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Old 14th April 2003, 11:52 AM   #71
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Default Re: Volume Pot (the famous one)

Quote:
Originally posted by holm
... maybe the designer had some gain preset
device in Mind, not a volume control.

Holm
And what about the phase splitter issue???
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Old 14th April 2003, 12:07 PM   #72
holm is offline holm  Germany
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Default Phasesplitter issue

Yea, it is a poor design anyway.
It looks to me, that the designer mixed several
peaces of schematics. The 2C51 is the wrong
tube in the phasesplitter, C4 and R6 arex'nt necessary, and the cathodes are connected to nowhere.

BTW: the not connected cathodes remebering me to an unusual schematic with the ECLL80.
They where groundet with the ping for the
triode section, floating around in the schematic ...


Holm
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Old 14th April 2003, 12:30 PM   #73
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hi tube_Dude,

Quote:
i presume that is one more case of a chinese product sell in west with a western name...but that i don't know!
their explaination is right, if not do this transaction.

how can get a good selling price.

they all sell fnish product & use western name.
Stated that in europe made.

thnaks

Thomas
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Old 15th April 2003, 06:20 PM   #74
Foes is offline Foes  Belgium
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Hi,

Despite of its bad trash design and after Jorge's advices, il's almost working properly.
But, i have fing something strange again (i think) The EL90 have 9 pins instead of 7. Is it a special chinease design? If the pinout is the same, is it possible to replace it with EL84 or by what ??

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Old 15th April 2003, 07:05 PM   #75
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An EL90 tube cannot have nine pins - the '9*' designation at the end means that it was designed for a B7G base - seven pins only. If your tubes have this designation they have been wrongly labelled.

As for changing them for EL84s if the pin connections are the same - I doubt if you would do any damage to the amp, especially as it seemed to be designed for EL41s anyway. You might have to experiment with bias resistors and suchlike for optimum operation.
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Old 15th April 2003, 07:15 PM   #76
Foes is offline Foes  Belgium
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Default EL90 for shure...

Hi Bournville,

I have checked it again. THey are well labeled EL90 and have 9 pins.
Again a mystery of the chinese electronic...
If you check on the shematics, you will see as alternate outupt tube, EL41 with 9 pins. It doesn't exist neither...
Anyway, i will check inside to find the tube pinout...
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Old 15th April 2003, 07:30 PM   #77
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...The EL41 is a eight pin tube, the '4*' designation meaning it has a B8A base - I assumed the errors on the original circuit were typographical errors. The EL90 designation is definately wrong if that tube has nine pins. It could be a mis-labelled EL84.

The original schematic does give EL84s as an alternative - why not try them if it does not mean too many circuit alterations?
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Old 15th April 2003, 07:36 PM   #78
Foes is offline Foes  Belgium
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Bournville,

You are righnt about the numbering. I dont realy understand <ht they do...
Anyway, i will first chech the pinout inside...
Rgrds,

Gauthier
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Old 15th April 2003, 11:16 PM   #79
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Default THE BETS ARE ON...

Hi,

From day one we all smelled something fishy regarding these output tubes anyway.

Quote:
The original schematic does give EL84s as an alternative
Yup, and I think these ought to be EL84s.

I bet you that our buddy Foes will never, ever buy a Chinese amp again...maybe just about a cup of tea...

Cheers,
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Old 16th April 2003, 05:08 AM   #80
Foes is offline Foes  Belgium
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Default Dans la M...

Hi Belgian !

Well "Je suis dans la m..."
If i want to retube, i am dead... I have checked, the pinout of the schematics match with the inside of the amplifier. And the pinout of this tube is completely ususual...
As it is wired on a PCB...

Regards,

Gauthier
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