Choke + Resistor

[Leevi]

I have reused the chassis of a commercial amp and its components for a 5D3 build.

There was a choke installed on the chassis and I thought to benefit from it.
I replaced the 10K resistor with that choke and feel that I should add some resistor there as well.

Choke and resistor in serial could be an option. Maybe not 10K but some smaller 5K or 3K?
Do you think the choke and resistor in serial is good way or is choke and separate screen resistors a better solution?

https://el34world.com/charts/Schematics/files/Fender/Fender_deluxe_5d3_schem.pdf


/Leevi

[shooter]

not sure your intent
me I'd probably move everybody left so
put choke where 10k is, move B+ tap to left of choke
add 1-5k, another cap left of the R and tap screens there
leave pre as is
 

[jjasilli]

The choke replaces the B+ R; though Fender added 470R screen resistors in some amps.

[sluckey]

Why do you want to put a choke in a 5D3? You risk ruining all the mojo of that old circuit.

[jjasilli]

IMHO, chokes make the world a better place.  Note that with the choke, downstream B+ will be higher.  Either keep that or compensate with larger dropping resistors downsteam.

[shooter]

chokes make the world a better place

yup, just not ready for that 1-5 stretch I'd get from 12 peers 

[pdf64]

Replacing the 10k HT dropper to the g2 node with a choke (assume low resistance) will significant increase the g2 voltage. That will increase plate current and hence dissipation significantly. ie totally screwing up the operating point. To get it back in line, moving to fixed bias is the obvious choice, otherwise squish will be significant.
Seems like the 5D3 has morphed into a 6G3.
If you want to keep it as a 5D3 and keep the choke, then add a resistor in series with it to make the total resistance up to 10k.

[jjasilli]

All these suggestions are good - differnet approches.   Note that @ idle the screen draws about 0 current.  So screnn voltage will show little difference at idle.  The effect will be more pronounced as signal voltage increases.  There is no right or wrong (within operational limits). 

[sluckey]

As long as you're 'improving' the 5D3 you may want to replace that lame paraphase inverter with a LTP. And fix that screwed up volume pot wiring.   

Hey, that sounds like the same path Leo took. That path leads to the Blues Deluxe.   

[PRR]

You can also change to 6L6, or four 6L6, etc.

If you want a 5D3, build it like Fender did. If you deviate from his path, you can have something else, bust as pdf64 says you may get into trouble.

[Leevi]

Thanks for the proposals. I'll test different options, anyway the choke just replacing the 10K
resistor is not an option.


/Leevi

[shooter]

the choke just replacing the 10K resistor is not an option.

because voltage is too high?
because the amp sounds like toilet water?
because it looks bad?
 

[Leevi]

because voltage is too high?because the amp sounds like toilet water?because it looks bad?

because screen voltage is almost the same as plate


because headroom has increased and typical 5D3 sound is partly lost.


It looks bad too, if some tech open it 


/Leevi