SUPPORT FORUMS FOR ZKITS >> ZKIT 1 Support forum >> First time build

Message started by jpv on 11/13/12 at 03:13:56

Title: First time build
Post by jpv on 11/13/12 at 03:13:56

When I was at Decfest 2012 I bought a board (ver 10 2012) to build this amp.
I always wanted to build a kit and this looks like a great place to start.
This is all new to me so I hope to learn a lot with some help from you guys.
I will be ordering the parts soon. Other then what is listed on the parts list are there any other items I need to get?
I will also be ordering a soldering iron from parts express. I have a VOM, solder. Do I need a de solderer sucker or the de soldering braid?
 The instuctions are not very clear as to how to go about building this so if you can list some pointers on how to proceed that would be great.

I have seen some really nice builds shown here and I hope mine comes out just as nice.


Title: Re: First time build
Post by marky on 11/13/12 at 10:58:33

Hi John,
A small piece of damp sponge to wipe the s.gun tip between solders
keeps it optimum. You can get these `all in one` in a station and
means you dont have to perch the gun somewhere when not using.
Solder guns are usually for removing old solder efficiently, again handy
just in case. Obviously a pair of long nose pliers and snips. Good luck
and have fun in overcoming those ` I wish I had another hand ` moments.

Title: Re: First time build
Post by mboxler on 11/13/12 at 14:47:38

Hey John...

Sounds like you got the new board with the corrected wiring (for the Edcor's), as well as the 100 Ohm virtual CT for the heaters???  These will help a lot.  I'm still working on mine.  I tested the 100 Ohm CT revision, and it did remove most of the AC hum from the heaters.

Be sure you have an alligator clip on you VOM.  Attach it to the grounded side of any component, and use the red lead to test voltages.  Very high don't want both hands near the board when powered on!

Take your time!  You will learn a lot!  I know I have.


Title: Re: First time build
Post by jpv on 11/14/12 at 02:50:26

Thanks for the tips and suggestions. I will add a IEC power connector and fuse holder to the list along with snips. I have a base with clips on it to hold the board as I work.

Are the any things you wish you did or would do over.
Is there any order to how this is to be built.
Can you show a pic of your completed board.

Title: Re: First time build
Post by mboxler on 11/14/12 at 19:50:39

If it's not too late, I got the IEC with the fuse holder built in.  Less wiring!  I spent hours trying to figure out why my voltage (D) was so high.  I finally swapped the 6922 tube with a 6N1P, and the voltage dropped to within specs.  Thought I had a bad solder joint or component.  What a relief.  Be sure to mount the big ol' 1K 5W resistor an inch from the board (and everything else).  It gets hot!!!

I plan on installing a standby switch

to let the tubes warm up before feeding the amp the full voltage.  Not required, but worth a Google.

Have you ever soldered before?  If not, and you would like to practice on something, you could buy a prototype board like this

Solder pieces of wire, unused resistors, etc, 'til you feel a little more comfortable.

I'll to get some pictures, if I can find my wife's camera.


Oh...I wish I hadn't sold my '71 Chevelle SS 454 when I was younger, but...

Title: Re: First time build
Post by jpv on 11/15/12 at 14:28:42

 I like the idea of the stand by switch and the built in fuse holder.
I have boxes and bags full of resistor, and other part left in the attic by the guy who sold me my house. Plenty of stuff to practice on.
I should go thru it all too see what I have. He had them in vaccum tube boxes so when I first saw it I thought I hit the jackpot.

Anyway I will order the parts this weekend.

I looked at the board last night and I have some question but I will ask them as time goes on.


Title: Re: First time build
Post by mboxler on 11/19/12 at 16:46:05


Here is a picture of my builds.  I soldered the 150 ohm 5W resistor and one of the 10K ohm 5W resistors to the tube side of the board, as it got crowded on the component side.  I plan on replacing the big black 1K 6W resistor, as I failed to allow for the 1 inch clearance.  This is the Rev 9 2011 board...yours should have the correct wiring colors and the 100 ohm virtual tap for the brown heater wires.


