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Hoffman Amps Forum image Author Topic: Rack ReVibe  (Read 55528 times)

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Offline EL34

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Rack ReVibe
« on: January 24, 2012, 03:52:13 pm »
The Rack ReVibe is done, and here's a couple sound clips

Press the play buttons Mon

ReVibe Test 2
ReVibe Test 1

The library of Info has lots more info on building a ReVibe
http://www.el34world.com/schematics.htm

Here's the link to the rack revibe build page
http://www.el34world.com/projects/ReVibeRack1.htm



I love my ReVibe, but I really like the form factor of the rack pre-amps and amps that I built way better
To me ,it's just so much nicer to have all the gear stacked in a rack in a nice vertical line with all the knobs facing you and no crap on the floor

Anywho, here's my Revibe in a rack project

It's in a 3U x 7 inch deep rack chassis that I had laying around
The tubes  stick out the back horizontally just like I did on my Stereo pre-amp project
http://www.el34world.com/projects/StereoPreAmp1.htm

I took apart a 3 spring reverb tank and only used the small middle section that holds the springs.
The metal section that floats inside the tank.

I jotted down some things during the build that apply to the rack build.

Forgot completely about the two 100ohms on the heaters but remembered as soon as I turned it on the first time (60 cycle Hmmmm, I know that sound)
After adding two 100 ohms to the heater chain, the 60 cycle hum was gone but I was left with a loud buzzing type hum.
The back panel that has the tubes and reverb springs was not making good contact with the rest of the chassis because of the anodized rack rails.
I added a 18 gauge ground wire from the back panel to the pot ground buss and the thing is dead quiet now.
I now remember that grounding issue with these rack chassis from many years ago when I built 30 watt heads and reverb units in these chassis.
It had me scrathing my head for a coupe minutes until I remembered, hooked up a quick test jumper wire and the hum stopped.

If I did another one of these, I would add a 3 lug terminal strip near the power trannny and terminate the tranny heater wires there.
From the terminal strip I would feed the tube heaters, wire up the LED and have your 2 x 100ohm resistors grounded right there
kill 3 birds with one terminal strip

I found a major error on the ReVibe layout diagram and I am surprised no one ever mentioned it.
There was no wire feeding B+ to point B on the board

Found another mistake on the layout, the speed pot was wired backwards
Turning it up made the vibrato slower

Scroll down to see all the images of this project

I will be doing a custom face panel for this as soon as I get time

The updated layout diagram
« Last Edit: July 29, 2014, 07:50:27 am by EL34 »

Offline sluckey

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Re: New project - Rack ReVibe
« Reply #1 on: January 24, 2012, 04:03:29 pm »
You have my attention!
A schematic, layout, and hi-rez pics are very useful for troubleshooting your amp. Don't wait to be asked. JUST DO IT!

Offline Willabe

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Re: New project - Rack ReVibe
« Reply #2 on: January 24, 2012, 04:12:53 pm »
I am taking apart a 3 spring reverb tank and only using the small middle section that holds the springs.
The metal section that floats inside the tank.
By doing that, I can fit the reverb springs inside the rack unit
No way a full sized reverb tank would fit inside with all the other stuff

You won't need it since your putting it in a metal (steel?) enclosure. I have an older PV rack mount tube verb/term and it's made like that. Sounds OK, but not as good as my stand alone 6G15 I made.

It looks real good so far Doug, as usual for you. Great idea. I bet some of the guys here will build one too.

Why did you put the choke on short stand offs?

              Brad       :icon_biggrin:

« Last Edit: January 24, 2012, 04:16:11 pm by Willabe »

Offline EL34

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Re: New project - Rack ReVibe
« Reply #3 on: January 24, 2012, 05:25:27 pm »
The case is all 6061 Alu, so no steel shielding going on.
The secret is to move the springs around till you find a spot where it's the quietest.
And the tank output end goes farthest away from the power tranny.

The choke is on standoffs cause it's so close to the power tranny, the screw head for the power tranny was hitting the case of the choke. Raised it up and it's just fine.
« Last Edit: January 24, 2012, 05:51:49 pm by EL34 »

Offline Willabe

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Re: New project - Rack ReVibe
« Reply #4 on: January 24, 2012, 05:42:02 pm »
You know what your doing. I'm sure it'll be great.

