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edcor transformer wiring (Read 6176 times)
MattG
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Posts: 30
Re: edcor transformer wiring
Reply #15 - 07/17/12 at 00:14:43
 
Mike, trannies show up?
That is a sweet chassis! I like the wood...

ok, some pics to followup on the wiring:
https://www.dropbox.com/sh/adsdzhsparh37d5/uIKLc4tBTq

1st pic Here are the OT connections to the PCB - red to red, blue edcor wires to pcb "white"

2nd pic - the full spaghetti shot, both amps in a box - the front side of the amp is on the left - volume pot in the middle, with power and standby switches on either side. RCA jacks are at the top of the pic, which is the right side of the box. Power and speaker jacks on the right side of the pic, which is the back of the box.

3rd pic Here's the serially connected OTs and speaker posts

4th pic Here's the PT connections to the PCB - red to red, brown edcor wires to pcb "green", "chassis gnd" is the blue wire connected to the chassis bolt to the right

5th pic Here's the back of the IEC power jack - 1 black wire from each PT to the IEC neutral on the left, IEC ground (middle lug) to chassis ground bolt, then IEC live goes first to the fuse holder (blue wires), then the middle purple wires (there are 2 blue & purple wires due to my earlier wiring goof) go to the power switch on the front. The other black PT wires go to the other side of the power switch.

Last is how it'll look in action, ahh pretty! Smiley
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mboxler
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Re: edcor transformer wiring
Reply #16 - 07/17/12 at 03:27:27
 
Hi Matt...

Got 'em.  They are a lot bigger (and heavier) than I thought!  Re-thinking my set-up...driving me crazy.  One chassis like you did, or two smaller ones.  

Glad you figured out the output issue.  Bummer on the standby switch.  

Thanks for the pictures!  I forgot you went the PCB/PTP route.  Can you tell any difference between the two?

What speakers are you driving?  I'm worried that I should have bought the 8 ohm tranny instead of the 6, but I'll give it a try.

While waiting for the Edcor's, I started another project building a linear power supply for my squeezebox touch.  Just ordered a small chassis from the same guy I'm thinking of using for the ZKIT1's.  Hope it's as nice as the picture.  

Back to the standby switch.  Would the DPST work, running the CT wire (red/black) to A and out from C?  The brown "heater" wires would open in the STBY position, then everything else in the ON position.  Sounds too easy to be right.

I'm sure I'll have more questions when I resume the project.  Thanks in advance for the help.  My soldering is getting pretty good...it's the de-soldering that gives me fits.

Mike





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MattG
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Re: edcor transformer wiring
Reply #17 - 07/17/12 at 05:48:06
 
Yeah, the transformers are beasts! but supposedly mo' iron = mo' better!

I know what you mean about set-up decisions, it can be maddening, but as soon as you decide 1 way or the other, everything will fall into place! Wink

Honestly, I can't tell any difference right now, but I've barely had the whole system up and running...I currently have ONE LP that's been kicking around the house forever - J Geils Freeze Frame - that I don't think would win any awards for recording quality Roll Eyes And since I couldn't resist, I've got different coupling caps (the 0.1uF jobbies) - Russian paper in oil K40Y in the PTP amp, and the standard white Mallory caps in the PCB amp, which probably have different "burn in" needs...oh well...I'm just happy the output levels are matched!

speakers are some 'custom' towers a friend built for me years ago...6" Vifa midrange and Scanspeak 2905 tweeters, with a nice crossover - Crescendo capacitors, Ohmite precision resistors, and North Creek Audio custom wound inductors. The bottoms are filled with sand and have bass reflex ports for low freq extension. I dunno, they sound great to me, without much for comparison - just happy to be using them again! Cool

I had to look up the squeezebox - cool stuff! So wifi music player can play your library from a different computer...so it's got a decent DAC built in? Which you can squeeze more out of with a nice PS?
I've just been using a Pure adapter for ipod/ipad connection to the old house system.

Standby switch - following that diagram you linked earlier - A would be the CT wire, C would be a wire to ground, B would be a fused wire from IEC live, and D would be one of the PT black wires (the other black wire goes to IEC neutral lug). Just hook the PT brown wires up to PCB "green" holes. The idea with Standby is that the heaters have a chance to fire up (Standby) before you apply high voltage to the tubes (ON). So the tubes should glow in Standby, but you don't get sound until ON. Make sense?

Desoldering - that copper mesh desoldering braid stuff is your friend!
http://www.radioshack.com/product/index.jsp?productId=2062744
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mboxler
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Re: edcor transformer wiring
Reply #18 - 07/17/12 at 21:48:28
 
Matt-

Standby wiring makes sense.  I couldn't tell where you ran your CT wire...must have gone to a chassis nut (?).  I'll solder it to RED/YL on the PCB for testing.

I tested the power transformer.  345V and 6.8V.  Did yours test that high?

Can I test voltages without inputs, pots, and output trannies connected?  Be nice to add "stuff" AFTER I know things are looking good.

Funny you should mention different coupling caps.  I have 4 .1uf Tone Factory Vitamin-Q Oil Paper caps from another project (don't ask).  I wonder how they will sound?

You are getting me motivated (starting to overcome the fear).  

Again, thanks for the hand holding.  Much appreciated.

Mike

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« Last Edit: 07/18/12 at 04:17:58 by mboxler »  
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MattG
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Re: edcor transformer wiring
Reply #19 - 07/18/12 at 08:28:52
 
I just grounded the CT wires to a chassis bolt. A popular option is to use one of your transformer bolts. Yup, looks like Red/Yl on the PCB is a ground point, so that'll work...make sure to have PCB "chassis gnd" connected to a chassis/transformer bolt! Should help keep out the squealing gremlins...

I did not fire up the PT beforehand...I installed, wired up, and then using the assembly instructions, loaded up tubes and fired it up! Kept my hand on the switch in case magic smoke erupted...but I'd triple checked the wiring and felt reasonably confident...still, it can be risky...I think the guy at Aiken amps has a guide on how to do a very controlled amp startup...but anyway, Steve's instructions on testing voltages include having the tubes in, so things are "under load" and the recommended voltages reflect that...

that being said, my incoming voltage on the red PT wires connected to the diodes is 330VAC - I too was surprised a bit by that, but regardless my other test points checked out ok (after I fixed my earlier problem!)

huh kinda funny, in my focus on all the other voltages, I never checked the heater voltage! I saw glowing tubes and went "hey, the heaters work!" Tongue

but to your question, yes I believe you can check your power rail and heater voltages once you've got the IEC plug, fuse and PT wired up - shouldn't need inputs, pots, OTs...

coupling caps - I try not to get too sucked into cork sniffery - mainly b/c my ears don't support the claims Wink but I was ordering the tubes from Russia (tubes-store.com, the tubes are wicked cheap!) and they had the PIO caps, so I figured I'd make the shipping price worth it!

of course, the real way to tell is listen for a while to one type, then change em out and listen again...I don't have the patience/aural memory...not to mention some caps supposedly need 100s of hours of burn in?! Roll Eyes

hey, if you can fit em on the PCB, use em!
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mboxler
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Re: edcor transformer wiring
Reply #20 - 07/18/12 at 14:27:37
 
Thanks (again) Matt

I got brave last night and...

1)  Hooked up the brown wires only.  The PT wires are well tinned, and I just stuck them into the GRN holes, the wire at an angle caused a good connection (?), and plugged it in.  Tubes lit up!.

2)  Hooked up the remaining wires CT to GRN/YL (I have everything on a 12" by 12" piece of ceramic tile, fireproof).  Plugged it in, no smoke.  But, when I measured the voltage at point A (red wire of multimeter to connections between 1K 5W and 6.8 K 2W, black to chassis ground) I got 425V, way over the 346v I should have seen.  I had hoped it was the high voltage from the PT, but sounds as though you have similar PT voltage, so now starts the trouble shooting.  Perhaps soldering the red wires will lower the voltage (?).

Going to Breckenridge for a couple of nights, will work on this Friday when I get home.

Wish me luck!

Mike  

Update...

I noticed the OT had .2 ohm resistance, so I hooked them up.  CPA dropped to 366v, CPB to 309.  CPC was 7.6V, too low.  Will check more on Friday.  The OT's must create a load that drops the voltages after all.
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« Last Edit: 07/18/12 at 18:52:05 by mboxler »  
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MattG
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Re: edcor transformer wiring
Reply #21 - 07/27/12 at 17:17:03
 
Mike,
Any news on your cathode voltage? Points A and B look reasonable...

Try DanK's advice and test with 1 output tube plugged in at a time, check the voltages around the tube that's plugged in, see if one of them 'sticks out', could be a bad solder connection or somesuch...
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mboxler
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Re: edcor transformer wiring
Reply #22 - 07/27/12 at 18:03:34
 
Hi Matt

My mom had open heart surgery Monday, and things haven't been going as smoothly as planned.  Needless to say, priorities have shifted.  Things seem to be settling down, so I hope to get back to this in a few days.  How's your amp doing?  BTW, what tube types are you using?  I have JJ E88CC Gold Pins and some EP15P-EV's from Ukraine.

Your pictures made me realize that the OT's can be mounted upside down in the chassis!  This is changing my thinking as well.

I'm also concerned that I didn't give the 1k 5W resistor the recommended 1 inch clearance (noticed after trimming the excess, have about 1/2 inch from PCB).  How much clearance did you give?  I may have to order a couple more and re-do.  

Will let you know when I resume testing.  I'm sure I'll have more questions.  Thanks for checking in.

Best, Mike

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« Last Edit: 07/27/12 at 18:21:51 by mboxler »  
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MattG
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Re: edcor transformer wiring
Reply #23 - 07/28/12 at 19:05:21
 
Sheeit man, sorry to hear about your mom, I hope things continue to improve...

After breaking the 2nd power switch (formerly the un-successful standby switch), I've finally got it back up and running Roll Eyes Went down to a record shop and picked up my 1st 'used' LP, and now I want more Smiley

I ordered the tubes from here, I believe they are from the "Reflector" factory somewhere in Russia. Got the 6N1P and 6P15P-EV. Took several weeks for them to show up, but hey pretty cheap...
http://tubes-store.com/product_info.php?cPath=30_78&products_id=212
http://tubes-store.com/product_info.php?cPath=30_77&products_id=11

Yup, transformers can be hidden away Wink

I missed the "1 inch clearance" on that resistor too! Yes it gets warm, but I don't think it'll melt anything nearby...but sure, "better safe" and all that...
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