RE: [Harp-L] Fender Vibrosonic

["Priest, Jim" <Jim.Priest@xxxxxx>]

Thanks for this, and to the others who responded to my request for help.

Just to clarify, for the benefit of anyone who might reference this later, the tube configuration is actually as follows (viewing the amp from the rear and reading from the left):
4 6L6GC - Power Tubes
12AT7 - Phase Inverter
12AX7 - Vibrato
12AX7/7025 - Reverb Return/Preamp Vibrato Channel
12AT7 - Reverb Driver
12AX7/7025 - Preamp Vibrato Channel
12AX7/7025 - Preamp Normal Channel

This is based on the tube layout diagram attached to the amp and the description of tube functions in the Fender Field Guide. The posting in the Steel Guitar Forum had the non-power tubes reversed in position.

Thanks for the suggestions. I'm going to work on the amp to restore it to full working order. I'll let you know how it turns out.

Cheers
Jim
________________________________
From: David Harris [mailto:snakehead_1@xxxxxxxxx]
Sent: 07 March 2008 14:43
To: Priest, Jim
Cc: harp-l@xxxxxxxxxx
Subject: Re: [Harp-L] Fender Vibrosonic

Jim,
My research show that this is the standard layout of the tube layout for the Vibrosonic:

http://bb.steelguitarforum.com/viewtopic.php?p=1095549&sid=9b8d27feec6f14b61cf9263c596f73f2
(Stock tube layout facing the rear of the amp)
4 6L6GC Power Tubes
12AX7A 1st stage gain
12AX7A 2nd stage gain
12AT7 Reverb Driver
12AX7A Reverb Return
12AX7 Tremolo
12AT7 Phase Inverter

Is that close to your current setup?
What I would suggest is concertrate on changing the Gain tubes and the Phase Inverter.  Don't even use the Reverb and Tremolo for harp.  You should, however, make sure that you replace any blown or worn out bulbs.  Especially since you mentioned intermittent performance for the tremolo.

Here are my suggested tube types:

12AX7 1st stage gain
12AU7 2nd stage gain
12AU7 Phase Inverter

or

12AT7 1st stage gain
12AU7 2nd stage gain
12AU7 Phase Inverter

or

12AT7 1st stage gain
12AU7 2nd stage gain
12AY7 Phase Inverter

Try those and see how they sounds.

Dave Harris
http://www.myspace.com/superdharris