I have the iron to build the re-vibe, had it for a few years. I was not looking forward to building it in the moded 6G15 chassis from Weber. Seems a little tight to wire and solder it up. This looks better to me so far as far as space.

I'll be watching this build.


                    Thanks,    Brad      :icon_biggrin:  

Offline EL34

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Re: New project - Rack ReVibe
« Reply #5 on: January 24, 2012, 05:56:31 pm »
Quote
What about to mount the PT like here, as to save more space inside the rack


There's no where out back to stick a power tranny.
It's already mounted where you see it now, which is a perfect spot
Fits like a glove

Check out this place
They make a ton of different rack chassis and the prices are not bad at all
http://www.par-metal.com/product-rmc-10series.php

Look at all the different series by clicking on the products tab

Offline Willabe

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Re: New project - Rack ReVibe
« Reply #6 on: January 24, 2012, 06:22:36 pm »
I have a good friend who has a recording studio with 2", 24 track tape and a lot of old studio processing gear.

He buys stuff on e-bay like pre amps and sometimes has to re-rack them together.

He likes the par-metal chassis a lot. Does not like the Hammond rack chassis.


                  Brad     :icon_biggrin:    
« Last Edit: January 24, 2012, 09:45:51 pm by Willabe »

Offline andrew_k

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Re: New project - Rack ReVibe
« Reply #7 on: January 24, 2012, 06:59:10 pm »
I've been collecting parts for a year with the intention of building exactly this. I have everything other than the turretboard, which I'll order from you when I clear the immediate todo list.

Following your progress with great enthusiasm :)

Offline nateflanigan

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Re: New project - Rack ReVibe
« Reply #8 on: January 24, 2012, 09:36:57 pm »
Quote
Insert Quote
I've been collecting parts for a year with the intention of building exactly this. I have everything other than the turretboard, which I'll order from you when I clear the immediate todo list.

Me too!  It's 2-3 projects down the list. 

+1 for par-metal, very nice stuff.

Doug, or anyone for that matter, what would be involved in integrating a revibe into a mixing situation?  Meaning line level in, line level out.

 

Offline EL34

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Re: New project - Rack ReVibe
« Reply #9 on: January 25, 2012, 12:46:50 pm »
Here's a few more shots of todays work.
Now I start the long process of wiring up the tubes sockets
Then I add all the components to the board

You might know I'd forget to drill something
Forgot the power cord hole in the back panel.

The inner reverb tank guts are bolted to the back panel on 1/4" standoffs
The reason again for standoffs is that there are screw heads under the reverb assembly.
I added two small grommets so the mini shielded cable can go through the back wall to the reverb assembly
It will be hard wired, no RCA plugs

Now you can see why the power tranny and choke work really well where they are mounted.

The 022905 Output tranny location is gonna work out great also.
« Last Edit: January 26, 2012, 04:35:01 pm by EL34 »

Offline spacelabstudio

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Re: New project - Rack ReVibe
« Reply #10 on: January 25, 2012, 02:48:05 pm »
I've thought about doing tube stuff in rackmount boxes myself.  I've used a Par-Metal case before for some studio stuff. My monitor controller is in 2U Par-Metal box.  I have a 1U that I haven't used for anything yet, because it doesn't really make efficient use of the available height.  With 1.75" to work with, there's only about 1.25" clearance inside.  I might use it for something solid state with an external PSU.

One thing that I hadn't figured out yet for tube stuff, was how to fabricate a divider down the middle of the box, like you've done, for mounting tubes to.  How are you doing that bit?

