OTL amplifier
Posted: Wed May 09, 2012 2:54 pmHello,
I have build lately this OTL amplifier, any improvement suggestions?
I have build lately this OTL amplifier, any improvement suggestions?
Chokes instead of 820R, too.
Cheers!
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Posted: Wed May 09, 2012 2:54 pmPosted: Wed May 09, 2012 7:42 pmTen 6080's
Chokes instead of 820R, too.
Cheers!
Chokes instead of 820R, too.
Cheers!
Posted: Thu May 10, 2012 12:06 amHi Geek, how are you doing?
Geek wrote:
Do you suggest to use ten 6080 per channel? That's a lot of stuff and... heat !!!
I get 18W into 16 ohms speakers with 3 tubes/channel. The frequency response is flat from 10 Hz (-0.5db) to 60kHz (-3db)
Geek wrote:
Ten 6080's
Do you suggest to use ten 6080 per channel? That's a lot of stuff and... heat !!!
I get 18W into 16 ohms speakers with 3 tubes/channel. The frequency response is flat from 10 Hz (-0.5db) to 60kHz (-3db)
Posted: Thu May 10, 2012 12:41 amDoing well, thanks. And you? 
That's awesome you're getting that. I am concerned about transconductance, etc. with only three.
If I were to build one for myself, I'd use 8/channel. Hence my reccommendation.
And heat and big 6.3V iron is just par for the course with these. A 6080 OTL is like driving a Hummer - if you're going to add to global warming, may as well do it right!
Cheers!
That's awesome you're getting that. I am concerned about transconductance, etc. with only three.
If I were to build one for myself, I'd use 8/channel. Hence my reccommendation.
And heat and big 6.3V iron is just par for the course with these. A 6080 OTL is like driving a Hummer - if you're going to add to global warming, may as well do it right!
Cheers!
Posted: Thu May 10, 2012 1:53 amI'm doing well too...hm.. except that I'm a bit short of 
You are right as regards transconductance and 8/channel would be great, but I don't want my OTL to contribute much in the global warming.....not to mention the thousand of the daily plane flights and the billion of cars and a/c units!!!!
You are right as regards transconductance and 8/channel would be great, but I don't want my OTL to contribute much in the global warming.....not to mention the thousand of the daily plane flights and the billion of cars and a/c units!!!!
Posted: Thu May 10, 2012 1:57 amHey Geek, I forgot to ask you, what chokes do you have in mind ?
Posted: Thu May 10, 2012 5:50 amSomething that will handel the current , a push pull output transformer would work as a choke . Its freqincy reponce wouldn't matter just its inductace ,the higher the beter
Posted: Thu May 10, 2012 12:10 pmHave you checekd Bruce Rozenblit's OTL that looks like yours? I think he added over-current protection somehow on the PSUs.
Posted: Thu May 10, 2012 11:11 pmTubeamp wrote:Hey Geek, I forgot to ask you, what chokes do you have in mind ?
Mark's right on the current. I had my eye on some larger Hammond reactor types (XL = ZL @ lowest freq... preferrably XL=4*ZL).
On holidays at the moment, so I'll recommend something more specific if you need when I get home.
Cheers!
Posted: Fri May 11, 2012 6:00 amThanks for your suggestions!
soundbrigade wrote:
Do you mean this circuit?
soundbrigade wrote:
Have you checekd Bruce Rozenblit's OTL that looks like yours? I think he added over-current protection somehow on the PSUs.
Do you mean this circuit?
Posted: Fri May 11, 2012 6:03 amI wonder though, how the choke will improve the amplifier's performance?
Posted: Sun May 13, 2012 7:38 pmBack home now.
I'd check out a Hammond 159ZA, good for 1A - it'll give 18 ohms reactance at 10Hz. Good for an 8 or 16 ohm speaker.
Chokes are nice because you get twice the swing of an active load for the same current.
Cheers!
I'd check out a Hammond 159ZA, good for 1A - it'll give 18 ohms reactance at 10Hz. Good for an 8 or 16 ohm speaker.
Chokes are nice because you get twice the swing of an active load for the same current.
Cheers!
Posted: Mon May 14, 2012 12:04 pmHi Geek, welcome back home, hope you had a great time!!
I assume I have to use 2 of those chokes per channel, right?
I assume I have to use 2 of those chokes per channel, right?
Posted: Mon May 14, 2012 1:25 pmI had a great time, thanks! :D
Yup! 2 per channel.
Cheers!
Yup! 2 per channel.
Cheers!
Posted: Wed May 16, 2012 1:06 amThanks Geek ! I will try the chokes as soon as I have some in hand.