Hoffman Amplifiers Tube Amplifier Forum

Amp Stuff => Tube Amp Building - Tweaks - Repairs => Topic started by: Bigjoedo on February 27, 2022, 05:12:04 pm

Title: Princeton 5F2-A Clone TONE Pot values
Post by: Bigjoedo on February 27, 2022, 05:12:04 pm
Hello folks,

      There is a ton of information regarding what different value potentiometers do with regards to different types of guitar pickups.

My question is: In a Tweed Princeton what does lowering the TONE pot value do to the sound of the amp? It calls for 1M linear taper pots. On 2 different class A type amps turning the tone pot fully clockwise causes "feedback" for lack of a better word. I am using the standard 5F2A Volume tone values. I was going to add a JPeg, I can't get it to attach to the message. Thanks

                                   J_Vee

Title: Re: Princeton 5F2-A Clone TONE Pot values
Post by: PRR on February 27, 2022, 07:47:47 pm
...what different value potentiometers do with regards to different types of guitar pickups.

Pickups are MUCH more complicated impedances than tubes.

...2 different class A type amps turning the tone pot fully clockwise causes "feedback"

Squeal. Output is leaking back to input. All wires are antennas, transmitting and receiving. Has nothing to do with "class". Just too much gain with too little separation.
Title: Re: Princeton 5F2-A Clone TONE Pot values
Post by: tubeswell on February 27, 2022, 08:29:48 pm
...In a Tweed Princeton what does lowering the TONE pot value do to the sound of the amp? ...


Talk about start of a rabbit hole -right there. 1M Linear tone control with 1MA vol pot (Vol pot in all these charts is at mid rotation, and if you build it with 1MA pot , it'll work 'nicer')
Title: Re: Princeton 5F2-A Clone TONE Pot values
Post by: tubeswell on February 27, 2022, 09:13:16 pm
With 500k Lin tone pot (The cut rotation looks a bit odd)
Title: Re: Princeton 5F2-A Clone TONE Pot values
Post by: tubeswell on February 27, 2022, 09:15:17 pm
With 250k Lin pot


(As you can see, the differences are very subtle for these values)
Title: Re: Princeton 5F2-A Clone TONE Pot values
Post by: Bigjoedo on February 28, 2022, 05:13:11 am
Thanks for the great replies!!

             J_Vee