Sir JJackson . . . . . .

" Why 'soitanly ! " . . . . myself, along with the incapable and incompetent help, from the Three Stooges, should

easily be able to deconstruct that unit to such an utter ends total state of dissarray , that even 'ole Thomas

Edison would no longer be able to conceive of its resultant end usage ! ( Great shades of Les Paul ! )

CIRCUITRY BREAKDOWN:

Initially, lets evaluate the schematics circuitry layout . . . and BTW did ye have to lay out a bit of yer hard

earned munny for that modern Pee Dee Eff of an old chicken scratch schematic . . . . oh well . . . its certainly

better than nothing !

Lets start at the top left corner where I have shifted a concerned area, somewhat even MORE over to the

left.

We are initially interested in the [Blue-Green] boxed in area:

Now you pull out your Svenska S/S Swedish surgical scalpel handle and peel out and insert a fresh #15 blade.

Then one makes a surgical extraction of the wiring connections at the inset [RED] X just to the right of C1

capacitor. I have then shown that circuitry positionally reset over to the right, where it still remains connected

into the 1st grid of the first preamp tube in the unit.

All of the photocell associative circuitry within that [Blue-Green] area is of no longer use to us.

Within the [Green] boxed in area, just below the above area:

All of the photocell prebiasing adjustment circuitry is no longer needed. Cut the circuitry free from the sub B+ at

the [RED] X inset.

(Additionally, there is one ground shown that flows up into that [ Blue-Green ] circuitry, and may or may not be

in that upper area, possibly being down in the switching circuitry shown in the the [ Orange ] boxed area. )

All of the switching and wiring of the [ Orange ] box area is not needed.The one ground connection just

mentioned is routed thru a switch contact and is going over to the centertap on the high voltage transformer.

That is being shown as the [ PURPLE ] X inserts, that break in the wiring needs to be made and the centertap

of the winding is then making a connection to ground as is shown down on the [ GREEN ] wiring inset to ground

in that same area.

All of the [LILAC ] boxed area can be eliminated.

The circuitry within the [MUSTARD ] boxed in area is the High Frequency AC power oscillator that is used for

driving the audio film strip illuminator lamp.

This design was to have averted the induced hum that would have been modulating the illuminator lamp sources

filament, should common 50/60 cycle AC have been used as the filament supply source.

The other aspect, in using variable DC for the filament supply, would have had the additional undesired effect

of blackening of the internal glass envelope.

Sooooooooo . . . all of the [MUSTARD ] area can go, by the four [BLUE] X snippets at the top and the one ground

connection at the bottom.

Observe the clarified electrolytic capacitor list at the right center boxing, along with them being remarked onto

the schematic. In the dropping of the [MUSTARD] circuitry you have now acquired the now unused C15 and the

internal C19 of the power osc circuitry.

Use C19 for the shunting of C3 and C15 for the additional capacitance shunting of C9.

The only critical capacitor uses are seen as the K-mart "Blue light special" boxed markings of C4,C10, C11 and

C12 up at the top of the schematic. Replace them or otherwise confirm ZEEEE-R-OOOO DC leakage is present

thru them.

Thassssitttt . . . . dis a heah' deeeee-vice now do be oh-fissh-a-mully destruc-ti-ma-fied.

Aside thoughts:

With due reverence this units age (audio transformer drive?) its only right that the unit ONLY be connected up

to a venerable old Fender-bender Stratocaster as its playing input source. . . . . .hmmmmm . . . or maybe, possibly

a vintage old eddie Ricketybacker, hollow body, might also suffice.

Also, with only that single pentode up front, it will only be adequate for strumming, to get in some HOT LICKS,

will require a series plug in frontal stomp box /fuzz master/whang-dang-do/echo master/pre amp . . . or you can

merely "GOGGGGGLE" . . . geetar amplifier schematics . . . and peruse over those 'lebenteen kazillion possibilities

and select a frontal preamp circuit to replicate and then build it into this unit. ( within all of that empty chassis

real estate that you had previously created.)

LOOK . . MOM ! . . . Six muntz agoe I just replaced the silents at the movies . . . . now I'm a Rockin' Geeee-tar Amp-lee-fryer ! ! ! (gaaaaaasp !)

You can remove the third 6v6 and everything connected to it, and plan on re-doing everything before the phase inverter. Good, you will now have a spare.

There are tons of schematics available for Fender and Similar guitar amps online. Tube manuals and other information is pretty easy to google. You shouldn't have to pay a penny for anything, as just about everything is in public domain, and there are many kind contributers out there.

Pick an easy one with the same kind of output topology. You will need 2 stages of amplification prior to the phase inverter, and you can just follow one of these amps circuits. The existing preamp stages would probably not be appropriate for guitar pickups. You can probably ues the pentodes in triode mode, if they are still good, and tweak the bias and plate resistors to come up with approximately the same gain as the circuit you have chosen to follow.

All capacitors including the electrolytics in the power supply should be replaced. Use a 3 wire (grounded) power supply cord for safety, and add a fuse (3 amps) if there is not one already.

The schematic is not clear enough for my tired eyes, but you should have enough tube sockets to get this going. I'd say there is about 20-25 hours of research and rework time involved,or more if you are just starting out with this kind of work, maybe $25 in parts if you don't have a "stash" so it has to be considered a labor of love. Try to figure out all the stuff you need so you can place one order with a supplier, and not get nickled and dimed by shipping and handling charges.

What you will end up with is about 10 watts before distortion, and depending on the quality of the speaker, you better not push it too hard.

IOW, you cannot make even minimum wage doing this work. A brand new solid state practice amp can be had for about $50.00.

But then again, nothing sounds like a tube amp, except another tube amp.

Go for it!

I'm considering cobbling together a guitar amp from an old Ampro projector amp and speaker. I want to consolidate the amp as much as possible and remove any unnecessary components... Some will be easy - others not. The photo cell and light source, motor switches, etc. aren't needed - but I am curious what else can go. There are two 6V6's in push-pull.... but a third 6V6 seems to be involved with the photo cell and light source - can it go? What else? Schematic is available here: