Could someone from Decware Please post the correct wiring color code for the recommend Edcor power transformer XPWR066-240 to match ZKIT-1  REV 9 2011 .

Regards,  Steve.

Hi Steve...

Did you end up following the recommended wiring posted by Kaloyanr, including the extra ground wire?  How long did Edcor take to deliver the transforms (still waiting).

Thanks, Mike

Thanks Steve!

Hard to get answers on this forum, and the documentation is outdated.  Sorry, but a few more questions.

1)  I was planning on wiring the speaker terminals directly to the output transformers, bypassing the PCB.  Is that what you did?  Seems cleaner.

2)  Sounds like you used an external pot.  Mind telling me which brand/part number?

3)  If you used external RCA inputs, how do you wire +/- from the RCA to the 4 holes on the PCB?  My guess is + (center of RCA)  to small hole, - to ANY of the three big holes.  

I can't tell you how much I appreciate the help.  Wish I could return the favor!  Hope not to bother you after this.  

Regards

Mike

Steve/Mike,
I've been reading this post with interest since I'm in a similar situation, thanks for confirming a few things! And Steve, congrats on getting it up and running with no smoke and no hum! Motivation for sure...

I'm wiring up 2 amps in the same box, each as a monoblock, with external volume pot, rca jacks and speaker jacks.

For the rca jacks I have single conductor shielded cable, with the shield soldered to the solder tab on the body of the jack. The other end bypasses the board and goes right to the volume pot, with the shield soldered to the pot body.

Then I have a 2 conductor shielded cable coming off the other 2 pot lugs - signal and ground - again with the shield soldered to the pot body. In my case, I've bridged the ground lugs together and again connected them to the pot body. At the other end, where the pot would otherwise connect to the board, I'll hook the signal wire to the center hole (bridging to the other center hole since again I'm going mono), and then the ground wire and shield will go to the grounded holes next to the center holes.

For speaker jacks, as shown in previous post, violet and white OT wires directly to the jacks.

I'm hoping this will provide hum-free operation. Steve, did you take any other grounding/hum precautions??

Right now I'm starting the PT wiring, trying to make sure I've got the fuse/switch situation sorted correctly. Also trying to figure out how to work in a Standby switch (I think right after the diodes, before the 1st filter cap, hmm?)

Anyway, thought I'd share since, yeah getting info like this on the forum can be 'difficult'!

If you guys see any glaring problems with my wiring scheme, pls chime in before I apply high voltage!  :)

and yeah, the edcor transformers take a while! they look nice tho...

Thanks
Matt

Hi Matt...

Welcome to our forum within a forum. I hope others start chiming in...the more the better.

This is my first tube build, so I won't be much help.  What kind of case are you going to use?  I also have two kits, one completed, and waiting for the transformers.  If it doesn't blow up, I'll start on the second.  I plan on two amps, set up for stereo.  I'll bridge using the speaker terminals if needed.  I can't comment on your RCA wiring, although I like the idea of bypassing the board whenever possible.  

As far as your speaker terminals, will you attach the violet wire from the left channel OT to the positive speaker terminal, attach the white wire from the right OT to the negative speaker terminal, and splice the left channel white wire to the right channel violet wire?  This sounds too simple, but...

Anyway, I hope someone can answer your RCA/Pot questions.  I'll be "listening" in.

Regards, Mike

No quad speaker setup.  I'm upgrading a pair of Klipschorns I bought in '85.  Thought I'd try to bi-amp them, using Marchand electronic crossovers I built from a kit.

Sounded like a fun project, I've heard that 'horns love tubes.  Wanted to hear it for myself.  

Have a safe 4th!  I live in Golden, CO, and the smoke from Wyoming has blown south.  Feels like the whole country is on fire!

Good luck with the point to point.

Mike

I'm down in Albuquerque, and various parts of the state had been on fire sending in smoke you can taste, lovely! We've finally gotten rain showers the last couple days, so hopefully that'll help...that Co Springs fire looks nasty...hadn't heard about WY fires tho, eesh...

uh oh, sorry if I got you scheming!  :)

I was just re-assessing my IEC/fuse/switch wiring - you should definitely be able to power both amps from the same IEC/switch - I went in thinking "I've got 2 amps, so I'll run 2 wires off the Live lug on the IEC jack to 2 separate fuse holders, then 2 more wires from fuses to the power switch"...but after I did all that (of course), I'm staring at it, and now I'm thinking I don't need 2 wires & 2 fuses...I've got 1 black wire from each PT going to the switch, same lug...but if EITHER amp has a problem, I want a fuse to blow and power to cut out. I would definitely NOT use a single 6A fuse. So I *think* I really only need 1 fuse, 1 wire to the power switch, and then the other side of the switch feeds both PTs  ??? I need to stare at it some more, maybe someone else can check my logic...

re: RCA and volume wiring -- I'm using the 1 dual-gang pot recommended for the kit (altho I probably should've gotten a bigger bodied, chassis mount pot with the bigger lugs, would've been easier to solder all the damn wires on it!)...so I've got a shielded wire going from each signal/center post on the RCAs to input lugs on pot. Shield is attached on the RCA body lug on that end, then pot case on the other end - b/c again these parts are mounted to wood, not the same piece of metal. Then I've got (2) two-conductor shielded wires coming off each side of the dual-gang pot, from the wiper & ground lugs, 1 pair for each amp. The wiper wire (signal) goes to the middle hole on the PCB, then I added a small jumper to feed the other middle hole (as opposed to 2 wires from the pot). The ground wire from the pot goes to one of the pot ground holes on the PCB, with the shield going to the other ground hole. On the pot end, the shield is soldered to the pot body. So I'm using 4 of the 6 holes where the pot would otherwise go on the PCB. Does that make sense? Hmm, pictures would be helpful...

I'm pretty sure this will give me simultaneous/matched volume control over both amps...

I've done mods to guitar amps before, but this is my first build from the ground up, so I too am learning as I go!  ;) it can be really helpful to bounce this stuff around until it starts making sense!

-Matt

Congrats Matt!

I just got an e-mail from EDCOR...trannys shipped today, so expect them in a few days.  Trying to make sure I have the voltage check points identified (instructions a little vague).

Also trying to decide on a case.  I may put both amps into this

http://www.ebay.com/itm/Tube-Amp-Chassis-DIY-18x12x2-5-Aluminum-Project-Box-Encl...

but still thinking.

No hurry, but I'd really be interested in pictures of your wiring, if it's not too much trouble.  

Mike

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

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

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.

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