Van Halen Tribute Amp

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crgfrench
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Re: Van Halen Tribute Amp

Post by crgfrench »

JMPGuitars wrote:
Sat 11/14/20 1:12 pm
ViperDoc wrote:
Sat 11/14/20 12:18 pm
Dave Friedman also noted that in addition to lowering the AC voltage, EVH would rebias the output tubes to proper current.
Proper current for what/when? That's an ambiguous statement for somebody using a variac.
I think he means Ed biased the 6CA7s in his main Marshall to 50mA when he had the variac dialed to 89-90VAC.
Dave discusses this at 7:50 in Pete Thorn's EVH Deep Dive video https://www.youtube.com/watch?v=aKejQ1WBybA
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Re: Van Halen Tribute Amp

Post by crgfrench »

Some of the Volcano parts laid out, waiting patiently while I paint 6 coats on the chassis.
Screen Shot 2020-12-13 at 11.16.34 PM.png
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Re: Van Halen Tribute Amp

Post by crgfrench »

Updated Layout, very close to final
Screen Shot 2020-12-13 at 11.43.27 PM.png
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Re: Van Halen Tribute Amp

Post by Bieworm »

what type of pots do you use for volume and magma?

Craig, I just love your OCD man!!! You should livestream your build...
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Re: Van Halen Tribute Amp

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All of the switched pots are 1M audio taper, I'm using these:
https://tubedepot.com/products/alpha-16 ... g-pc-mount
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Re: Van Halen Tribute Amp

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Chassis paint fail. Originally my plan was to paint the chassis like the frankenstrat, same process Eddie used: paint it black, tape first pattern, paint it white, untape, tape second pattern, paint it red, untape, frankenchassis. I mocked up the first tape pattern over the cling film.
20201212_043510.jpg
After removing the film, I saw that my Hoffman Stout chassis was produced with some kind of petroleum residue on the aluminum, underneath the protective plastic cling film. I wiped it down with isopropyl alcohol which didn't seem to do much. I thought about going at it with a scotchbrite pad and acetone, which is the way I used to clean aluminum when I was TIG welding 35 years ago. "Nah," I thought, "It's clean enough, I'll just hit it with the Krylon."

Two layers of Krylon gloss black 2X ultracover paint+primer later... Disaster! Whatever that residue was, it ruined the paint job.
20201217_133930.jpg
OK, strip it down with a can of Jasco paint remover, then scotchbrite & acetone.
20201217_165344.jpg
Forget the paint.
20201217_180443.jpg


Nobody's going to see the chassis anyway, inside the 1x12 combo with the tubes pointing forward horizontally.

The Hoffman stout chassis does not have welded corners, so I'm out shopping for a little AC/DC TIG machine...
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Re: Van Halen Tribute Amp

Post by crgfrench »

Here's my "Volcano" drilling template for the Hoffman Stout Chassis.
The layout (everything except what's in green) is cobbled together from Doug's site https://el34world.com/ . My mods are annotated in green.

Stout_Volcano Drill Mods.png

Hole "G" is unnecessary if you mount the PT standup style, but I'm mounting it laydown style to save a little space ( about 1") in the cabinet. You'll notice my drill bit wandered about 1mm for this hole, I drilled everything by hand. I used a center punch but I went from a 1/8" bit right to a 1/2" bit and the latter just went off center a little. Oh well, it ain't rocket surgery...
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Re: Van Halen Tribute Amp

Post by crgfrench »

OK the chassis is at 1978 specs now. It's a little rough (mainly just the 3rd diagonal on the upper horn) but what the hell, the frankenstrat was rough. Red coming next to bring it up to '79...
1978frontside.png
1978rearside.png
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Re: Van Halen Tribute Amp

Post by geoff 1965 »

Craig when painting bare aluminium you need to use a coat of self etching primer first for best results,over time just paint tends to flake.
EF515F34-3144-4E25-962F-4732CF314307.jpeg
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Re: Van Halen Tribute Amp

Post by crgfrench »

Thanks! I used 2 coats of gloss black Rust-oleum "2X ultracover paint+primer". Then 2 coats of the same, in gloss white. Next up, 2 coats of Sunrise Red Rust-oleum Gloss Protective Enamel. I think the first primer coats will be OK, as I basically hand-etched the chassis with a scotchbrite pad and acetone right before applying the first coat. Put it this way: there was no oxide layer on this chassis when the first primer layer went on. Fingers crossed...
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Re: Van Halen Tribute Amp

Post by TriodeLuvr »

crgfrench wrote:
Thu 12/24/20 3:55 pm
Thanks! I used 2 coats of gloss black Rust-oleum "2X ultracover paint+primer". Then 2 coats of the same, in gloss white. Next up, 2 coats of Sunrise Red Rust-oleum Gloss Protective Enamel. I think the first primer coats will be OK, as I basically hand-etched the chassis with a scotchbrite pad and acetone right before applying the first coat. Put it this way: there was no oxide layer on this chassis when the first primer layer went on. Fingers crossed...
Aluminum oxidizes immediately on contact with air. You would have to apply the paint with the abrasive pad to prevent that from happening. I hope this works out for you, but it's a lot easier and consistent if you just clean it with dishwashing soap, then spray it with an etching primer before the color coat. The Dupli-Color brand is available at auto parts stores and has never failed me.

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Re: Van Halen Tribute Amp

Post by crgfrench »

Quality of chassis paint job ...similar... I'd say, to EVH's quality of Frankie paint job. Looking pretty cool.
Front.png
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Re: Van Halen Tribute Amp

Post by JMPGuitars »

crgfrench wrote:
Mon 12/28/20 1:02 am
Quality of chassis paint job ...similar... I'd say, to EVH's quality of Frankie paint job. Looking pretty cool.
Definitely looks cool. If you ever do something where you want cleaner edges, try green Frog Tape instead of the standard blue painter's tape.
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Re: Van Halen Tribute Amp

Post by jchrisf »

That looks awesome.. can't wait to see it and hear it completed.
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Re: Van Halen Tribute Amp

Post by crgfrench »

Got some hardware installed
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Re: Van Halen Tribute Amp

Post by crgfrench »

I was having trouble shimming the Floyd Rose...
...I mean, the power transformer.
Found a cool solution!
VolcanoQuarter2.jpg
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Re: Van Halen Tribute Amp

Post by Bieworm »

crgfrench wrote:
Fri 01/08/21 12:56 pm
I was having trouble shimming the Floyd Rose...
...I mean, the power transformer.
Found a cool solution!VolcanoQuarter2.jpg
Now you can charge extra when selling the amp.. legit !!!😄😄😄
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Re: Van Halen Tribute Amp

Post by Bieworm »

What would you have done if you only had a 100$ Bill? Folded it over and over until the right thickness was reached?😉
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Re: Van Halen Tribute Amp

Post by crgfrench »

Wiring the heaters today.
Here is a pre-solder gutshot, with 2 of the 3 can caps installed and the bias circuit laid out. There are 4 ground points: 1) the mains earth ground next to the IEC jack, 2) the preamp bus ground above the first preamp tube, next to where the input jack will be, and 3) the power ground star next to the bottom-mounted can cap, and 4) a bias ground point on the power tube socket bolt, next to the bias trimpot.
Volcano20210117.JPG
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Re: Van Halen Tribute Amp

Post by crgfrench »

Heater wiring came out nice & tidy
Volcano Heater Wiring.JPG
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