Hello ! If I have a 5000 ohm plate to plate output transformer but I want to use it for 6V6 8000 ohm plate to plate can I insert 3000 ohm power resistors in series from each plate to make it 8000 ohms? Thanks for info!

Chris

No need to add resistors. This will just reduce output as some signal will be lost across the resistors.

Use the transformer that you have. Signal output may be less but overall quality can be better. A tranformer made for 6L6's will have more iron.

Norm

:Hello ! If I have a 5000 ohm plate to plate output transformer but I want to use it for 6V6 8000 ohm plate to plate can I insert 3000 ohm power resistors in series from each plate to make it 8000 ohms? Thanks for info!
:

:Chris
:Oh, I thought it would shorten tube life if impedance was to low (exceed heat dissipation)??
: No need to add resistors. This will just reduce output as some signal will be lost across the resistors.
:
: Use the transformer that you have. Signal output may be less but overall quality can be better. A tranformer made for 6L6's will have more iron.
:
:Norm
:
::Hello ! If I have a 5000 ohm plate to plate output transformer but I want to use it for 6V6 8000 ohm plate to plate can I insert 3000 ohm power resistors in series from each plate to make it 8000 ohms? Thanks for info!
::
:

Chris

That 8000 ohms is impedance not DC resistance. Actual DC resistance will just be a couple hundred ohms. Not adding resistance won't shorten tube life. Adding resistance will reduce plate voltage and could cause a longer tube life. This will be at the sacrifice of performance.

Norm

::Chris
::Oh, I thought it would shorten tube life if impedance was to low (exceed heat dissipation)??
:: No need to add resistors. This will just reduce output as some signal will be lost across the resistors.
::
:: Use the transformer that you have. Signal output may be less but overall quality can be better. A tranformer made for 6L6's will have more iron.
::
::Norm
::
:::Hello ! If I have a 5000 ohm plate to plate output transformer but I want to use it for 6V6 8000 ohm plate to plate can I insert 3000 ohm power resistors in series from each plate to make it 8000 ohms? Thanks for info!
:::
::
:

Agrree with all. The windings ratio will not change, so you may be better off using the 4 ohm winding for an 8 ohm load, providing you have multiple secondary windings. But you should be ok in any case. By the way, once you get it built, if it squeals like a stuck pig, unplug immediately and reverse your primary wires to the output tubes.

:Chris
:
: That 8000 ohms is impedance not DC resistance. Actual DC resistance will just be a couple hundred ohms. Not adding resistance won't shorten tube life. Adding resistance will reduce plate voltage and could cause a longer tube life. This will be at the sacrifice of performance.
:
:Norm
:
:::Chris
:::Oh, I thought it would shorten tube life if impedance was to low (exceed heat dissipation)??
::: No need to add resistors. This will just reduce output as some signal will be lost across the resistors.
:::
::: Use the transformer that you have. Signal output may be less but overall quality can be better. A tranformer made for 6L6's will have more iron.
:::
:::Norm
:::
::::Hello ! If I have a 5000 ohm plate to plate output transformer but I want to use it for 6V6 8000 ohm plate to plate can I insert 3000 ohm power resistors in series from each plate to make it 8000 ohms? Thanks for info!
::::
:::
::
: