Re: [Harp-L] 59 Bassman (generalizing tube swaps)

["Bob Maglinte" <bbqbob917@xxxxxxxxxxx>]

----- Original Message ----- 
From: "Michael Fugazzi" <mfugazzi67@xxxxxxxxx>
To: <harp-l@xxxxxxxxxx>
Sent: Tuesday, January 18, 2005 12:37 PM
Subject: Re: [Harp-L] 59 Bassman (generalizing tube swaps)


> This is for Bob, and anybody else who'd like to share:
> f
> In general, is it best practice on an amp to(for tone
> and feedback elimination) start with a strong signal
> and then use use lower gain tubes, or start with a
> lower signal and use higher gain tubes?
>
> So lets say you're going for tone and the most
> possible volume before feedback.  Would you start with
> a 12au in the first stage, use a higher gain tube for
> the other stages and then use another high gain tube
> for the phase inverter?
>
> or
>
> Would it make more sense to start with a strong signal
> from a tube like the 12ax7, use a low gain tube for
> the the other stages, and then a high gain tube for
> the phase inverter?
>
> I hope my questions make sense.
Hi,
On the '59 Bassman, I left it with the original tubes that it called for and 
I have few problems and the real tone quality comes more from the chops. I 
find putting a 12AX7 in the first gain stage will give a louder signal, but 
a considerably more trebly sound, and it makes it much more feedback prone. 
In the first gain stage, a better alternative would be an NOS 5751, which is 
somewhere inbetween a 12AX7 and a 12AY7. You're better off IMO leaving the 
12AX7 in the phase inverter position as is because it will lower the signal 
strength going into the power tubes, requiring more juice from the power 
tubes, and will shorten their lifespan, and using most newer production 
tubes already have a considerably shorter lifespan than the NOS tubes do by 
at least 50%.  If you have the reissue, get rid of the solid state 
rectifier, which makes a harder sound with more volume, but more feedback 
prone, and the 5AR4/GZ34 is what a real Bassman calls for and will allow a 
much smoother sounding distortion and the best quality ones are the NOS 
Mullards, which are getting rarer and more expensive everyday, but nothing 
being made presently is anywhere near as good, nor do they last as long. I 
personally feel that using a preamp tube with a lower gain quality less than 
what a 12AY7 is in this amp will make the instrument sound really mushy, 
especially in the bottom end, and will lack definition. HOWEVER, if one's 
acoustic tone and chops aren't together in the first place, NOT ONE OF THESE 
THINGS WILL EVER HELP YOU!!!!!!!

Sincerely,
Barbeque Bob Maglinte
Boston, MA
http://www.barbequebob.com
MP3's: http://music.mp3lizard.com/barbequebob/