Common, Rare, Odd, & Obscure Amplifier Poker

[Thespeakerdude8]

Okay, I tried to resist, but I guess some of these PA amplifiers are becoming quite rare, and are definitely obscure, so I will post my collection.


Bogen made Challenger CH-18 (Challenger amplifier company of New York, used David Bogen parts, built like a tank) Circa 1947. 6v6GT (now G) push pull, 6SF5 preamps, 6SL7 PI, 5Y3GT rectifier.

Knight Model 7S, made by Allied with a slightly different body than most 7S models (they had ribs around the sides instead of the louvers)
Dated September of 1940, completely stripped, resto-modded, and turned into a guitar amp. SE 6L6 puts out close to 10 watts. Originally had a 6SC7 for preamp, switched over to 6SL7, 5Y3G rectifier. Original RCA tubes.

Knight model 14W. Dated August of 1939. This one surprised me, 100% original caps and tubes. Tubes test NOS, capacitors are not leaky, and the filter caps test good for ESR. Resistors within 2% tolerance, and voltages spot on with the schematic. Odd tube lineup: 6V6G pp, 80G rectifier, 6Z7G PI, and common 6J7 pentode preamp.

Stromberg Carlson Au-32 PA amp. Dated around 1947, Push pull 6v6G's, 5y3, 6SC7 x2, 6J5. Converted to guitar amp, but circuit is stock. The cool obscure thing about this amp is that EVERYTHING was copper plated before painted-even the transformers!! It is VERY quiet due to all the shielding, SC made quality products.

Okay there is my small collection. Thanks for letting me show off with your guys' more rare amps around me

 

[vendo81]

This nameless one is dated 1957. Uses 2 6L6GC's for push pull output. Has some great iron on it. I'm going to recap this one someday and if I like it I'll recap the mate I have. I'll dig a few others out of storage and get some photos including a couple of 1930's amplifiers, one that uses 2A3's and the other uses 45's for output. Still looking for mates for them...

 

[WopOnTour]

This nameless one is dated 1957. Uses 2 6L6GC's for push pull output. Has some great iron on it. I'm going to recap this one someday and if I like it I'll recap the mate I have. I'll dig a few others out of storage and get some photos including a couple of 1930's amplifiers, one that uses 2A3's and the other uses 45's for output. Still looking for mates for them...

Boy I'd like to find a PAIR of those
Have you found or made a schematic?
Is it UL?
I would think it woul be pretty hard to go wrong, especially if they BOTH have RCA black-plates...
WopOnTour

 

[vendo81]

Boy I'd like to find a PAIR of those
Have you found or made a schematic?
Is it UL?
I would think it woul be pretty hard to go wrong, especially if they BOTH have RCA black-plates...
WopOnTour

I think these were made for jukeboxes as they have a muting relay that can be activated and a separate AVC unit that plugs into the amp and uses a 12AU7 and a 6B7KA. The schematic is still on the inside of the bottom cover. It has a hum balance, fidelity EQ and a high freq. range pots. It uses a 12ax7, 2 12au7's, a 5U4 and 2 6L6G's. Both came with RCA blackplates installed. Here's a top shot...

 

[vendo81]

Here's one you don't see much: A Futterman H3 Output Transformerless Amp (OTL). This one is rare as it has the very inexpensive but wonderful 6FW5 sweep tubes in it which are cheap and plentiful.

Kcin

How does it sound with its transformerless output?
VERY cool amp

 

[ecoak]

Well, I'll put this in as the integrated sibling of radioactive's Electro-Voice Preamp. This is the Elecro-Voice A20CL Circlotron. 20 watts of Mono from a pair of 6V6's. God only knows who chose the colour of the case work!

 

[bob smog]

I know this is an old thread, but I'd really love to get an ID on these EL84 PP amps. The ones in the pic aren't mine, but I have a complete single and another with just the chassis and iron.

These were installed in the bottom of a weird upward firing speaker that was made in the 60s. The output tubes were Amperex Bugleboy. I found the single at an estate sale still installed in the speaker for $8. I picked up the chassis and iron on Ebay for $20 after doing an extensive search.

Not Heathkit - no names on the transformer or anywhere else.

