REWARD offered: Looking for a schematic for an Applied tube PA (See the picture)

[LooseChange]

$10.00 !!!  Cash.

Looking for a schematic for this amp... There are no other markings.
It has four preamp tubes (12AX7) and a pair of EL34's.
Thanks!

[John]

I can't even find a listing for Applied Amps. Closest name is Applied Research and Tech, but it seems they're a completely different outfit.

[LooseChange]

I'm offering a reward to the person who finds and delivers this schematic to me. Dead or Alive.

[sluckey]

Can you post a couple gut shots?

[LooseChange]

These any help?

[kagliostro]

I'm afraid that you will must reverse engineer the amp

not able to find schematics of that brand 

Kagliostro

[Ritchie200]

WOW! for a P-to-P that thing looks really nice!  I might be able to find it for.....$100 

Jim

[Platefire]

I found an "Applied" Company site thats been around since 1958. I did look at their service page and didn't see anything about vintage equipment schematics. Here is their site, you might could contact them to see what you could find out? Platefire

http://www.appliedelectronics.com

[Ritchie200]

Hey Plate, those guys are in communications, not the ones we are looking for.  

I did find a little history on Applied Audio Products.  They were around in the mid to late 60's.  They marketed a few stomp boxes similar to the Hornby-Skews Zonk Machine and Rangemaster.  There were three product "manufacturers" that had identical innards - they were Goya, Applied, and Kadent.  Some think they were boutique products made by one guy and rebranded.  Others think it may be Japanese circuitry assembled into chassis here and labeled "Made in USA".  If you check out the link below, you will see the shipping box the fuzz came in.  If you zoom in, you will see the correct "Applied" logo that matches your amp.  The company is Applied Audio Products, South Plainfield, New Jersey.  So, if these guys were just rebranding, it might share its innards with another amp of that era.

I could not find any other info, but I gotta run.  Maybe someone can take it from here?
Jim
http://www.effectsdatabase.com/model/applied/fuzztreblebooster

[PRR]

> Looking for a schematic for this amp...

Why? Is it broken?

The tube-works can easily be traced out. Even from pictures, if they were better, though $100 is not generous.

The four input channels are each 2 jacks mixed through 150K resistors, box-cap, 470K grid resistor, 330K plate resistor (thus 12AX7), probably 2K2 cathode resistor (your lighting muddles red and brown, and the preamp Rs are hidden under their caps). V1a V1b V2a V2b are the four preamps. This is fed through yellow caps to tone control, apparently passive James. The bass-limit resistor is 100K; we infer 1Meg bass pot with 10K on the bottom. Bass-pot will have 0.01uFd and 1000pFd caps with 10K to ground. Treble will also be 1Meg, likely with 250pF on top and 0.002,5uFd on bottom. Then apparently to channel volume, four wipers mixed in 220K resistors

The main B+ is a voltage doubler, like late Bogens. The brown/wax electrolytic far right MUST be insulated from chassis.

The EL34s are run fixed-bias (trimmer accessed through bottom cover) with 330K(!) grid resistors, coupling caps are greenish. Driver V4 is self-biased cathodyne with 100K plate and cathode resistors, 470K grid resistor. Volt-amp stage before it seems to be loaded in 100K with a few hundred pFd across it, bypassed 2K2(?) cathode biased. There is a NFB divider under that, gold-stripe, fed from a dedicated OT tap.

There is a board of transistors. I think I would have to have it in-hand to trace it, and that might be more than $100 of pain (not to mention shipping).

It is probably not Japanese.

[LooseChange]

Wow PRR, you never cease to amaze me... But what's V3 doing? :-)
I would be reverse engineering If I didn't find a schematic. Just need to figure out how the reverb is inserted.

>>> The brown/wax electrolytic far right MUST be insulated from chassis. ????

[DummyLoad]

>>> The brown/wax electrolytic far right MUST be insulated from chassis. ????

that cap is at the top of the doubler. the body is tied to negative and the negative side of that cap is at 1/2 B+ potential. that's why the paper insulator. nowadays the insulator is a PVC sleeve. the case tied to negative is usually the norm with axial lead caps and SOME radial lead caps, however, modern radial lead caps are fully insulated.

 

[LooseChange]

I see it now. The bottom half is connected to the cap can (right above the speasker jaacks).

[jojokeo]

These guys have quite an extensive list of american, european, and canadian schems if it's really necessary and might be worth a try? http://www.justradios.com/PA.html
With Ricthie's info they may respond w/out paying up front but you'll need a model # or other info as well?