[Grimlock]

So I've made my own SLO chassis (kinda)

I got the measurements from the pdf thx to mister Joachim (if I'm not mistaken?). So in a metal shop near my home I've bought an aluminum plate and got it folded really nicely into the shape of the frame. I adjusted the drilplan from the PDF in Photoshop and made a sticker (with the graphics of the front and back-panel) to stick on the frame. Also bought a spraycan of white paint and this weekend I painted the frame, pasted the sticker and drilled the holes for the front potentiometers. (not all the holes are drilled cause I didn't have that much time on my hands)

total cost: 15 euro metal frame folded and everything + 7,5 for the spraypaint + 25 euro for the sticker = 47,5 euro's...and a lot more work I could've saved 7;5 euro's If I just got the sticker printed on a white backgrond instead of a transparant one...

I'll upload a picture as soon as I drilled all the holes etc!

[Grimlock]

ok! other than the fact that making your own chassis is a hell of a lot cheaper (about 35 euro's) it takes you a lot more efford and I doubt if it was worth that efford. Anyway, I made some pictures. but hey, if it does what it has to do, I'm ok with it!

[Chryz]

Hey,
it goes up to eleven!!! 
Nice Work!

mfg

Chryz

[Grimlock]

haha it was standard on the PDF that i used to make the sticker but cool indeed
I sure hope it'll sound cool too

[Joachim]

Wow Dimitri, indeed a great job!

I admire and envy you for your mechanical skills. But I'm afraid that the dimensional drawing was not my piece of work. I'm one of these guys who make themselves life easy and bought a ready-to-go chassis from Stefano .

I have some comments on the mounting of the input jack and the switches. I can not clearly identify if the input jack's ground contact is isolated from the chassis or not. If not, it is strongly recommended, to add some insulating washers to this and the other jacks to avoid some nicely humming ground loops. These are examples for the Switchcraft washers:

flat phenolic washer
extruded fiber washer

See also the attached picture.

Also I would not recommend to mount the large locking rings of the toggle switches outside of the chassis. If your intension is to preserve the chassis' surface a simple washer will do a good job and will look so much better .

Cheers!
Joachim

[Grimlock]

thx for the tip! but I've got a question about that.

In an other tread from...Cliff I think, he connected the ground from the powerconnector to the chassis. So the chassis is grounded. Now i wonder why it is a problem when the ground from the input jack is connected, in fact, to the ground of the power connector?

might be a dumb question...? is it?

[Joachim]

No, not a dumb question at all - quite the opposite. Yes, you need to connect ground and protective earth on the chassis for security reasons. Well grounding is not a short story, however here is my approach of a (very) brief explanation: due to the existing electrical resistance of the chassis you will have slightly different ground potentials at different places when current flows through the chassis. Only millivolts of course, but these differences are enough to produce a more or less hum in your amp. So it is a not good idea to use the chassis for the ditribution of the ground potential (it is possible but it needs some experience with this issue)

One reliable method to avoid these ground loops is to isolate the jacks from the chassis in conjunction with Mike Soldanos well determined grounding scheme. I strongly recommed to use exactly this grounding scheme in your amp. Some guys who had the intention to "improve" the SLO by their personal illusion of a star ground failed at their attempts to cap Mike Soldano.



Cheers!
Joachim

[Grimlock]

so it's about the same effect as when you're playing a gig and you get "electrocuted" when your moutch touch the mic and hands touch your guitarstrings because the PA and your amp are not on the same powercircuit...

and it only gets worse when you're sweating! i presumed it was something like that.

anyway..If I just follow the schematics of the wiring that you posted in an other tread (a pdf), i'll be fine I guess?

credits by the way for my mechanical skillz to my father. If he wasn't such a handy-man, I didn't have the proper equipment to work with. a craftsman is only as good as the tools he can work with. I only hope that my electronic-skills will develope just as good. Doesn't really matter if it "looks" good...it's gotta sound good!!!

[Joachim]

so it's about the same effect as when you're playing a gig and you get "electrocuted" when your moutch touch the mic and hands touch your guitarstrings because the PA and your amp are not on the same powercircuit...

Yep, that's the reason for connecting ground with protective earth. The hum is an other chapter of the story 

anyway..If I just follow the schematics of the wiring that you posted in an other tread (a pdf), i'll be fine I guess?

Hmm I can't recall that I published a grounding scheme in pdf format. I posted only the picture with the ground wiring shown above. Speaking from my own experience it works very well.

[Grimlock]

I'll use the drawing and the attached PDF. It says "Joachim Muller" on the bottom. I don't recall finding these PDf's anywhere else then on the tubetown forum...strange. You're not joachim Muller maybe?

[Joachim]

Ah okay, you talked about the schematic - yes that's my piece of work. I supposed you meant a dimensional drawing of the chassis. I should read your postings more carefully

But a schematic is not a layout. To avoid ground loops you should follow the ground layout I posted above.

Joachim

[cliff]

thx for the tip! but I've got a question about that.

In an other tread from...Cliff I think, he connected the ground from the powerconnector to the chassis. So the chassis is grounded. Now i wonder why it is a problem when the ground from the input jack is connected, in fact, to the ground of the power connector?

might be a dumb question...? is it?

Hi there!

I have all the jacks (even the one for the footswitch) isolated from the chassis.

A picture will show this fact.

Greetz cliff!

[Grimlock]

that was a tripple quote?

I can see it now. I just didn't know that was protected from the chassis!

another question:
what kind of diameter are the wiring? I guess it depends on what current flows trough it. I could calculate the currents I guess, but that would take ages...and...are the wiring wounded or full wiring? also...I've read in an other topic something about silver as wiring?? is'nt cupper/copper/.. just as well?

[cliff]

that was a tripple quote?

I can see it now. I just didn't know that was protected from the chassis!

another question:
what kind of diameter are the wiring? I guess it depends on what current flows trough it. I could calculate the currents I guess, but that would take ages...and...are the wiring wounded or full wiring? also...I've read in an other topic something about silver as wiring?? is'nt cupper/copper/.. just as well?

So, looks quit better?

I use 1,0mm silvered copper wire on the power tube sockets and 1,5mm silvered wire for grounding. This 1,5mm wire leads almost from the starground to the speaker jacks. I solderderd the 1 Ohm resistors on this wire for bias measuring. In fact this is one wire. I think in a real SLO they use two wires.

After all i use the silicon covered wire from Dirk.

Hope that helps. Excuse my english.

Greetz Klaus

[Grimlock]

euhm...any difference between the silver wire type and regular copper wire?