Chris

Offline EL34

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Re: New project - Rack ReVibe
« Reply #11 on: January 25, 2012, 03:09:45 pm »
Quote
how to fabricate a divider down the middle of the box

I took the two back rack rails off and drilled new mounting holes.
I had two pieces of 17" x 3.125 aluminum laying around so those became the floor under the board and the roof over the board (not shown yet)

This rack is weird the way is is put togather.
It all screws together with 6 panels, 4 rails and two sides.
It was left over from the racks I built my amps in many, many years ago

If I was using a Par metal rack, I would probably use two angle pieces bolted to the sides and then bolt a divider to the angles

Here' my idea of how I would add a divider to a rack
« Last Edit: January 26, 2012, 04:34:07 pm by EL34 »

Offline EL34

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Re: New project - Rack ReVibe
« Reply #12 on: January 26, 2012, 12:57:58 pm »
More pics

Tube sockets all wired up
All the parts added to the board
Reverb tank wired up

Ready to start on the front panel - pots, knobs, jacks, power switch, fuse holder, LED
« Last Edit: January 26, 2012, 04:31:37 pm by EL34 »

Offline spacelabstudio

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Re: New project - Rack ReVibe
« Reply #13 on: January 26, 2012, 01:34:59 pm »

Here' my idea of how I would add a divider to a rack


Cool! Are there places that sell small pieces of sheet metal cut to size? 

Chris

Offline EL34

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Re: New project - Rack ReVibe
« Reply #14 on: January 26, 2012, 01:41:05 pm »
I am sure Par-Metal could supply a blank panel

I have a sheet metal place down the road from me here.
I had them chop up several pieces using 6061 alu, a year or so ago
and it was cheap

Just find a sheet metal/fabrication shop
They will also have Alu angle that they could cut to size

You could also use G10 or some other type of material for the divider.
Does not have to be metal



« Last Edit: January 26, 2012, 02:20:44 pm by EL34 »

Offline EL34

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Re: New project - Rack ReVibe
« Reply #15 on: January 26, 2012, 04:25:46 pm »
More pics

A pic showing the filter caps an how they sit right under the row of pots
The negative leads to the filter caps will be grounded on the pot buss wire.

The front panel is wired up and ready to be installed

That's enough for today
« Last Edit: January 26, 2012, 04:32:14 pm by EL34 »

Offline EL34

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Re: New project - Rack ReVibe
« Reply #16 on: January 27, 2012, 01:59:27 pm »
More pics
« Last Edit: February 03, 2012, 03:14:01 pm by EL34 »

Offline EL34

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Re: New project - Rack ReVibe
« Reply #17 on: January 27, 2012, 02:34:29 pm »
It's done

I updated post #1 with some build info

See the images above and play the sound clip

Don't be afraid to comment
« Last Edit: January 27, 2012, 05:19:51 pm by EL34 »

Offline Willabe

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Re: New project - Rack ReVibe
« Reply #18 on: January 27, 2012, 05:41:21 pm »
Looks great Doug and the sound clip sounds great too. Did you record the sound clip running the revibe into an amp?

Does it sound or perform any different to you than you other revibe?

How do you eliminate the ground loop from running the revibe into an amp?


                 
                          Brad      :icon_biggrin:

Offline EL34

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Re: New project - Rack ReVibe
« Reply #19 on: January 27, 2012, 07:15:08 pm »
Thanks,

I will be doing a custom face panel for this as soon as I get time

It's not going into an amp

Guitar plugged into revibe
Revibe goes into My rack tube pre amp
Tube pre amp goes into computer sound card line in
Signal goes to guitar rig and I added a HiWatt amp and Hiwatt cabinet

Signal gets recorded into Mixcraft

The ReVibe only has a two prong plug, so when you plug it into an amp, you don't get a ground loop.

You don't need 3 prong cords on reverb units and Revibes
« Last Edit: January 27, 2012, 07:20:56 pm by EL34 »

Offline EL34

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Re: New project - Rack ReVibe
« Reply #20 on: February 01, 2012, 11:23:26 am »
Face plate is done and mounted on the ReVibe.

The face plate is rear engraved and some white paint laid down into the gooves

Here's some final pics
« Last Edit: February 01, 2012, 11:26:08 am by EL34 »

Offline EL34

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Re: New project - Rack ReVibe
« Reply #21 on: February 01, 2012, 11:24:35 am »
More pics

Here it is with the top lid on and mounted in my rack unit

In the rack starting from the top
Palmer speaker load box
ReVibe
Stereo tube pre amp
Stereo EL84 power amp
« Last Edit: February 01, 2012, 11:28:02 am by EL34 »

 


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