Using mains transformer as output transformer

[hoktuna]

Goooooodmorning amerika
One channel of "the prototype"is upp and playing sweeeet music.
The other channel need some tweeking,it is distorted(right word?)
Maybe core satur,we´l se tomorrow.

[Elias]

Hello and Good evening!

Originally posted by hoktuna
Goooooodmorning amerika
One channel of "the prototype"is upp and playing sweeeet music.
The other channel need some tweeking,it is distorted(right word?)
Maybe core satur,we´l se tomorrow.

Congratulations of working proto! (even only one channel)

If the problem is core saturation, this thread is the right place to get that solved!

- Elias

[revintage]

This is the proto hoktuna built, but with 6P3S instead of 6V6. We discussed over the phone and came to the conclusion that the second channel probably had a faulty 6P3S or a leaking coupling cap. If not so, it could also be a self-oscillating 6C45.



We are looking forward to both channels working, to evaluate the amp soundwise.

[Elias]

Hello,

My second proto of current compensated toroidal SE amp is coming! Next thing to do is to wire it up.

In the pic background can see the output toroid. I wound some extra turns to have more variety of impedances.

- Elias

[revintage]

Both channels of hoktunas proto is now up and running. Plays with authority, good bottom and very good depth of image through a pair of 87dB sensitivity speakers !

C1 is 100u between the tubes cathodes, 6V6 is a 6P3Sand 6C45 is choke-loaded though.

[hoktuna]

Next thing will be too hook the amp on my main speakers.
Onken 360L whith Altec 416 8A
Homebrewed Altec multiell with JBL 2441.http://i194.photobucket.com/albums/z...a/DSC04462.jpg

[hoktuna]

Here is the amp with ps.
http://i194.photobucket.com/albums/z...a/DSC07103.jpg

[Michael Koster]

Congratulations Hoktuna and Lars!

You have a working push-pull signal-mirrored amplifier.

The bypassed current mirror may be a very good solution to DC
balance and AC drive. I look forward to some measurements.

It looks like you're working into about 11K anode-anode based
on the transformer ratio. What's your output at OPT saturation?

Also, a great use of a pentode, pushing current around under the
control of a DHT.

I have a pair of 414s, I'm thinking about baby Onkens and 511
horns. What drivers do you use?

Cheers,

Michael

[revintage]

Actually the impedance ratio is 9000:8.
One must measure the unloaded secondary to determine voltage ratio and for this Autema 30VA it is 230:6,8V.

A 230:9V unwound to 8,4V unloaded would be perfect......

Anyway we will soon measure and listen more.

Michael,
I used 414 Onkens earlier together with 511/802s and 077. Now the 511 are being rebuilt to take a 2" driver.

http://www.revintage.se/narbak.JPG
http://www.revintage.se/frontred.JPG

Hoktunas DIY-multicells with 2441(!) and Onken 416
http://img385.imageshack.us/img385/435/multicellfr8.jpg

[Michael Koster]

That tower looks like an open baffle. If you have
experience with 414s in OBs I'd be very interested
indeed, because I have a Heil AMT I'd like to pair up
with a dipole mid. Conventional wisdom is the 414s
too low Qt for OB but what if I use it as a mid down
to 100-120 Hz and make my sub go up to that?

Also that octagon tube looks like an interesting sub.
I'm also working on a tube sub design.

I guess there is speaker design forum...

Can't wait to hear more about the SETOR.

Cheers,

Michael