Hoffman Amplifiers Tube Amplifier Forum

Amp Stuff => Tube Amp Building - Tweaks - Repairs => Topic started by: sclinchy on December 29, 2014, 03:49:02 pm

Title: Bass and Treble Controls for a 5F2-A
Post by: sclinchy on December 29, 2014, 03:49:02 pm
As my title indicates, I've built a 5F2-A, and overall, I'm quite pleased with it.  I would, though like to replace the tone control with separate bass and treble controls.  I took a peek at an AA764, which looks pretty much like the 5F2-A but with the controls I want.  It doesn't seem to be entirely straightforward (can you tell I'm new to this?), but does this look like a reasonable way to approach this?  Anyone have any advice or better ideas?


Thanks.
Title: Re: Bass and Treble Controls for a 5F2-A
Post by: Willabe on December 29, 2014, 04:11:49 pm
If you do that there will be more gain loss than with the stock 1 knob tone control.

If you look at the AA764 schematic, like most/all amps with a tone stack, they have an extra gain stage for recovery of the tone stack losses.

You might not like it, but if you play on the clean side or use stomp boxes for dirt/gain then it might be fine to do it.


              Brad    :icon_biggrin:


Edit; my mistake thought you wrote AA763. The Bronco does have a bass/treble without the extra gain stage added like in bigger amps.
Title: Re: Bass and Treble Controls for a 5F2-A
Post by: Willabe on December 29, 2014, 04:34:45 pm
I should have asked why you want separate bass/treble controls.

You might be able to just tweak some resistor/cap (R/C) values to get your amp in a more likeable place so then your single knob tone control will work for you.

Do you need more bass? Or more treble?

What speaker are you using? Changing the speaker might be the way to go.


                   Brad     :icon_biggrin:
Title: Re: Bass and Treble Controls for a 5F2-A
Post by: sclinchy on December 29, 2014, 04:41:33 pm
Thanks, just trying to add a little flexibility.


I play a Strat and find the bridge pickup in particular to be a little trebly.  I'm moving the tone control  on the middle pickup to the bridge, so that might solve the problem right there.
Title: Re: Bass and Treble Controls for a 5F2-A
Post by: Willabe on December 29, 2014, 04:52:16 pm
I play a Strat and find the bridge pickup in particular to be a little trebly. 

Some bridge PUP's are to bright, no matter how you set an amp.

My strat bridge PUP is, but I never use it (alone) so I never cared.


            Brad    :laugh:
Title: Re: Bass and Treble Controls for a 5F2-A
Post by: Willabe on December 29, 2014, 04:54:21 pm
I'm moving the tone control  on the middle pickup to the bridge, so that might solve the problem right there.

Yeah that might work.

I think you can set it up as master tone control?

Start a thread in guitars if you want.


                Brad    :icon_biggrin:
Title: Re: Bass and Treble Controls for a 5F2-A
Post by: HotBluePlates on December 29, 2014, 06:09:29 pm
I think you'll also find that with the typical Treble/Bass setup, there is a very large midrange scoop, which will change the overall character of your amp.

This is also a big part of the "gain loss" of the Treble/Bass tone circuit, and the reason for the resulting loss of distortion.
Title: Re: Bass and Treble Controls for a 5F2-A
Post by: g-man on December 29, 2014, 08:02:27 pm
Deleted