New PCB Express build - seeking advice

[Ekometti]

Very nice. I'm new here yet I am very interested in this build. How can I obtain / order one?

Thanks
Erik

[mattvon]

Hey, thanks for the encouragement! I appreciate it...I can say that wiring heaters is my least favorite part of this build so far, lol...

So here's the latest version...I'm cautiously optimistic with this one. I took my time and really made sure I got as close as possible before splitting the twists.

Solders all test good, though it was a challenge to get some of them seated with the extra-short wires.

Thoughts? Does it pass inspection?

[IMG:800:600]http://img.photobucket.com/albums/v519/ ... 192915.jpg[/img]

As frustrating as this has been, I'm really glad you all were honest...I'd MUCH prefer to struggle now than to try and debug an oscillating, humming mess later.

[Drew.12345]

Nicely done my friend

Looks a lot better to me.

You'll be glad you spent the extra time to get this right.
Stick with it and keep everyone posted:)
Your gonna love this amp

[Colossal]

Really nice job on your heater wiring. Much, much better

I'd MUCH prefer to struggle now than to try and debug an oscillating, humming mess later.

The key to success in amp building!

[mattvon]

Thanks, guys! I appreciate the positive reinforcement...it really is an awesome way to learn.

@Erik: I used the BOM (bill of materials) for a scratch build to source all my parts. The BOM, as well as scratch build layout, schematic, and the all-important build guide can be found here: http://ampgarage.com/forum/viewtopic.php?t=5691

A few of the components are going to be a bit different from what's called for on the BOM, but my labeled PCB (found earlier in this thread) should help.

The PCB and chassis (and a headbox) were ordered from rj at http://www.rjguitars.net/
rj has been taking a break, but I believe he's getting back into the swing of things slowly. You can email him for info on those parts.

I believe rj also has the proper transformers as well, although I got mine from a different source.

I've been learning a ton by referencing the original PCB build thread, found here: http://ampgarage.com/forum/viewtopic.php?t=17524

[Ekometti]

Thanks Matt.

E

[Ekometti]

Uh oh. info@rjguitars.net was bounced back to me stating mailbox is full.

Bummer

[Koop]

OK, my turn for a PCB-XP question. The kit rj sent me contains 4 diodes, the schematic shows 4 in the rectifier and another one in the bias line. Then there are 6 more in between the power tubes and OT, making 11 total. Looking at Mark Fowler's build in the other thread, it looks like I can see 4 in the rectifier and another in the bias supply. I don't see the OT diodes. Am I short a diode?

[M Fowler]

Yes you need one more diode (1n4007) for the bias.

I don't use the protection diodes on my output tubes. You certainly can if you like to.

Mark

[Koop]

Thanks Mark. That's a common part I should be able to source locally. I don't know why rj only shows 4 in his parts kit.

[Koop]

The PEC pots came with ground lug adapters, at least I think that's what they are. They're like an extra lug that fits over the shaft housing and are drilled so you can solder a wire to them.

Here's my question...why? It appears to me VR3, VR4 and VR5 ground to the board via existing lugs. What are these additional lugs used for?

[rock_mumbles]

I don't think you can solder to the PEC pot housings so the ground lugs are included if you want to do the 'pot ground bus' thing

[Koop]

I don't think you can solder to the PEC pot housings so the ground lugs are included if you want to do the 'pot ground bus' thing

Thanks. In other words, they're not needed for this build.

[rock_mumbles]

I don't think you can solder to the PEC pot housings so the ground lugs are included if you want to do the 'pot ground bus' thing

Thanks. In other words, they're not needed for this build.

Correct, with the pcb use the pcb's ground bus.

[Colossal]

Thanks. In other words, they're not needed for this build.

No buss bar needed or recommended for the PCB build. Run your pot grounds back to the ground pads provided on the board.