Alamo Paragon Bass Amp Head

[dugdiamond]

I am looking for schematics for Alamo Paragon Bass Amp Head circa- mid 60's to early 70's. This would be an all tube model with two 12ax7's, one 7199(interesting tube) and two 6L6GT's. Oh and almost forgot tube recto too.
This amp has a bass channel and a normal channel with four inputs.
Does anyone have any tips or tricks for working with the 7199 triode/pentode phase inverter topology?
I am seeking those elusive Alamo schematics and soliciting any Hints n Kinks or other input concerning maintaining this amp or special tone tips.
So far the gnd reversal switch with its two "death caps" is being disabled and a new proper three conductor power cable is being exchanged for the old nonpolarized AC Mains cord. The fuse will go inline ahead of the power switch on the "hot" or black lead.
I also noted that there is no center tap for the heater filaments of the PT.... I am wondering if after removing the death caps I should add a couple of resistors to create a psuedo center tap to gnd on the heater supplies right at the pilot lamp???
This amp as is, functions and seemingly has little noise, hums or other bad behaviours such as audible oscillations. However, it doesn't have outstanding tone or amazing sounding. It's just ok...
I think that a cap job cant hurt. It has a four section 20/20/20/20 electrolytic above chassis and two 10 mF Paper Wax Caps wired below. All are 600V monsters. I think I could easily get away with a single modern 500V 22uF replacements for the two paper caps.
Maybe leave the multican in place for looks but rewire in a 47uF for the two section of the multi that filter the output section and two more 22's for the other remaining sections. There should be room to add a couple of terminal strips to keep it all neat and clean. Modern caps are much smaller these days, however I dont think 600V caps are going to be a quick or thrifty order to procure. I havent tested the PT but I gotta a good feeling that 500v devices will suffice.
Also I note that every remaining Cap is ceramic disc. I cant help but wonder if I changed the ceramic disc signal caps to foil or mica, I might experience a big improvement in the percieved quality of tone......
Comments, thoughts, suggestions?
Thanks to everyone in advance for taking the time to read my rambling!

[Enzo]

Probably similar:
http://bmamps.com/Schematics/Alamo/alamo_montclair.pdf

it isn't all that complex an amp. Consider the above as a loose equivalent and draw up your own schematic from the circuits in the chassis.

Old Sunn amps used a pentode/triode. The 7199 and the similar 6AN8.

Don't solve problems until you know you have them. You may not have a center tapped heater supply, but it is possible one side is grounded. And even if not, the purpose of the center tap is hum reduction, but if the amp does not hum, then what is to reduce?

600v? 500v? Since the amp works, get out your meter and find out what voltages are in it. That will answer the question of what voltage caps are needed.

[dugdiamond]

Thanks Enzo!
Yes, you are very wise. I already made the determination that no changes need be done to balance the heater supply. After changing the power cord and disabling the gnd polarity switch/bypass(deathcaps) the amp still remains quiet if not quieter, (iirc how it sounded before) . The heater supply does in fact gnd out on one side on the pilot lamp .... As a matter of fact, I am now having second thoughts about even messing with the filter caps for the time being.
I am going to go straight to experimenting with changing out a few of the ceramic discs with some higher quality mylar style caps in the signal path next and see if I can percieve any great audio improvement or effect... Good/Bad or different.
Your wisdom is a good reminder to me, if it isnt broke dont fix it and even more important at this point, dont wholesale change out or shotgun in a whole bunch of stuff without testing each individual change for desired or undesired effect, least not know where you are at and end up lost along the yellow brick road with no way outta Oz!!!
I've found myself too enthusiastic before and unable to realize just what did what. Luckily in most instances the effects accumulatively have been positive. However, makes it more difficult to repeat again and really does nothing to increase my learning curve. Well, maybe learned to recognize the wisdom of your advice!!!!!

***BTW,,, we also steam all our veggies including corn just the same as you.

[dugdiamond]

Everyone seems to enjoy pictures....
Except maybe those pictures of your co-workers kids.

[rf7]

A friend of mine has one of those amps with the original 2 x 15 speaker cabinet and it sounds amazing for guitar. He was using it one night when we jammed and I asked him what pedal are you using and he pointed at the amp and said no pedals at all. It was seriously killer when dimed. I think I re-capped it for him once. I just replaced the filter caps, I didn't want to change that tone.

[dugdiamond]

I dunno if its just my perception or tonal preference but this amp just isnt the tonal nirvana that I keep reading about..... Its not bad but not sliced bread either......
I suppose I need to find a less efficient speaker to run it through. Currently my 412 1960 cab prolly isnt the greatest test bed either. Maybe an opened back cab with a Jenson or Weber might be just the appropriate audio frequency radiator to appreciate this amp through?! I know someone that has an old original blackface Bassman Cab that could prove interesting experiment too.
It does seem that the tone comes on after the volume knob is turned clockwise past the number seven on the dial!