choke transformer question

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salute again !


SORRY FOR MY MISTAKE !

i was confused. the tube wasnt 6c33, it was an 6h30 !
recently used on mark levinsons pre & power.

on the counterpoint the cathode is tied to ground.
(checked literally & seen on schematic)
m. e. philosophy of zero feedback.

in this way the tube tends to draw a lot of current !
22k ohm resistor that almost burned the pcb, and sounded
very harshy (50 vdc on plate)

i replaced that resistor with a 100k ohm & dropped to 37 vdc
& sounded great, no harshiness at all !

i am happy with my pre but as diy as us in the quest for the holy grail , i was wondering if there a difference with the 500 ohm
resistor on the cathode tied to ground.

for my personal opinion , i dont like to use any solid state device
for the tubes because the experience that i had switching from
s.s. to tube rect was huge.

2 weeks ago i repaired a mark levinson latest pre to a local audiophile store.i dont remember the model but was the mnodel
with full wireless remote, a lot of nice functions, 6h30 on the outputs & a solid state harshy sound.

the price was over 2000 bucks & made a listening test one nite
and i was happy !!!!!! :cool:

all my mods worth it !

i feel that on audio chain simpler designs are better.

i have 2 mcintosh mc 75 amps heavily modified,

removed 2 tubes (no feedback & no 600 ohm option for pa)
triode mode
class a/ab with a flip of a switch
now am tryng to remove the s.s. diodes to tubes.

another proyect that i have is an power amp coupled with transformers. (no caps on the audio chain)

lets see what happens.

thanks
richt
 
diyAudio Senior Member
Joined 2002
KONTRAPUNKT III

Hi Richt,

It is pretty hard to explain everything in just a couple of posts but here goes:


i was confused. the tube wasnt 6c33, it was an 6h30 !

Mark Levinson using tubes?? Need to double check but what else is new.
Those tubes can't be interchanged with the one you got so better forget it.



on the counterpoint the cathode is tied to ground.

Alright,so the cathode is tied to ground.Then you should look for a resistor from grid to ground (~10M if memory serves me correctly)


m. e. philosophy of zero feedback.

No,nothing to do with feedback really.


(50 vdc on plate)

That's not correct,a 50 VDC drop across is more likely.

i replaced that resistor with a 100k ohm & dropped to 37 vdc

That's a very high value for a 6922 anode resistor but if you're happy so am I.

for my personal opinion , i dont like to use any solid state device

My philosophy entirely.But you still have some in the circuit and I don't want to tempt any devils here.

And I still don't know much more then last post to be quite frank with you.Line stage? Phono section.

BTW,since you seem to have the circuit diagram,why not scan it in and e-mail it to me?
You can then show your changes on a copy of the original perhaps?
It would make my guesswork a lot easier.

Regards,;)
 
hi frank

sorry , i read fast my logbook of equipment for service and
the pre is an audio research, the mark levinson was an power amp. nothing to do with our discussion. sorry

i rechecked the schematic and the cathode is tied to ground plane !

i dont have a scanner right now.



J = plate with 37 vdc from 100k res.
---- = audio in from volume pot. 0 vdc
T = tied to ground

thanks for your time
richt
 
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