Title: Re: First time build
Post by jpv on 11/19/12 at 20:15:31

 I like that case you are using. Where did you get that?
Are you making two of them?
I see you are mounting the RCA and Speaker terninals on the case.
I was thinking of doing the same thing.
The parts were ordered today so now I have to wait for them to arrive.

Thanks for posting the photo I will use it as my guide.


Title: Re: First time build
Post by mboxler on 11/19/12 at 22:26:54

Yep, two amps.  I was going to wire them both mono, but now I'm not sure.  I got them from Keith (Ebay member po1019).  They were already made, and I took a chance that I could fit everything.  It's tight, but I think they will work.  He does great work, and will build any size you need.  Here is a link to his products.


Title: Re: First time build
Post by jpv on 11/20/12 at 01:06:55

Thanks for the link. What size did you get?
Do you think the 8 x 7.4 x 2.2 would be big enough?

Title: Re: First time build
Post by mboxler on 11/20/12 at 14:36:51

Hey John...

The inside dimensions of the matching pair I bought were ~ 8.25 W, 8 D, and 2.25 H.  The board (I think) is 6 x 6.  Very tight (hope I can pull it off).  The one you are looking at is 6.3125" x 7.25" x 2.0625" internally.  I think that is way too small.

Are you going to mount a separate pot to the chassis?  I cheated.  I used the PCB pot, and drilled a hole in the front of the case where it would poke through after mounting the board to the top of the case...about 1/4" from the front.  This was easier for me (I'm still new at this as well), and gave me 2 inches on one side and the back.

The transformers on top are a little tight as well (I'll try to get more pictures tonite).  I know a lot a others have mounted the OT's in the case.  Again...I hope my idea works!

Anyway, if I were to do this again for a single stereo amp, I'd add 1 to 2 inches in width, and 1 inch in depth.  The 2.25 H is okay...2.5 would be a little better.  Again, an external pot might change things a little???  I'd order a custom one from Keith.  He needs the INTERNAL dimensions, and you could select the wood that you like.  Again, he is wonderful to work with, and they usually take about a week to build.

Give it some thought while you are building the board.  Did you order Edcor transformers?  Mine took a full six weeks to arrive, so you have plenty of time to think about it.

I'm new to this too, but will be happy to help as much as I can.


Title: Re: First time build
Post by jpv on 11/21/12 at 05:11:20

I ordered the transformers yesterday. I know 6 weeks is a long time.
Two of the parts from Mouser are not in stock so I will have to wait on that also.
 The case I will wait on untill I layout the parts. A 1-2 week leadtime is not bad. I made a case for my subwoofer plate amp and I might follow that design concept.
Keep us posted on your progress

Title: Re: First time build
Post by mboxler on 11/21/12 at 14:43:57

Sounds good.  I noticed that the new 100 ohm resistors for the virtual CT for the heater wires were not in the parts list (at least I didn't see them).  If you need a couple, I bought 10 (since they were cheap, but shipping isn't).  I'd be happy to mail you a couple if that helps.


Title: Re: First time build
Post by jpv on 11/23/12 at 21:16:38

Your right they are not on the list or is it shown on the schematic.
I also noticed a part# that is not correct for on set of resistors.
You can send me the resitor if its not that much of a problem.
I can send you a PM with my address.
I am going to add two sets of inputs to my amp for some added flexability. I did order the RCA phono connected listed just incase I change my mind.
Did you add the 3-way power switch to keep the heaters on?

Title: Re: First time build
Post by mboxler on 11/24/12 at 01:17:49

Good thing I bought extras!  PM me, I'd be happy to send you a couple.  Received the switches yesterday.  DMM shows they should work...will rig up a test to be sure before I stuff everything onto the case.'s the top view of the chassis.  Drilled a few more holes today, but taking it slow.  Notice the hole under the PS transformer?  That's what happens when I get tired.  Good thing the transformer covers it up when I remove the spacers.


Title: Re: First time build
Post by jpv on 11/30/12 at 13:21:59

Just a little update: My parts from Parts Express arrived yesterday.
I still need the transformers and the items from Mouser.
Mouser was out of stock on two items so they will not ship the other stuff until the order is complete. I figure the transformers will take a long time so there is no rush on the other stuff.