 

[stereorob]

adding my two cents..

arkay sa-25 int.amp, early stereo unit, mono power amp with a stereo preamp..

1930s philco intercom amp

i dont know if this is rare or not, but this is my hh scott lk-72b (kit model) int.amp

 

[Blitzen]

Rca

An RCA Theremin, probably 1929.

 

[radioactive]

Well, I'll put this in as the integrated sibling of radioactive's Electro-Voice Preamp. This is the Elecro-Voice A20CL Circlotron. 20 watts of Mono from a pair of 6V6's. God only knows who chose the colour of the case work!

i like:thmbsp: ev made some interesting gear ,do some reading on their circlotron amps.

 

[Naptown Rob]

The 612. A nice little EL-84 mono amp by Teeco. Made by Trutone Electronics, Hollywood, California in the late 50's/early 60's. Only one - hell, only Teeco - I've ever seen. Actually sounds very good.

 

[RossW]

National Horizon 20 amp with Horizon 5 preamp plugin. 2x 6L6 for 20w of mono power.

I have a pair of these, only one of which has been restored to far. I believe Soundmotor also has a pair.

 

[pqrannes]

"I'll see your amplifier and...."

Post any tube amp but let's see the truly rare, odd, & obscure ones dragged out for the camera. Make this thread one stop shopping for anyone interested in tube amps they have not seen before. Be sure to include a brief description too.

I'll open with a Techmaster Model 22, dual-channel MONO amplifier. It uses SE 6BQ5's but get this, one channel is highpass to the tweeter, and the other side is lowpass to the woofer. It was a biamplifier amplifer! I've never seen another or found any reference to it. It is rare, odd & obscure all in one and Hi-Fi too! (Says so right on the front!)

When I first saw this tread I figured that I should flash my little US made Shell Electronics "Northport" SE 7189 amp (http://www.audiokarma.org/forums/showthread.php?t=156859).

But after reading the first post I think it is more obvious to mention that another bi-ampli mono tube amp exist here in Europe, namely the Philips AG-9009.

It is an OTL (OutputTransformerLess) amp driven by 2x 2 el86 tubes and looking like this:

The device on the top is a Philips mono tuner, below is a cab with a Philips 9710 speaker:

Here is a picture without the cage:

I like the sound of this mono bi-ampli setup.

PQR

 

[gadget73]

Interesting. the only bi-ampli Phillips circuit I've messed with before had an EL84 and an EL86 for output. I'm assuming this is still the 800 ohm speaker ?

 

[Mike Stehr]

The 612. A nice little EL-84 mono amp by Teeco. Made by Trutone Electronics, Hollywood, California in the late 50's/early 60's. Only one - hell, only Teeco - I've ever seen. Actually sounds very good.

I've got a Teeco model 612 just like the one you posted.

 

[Naptown Rob]

I've got a Teeco model 612 just like the one you posted.

Sez you!Let's see yer pics, pardner.:scratch2:
Posts like yours prove to me that I'm in the right place...
Do you know anything at all about the outfit that made the Teeco? Info seems scarce. Does yours have a cage or any cabinetry?

 

[pqrannes]

Interesting. the only bi-ampli Phillips circuit I've messed with before had an EL84 and an EL86 for output. I'm assuming this is still the 800 ohm speaker ?

All my Philips OTL amps are driven by el86s.

Yes, both speakers are 800 ohm.

PQR

 

[Mike Stehr]

Sez you!Let's see yer pics, pardner.:scratch2:
Posts like yours prove to me that I'm in the right place...
Do you know anything at all about the outfit that made the Teeco? Info seems scarce. Does yours have a cage or any cabinetry?

I picked it up from a friend with other stuff. I have no idea about the company that made the 612.

 

[chinacave]

Sarser / Sprinkle 'Musician's Amp'

Built from a kit or from plans. Who knows?

Article published in 1949 issue of Audio Engineering Magazine -

First US version / adaptation of the 'Williamson' circuit, giving birth to or copied by Heathkit for the W series - W1, W2, W3, W4 and W5

-Separate power supply - not shown

 

[Tsushima1]

My Pye PF91's Circa 1956

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