (sig. Guerra) providing OT custom-made. Even if not Sowter they are of high quality.