Title: Re: First time build
Post by mboxler on 12/04/12 at 16:56:03


PM'd you, missed your request for the resistors.  My bad!  Will get them out tomorrow.


Title: Re: First time build
Post by jpv on 12/04/12 at 19:45:51

Thanks for sending them.
I got the Mouser parts yesterday. Just waiting on the transformers.
The more I look at your build the more I see I need. The parts list is not all that complete. I guess the more you want to dress it up the more you need. I forgot to order the power socket, fuse holder, power switch, the output tubes. I have plenty of 6JD8's.
 I got some old resistors to practice soldering on until all the parts arrive.

Title: Re: First time build
Post by jpv on 12/11/12 at 01:23:42

Your parts arrived today. :)  I think all I need are the transformers.

Title: Re: First time build
Post by jpv on 12/22/12 at 22:38:37

My transformers shipped on the19th so I should getting them soon
Just in time for a long Christmas vacation.  :)

Title: Re: First time build
Post by jpv on 12/29/12 at 01:16:15

The tranformer arrived yesterday. Bigger and heavier then I thought they would be.
Now that I have all the parts (I thinK) where do I start?

Maybe this could be a newbe guide to building a Zkit 1.

Title: Re: First time build
Post by mboxler on 12/29/12 at 02:02:28

Now the fun begins!  Have you decided on a case, or build on a board?  This may dictate which side of the PCB you solder the components, although the sockets MUST go on the blank side.

Since my board attached to the top of the case, I soldered most components to the printed side, although I put 1 of the 5W 10K resistors on the blank side...more room.  Also put the 150 5W on the blank side for the same reason.

It's always easier to solder the small parts first (including the jumpers, which are the cut ends of other components).  Working from the middle to the outside og the board helps too.

For fun, solder the sockets on first.  Then, insert your tubes.  You'll get a me.  If you need more pictures, let me know.

Take your time.  Ask questions.  Learn.  It's great!


Title: Re: First time build
Post by Real on 12/29/12 at 12:46:28

Hello Mike,

I have a capacitor question.
Reguarding the 4, 1uf 400volt metal poly film cap.
Do these cap have polarities? Or does it mater.

My transformers have shipped and I should get them for next weekend.

Have you had a chance to hook up your amp to your Klipschorn?

Title: Re: First time build
Post by mboxler on 12/29/12 at 14:37:00

Hi Real

I assume you mean the four .1 uf caps...two for the coupling caps and 2 for the CCE mod?  If so, no, they are not polarized.

The only ones that are polorized are the Aluminum Electrolytic Capacitors (5 total).  The boards are clearly marked as to which side is positive.  The Aluminum Electrolytic Capacitors MUST BE MOUNTED correctly, or they will blow.  They are clearly marked, hopefully this picture helps.

Also, the CCE cap on the left is very tight to the 1000uf 25V cap.  Notice how I left it's leads long enough to bend it away from the cap.  

I'm planning to hook the amp to the 'Horns the weekend.  Right now, it sounds really good with the single driver speakers.

I'll be in and out all weekend, but will be happy to answer ANY questions as soon as I can.

Best, Mike

Title: Re: First time build
Post by Real on 12/29/12 at 19:24:02

Thanks Mike,

My board looks much like yours.
I hope I have every thing correct.
I tracked my transformers and should be getting them by next weekend.
I plan on building my own case. I will most likely start on it next weekend.

Title: Re: First time build
Post by jpv on 12/30/12 at 02:59:12

I started today after getting most of the part.
There are a few things about this kit you need to keep in mind.
First the parts list doesn't list all the items needed. You will also need a power switch, tubes, power cord, fuse holder, case or a board to mount it to, etc...

I also need snips, and a soldering station. I ordered this one from parts Express. It was only $13.00 on sale. It is a Stahl STSSVT. It works a lot better then the Radio Shack POS I bought many years ago. For the amount of soldering I will be doing it does just fine. I would order the larger tips, This one only comes with a fine pencil point tip.

I did this today in a couple of hours.

