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    Building, troubleshooting and testing of these amplifiers should only be
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    the safety precautions around high voltages.

Filament supply ARC D115mk2

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I would get at least one but preferably 3 E88CC / 6922 and replace the 6n23 as this is
what the amp is built for.
The 12AT7 / ECC81 might be damaged due to the wrong filament, this should also be replaced.
Changing component values to compensate for wrong tube will only make life harder for
next person that looks into this amp.
 
Hey, guys...Let me ask this...Pins 4 &5 of the 12at7 are tied together, the voltage to this point is 12.3vdc . That would mean its parallel, right? The data sheet for the at7 says 6.3 for parallel and 12.6 series. Is this correct? Thank you guys for the support. I'm trying to learn, it's got to be an obvious issue...
 
Hey, guys...Let me ask this...Pins 4 &5 of the 12at7 are tied together, the voltage to this point is 12.3vdc . That would mean its parallel, right? The data sheet for the at7 says 6.3 for parallel and 12.6 series. Is this correct? Thank you guys for the support. I'm trying to learn, it's got to be an obvious issue...

A lot of people are trying to help you, so far (more than a month) you did not follow any advice, your learning process is a bit weird, no offence intended. :rolleyes:
 
Hey, guys...Let me ask this...Pins 4 &5 of the 12at7 are tied together, the voltage to this point is 12.3vdc . That would mean its parallel, right? The data sheet for the at7 says 6.3 for parallel and 12.6 series. Is this correct? Thank you guys for the support. I'm trying to learn, it's got to be an obvious issue...
When 4&5 are tied together and 9 is the other end of the filament then it's
connected as 6.3V @300mA.
ecc88 draws 0.365mA , thus a resistor is needed to compensate when these two
tubes are series connected.
Note that variants of ecc88 ( 6922 e88cc etc) might have other filament currents
thus the setup used in ARD115 is somewhat bad engerneering.
To keep the original design the original tubes should be used.
 
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