Rack PreAmp Selector Rehouse/Build

[ccouch7]

I wanted to use an A/B box as a preamp selector in my amps FX loop so I could switch between my amps preamp
and an external preamp, for kind of a two channel bass amp. Wired like this Tech21 diagram.


So after experimenting with a few different A/B box's I decided to use a Boss LS-2 which was totally silent when
switching and sounded transparent to me.
I did some photochopping to try and visualize how I would put this thing together first.



Then I ordered a shallow (4") all aluminum 1u rack enclosure and degutted one of my LS-2's, which wasn't nearly as hard
as I thought it'd be. I only had to extend four wires. In the picture below you can see the purple wire on the left and the
grey wire on the right which are for the switch.



The other two wires I had to extend were from the return jacks to the send jacks (one on A and one on B).
On the back of the sends jack in the pic below you can see the blue and grey short pieces of cut off wire.


After getting some measurements from the LS-2 and the rack case, I moved to CAD to lay it out for real.
I used these layouts for CNC machining and scribing the rack enclosure myself.






After machining I loose fitted some switches and stuck it in the rack to check it out.

[ccouch7]

I wanted to get the LS-2 all wired up and tested to make sure everything worked right before I went any further.
It still works great, even the external footswitch jack and the switch on the front of the unit.




I decided to take a break and get my accual rack case ready and add a few things that I've wanted to do for a while.
Put rubber feet on the bottom, drilled a bunch of vent holes with a hole saw, mounted a couple leds and mounted my
power strip where it was the most out of the way.








Back to the preamp selector, got my power, mute switch for the M6, lights and feed throughs all wired up and working.












more to come.

[onegunguitar]

Hows the Sansamp sound with the Mesa?

[ccouch7]

Some close ups of the machine scribing on the rack enclosure.








FRONT


BACK


TOP


BOTTOM


Sandblasted and rebuilt an old foot switch I had laying around.


Mounted in the rack.

[johnmark]

Nice work!

[ccouch7]

Originally Posted by onegunguitar

Hows the Sansamp sound with the Mesa?

I've been using the preamps in A>B mode on the LS-2 so it's one or the other, the A+Bmix mode works but I haven't messed
with it much yet -could be interesting.
The RBI sounds killer through the Mesa's power amp to me though, it can get dirtier than the Mesa which is kind of cool.

I've read people saying that the master knob on the M6 affects the FX send but it doesn't on mine.
And both preamps feed though the M6's D.I. which I was kinda glad to find out.

[1n3]

Originally Posted by johnmark

Nice work!

Indeed.

[ccouch7]

Originally Posted by johnmark

Nice work!

Thanks Man!

More pics.

A couple of the back all wired up except the speakers, D.I. and footswitch.




And a couple of the whole rig.






Orange LED in the back.


I really enjoyed building this thing and it works just like I wanted it to.
Thanks for looking!

[ccouch7]

Originally Posted by 1n3

Indeed.

Thank you sir.

[RickenBoogie]

Awesome looking final product, and great work- both electronic and otherwise.

[Wes Whitmore]

I like it, and it turned out great. If you make another one, stuff a TU-2 tuner in there for an added touch!

[Bob Lo]

Very Nice.Good design.I've thought about doing something similar,multiple basses with different preamps into the same power amp.You made it look easy

[BassmanPaul]

How's the no signal hum level?? Can you get the back cover on passed the power strip?

[ccouch7]

Originally Posted by RickenBoogie

Awesome looking final product, and great work- both electronic and otherwise.

Thanks man, I appreciate it!

Originally Posted by Wes Whitmore

I like it, and it turned out great. If you make another one, stuff a TU-2 tuner in there for an added touch!

Thanks, a TU-2 would be cool in the rack, I could barely handle this much though.

Originally Posted by Bob Lo

Very Nice.Good design.I've thought about doing something similar,multiple basses with different preamps into the same power amp.You made it look easy

Thank you sir, I appreciate it!

Originally Posted by BassmanPaul

How's the no signal hum level?? Can you get the back cover on past the power strip?

You know I had the hum all sorted out before I started this project.
I had a bad AC hum when I first hooked the RBI to the front of the Mesa, so I tried one of those 3 prong to 2 prong adapters
on the AC cord of the RBI and it took the hum away totally. So I went out a bought a HumX and plugged the AC cord of the RBI
into that and got the same results (no hum).

I should have took a pic with the covers on, I'll do that later.
But yes sir, I made sure both covers go on with no problems.

[BassmanPaul]

Good! I'm glad you removed the cheater from the rack! Them things just ain't safe! I like your lights on the project box. I've not seen their like before but I do love blue lights!!

[ccouch7]

Originally Posted by BassmanPaul

Good! I'm glad you removed the cheater from the rack! Them things just ain't safe! I like your lights on the project box. I've not seen their like before but I do love blue lights!!

Yea, I used the cheater plug just to trouble shoot, they ain't safe and I wouldn't trust it especially
when playing and singing through a P.A..
The lights are the kind used for computer modding, running at 9volts when they should be running
at 12volts but I like that they're not overly bright.
Thank you for your comments good sir!

[Eric Moesle]

Awesome work. Creative, professional, clean.

The only problem is the LS2. Those things are tone suckers that rob low end balls from your tone. Well documented here that they are NOT transparent... Nowhere near. They really thin out low end. Fine for guitar, but for bass ..... Fuggedaboutit.

I used one for more than a year before I did a gig without it and was amazed by my tone. Never again.

[bassgod0dmw]

Very nice work!!!

[ccouch7]

Originally Posted by Eric Moesle

Awesome work. Creative, professional, clean.

The only problem is the LS2. Those things are tone suckers that rob low end balls from your tone. Well documented here that they are NOT transparent... Nowhere near. They really thin out low end. Fine for guitar, but for bass ..... Fuggedaboutit.

I used one for more than a year before I did a gig without it and was amazed by my tone. Never again.

Thanks for the words, on the LS-2, I kinda knew I would run into this that's why I said "sounds transparent to me"
at the top of the thread and it is to me, IMO, IME.
There's no low end getting robbed from my rig, this thing is a cannon. I just agree to disagree with you on that.

[ccouch7]

Originally Posted by bassgod0dmw

Very nice work!!!

Thanks man!