The soldering is not as differcult as I thought it would be and I used a magnifying glass to see the work as I solderd and after to inspect the joints. I still need to add the high watteage resistor and caps.
When I figure out how I will mount it I will add those.

Mike .. I can feel the power already

Title: Re: First time build
Post by mboxler on 12/30/12 at 03:13:42

Lookin' good, guys!  

Odd.  Looks like the new board has a place to solder the white/blue screen wires.  I assume they go nowhere???  I just cut the wires at the transformer.

Keep us updated!


Title: Re: First time build
Post by jpv on 12/30/12 at 03:28:54

Your OK with that. The holes for the white/blu go no where - do nothing.

Title: Re: First time build
Post by jpv on 01/03/13 at 23:27:31

I am working on the layout tonight and I am wondering if there is a min distance the transformers should stay away from the board?
I am thinking of hanging the board from a steel plate amd mounting the transformers on top. I am looking at an area of approx. 9 x 18.
That looks like I will have more than enough space to work in.


Title: Re: First time build
Post by Real on 01/03/13 at 23:57:11

I just received my transformer Today.

The power transformer is much larger than I expected.
I was wondering the same if the transformer should be a certain distance from the board.
I was going to put every thing on a 8X12 plate and build a box aound it.
Looks like I need more room.


Title: Re: First time build
Post by mboxler on 01/04/13 at 14:50:46

My "plate" is 8X8.  

As you can see in post 23, as long as the two holes you drill to pass the wires through the plate are not on top of the board, you should be okay.  My enclosures were a little small, and the first time, I had the PS transformer turned 90 degrees from where it is now.  That's when I realized the wires were above the board, and difficult to work with.

I have an inch clearance between the holes and the board, and had no problem.  Unfortunately, the transformers overlap the board by and inch, so a couple of board mounting screws are under a transformer.  

Reminder.  I was told it is a good idea to turn the PS transformer 90 degrees from the OP transformers.

With my setup, 10 inches wide and 9 inches deep would have been much easier to work with.  Again, I'm using the PCB mounted pot, so the board is 1/8 inch from the front.  If I had used a separate pot, I would have needed more room in front.

Good luck guys!


Title: Re: First time build
Post by jpv on 01/25/13 at 01:22:25

Ok find the mistakes. Don't look too hard.
I got the plate I am mounting the board to cut and painted. I used a heavy guage steel and would go with a much thinner metal next time. It was a major pain to cut.  The plate is big 12 x 18 and gives me plenty of room.
I was going to cut it down but I figured I could use the room and it looks nice. I have from the top left, a standby switch, Power switch and the volume control, The power transformer on the left, Holes for the tubes then the two speaker transformers. On the bottom is the power jack, two sets of inputs, The small hole is for a toggle switch to select the input, then the speaker post holes.

So now that I am ready to assemble whats next?
I put the input and selector switch on and mounted the speaker post.
I am not sure how to ground this. If the wires need to be twisted, separated, or any of the little details going from here on.
Do I complete the build then power it up or do I test it before I get to far?

Title: Re: First time build
Post by mboxler on 01/25/13 at 15:24:52

Hi John...

Don't you hate learning curves?  I'm glad I started with aluminum...easier to drill.

Did you use step down drill bits?  If not, an investment would do wonders, although I don't know how much they would cost to deal with heavy gauge steel.  You can easily round out the holes, and smooth out the edges.  The holes you drilled for the transformer wires need to be very clean, or do what I did and buy rubber grommets to "snap" inside the holes to prevent cutting the coating around the wires.

I tested my board "outside the box".  Granted, it meant a lot of temporary solders, but I wasn't brave enough to put everything together first.  You may be braver!

The most important ground is attaching the IEC ground to the chassis.  This can save your life.  Drill another hole a couple of inches from the IEC hole, and run a short wire from the IEC ground to a bolt through that hole.  I used a bolt, nut, washer, and lock washer.  I ended up attaching the chassis ground to this as well.  Make sure you scrap any paint from the edges of the hole.  You want a good electrical connection.

I've been told...always twist wires.  I could only twist the heater wires, as everything else had such short runs that I had no room to twist.

If two sets of wires cross, make sure they cross at 90 degrees, if possible.

