Conn Organ Into Guitar Tube Amp

[Bluesnate78]

Hello, i am on a new adventure, and im coming from working with guitars and other passive circuits, so i decided to dive into a deal i snatched on ebay, which is a decent looking tube power amp from a conn organ, i know, everyones doing it. I just need some simple help in identifying the input, or where to look, and the speaker opts. I plan on relocating the volume control when i build a base for this, but i hope someone out there can give me the go to.
Ive read many of the posts, but havent seen anything helpful in the direction with the particular Power amp i found. It has 2 6l6gc tubes, 1 12au7, 1 12at7, one OA3 tube, and one 5u4g. I have the pictures from the auction, and im still waiting for it to be delivered, im just trying to be prepared, because ive already designed a cabinet.

[Bluesnate78]

Hello, i am on a new adventure, and im coming from working with guitars and other passive circuits, so i decided to dive into a deal i snatched on ebay, which is a decent looking tube power amp from a conn organ, i know, everyones doing it. I just need some simple help in identifying the input, or where to look, and the speaker opts. I plan on relocating the volume control when i build a base for this, but i hope someone out there can give me the go to.
Ive read many of the posts, but havent seen anything helpful in the direction with the particular Power amp i found. It has 2 6l6gc tubes, 1 12au7, 1 12at7, one OA3 tube, and one 5u4g. I have the pictures from the auction, and im still waiting for it to be delivered, im just trying to be prepared, because ive already designed a cabinet.

also the seller told me he put the base plate from the organ in with the amp, and also added that the model number was 606 4311, which i cant find anything about online so far, except that by the looks of the casing its from maybe an earlier 50's model, maybe a 700 or such. Hopefully some cool person will come along and say hey!!!!!

[Bluesnate78]

follow up to anyone interested!!

OK, finally got home from work and took a good once over this particular model....very clean, and all of the necessary info was very well represented on the front label for the amp. The front socket with the wires hanging out, refer to the pic, was the speaker output. And the mono input is in good shape on the side of the amp with the volume pot... thats it in the box with a shaft sticking out by the 12at7 tube. for those that are going to try doing this, it doesnt get any easier than this, most connections can be soldered direct inside the case, and with adequate spacers this amp can be mounted to whatever chassis u select or design, wires can be ran wherever and however long u want.im gonna put a 1meg pot and test that as well as other values of potentiometers!! Even the old bumblebee capacitors are in good shiny shape!! I was expecting an old worn piece that needed some work to just find the connections, whew!! now to test and replace the old frayed power cord. I hear that volume might be an issue, and that a preamp might be necassary, but that might be debunked here soon too, lol. Thanks to anyone reading this, i hope i can encourage others to be creative and have the fun im having!!

[soundmasterg]

What you have there is a power amp from a Conn organ. You will need a preamp, but if you reorganize some things in that chassis, you may be able to just add the preamp to that chassis. If you go that route, make sure to locate preamp stuff as far away from the power transformer as possible, and make sure that your circuitry goes in a straight line from input to output without crossing over on itself as much as possible. Conn made good stuff and used good components and construction techniques. I have a power amp that had 3 output sections/transformers in it that all share a power transformer. I added a preamp chassis to it so when I get done it will be 3 seperate amps in one head. That is WAY more complicated that what you have there however. Good luck with your project, it looks like fun!

Greg

[Bluesnate78]

well, onward we go, Thanks for the reply greg, i appreciate your time to put something in. So far i have soldered within the chassis and created an 1/4" input, volume control lines are in place when i need to use my own pot and not the original conn pot, for now we will just test. I put on a new grounded power cord, put the tubes in place and plugged her in.......nothing. SO unplugged again, flipped over, and thats where i saw what might slow me down from just plugging and playing. Behind the 5u4g tube are two slots, which are labeled HEATER and Power, which i assume are connections for the rest of the organ (Switches reverb unit and such), which apparently as i look closer to the "neutral" white of my power cord, which isnt running to anything at all now that i dont have those connections present. STUMPED, that slot is all over the circuit in the chassis, now im thinking i have to rewire the whole circuit to accomadate that missing element, PLEASE SOMEONE TELL ME THERE is an easy solution..i doubt it..lol. So i need to get power to the transformer, and then make sure its getting to the tubes, that sounds so easy yet i cant comprehend the rest of the organ i will never see...time to buck up and find a service manual that might actually contain the diagram. I hope i can complete this so i can serve the next noobie, dont give up guys!!!! Im headed downstairs!! And yes i know how to discharge the circuit in case i do get power, calling gator to chassis!!

[hasserl]

With two 9 pin tube sockets he can wire up a simple preamp, no problem. There are lot's of existing guitar amps he could draw from to come up with a very cool single input guitar amp.

[Bluesnate78]

Here are some pics of my jumps onto the circuit and where i replaced the power cord!! Plus some close ups of what i have.

[Bluesnate78]

Here are some pics of my jumps onto the circuit and where i replaced the power cord!! Plus some close ups of what i have.

as soon as i lower the image quality on my camera..lol..sorry..pearl jam deserved to be shot with the highest definition..see ya all tommorrow

[Bluesnate78]

With two 9 pin tube sockets he can wire up a simple preamp, no problem. There are lot's of existing guitar amps he could draw from to come up with a very cool single input guitar amp.

Thanks, yeah i have been looking over some fender and hiwatt schematics, got myself into this, better finish it or it will haunt me!! I was hoping that i could build a seperate preamp later on, just wanted to get this thing going, spending to much time tinkering and not enough time playing!!lol..

[Bluesnate78]

HAHA...another night of the tinkering and study, finally decided to go on my assumption that the two black wirees going into the power tranny were of course what i was looking for, one is neutral and one is hot. After i moved the white wire from my new cord over on the unused "power" socket to the next pin and finally found the right one, all the tubes lit up and my speaker started humming...lol. BE CAREFul if you are hooking up leads on the outside of the speaker output socket, these also have a power set to drive something else, from what i hear a Leslie motor. So make your own speaker leads coming hot off the thin gray wire coming from the tubes and jumping off that unused power socket, and just ground directly to the ground bar that runs to the speaker socket. TESTED this with a 5 inch speaker and the stock volume, which has a ton of resistors on it, gonna bypass that on my new pot, and yes the output sucks!!Like i said this is for someone thats ready to learn, i still dont know jack, but im going to build a seperate preamp for this, and see if it gets the output up. I also have an old practice amp, about 10watts that i was thinking of running the guitar through that first and then into the conn chassis, any one got any ideas if ill fry anything doing that?

[Ran Randle]

conn amp conversion

I just recently got the same amp(or very similar) and just starting out doing my first conversion project.
My idea for now is to use it as a power amp because I have a preamp unit already. It's just a matter of changing the power chord, wiring in the input jack, and output jack to the speaker. I'm waiting on a OA3 tube I ordered then see if the unit powers up and is functional so just wondering if you could post some photos of the updated wiring done on your amp for comparison. I haven't had any luck finding a schematic for this amp. I was considering eventually wiring in a simple preamp but for now I just want to get it working as a power amp first so I can use it. Any advice and suggestions would be great, thanks!