Hoffman Amplifiers Tube Amplifier Forum

Amp Stuff => Tube Amp Building - Tweaks - Repairs => Topic started by: Tone Junkie on September 05, 2016, 01:44:55 am

Title: SE cathode cap for 6l6
Post by: Tone Junkie on September 05, 2016, 01:44:55 am

Whats a good cathode bypass resister and cap combo for 6l6 at 365 to 370 volts B+ . Im making a champ for the neighbor kid.
Ive done everything but SE style amps. I seem to be on a help the young guitar players around me kick. LOL
 Ive collected so many parts over the years. I figured I might as well put them to good use.
Bill

Title: Re: SE cathode cap for 6l6
Post by: sluckey on September 05, 2016, 08:29:34 am

250Ω 500Ω and 50µF is very common.

Title: Re: SE cathode cap for 6l6
Post by: Tone Junkie on September 06, 2016, 03:31:16 am

 I have those. I can get right on it.
Many thanks for your constant help.
Bill

Title: Re: SE cathode cap for 6l6
Post by: tubenit on September 06, 2016, 05:01:17 am

http://el34world.com/Forum/index.php?topic=20470.0 (http://el34world.com/Forum/index.php?topic=20470.0)

With respect, Tubenit

Title: Re: SE cathode cap for 6l6
Post by: TIMBO on September 06, 2016, 05:06:34 am

Hey Bill, Champ schem below. :icon_biggrin:

Title: Re: SE cathode cap for 6l6
Post by: shooter on September 06, 2016, 08:16:18 am

Sluckey picked it, 50uF is a good value.  I tend to increase the cap size with power, no logic other than everything sounds *tighter*, I typically use 100uf for KT88, 50uF (each tube) on PSE '84's, 6V6's and 6L6's.

Timbo, how well does the *bias* pot work on that champ?

Title: Re: SE cathode cap for 6l6
Post by: sluckey on September 06, 2016, 09:15:21 am

Hey, I jumped the gun on the resistor value. I had blinders on and overlooked the "SE" for some reason. A 500Ω or 470Ω would be a better choice for a single 6L6. Sorry.

Title: Re: SE cathode cap for 6l6
Post by: TIMBO on September 06, 2016, 01:56:46 pm

Hey shooter, This schem was in my library and I have no idea of its origans, but looks interesting :icon_biggrin:

Title: Re: SE cathode cap for 6l6
Post by: kagliostro on September 06, 2016, 02:02:45 pm

On the link Tubenit posted

http://el34world.com/Forum/index.php?topic=20470.0 (http://el34world.com/Forum/index.php?topic=20470.0)

I posted a Weber schematic that uses 807 tube, the 807 is the same of 6L6 (only with TopCap)

and there the choice was 300R + 25uF

on one other schematic with 6L6 that I posted in the same thread

the choice was 500R + 50uF

I think that a bit of experimentation must be done before to decide a definite way

Franco

Title: Re: SE cathode cap for 6l6
Post by: PRR on September 06, 2016, 03:02:30 pm

If the cathode resistor isn't something like Rload/14 (for 6V6 6L6 EL34 6550), then something is mis-matched.

I'd worry first about a reasonable fit between available B+, load, and plate dissipation.

Title: Re: SE cathode cap for 6l6
Post by: shooter on September 06, 2016, 08:34:02 pm

Quote

but looks interesting :icon_biggrin:

Thanks Timbo, that it does, I see a stand-alone PA in my crystal skull,
might add some biased pot :icon_biggrin:

Title: Re: SE cathode cap for 6l6
Post by: Tone Junkie on September 06, 2016, 11:11:52 pm

Thanks guys