700/1 “Tim” WOPL driver board

AngrySailor

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The one set of RCA jacks marked DC Input bypasses the POT when the switch is put in that direct mode. They changed that on the 700B where both normal and direct route through the volume pots.
I was wondering if I could parallel the input jacks? Retain the four (two left and right), wire so the switch allows direct and through the .47uf, but would this allow me to “daisy chain” another amp of those parallel RCA’s? Or allow two signal sources?
 

laatsch55

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I was wondering if I could parallel the input jacks? Retain the four (two left and right), wire so the switch allows direct and through the .47uf, but would this allow me to “daisy chain” another amp of those parallel RCA’s? Or allow two signal sources?
I wouldn't.....I'm thinkin you might develop ground loops.
 

AngrySailor

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Been offline a few days. Changed service providers, took a few lazy days. Been working on tractor shit last couple days. Got this museum tractor almost mechanically back together. Finished the Ignition today. Basically this could be considered a prohibited weapon in canuckistan, Justin Trudeau would surely cry if he knew I was in possession of a quad core TASER. Little does he know every car has at least one. That said, you COULD strap this to your belt along with a 12v motorcycle battery, attach a couple wands and clear a Walmart PDQ... this old tractor almost ready to run. A few wires and all that’s left is carb/kerosene vaporizer rebuild. She’s close then it’s WOPL focus.
 

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AngrySailor

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This actually took some epic soldering... I had a broken wire on one coil and it was potted in some surely PCB laden tar. Dug an 1/8” of wire out, managed to tag a lead on and save it. It was greasy but model T coils aren’t easy to come by...
 

George S.

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Tell us about your metal lathe. I didn't see much manufacturing on the island. Did it come from the rail road or a ship yard?
 

AngrySailor

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Tell us about your metal lathe. I didn't see much manufacturing on the island. Did it come from the rail road or a ship yard?
it’s a SIRCO PA-24. Yugoslavian made, 24”x80” weighs almost 10k lbs. I bought it from a machine shop in southern Ontario almost 20 years ago now. That was a bugger to ship east. We built an 8” I beam base for it so it could be loaded into a refer trailer lengthwise and not stress it, I then sectioned the beam together and used it as my overhead lifting beam in the shop. There’s a good bit of manufacturing hidden away here. Couple of the larger ones being Charlottetown metal products and Linkletter welding, also trout river trailers is located here. They sell rig trailers world wide. Mostly live bottom stuff. Tons of small shops servicing the fishing and agriculture industry too. A lot of them just don’t jump out at you I guess.
 

George S.

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it’s a SIRCO PA-24. Yugoslavian made, 24”x80” weighs almost 10k lbs. I bought it from a machine shop in southern Ontario almost 20 years ago now. That was a bugger to ship east. We built an 8” I beam base for it so it could be loaded into a refer trailer lengthwise and not stress it, I then sectioned the beam together and used it as my overhead lifting beam in the shop. There’s a good bit of manufacturing hidden away here. Couple of the larger ones being Charlottetown metal products and Linkletter welding, also trout river trailers is located here. They sell rig trailers world wide. Mostly live bottom stuff. Tons of small shops servicing the fishing and agriculture industry too. A lot of them just don’t jump out at you I guess.
Nice! I had machine shop in junior high school and we made aluminum salt and pepper shakers using fairly large metal lathes. Yeah, I know, how lame, but machining with a metal lathe is so interesting. Wood shop, metal shop, welding, electrical were all part of the standard curriculum. High school was different, open classrooms with office type dividers, no more hands on trade type instruction was offered, all liberal arts like teaching. Such a shame. Not a wonder so many students dropped out and went to work.
 

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Nice! I had machine shop in junior high school and we made aluminum salt and pepper shakers using fairly large metal lathes. Yeah, I know, how lame, but machining with a metal lathe is so interesting. Wood shop, metal shop, welding, electrical were all part of the standard curriculum. High school was different, open classrooms with office type dividers, no more hands on trade type instruction was offered, all liberal arts like teaching. Such a shame. Not a wonder so many students dropped out and went to work.
Such a shame...
 

AngrySailor

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I caught the end of trades classes at my high school. We had a machine shop, welding and auto shop. My last year they canned it all and the school focused on “performing arts”... pretty gayee really. My last year the only trades class was construction and all we did was build stages and props for dance fruit loops. There’s deals to be had buying up the machinery from those schools though...
 

AngrySailor

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Ok finally trying to get off my ass and work on Tim. Haven’t touched it in ages. Finished cleaning all that f’n heat compound off, gave my head a shake and said “wtf am I thinking working around this face plate” and desoldered it, set it aside. Couldn’t sleep so I’m gearing up tools and stuff to make a go at it tomorrow.
 

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AngrySailor

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Input wiring done. Just got to wire to the pots and down to the board.

This thing was quite a bit different than a 700/2 or 700b. Obviously accomplished the same job but weird. The input caps were on the old driver board, double run of signal wiring up to the pots and back. Sure hope this works! I retained both sets of RCA jacks and the switch selects between cap or direct coupling and now keeps the 220k resistor in circuit at all times. This seems to be how the later series are wired in that the 220k is in at all times. This one removed it from circuit when in direct when wired as I got it. Either way it’s now wired like the later amps which obviously work with Joes boards.

I probably should have just removed the RCA assembly and soldered on the bench. I’m sure I got good solid solder joints and everything is mechanically fastened also (J hooked or twisted). I reused some of that Belden wire and never again. Even with a regulated iron it’s insulation shrinks back like a frightened turtle.

Next I have to drill the holes for the stand offs for the new board and also mount the bias transistors. I’m thinking to use the old bottom holes from the PL board stand offs. They’re low though, down between the drivers however the 400/1 has them down there too... those existing holes also don’t interfere with the heat sinks. Looks like the wire lead length will be similar to the 400/1 also.
Man that heat transfer compound stays everywhere...

Linda will be nice to WOPL as she’s going right down to the bare chassis. This is an absolute bugger to clean. Looked not bad in the shop lighting but with my LED work light it’s still a mess. Just needs a wipe down and a little time with some Q-tips.


Let me know if you see any big frig ups in the works.
 

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AngrySailor

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Is there a schematic for the DCP rather than the step by step verbal instructions? This amp does not seem conform to the written instructions. I’m going to look for my 700/1 service manual see if I can figure these differences out...
 

AngrySailor

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You have to check with the inventor and developer, Don Imlay. Send him a note from his webpage.
http://www.wattsabundant.com/id17.html
I never even seen he has an email listed there, only ever talked with him here. doing “day time” jobs rn so it’s no panic. Really looking forward to finishing the wiring and starting the bring up process though.
 
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