Hi Quinnling 
It's a 50w per-block-pair, it sounds wonderful, especially on my A5 VOTTs . Sound isn't neither like a "normal" tubed amp, nor like transistors . Incredible high sound levels , unsaturated, astonishing dynamic , extremly precise on Schubert string quartet or Malher orchestra ... or tremendous for Pink Floyd or Beatles I would say : the subtle art of flamenco dance with the power of a V12 Jaguar engine The are 2 different OTLs shown , the latest : with 4 blue Tek transformers, the former : PSU only shown , in an old RADAR receiver mainframe ... hold on, more pictures in the next days , Wagtbtoobz
It's a 50w per-block-pair, it sounds wonderful, especially on my A5 VOTTs . Sound isn't neither like a "normal" tubed amp, nor like transistors . Incredible high sound levels , unsaturated, astonishing dynamic , extremly precise on Schubert string quartet or Malher orchestra ... or tremendous for Pink Floyd or Beatles I would say : the subtle art of flamenco dance with the power of a V12 Jaguar engine The are 2 different OTLs shown , the latest : with 4 blue Tek transformers, the former : PSU only shown , in an old RADAR receiver mainframe ... hold on, more pictures in the next days , Wagtbtoobz
coresta said:Hi , have a look at my last new OTLs on the french website : "radiofil " then "Forum", then "realisations personnelles" , then "un demi-mètre carré d'OTLs" ... in french but , photos and schematic included !
Hi
Can you tell me where the schematic is? I can only find extracts.
Andy
Coresta,
Looking forward to see your new pictures ... it is great for inspiration !
I recently finished one channel of an OTL , using 6C33 configured as an SRPP output stage. Very similar to the design from Sound Practice issue #16? Beside throwing some scary amount of heat and I could not get the DC offset to stablize. I hook it up to some cheap speakers ... there is magic in OTLs.
I'm converting the amp to Transcedent T8 OTL from the book Audio Reality.
Keep posting those pictures !
Quinnling
Looking forward to see your new pictures ... it is great for inspiration !
I recently finished one channel of an OTL , using 6C33 configured as an SRPP output stage. Very similar to the design from Sound Practice issue #16? Beside throwing some scary amount of heat and I could not get the DC offset to stablize. I hook it up to some cheap speakers ... there is magic in OTLs.
I'm converting the amp to Transcedent T8 OTL from the book Audio Reality.
Keep posting those pictures !
Quinnling
Poynton,
The T8 OTL is from Bruce Rozenblit. He has a patent on the design and published it on his book. I cannot give any schematics because he sells the cdrom version of his book on his web site.
http://www.transcendentsound.com/T8OTL.htm
You may want to try a patent search on google for more details.
QuinnLing
The T8 OTL is from Bruce Rozenblit. He has a patent on the design and published it on his book. I cannot give any schematics because he sells the cdrom version of his book on his web site.
http://www.transcendentsound.com/T8OTL.htm
You may want to try a patent search on google for more details.
QuinnLing
poynton said:
Hi Andy
I'm currently building a Transcendent T8 OTL. Like Quinnling, I can't give out the schematic as it is copyright. However Bruce's Audio Reality book is inexpensive and excellent value as an email download from his site. It has plenty of projects to keep one going.
I'm using the JJ EL509S as the power tube which is an electrically identical octal version of the older top cap EL509. The only difference is that due to the octal base it won't take 8000V pulses like the old one did!
The pics below show my layout which includes a 12B4A preamp section at the front before the driver stages. The second pic is of the subchassis modules undergoing their heater tests.
An externally hosted image should be here but it was not working when we last tested it.
An externally hosted image should be here but it was not working when we last tested it.
This next pic is of the completed preamp/driver stage module
An externally hosted image should be here but it was not working when we last tested it.
Although it looks complex it is actually pretty straightforward so long as you don't panic
Steve
Steve,
Just a word of warning on the JJ 509s
http://www.audioasylum.com/forums/tubediy/messages/12/124473.html
cheers
Just a word of warning on the JJ 509s
http://www.audioasylum.com/forums/tubediy/messages/12/124473.html
cheers
Hmm
Looking at Allen Wright's post I have to say that I have been running the EL509s in using my present EL37 single ended ultralinear amp and they have been happily running at 400V on the plates and the same on the screens with no ill effects or any nasty noises.
I've had them six weeks and have just plugged in the the last pair for burning in duties.
I had them going at around 200mA on plate and screen with 200V at one point, again with no problems.
Anyway we'll see how they work out.
Steve.
Looking at Allen Wright's post I have to say that I have been running the EL509s in using my present EL37 single ended ultralinear amp and they have been happily running at 400V on the plates and the same on the screens with no ill effects or any nasty noises.
I've had them six weeks and have just plugged in the the last pair for burning in duties.
I had them going at around 200mA on plate and screen with 200V at one point, again with no problems.
Anyway we'll see how they work out.
Steve.
Hi Quinnling , i dunnot have any offset as the cold (-) speaker output is tied to a floating 0v psu : The huge capacitors bank (2 x 4 x 3100 UF) is not tied itself to a centertap of the mains xformers . Any +3 v to -5v (average) variation of the center +140v /- 140V is effortless for my cherished 515-8Gquinnling said:
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