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DIY Stompboxes => Building your own stompbox => Topic started by: rangermaster on February 07, 2021, 02:26:14 PM

Title: Adding gain & volume
Post by: rangermaster on February 07, 2021, 02:26:14 PM
Hi there. Maybe a noob question but i cant find anything about it that helps me out.

I would like to try this schematic

(https://i.postimg.cc/JyZ2SWmJ/joesodsc.gif) (https://postimg.cc/JyZ2SWmJ)

Is it possible to add a gain and a volume pot to this ? If so.. what should be good pot values and how/where to add them ?

Thanks !
Title: Re: Adding gain & volume
Post by: antonis on February 07, 2021, 02:57:26 PM
It depends on whether you are satisfied of present configuration gain as maximum one..

If so, you can replace 680R Emitter resistor with with a 500R pot + 180R resistor and wire upper leg of 22μF cap on pot's wiper..

As for Volume control, a 100k pot on output should be fine..

P.S.
Schematic is coming asap..
Title: Re: Adding gain & volume
Post by: rangermaster on February 07, 2021, 03:09:15 PM
Ok thanks ! I'll wait for your schematic!
Title: Re: Adding gain & volume
Post by: antonis on February 07, 2021, 03:11:21 PM
Here you are..  :icon_wink:

(https://i.imgur.com/dVBVJVi.gif)

P.S.
You can study Big Muff Π clipping stages 'cause it's just a modified one..
(470k feedback resistor in original design is splitted into 2 X 220k, one of them decoupled by 10nF cap for raising stage input impedance..)
Title: Re: Adding gain & volume
Post by: rangermaster on February 07, 2021, 03:29:55 PM
Thanks man! That's quick

I'll try this tomorrow and see if i can understand these schematics!

Normally i use those vero layouts
Title: Re: Adding gain & volume
Post by: rangermaster on February 07, 2021, 05:23:48 PM
I think you mean a 500K pot with a 180ohms resistor ?
Title: Re: Adding gain & volume
Post by: antonis on February 07, 2021, 05:50:26 PM
Quote from: rangermaster on February 07, 2021, 05:23:48 PM
I think you mean a 500K pot with a 180ohms resistor ?

Definately not..!! :icon_wink:

500k for Emitter resistor should keep the transistor permanently topped..
500R (Ohms) in series with 180Ohms make 680Ohms as in original schematic..
It could be a single 680Ohms pot if only it could be commercially availiable.. :icon_wink:
Title: Re: Adding gain & volume
Post by: rangermaster on February 07, 2021, 05:53:35 PM
Ah ok. Well i dont have any ohm pots here.. just K pots. 10, 250, 500 etc

I'm still a little confused about how to wire the resistors/caps to or from the pot in this schematic. Just a nother noob thing though  :icon_rolleyes:
Title: Re: Adding gain & volume
Post by: antonis on February 07, 2021, 06:16:28 PM
(https://i.imgur.com/fb67bgI.png)

You can use 250k pot instead of 100k one without any issue.. :icon_wink:
(considering next stage input impedance high enough..)
Title: Re: Adding gain & volume
Post by: rangermaster on February 08, 2021, 02:51:32 AM
Quote from: antonis on February 07, 2021, 06:16:28 PM
(https://i.imgur.com/fb67bgI.png)

You can use 250k pot instead of 100k one without any issue.. :icon_wink:
(considering next stage input impedance high enough..)

thanks man !
Title: Re: Adding gain & volume
Post by: antonis on February 08, 2021, 06:18:38 AM
Lets make it more clear.. :icon_wink:

(https://i.imgur.com/5UhMWoR.jpg)


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