Single ended OTL Transcendent

[adason]

http://www.transcendentsound.com/singleended.htm

Has anyone built or heard the small power SE OTL from Transcendent?

I have over 100 dB speakers and I am tempted. Just as gift for X mass for myself. I have numerous tube amps, but have never ever had OTL in my system.

Any input?

Thanks,
ed

[Andrewbee]

I built a kit. IMHO it is an excellent amp. Most powerful 1.5 Watts I ever used.
I use with Jerico Horns. One thing though, it runs HOT, yes its class A and it should run warmer than usual. Did I say it runs HOT?
I mean it runs HOT so make sure it has room around it and is not placed in an enclosed rack or something similar.
I of course had to play around with it and replaced the stock Solen interstage coupling caps with Dynamicaps and replaced the stock rectifiers with hexfreds.

Did that make a difference? Dunno, it sounded great stock and still does, it might be smoother now.
I also tried replacing the stock output caps with fancy $$$$ Black Gates. Put back in the stock electrolytics after a few months, the Black Gates do not work in this application.

Standouts for me are the bass and clarity, the rest of it sounds very good

Andrew

[korneluk]

Originally posted by adason
I have over 100 dB speakers and I am tempted... I have numerous tube amps, but have never ever had OTL in my system.

Neither have I. My horns are over 100dB efficient horns and I was contemplating building an Atma-Sphere M-60 Mk.II clone, but the old ASOG (Atma Sphere Owner's Group) website is gone and have not been able to find a schematic - still looking.

Like someone else pointed out, the amps run hot! The reason I like the Atma-Sphere fully balanced differential bridge design is that one should be able to reduce the number of tubes, equal number per side, to better manage the heat.

[adason]

Hi Andrew,
thanks for great info. I think I will give it a try.
ed

[Andrewbee]

I think I will give it a try

Great!

I'll let Bruce know to prepare my commission

Just kidding!

It really is a great amp.


Andrew

[adason]

Well, folks, the kit arrived, and four evenings of labour later, I have single ended output transformerless house heater...err, amplifier. Its happily burning in right now with just a testing speakers for now. Too soon to be plugged in into line array or horns. Will report later. Here is pic of finished amp.
ed

[adason]

and the guts

[Jeb-D.]

Very nice! Have you got a chance to listen to it yet on a efficient pair of speakers? Their T-16 stereo kit looks pretty sweet too.

[adason]

yes, after few days of testing, i decided to plug it into my horn speakers (18" cervin vega, radian compression for midrange, cervin vega horn tweeter)
amp is not fully after break in, so I expect the sound to further change
here are the first impressions:

transcendent otl amp replaced my highly tweaked magnavox single ended el84 amp
sound is different, much cleaner, less sweet, much more transparent, if that is what one prefers
magnavox has 2-5% distortion, so the sweetness is probably overdone
transcendent does not seems to have much distortion at all
if one word should describe the sound, clean would be the word
it has nice hights, which were little sharp at first, but once tubes had hours on them, it got better, nice shimmering hights, midrange is crystal clear, from first moment, like no glass in windows clean, bass is there, its deep, but its not as authoritative as solid state bass, definitely not muddy as se tube bass can be
i was expecting a little more bass, but that might improve later, but than again, I am comparing to solid state amp, since I had system biamped

so far very happy with the result

[Ricdelros]

hi korneluk,
Did you find Atma-Sphere 60mkII? I also want to clone this unit.
'just tired of interneting to find this circuit. If you have now, I'll appreciate if you could share it to me. tks