Introduction and Express question.

[cigarman]

Hello all,
I’m new to the forum but have been building amps for a couple of years now. Most of which have been low watt or single ended designs and have learned a lot of valuable information from folks like yourselves on several forums! This is my first post on the forum so go easy on me! I recently decided to undertake an Express type build and have down loaded and studied the documents available here on TAG. I purchased a chassis from rjguitars along with the turret boards and Pacific transformers. Last night I started a mock up of components to check component fit and get a general idea of how this will go together. That being said, while placing the 40uF filter caps (Sprague Atoms) I do not have enough room between the power board and the preamp board. I have inverted the transformer mounting screw and tried aligning the screw with the indent in the capacitor to allow more room, but to no avail!. I know this has been addressed but after a couple of hours using the search function I decided to post the question here.
1. What is the best way to approach this? I have considered moving the preamp board closer to the side of the chassis and redrilling the board mounting holes. Is there a better alternative? I just can’t seem to get enough clearance for the caps using the current mounting holes!

Thanks for adding me to the forum and thanks in advance for any help!

Randall Ely aka cigarman

[xtian]

Will it help to rotate the cap stack 90 degrees? Post a photo.

[cigarman]

Keep in mind that this is only for the mock up. You can clearly see that the screw for the tranny is hiting almost dead center of the cap on the right, and there is not enough room to go either left or right. In the pic, the boards are attached using the current hole locations. Rotating the cap stack is an option I suppose.

[RJ Guitars]

Pull the screws and use a countersink on the inside of the chassis, then use flathead screws from the bottom. That is how the real Wrecks are setup. I should have a photo for you once i get home later tonight and I'll post that for you. The 500v spragues are a bit large but you should be able to get them in there. For a while you could find the 450v version and they fit much nicer.

[cigarman]

Thanks rj, I just ordered a counter sink for the #6 standoff screws that go underneath the tranny from McMaster Carr yesterday. Any idea if the same counter sink will work for the inside tranny screw, # 10 I think, or will I need another size tool? What are others using to counter sink the screws?

[M Fowler]

I have some counter sinking drill bits but many times I do what I did before I bought those fancy counter sink bits: A larger drill bit to make the v shape for your screw.

On the Express and Liverpool I run the PT and OT mounting bolts from inside chassis up through to the top (nut is on top of chassis).

Also I push the tone board as far to the left as I can and cut away part of rectifier/bias board both for the cap stack and power/standby switches.

Have fun.

Mark

[cigarman]

I have some counter sinking drill bits but many times I do what I did before I bought those fancy counter sink bits: A larger drill bit to make the v shape for your screw.

On the Express and Liverpool I run the PT and OT mounting bolts from inside chassis up through to the top (nut is on top of chassis).

Also I push the tone board as far to the left as I can and cut away part of rectifier/bias board both for the cap stack and power/standby switches.

Have fun.

Mark

Thanks,
I figured that would work and may do that for the PT mounting screws. So you countersink all screws for both PT and OT? I like that idea because they will all be the same ...maybe I'm being a little OCD but the devil is in the details.

[M Fowler]

No I only countersink if I need to the rest are regular #10 machine bolts and I use keeps nuts rather then nylock nuts. Use what you have or can get easy.

[cigarman]

No I only countersink if I need to the rest are regular #10 machine bolts and I use keeps nuts rather then nylock nuts. Use what you have or can get easy.

Ok, gotcha! I really appreciate the information!

[RJ Guitars]

Cigarman, Here is a look at the top of the chassis from the original Wreck "Francesca"... it is not a thing of beauty but you can see the nuts on the top side with the screws coming in from the bottom.

I'll also post a couple pictures of one of my "Rocket" chassis with the PT transformer mounted with flathead screws from the underside.

There are several tapers that are used for countersinking but anything from 82-100 degrees will work fine for this effort. Ideally you'll match the countersink to the screw taper.

[cigarman]

Thanks Rj and M fowler for the help and insight. I will start a new thread when I get a little further along in the build and maybe post a few pics along the way!