Poor Man's 660 Progress Report

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I just found out that Narma co-founded Gotham.
Sheesh. Wish I would have known that during the interview.
Or about his 4 articles in AES.
660 was all Narma, 670 was help from Fairchild, Alexandrovich and the gang.
 
[quote author="soundguy"]analag, I like the front panel your simulator made, that thing almost looks real.

dave[/quote]

Real front panel, all simulation is done at this point.

For the toroid I used a cardboard tube almost like what's inside the toilet paper thingy, I cut a U shape into it to prevent the wire from sliding off. I count 1 turn on the tube then check how many turns I get around the core. Then I wind off just enough wire to do the job. No pre wound stuff. I paid $6.02 for the core.

analag
 
[quote author="analag"][quote author="soundguy"]analag, I like the front panel your simulator made, that thing almost looks real.

dave[/quote]

Real front panel, all simulation is done at this point.[/quote]

Joke! Very dry, shaken, not stirred. Good one, Dave.

For the toroid I used a cardboard tube almost like what's inside the toilet paper thingy, I cut a U shape into it to prevent the wire from sliding off. I count 1 turn on the tube then check how many turns I get around the core. Then I wind off just enough wire to do the job. No pre wound stuff. I paid $6.02 for the core.

So you cut notches into the ends of the tube and wind the wire onto it lengthwise? And then you use this "shuttle" to wind the wire onto the core? I think I get that part. What about separating the primary and secondary? Do you wind them over each other with extra insulation between or are they located on different "sectors" of the toroid? Looks like the former in the pics. Do you have a heater winding on there, too? Is the outer insulation just tape? Where did you get the varnish? Thanks for the info...

A P
 
[quote author="AnalogPackrat"]

So you cut notches into the ends of the tube and wind the wire onto it lengthwise? And then you use this "shuttle" to wind the wire onto the core? I think I get that part. What about separating the primary and secondary? Do you wind them over each other with extra insulation between or are they located on different "sectors" of the toroid? Looks like the former in the pics. Do you have a heater winding on there, too? Is the outer insulation just tape? Where did you get the varnish? Thanks for the info...

A P[/quote]

nag, nag, nag!! AP if you're gonna build one, i wanna be there when you plug in that monster? :grin:
but seriously, way to go analag! :thumb: beauty of a power tx.
 
[quote author="dissonantstring"]
nag, nag, nag!! AP if you're gonna build one, i wanna be there when you plug in that monster? :grin: [/quote]

Well, I would want someone there to run the fire extinguisher! You're invited!
 
I unwound a toroid because it had an open secondary. Found that it had a thermal fuse in side of it.. had blown. Rewind was a pain. the process took hours.

The toroid still works to this day though.. 15$ saved.. for 5 hours worth of work. hardly a deal.. :shock:
 
We're not talking about winding a little low voltage thing--no point as there are cheap off the shelf options there. Its the HV stuff where you get limited. I would only do it a) to learn something by doing it once and b) to make a transformer that met my requirements rather than having to buy the closest available unit and make design compromises because of it.

I could have bought a pair of CMO-2S for my 312s, but I wound my own similar types instead to learn about the process. It took me a couple or three hours each and in that respect wasn't cost effective, but since when is DIY really cost effective when you charge for your time?

A P
 
I wound the primary, then varnish, let it dry (Dolph AC43). I don't know if this stuff is available to non-commercial buyers. Got it from the local electric motor repair guys. Wrap it up real good with Kapton tape, wound three secondaries (250V,15V,6V) in the same fashion. The trick is in how you bring out the terminals arcing may result if you don't know what you're doing.

Starting to power up now, guys. So far the simulator ain't been lying.

analag
 
Three days steady building. At 6:05am I am pleased to say "IT WORKS"
it's a fucking crusher.
From sweet and rounder to as hard as you want.
My simulator did not lie.

analag
 
As I play with the controls...it's doing some crazy stuff, like companding and compressing...in other words the VU on my desk just sits at +4 and flickers. Seriously huge sounding. Once again the Edcor XSM range deliver the right punch and tonality, there is something to be said about the M6 saturation curve, drums and bass seem the explode much better. Top end is extended and clean, really nice without any coupling caps in the signal path. Dead quiet and no feedback whatsoever(ain't got around to that yet, maybe never). Fast an I mean fast, I find myself using medium attack to tame this beast.
This experiment proves you don't need the excessive approach to acheive a Fairchild 660/670 topology. I think much of that was done for hype and retail power, if not then what is this I am listening to right now as we speak. Nevertheless I thank them for the idea which I was able to simulate down to a radically less expensive compromise. It may not sound exactly like it but it sure as hell work off of the same "EXACT" principle, no 6AL5 here.
I'm tire, elated and I'm babbling. Going to hit the sack. See ya.

analag

analag
 

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