Hoffman Amplifiers Tube Amplifier Forum

Amp Stuff => Tube Amp Building - Tweaks - Repairs => Topic started by: madnis on December 16, 2022, 05:03:09 pm

Title: not so new But... pop when switching parallel TBM caps
Post by: madnis on December 16, 2022, 05:03:09 pm
Tone Stack set up to switch from Marshall to Fender
4PDT on-on. Pops when switched?
 
(Sorry this went way off topic
Schematic 07-29-2024 correct
let me know if you see errors)
Title: Re: not so new But... pop when switching parallel TBM caps
Post by: sluckey on December 16, 2022, 06:55:43 pm
Tone Stack set up to switch from Marshall to Fender
Nice idea.
Title: Re: not so new But... pop when switching parallel TBM caps
Post by: PRR on December 16, 2022, 09:23:43 pm
> I can't figuire out where to put "pull downs" on TMB TS parallel caps?!

The Fender and Marshal tonestacks use the tone caps AS blocking for DC.

You need to add a large cap in front.

DRAW A PICTURE! We can't talk about it all arm-wave abstract.
Title: Re: not so new But... pop when switching parallel TBM caps
Post by: madnis on December 16, 2022, 11:57:51 pm
Schematic 07/31/24
(Not shown in schem.
Zero Loss effects loop between
tone stack treble out and MV)

Went with switch for gain stage
10k/4.7k/2.7k

Add 1.2k and 16uf to de-couple V1

Decided to use PIO coupling caps
V1a & V1b .047uf and .01uf
Title: Re: not so new But... pop when switching parallel TBM caps
Post by: sluckey on December 17, 2022, 06:18:46 am
Check with sluckey. He gets it.
NOT SO!
Title: Re: not so new But... pop when switching parallel TBM caps
Post by: PRR on December 17, 2022, 09:31:52 am
https://el34world.com/Forum/index.php?topic=4207.0
Title: Re: not so new But... pop when switching parallel TBM caps
Post by: madnis on December 17, 2022, 11:04:34 am
My sincerest apologize to both of you. I thought
I was presenting my idea and implementation in
the venaculer of the posts I'd been reading over
the years. (sluckey when you said "nice idea"
I thought that meant I'd conveyed my thoughts
and I was happy that it was understood.)
Title: Re: not so new But... pop when switching parallel TBM caps
Post by: sluckey on December 17, 2022, 11:32:26 am
Now was that so hard? Certainly much clearer than your verbose description.

My "Nice idea" comment was just fluff. My real comment was in my signature line.  :wink:

Anytime you switch capacitors in an audio signal path you are very likely to cause a pop. Many times you can avoid the pop by placing a high value resistor across the switch contacts. Easy to try. No guarantees though.
Title: Re: not so new But... pop when switching parallel TBM caps
Post by: madnis on December 17, 2022, 12:45:24 pm
Yep, that worked.

6.8meg across switch

Thank you all for the response!

Title: Re: not so new But... pop when switching parallel TBM caps
Post by: sluckey on December 17, 2022, 12:51:00 pm
No annoy. I play with you 'til you get it.   :icon_biggrin:
Title: Re: not so new But... pop when switching parallel TBM caps
Post by: madnis on December 17, 2022, 01:00:37 pm
I will live by from now on


"A schematic, layout, and hi-rez pics are very useful for troubleshooting your amp. Don't wait to be asked. JUST DO IT!"
Title: Re: not so new But... pop when switching parallel TBM caps
Post by: tubenit on December 17, 2022, 01:09:17 pm
Just an idea for discussion.  Not saying this would work well.  If it did work, I'd think one would have to switch settings between songs and not on the fly.


With respect, Tubenit
Title: Re: not so new But... pop when switching parallel TBM caps
Post by: madnis on December 17, 2022, 01:16:39 pm
Schematic: "2 For 1 SE EL34 "

I'm using Digikey Schem-it
to draw these.

Schematic 07/31/24
Zero Loss effects loop between
tone stack treble out and MV

Went with switch for gain stage10k/4.7k/2.7k

Decided to use PIO coupling caps
V1a & V1b .047uf and .01uf
Title: Re: not so new But... pop when switching parallel TBM caps
Post by: pullshocks on December 17, 2022, 02:03:34 pm
Years ago the late Steve Ahola had a couple designs, the Promaniac and Son of Promaniac that featured tone stack switching


sopm_1.pdf (blueguitar.net) (https://blueguitar.net/new/schem/blue_gtr/promaniac/sopm_1.pdf)


https://blueguitar.net/new/schem/blue_gtr/promaniac/pro_man7.pdf
Title: Re: not so new But... pop when switching parallel TBM caps
Post by: madnis on December 17, 2022, 02:11:48 pm


07/31/2024

max. dissp. ~88%

329 plate
320 screen
303 A to K     
-20 at K
~65ma