This part of the project is nerve racking.  Take youe time.


Title: Re: First time build
Post by jpv on 01/27/13 at 18:37:57

Here is an overview of the backside so far. The red/black wire has not been attached yet. I have one SPST switch with nothing going to it yet. The plan is to use it for a stand by switch. I need help with that.
I have it grounded in from two spots. One IEC groung and the Chassis Ground. Is that all I need?
Do you see any mistakes with what I have done so far?

Once I get this looked over I will do the power up. I will post that later.


Title: Re: First time build
Post by mboxler on 01/27/13 at 20:03:09

I can't see anything wrong.  Actually, without the red/black CT wire attached, you could fire it up!  The brown wires are connected, so you should see the tube filaments glow.  That will be cool!  Uh, I mean hot.  Great first test.  There will still be high voltage going thru the diodes, but without the center tap wire connected, the voltage cannot be rectified.  The buck will stop there.  Make sure the loose red/black wire cannot touch anything.  

Now you will understand how to hook up the red/black center tap wire.  Run the red/black wire from the transformer to the second switch.  Run a wire from the other pole of the switch to red/blk on the pcb.  Actually, I'd call the first switch the standby switch, as it will only conduct heater current.  The second switch will power on the amp.

Turn on sequence...

1)  Standby switch on.  Let tubes heat up for 20 to 30 seconds.

2)  Power switch on.  B+ DC current can now flow, because the power supply has a center tap.  Now you can measure test points.

Turn off sequence...turn both off at the same time, or turn off the power switch, followed by the standby switch.

Make sense?


Title: Re: First time build
Post by jpv on 01/27/13 at 21:14:39

Does the Volume control need to be grounded? I see a Ground case of Vol control on th PCB. What is that for? When is it used?

Title: Re: First time build
Post by mboxler on 01/27/13 at 23:22:53

From Nimrod...scroll to the bottom

I used the pots soldered to the board.  Perhaps you could PM him for more specifics.


Title: Re: First time build
Post by jpv on 01/31/13 at 02:19:35

Well It works :) :) :)
No smoke, Hum,or  exploding parts yet.
My plan is to run it for the next hr or so and do this a few times until I am sure it all OK. Then it on to the main system.
Right now I have it hooked up to the PC audio outs. Sound good thru the POS speaker I am using to test.
The voltages measured in the range.
I will post photos later.

Title: Re: First time build
Post by jpv on 02/01/13 at 00:54:11

Title: Re: First time build
Post by jpv on 02/01/13 at 01:22:02

The picture in the previous post is the underside of this amp. I put the labels from Edcor on the plate for reference. I tried to keep the wiring as neat as possible. I mounted the 3 large resistors on the socket side to keep the heat producing items on top. The speaker wires are connected directly to the binding post bypassing the PCB.
I also color coded the wire with shrink tubing red right blue left.. Just a little OCD  :)

There is a front view. I have two power switches the rt side one is the power for the heaters. Next to that is the power to turn the power on to the rest of the system.
In the rear are two sets of inputs and toggle switch. IEC plug on the rt and the speaker post on the left. The base is red oak stained and polished with a satin wax.

Title: Re: First time build
Post by mboxler on 02/01/13 at 14:23:59

Great Job!  Love the red oak.  You may have mentioned this already, but what kind of speakers will this amp drive?


Title: Re: First time build
Post by jpv on 02/01/13 at 14:38:25

Well thats my next project for the spring time. I will hook this up to my main system and see how it does driving Proac Tablettes.
My other thought is to create a desk top speaker to use with my PC.

I need to research ideas on what is out there.

Title: Re: First time build
Post by jpv on 04/29/13 at 00:36:13

Well it has been a few months since I finished and I have done a lot of listening. I am really happy with the results. While the amp doesn't have the power my SA-12 has, I can get my Proac Tabeletts to an good listening volume. I did have a friend bring over her Klipisch Heresy speakers. Now that was the ticket. She was amazed how a 2 watt amp could "get so much sound out of them". We played music until 3:00 AM
What was really crazy her kids in their 20's never saw a LP or a turntable before.

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