Hoffman Amplifiers Tube Amplifier Forum
Amp Stuff => Tube Amp Building - Tweaks - Repairs => Topic started by: scstill on April 15, 2021, 04:43:56 pm
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How would the Mod Tank 9AB1C1B with a 10ohm input work in a Fender twin reverb circuit with a 125A20B xfmr secondary impendence of 8ohm? I have the tank and want to build this reverb circuit to drive it.
It is tough to find a transformer with a 10ohm secondary. Is there a way to match the 8ohm xfmr to the 10ohm tank?
The 12AT7 driver plate voltage is noted at 400v on the Fender layout with a 25kohm primary that is 6.4w, yet the 125a20b is rated at 3.5w. Is that right?
How would the short delay of the 9AB1C1B compare with the long delay of the Twin Reverb?
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The 12AT7 driver plate voltage is noted at 400v on the Fender layout with a 25kohm primary that is 6.4w, yet the 125a20b is rated at 3.5w. Is that right?
No.
It's not 400V across the primary. It's 400V across the strapped 12AT7's. The 3.5W refers to the power at the secondary.
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I think the "10" windings are the same as the "8" windings for all practical purpose.
DC Volts across an impedance is NOT audio power.
Just do it.