Hoffman Amplifiers Tube Amplifier Forum
Other Stuff => Effects => Topic started by: firemedic on March 28, 2014, 09:13:46 am
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I ran into an old friend at USF and while we were chatting, the subject of tubes came up. Within minutes, he presented to me an old Dynacord Echochord Super with a row of beautiful telefunken ECC83s in it, to fix. He says it does work, & I offered to recap it for the price of parts.
This thing is exquisitely made. I'm almost afraid to touch it since it's in such good shape. The tape is intact & everything.
The components are arranged such that there's one big filter cap that is hard to access without taking the whole thing apart. So I'm treading VERY lightly.
In addition, it needs(?) a grounded power cord connection, and the I/O connections are all that old-school audiophile kind that you don't see used anymore. Are there adapters I can use to keep this thing as original as possible? He says it's a very rare item & I don't want to completely ruin its value. But he does intend to use it so it needs a cap job at least. Also, all the mounting screws & pot mount nuts are missing, so this will be a bit more than a simple cap replacement. The schematic in the library is in German, though that shouldn't be too big of a hurdle.
He was planning to strip & paint the chassis but I disabused him of that notion.
So, any advice on thislittle gem is welcome.
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Just jumped on to say what a killer opportunity.
Got any pics/gut shots for kicks?
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I would most certainly limit the current if you are going to try and power up before doing any changes. Is your friend wanting to use it with a home stereo?
:icon_biggrin:
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Stand by for the gut shots, I'm technologically slow in that regard. My friend is in charge of the wood & metal shop at USF's Art dept. He wants to use it for various projects his students will use.
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My feet hurt from standing so long :icon_biggrin:
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My feet hurt from standing so long :icon_biggrin:
:laugh:
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Very funny. A lot of people I know take pictures with their phone & within 30 seconds, it's on FB.
I am not one of those people.
So keep your pants on.
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I was just funnin' Fire. I don't have a FB account or any social network account so I'm not one of those either.
I'm just really interested in seeing the pics, guts would be killer, but no worries either way of course.
But I have to warn you...these pants are coming off man it's Friday !! Whoot!
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Got Pics? :laugh:
Didn't mean to sound snarky. Between Field Day at the elementary school, applying for a Bachelor's program, dealing w/ medic students, etc. etc. ad nauseam, I find myself w/ not enough time.
I was waiting for the local audio repair store to fix my lightning-fried stereo tuner (SS), so I could pick their brain about the weird connections on this thing. They've had the tuner for 2 weeks without calling me, so screw them, I'll post pics already.
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Well I tried to upload some great gutshots, one at a time, but the file size was too big. So there.
I'll have to "paint a picture" instead.
It's a metal box with wires all over the place. Capacitors. Resistors. A big motor. It's partially disassembled. Also some buttons and knobs. It used to be brown but not so much anymore. The faceplate is pretty cherry. A lot of the labels are in German which is really cool.
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Well I tried to upload some great gutshots, one at a time, but the file size was too big.
Load them into a graphics program (say, Microsoft Picture Manager on a Windows machine), resize the picture (to something like 600-800 pixels in one direction) and the file size will liekly be much-reduced.
Most cameras (even on your phone) take pictures in high enough resolution to have huge file sizes and high pixel counts, to give a decent-looking printed picture.
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Well I tried to upload some great gutshots, one at a time, but the file size was too big. So there.
I'll have to "paint a picture" instead.
It's a metal box with wires all over the place. Capacitors. Resistors. A big motor. It's partially disassembled. Also some buttons and knobs. It used to be brown but not so much anymore. The faceplate is pretty cherry. A lot of the labels are in German which is really cool.
Send the metal box to me and I'll snap some photos and send it back :icon_biggrin:
Oh well but +1 to what Hotblueplates says if you find time.
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Ok, here goes.
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And the rest....
You see the weird connectors in question, on the back panel. What are they called?
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You see the weird connectors in question, on the back panel. What are they called?
DIN
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Excellent! Any idea where to get adapters, or plugs to make adapters with?
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Cool. Most interesting.
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Excellent! Any idea where to get adapters, or plugs to make adapters with?
You could try Mouser and Digikey to start with. Or ebay.
Brad :icon_biggrin:
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I've replaced the caps & selenium rectifier, cut out the death cap, and installed a grounded power cord. Powers up fine, and that old german motor purrs along nicely. The nominal voltages seem OK so far, on the B+ rail at least. High by @12-20vdc but that's no big deal.
The lady at radio snack didn't have any DIN plugs but thinks a mini-MIDI cable would also fit. I happen to have one around here somewhere....
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...There it is. Yes indeedy it does fit. Now to figure out which conductors to use.
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I made the plug adapters and turned it on; at first there was this terrible 60Hz hum but twiddling the knobs & stuff somehow took care of it.
What a cool effect! It sounds awesome! I could sit & noodle all day with this thing.
I can't seem to find mounting nuts for the 3 pots, that's really the only thing I need to wrap up at this point. I'll replace the tape, which has little holes in it, as well.