Nfb in this circuit?

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guile
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Nfb in this circuit?

Post by guile »

Could anyone tell me if this circuit has a nfb-loop?
Thanks
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xtian
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Re: Nfb in this circuit?

Post by xtian »

It does not.
I build and repair tube amps. http://amps.monkeymatic.com
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guile
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Re: Nfb in this circuit?

Post by guile »

Thanks.

The reason for this question is that I suspect that some effectpedals (notably dirt etc.) oscillate or whine more often with amps that do not have a nfb-loop.
What do you think?
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xtian
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Re: Nfb in this circuit?

Post by xtian »

I have not heard that, and cannot imagine why it might be the case.
I build and repair tube amps. http://amps.monkeymatic.com
TUBEDUDE
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Re: Nfb in this circuit?

Post by TUBEDUDE »

No feedback there.

A poorly designed amp may be more stable with feedback. And likewise, a poorly designed amp with no feedback can be conditionally stable and become unstable in some circumstances, i.e. pedal inserted with differing impedance, output level, open, etc.
Tube junkie that aspires to become a tri-state bidirectional buss driver.
TUBEDUDE
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Re: Nfb in this circuit?

Post by TUBEDUDE »

Incidentally, looking at your schematic, i see you have a cathode biased output. If you lift the heater balancing resistors (100R) from ground, and connect them to the power tube cathode, you can reduce noise as the heater hum is no longer coupled as strongly to the cathode in each tube. Just an observation.
Tube junkie that aspires to become a tri-state bidirectional buss driver.
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guile
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Re: Nfb in this circuit?

Post by guile »

Thanks for the replies guys.
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