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Hoffman Amps Forum image Author Topic: Are these heater voltages now too low?  (Read 2449 times)

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Offline frank57

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Are these heater voltages now too low?
« on: November 22, 2011, 09:51:22 am »
Well I've gone from 7.7 down to this:
Voltages on el84:
pin 4 2.87
pin 5 2.96

so a bit off.
The balance was off by 3.86 and 2.97 before.
 12ax7:
2.87 on both
pin9 2.98
9 to 4/5 5.87

Can any problems result from these voltages?
I'll check with my other multimeter.
What I don't get is why there's an unbalance there.
It's less than before.
If I use one set of diodes an artificial ct it's balanced but adds hiss.
Not sure what's the best route.

voltages today a little higher at 6.16 and 3.02 3.13
« Last Edit: November 22, 2011, 12:03:34 pm by frank57 »

Offline tubenit

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Re: Are these heater voltages now too low?
« Reply #1 on: November 22, 2011, 12:15:26 pm »
I played a Dan Electro Centurian 275 for yrs with heater voltage at 5.76 vac. It was the best sounding mass produced amp I've owned.

With respect, Tubenit

Offline frank57

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Re: Are these heater voltages now too low?
« Reply #2 on: November 22, 2011, 03:18:30 pm »
I think I'm ok too.
I don't think it will go below 5.87.

Offline FYL

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Re: Are these heater voltages now too low?
« Reply #3 on: November 22, 2011, 04:34:03 pm »
Quote
Can any problems result from these voltages?

The spec is 6.3 V ± 10%, anything between 5.67 and 6.93 V is AOK.


 


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