CV2799

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Mike H
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#76

Post by Mike H »

pre65 wrote:The OPT are 5K single ended, huge great things that I purchased for my 833a project.
Ah thought so :D
 
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pre65
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#77

Post by pre65 »

I've had another C3g go dead on me, so I've only got 1 working now. :cry:

What's a good (preferably inexpensive) single triode with a similar gain to try. I have got a couple of D3a but they are getting a bit expensive these days.

What about those Russian pentodes that everyone was raving about when connected as triodes ? Can't remember the number.

Anyway, I've got the simple KT66 push pull filling in at the moment, it goes louder, that's for sure. :wink: :lol:
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andrew Ivimey
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#78

Post by andrew Ivimey »

4p1L very cheap.
Philosophers have only interpreted the world - the point, however, is to change it. No it isn't ... maybe we should leave it alone for a while.
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andrew Ivimey
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#79

Post by andrew Ivimey »

4p1L very cheap.
Philosophers have only interpreted the world - the point, however, is to change it. No it isn't ... maybe we should leave it alone for a while.
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pre65
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#80

Post by pre65 »

andrew Ivimey wrote:4p1L very cheap.
That's handy, they use the same socket as C3g, and also they seem directly heated.

Unusual for a pentode ?
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#81

Post by simon »

I've a feeling they're not that similar though Phil, C3g triode connected has a gain of 40-odd, can't remember what 4P1L is , but much less as it's DHT? Might not be a problem to you though.
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pre65
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#82

Post by pre65 »

simon wrote:I've a feeling they're not that similar though Phil, C3g triode connected has a gain of 40-odd, can't remember what 4P1L is , but much less as it's DHT? Might not be a problem to you though.
And it's NOT a 6.3v heater either. :cry:

Filament Voltage: 2.1/4.2 volts @ 650mA/325mA respectively
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pre65
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#83

Post by pre65 »

What about the 6s45 ?
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pre65
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#84

Post by pre65 »

I could use my pair of 6N7 (not 6SN7) and parallel up the anodes and grids, the cathode is common.

At least I could get the amp up and running again without

A) waiting weeks for delivery

B) no cost option

C) cos I fancy it

D) there is no D (copyright Bedford towers)

E) it might sound better

F) why not ?

G) where's Nurse gone, I need the toilet (again). :wink:
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#85

Post by pre65 »

Actually, the anode load for the C3g was one of Mikes interstage transformers, so as the 6N7 anodes are in parallel the resistance will be halved, which should be a good thing ?
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Mike H
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#86

Post by Mike H »

C3G is that special one by Siemens innit? Can't find an equivalent that's like
 
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pre65
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#87

Post by pre65 »

Mike H wrote:C3G is that special one by Siemens innit? Can't find an equivalent that's like
No worry Mike, the whole ethos of this amp is about not knowing what I'm doing. :wink:

At this very moment octal bases are in position and wiring up has commenced. Just got to find the 800R resistors that my list says are in stock. :)
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Mike H
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#88

Post by Mike H »

You have lists? :shock:
 
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pre65
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#89

Post by pre65 »

Mike H wrote:You have lists? :shock:
Indeed I do, in fact not only have I got 800R but also some 778R, but I may go to 1K which is a bit more on the safe side. (5ma instead of 6ma).

EDIT

My 800R are all in fact 778R
Last edited by pre65 on Wed Nov 14, 2012 4:01 pm, edited 1 time in total.
The only thing necessary for the triumph of evil is for good men to do nothing.

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pre65
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#90

Post by pre65 »

I've just slipped with the scalpel and invoked Ivimeys 3rd law.

Man who builds amps WILL spill blood. :wink: :lol: :lol:
The only thing necessary for the triumph of evil is for good men to do nothing.

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