Here photos of the stereo test environment in a sonic performance test with Tango output transf. and the final driver circuit with Lundahl 100H.
http://www.audiodesignguide.com/Claudio845/photoAll1a.jpg
and a beatiful night view
http://www.audiodesignguide.com/Claudio845/photoBlue1a.jpg
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Using only two simple resistors on catode and ac filaments I ear no noise on the my Monitor 2 and Martin Logan Aerius loudspeakers.
Probably if you have high efficiency loudspeakers it is necessary a use dc filaments or a simple trimmer on cathode.
The power is enough to drive any 88-90db loudspeakers.
The sound depend in great part by the interstage capacitor.
http://www.audiodesignguide.com/Claudio845/photoAll1a.jpg
and a beatiful night view
http://www.audiodesignguide.com/Claudio845/photoBlue1a.jpg
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Using only two simple resistors on catode and ac filaments I ear no noise on the my Monitor 2 and Martin Logan Aerius loudspeakers.
Probably if you have high efficiency loudspeakers it is necessary a use dc filaments or a simple trimmer on cathode.
The power is enough to drive any 88-90db loudspeakers.
The sound depend in great part by the interstage capacitor.
Rod,
In any case I prefer the sound of the new 845 v2 but this only my opinion.
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I don't see real solutions to have a Jensen copper film like interstage in this design with 6HV5A.
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Probably a solution could be use the Bartolucci interstage transf. INT7 with 100H.
In any case I prefer the sound of the new 845 v2 but this only my opinion.
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I don't see real solutions to have a Jensen copper film like interstage in this design with 6HV5A.
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Probably a solution could be use the Bartolucci interstage transf. INT7 with 100H.
I am speaking with Bartolucci to find the best component for this use.
Probably the INT.XR-B should be the best choice.
There are no other products with these characteristics:
Lprim=100H
Rdc=200 400ohm max
Idc=25mA
Vout=Vin=120-140Vrms
Rapporto=1:1
Probably the INT.XR-B should be the best choice.
There are no other products with these characteristics:
Lprim=100H
Rdc=200 400ohm max
Idc=25mA
Vout=Vin=120-140Vrms
Rapporto=1:1
The price 130 euro each is only for my first 2 samples to test, I don't know final price.
Please ask to:
BARTOLUCCI TRANSFORMERS
Nuova Ricerca e Sviluppo
Via San Martino, 3 - 61032 Fano (PU)
Phone: +39 0721.820225
Phone: +39 0721.861238
Mobile: 334.3863576
e-mail: ricercaesviluppo@mobilia.it
Please ask to:
BARTOLUCCI TRANSFORMERS
Nuova Ricerca e Sviluppo
Via San Martino, 3 - 61032 Fano (PU)
Phone: +39 0721.820225
Phone: +39 0721.861238
Mobile: 334.3863576
e-mail: ricercaesviluppo@mobilia.it
I see it is possible use LL1692A normal or amorph version
Lprim. = 125H with 18mA
in the 4:3.5 configuration
Lprim. = 125H with 18mA
in the 4:3.5 configuration
I am waiting on the first days of January both the interstage transformers, Lundahl and Bartolucci.
So soon I will update this Forum with new test.
It is sure that the first LC solution with not the best and in many case the interstage + inductance cost is quite equal to a good interstage.
So soon I will update this Forum with new test.
It is sure that the first LC solution with not the best and in many case the interstage + inductance cost is quite equal to a good interstage.
Nice. I've only used the 6HV5A in choke loaded cathode follower duty. How do you like it plate loaded?
Having >1000v between primary and secondary of the interstage transformer seems dangerous to me. Have you checked with Lundahl regarding the insulation rating?
Generally, Ra of a pentode run in triode mode is much less than the pentode Ra. Possibly the Ra is ~ 1000 ohms or less so IT's with less than 100 H should work. The pentode Ra of the 6HV5A is 4600.
I'm no engineer so please correct me.
I'm no engineer so please correct me.
dshortt9 said:
There can be no pentode mode of a 6HV5 since it only has one grid. It is a true physical triode. It has added beam forming plates that prevent the electron stream from irradiating parts of the inner tube structure and anode by statically fixed physical shadowing.
Someone please correct me if I am mistaken.
Doh! Thanks, I was looking at the GE datasheet and they showed the beam forming plates as grid lines. Actually reading the info confirmed what you said. Now I get it.
What's the miller like for this first stage? From nj7p it would look like the miller is 300*1.8pf + 22pf. That seems pretty tough to drive for most sources. Are you going to preceed it with a buffer?
I have spoken with Lundahl about the LL1668 problem.
It is not an isulation problem, the Lundahl product can work until 1500V without problem.
It depend by the parasite capacitor so It can be resolved with a simple separation of the LL1668 and the chassie ground.
Follows the new frequency response of the last LC version using Ll1668 and Mundorf 2.2uF.
I will test soon the interstage transformers Lundahl LL1692A and Bartolucci.
It is not an isulation problem, the Lundahl product can work until 1500V without problem.
It depend by the parasite capacitor so It can be resolved with a simple separation of the LL1668 and the chassie ground.
Follows the new frequency response of the last LC version using Ll1668 and Mundorf 2.2uF.
I will test soon the interstage transformers Lundahl LL1692A and Bartolucci.
Attachments
Andrea
You used to play with OTLs some time ago and you got a lot of us hooked up on them. Now you seems to concentrate on high voltage single ended designs. Do you get more out of these designs than OTL? I am really interested to know what your sonic results are in comparison with all these designs....
You used to play with OTLs some time ago and you got a lot of us hooked up on them. Now you seems to concentrate on high voltage single ended designs. Do you get more out of these designs than OTL? I am really interested to know what your sonic results are in comparison with all these designs....