If i made an overdrive special chassis

[stretch2011]

Here's the version for the weld nuts. I also found aircraft nuts that would work great.

[ayan]

Last 2 question:

.625" flange? .5" over hang plus the material thickness. Since the weld nut is 7/16" wide.


Mounting holes on 1" centers from the ends?

I just measured. The flange is about .5 in wide, so 7/16 makes sense. The mounting centers are .75 in and the bolts 10-32. The weld nuts are secured using keps nuts and what looks like 4-40 bolts.

You have to be careful to make sure the weld nut clears the input jacks and the preamp volume pot.

Gil

[Charlie Wilson]

Good point Gil on clearing the input jacks and volume pot. The photo of one of Jelle's nice looking amps is a similar chassis design as the one you have rendered. Another thing is I notice you have cut outs for slider switches on the back panel. I think these days most guys are using toggle switches.
CW

[ToneMerc]

BTW, the problem with the CE chassis was the use of stainless hardware and galling. I know as I purchased two of their early chassis, additionally there was a thread on this issue 3 or 4 years ago.... Speaking of the CE chassis they are actually very nice.

https://tubeamparchive.com/viewtopic.php?t=17108


https://tubeamparchive.com/viewtopic.php?t=17378

TM

[ayan]

OK, I am uploading these files with several caveats. These are the first chassis ever made, which I laid out with Bill Morgan and Chris Sanford back in 2000, so they are the mother of all chassis that came afterward and were used and evolved by everyone else. I am just showing them here for reference so that the hole size for the toggle switches, LEDs, pots, etc., can be referenced. Very important to note:

1. These chassis had the dreaded side lips which are good for nothing.

2. The mounting is achieved with 8-32 PEM inserts which should be changed to the 10-32 weld nuts discussed.

3. The back panel is designed to accommodate an XLR type footswich, whereas the modern preferred method is a 5-pin, 1/4 turn DIN type. Mouser P/N is 502-61HA5FX for the chassis female (the male mating part is 502-12CL5MX).

4. There are holes for a 100/50 W toggle switch and LED on the back panel that should also be left out.

5. There is a hole on the back panel for an old Amphenol AC courtesy outlet which we put in the first batch of amps. I bought the old stock out back in the day and there were no more, so that was left out later on.

6. There is no hole for an impedance selector switch since were were using "transfer" jacks like in the older amps to switch between 4 and 8 ohms. An impedance selector switch is an excellent idea, and the one Dumble used is Mouser P/N 690-D4G0303N. Getting rid of the 100/50 W switch and the AC outlet should make room on the back panel for the impedance selector switch. That switch is large and the redundant wiring used makes it even more bulky, so ample space should be left around it.

7. The distance between the pot holes was to accommodate the "round dome" chicken head knobs, NOT the Fender style that Dumble mostly used. The latter will require the hole centers to be spread out some more.

8. There are probably more disclaimers that I cannot think of at this time...

Please use this as a notional reference only! All and probably more than the changes above were incorporated in the next two generation chassis that Brandon and I came up with back in 2006. I don't have a drawing for those chassis, otherwise I'd offer them here, but I have one amp with each version of the "improved" chassis (Rev 1 and Rev 2, if you will) which I could measure if there are any questions. The main difference is that Rev 1 still used PEM inserts, the XLR connector for the footswitch and had holes for the smaller chicken head knobs. Rev 2 would be what I consider to be the fully mature chassis from 2007, I think. But, Brandon continued to make further changes, like implementing a detachable power cord, for example, but I never used a chassis like that so I couldn't provide any measurements of those.

Use carefully and enjoy! Cheers,

G.

[stretch2011]

Ayan, your the man.
NOT trying to talk down anyone else on here.
But thank you for the wealth of information.

[ayan]

Ayan, your the man.
NOT trying to talk down anyone else on here.
But thank you for the wealth of information.

You're very welcome.

Gil