Hoffman Amplifiers Tube Amplifier Forum

Amp Stuff => Tube Amp Building - Tweaks - Repairs => Topic started by: LooseChange on August 03, 2012, 12:25:20 pm

Title: Tone stack wiring: 5F6A vs All the blackface amps with TMB
Post by: LooseChange on August 03, 2012, 12:25:20 pm
The tone stack wiring on the 5F6A (59' Bassman) is a bit different than the Blackface version we all use.
Any comments as to which one you like better and why?

My observation is that the 5F6A does not kill the Audio when all controls are turned down whereas the Blackface version does.
Thanks!
Title: Re: Tone stack wiring: 5F6A vs All the blackface amps with TMB
Post by: Ed_Chambley on August 03, 2012, 01:10:10 pm
Both are great to me.  As to preference, I find myself plugged into a Blackface more times than my Bassman.  I am comparing a Super Reverb to my Bassman.  I seem to get a thicker/punch bass note.  It is quite interactive with the volume.  To tell you the truth, I think it is because of reverb on the SR.  Doesn't mean I don't like the bassman as I use it often (room size permitting).  I drag the bassman to jam sessions where I know blues playing is going on.  My main gig is with a contemporary Country Band which sort of keeps me in the blackface deluxe and SR territory unless we have a outside gig then it is a Twin.  All AB763.  There is a killer sweet spot on a bassman that I cannot replicate, but it is more in the blues area and also in the loud area.

For what it is worth.
Title: Re: Tone stack wiring: 5F6A vs All the blackface amps with TMB
Post by: The_Gaz on August 04, 2012, 01:09:19 am
Loosechange, you're talking about the tone control wiring, not the tonal difference between the values, right?

I think you are, and I personally prefer the Blackface wiring in any amp as it can provide more bass cut (which is useful in a Tweed). It's also fun to be able to hear what each tone control is doing in isolation -  that helps with tweaking values as well.
Title: Re: Tone stack wiring: 5F6A vs All the blackface amps with TMB
Post by: LooseChange on August 04, 2012, 05:52:36 am
Yes, I am asking about the wiring. Values remain the same. Thanks.
Title: Re: Tone stack wiring: 5F6A vs All the blackface amps with TMB
Post by: tubenit on August 04, 2012, 08:52:02 am
I don't know the answer to that?  But it is a very interesting question.  My best very uneducated guess is that with the exact same values in the same position in amp topology that there would be only slight differences?  The "exact" values would mean how the potentiometer splits the resistance (hope that makes sense?).

So much of it is that we think about the AB763 sound that has MUCH different values in the tonestack between the 1st & 2nd gain stages VS.  5F6-A again with much different values  in a cathode follower position with no volume pot following the tone stack.

Obviously topology location and value differences of what we're familiar with make it a challenging comparison. I have simply moved the same tone stack with no value changes in different positions of the topology and it makes a BIG difference in the tone. I find the tone stack after the cathode follower has a "softer" and more compressed tone to my ears.

With respect, Tubenit
Title: Re: Tone stack wiring: 5F6A vs All the blackface amps with TMB
Post by: LooseChange on August 05, 2012, 11:00:24 am
I think it all boils down to control if it's just a variation in pot wiring. I wire all my amps with the Blackface circuit. Thanks!