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EVH's original Plexi and the FAS Brit Brown amp

Narzugon

Forum Addict
A question for Cliff. After being in the biz for a while now, what info have you gathered on Eddie's original plexi and cab(s)? Facts or what you've heard through the grape vine. Either will do!

I've read that the Brit Brown Amp is an idealized version. How did you go about building it?
 

FractalAudio

Administrator
Fractal Audio Systems
Moderator
A question for Cliff. After being in the biz for a while now, what info have you gathered on Eddie's original plexi and cab(s)? Facts or what you've heard through the grape vine. Either will do!

I've read that the Brit Brown Amp is an idealized version. How did you go about building it?
I don't really know much about Eddie's original Plexi other than what is on the web.

The Brit Brown was built by ear.
 

R.D.

Forum Addict
I don't really know much about Eddie's original Plexi other than what is on the web.

The Brit Brown was built by ear.
I've got all kinds of quotes from both John Suhr and Dave Friedman on the differences between a "nomal" 12xxx series plexi an Eddie's # 1 ....

PM me if you want the word doc I created ....
 
EVH's Super Lead 100 (#12301) has changed over the years (parts, tone, etc). There's plenty of research and speculation on the web. Most seem to insist the VH1-era amp was stock, perhaps with one minor (insignificant?) exception. Then again, no two "stock" 12xxx amps had identical parts. For in 1968, Marshall built the 12xxx's using whatever was lying around (at least for some parts). Plus, there's the infamous Variac that many claim EVH used to lower the amp to ~90 volts to get the "brown sound". Since VH1, there have been some changes made to the amp. But there's ongoing debate regarding the details (maintenance only or mods, too?)

Here are just a few of the numerous related links available on the web:


Finally, it's been said numerous times, but bears repeating... Much of EVH's tone comes from his fingers! Still, other non-amp tone factors include:

  • Guitars (wood, bridge, pickup, etc)
  • Effects (Echoplex, MXR Phase 90, etc)
  • Speaker Cabinets (Pre-Rola Greenbacks, JBL D-120s, etc)
  • Recording Techniques (Mics, Post-EQ, Delay, Reverb, Donn Landee, Ted Templeman, Sunset Studios, etc)
 
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Narzugon

Forum Addict
When Tyler Grund mentioned the D120's in another thread I realized how out dated my knowledge was on the subject and went in search of. I don't think I left a stone unturned. I was hoping Cliff had some unique insight.

After doing all this digging I thought why not try to recreate a version of Ed's rig in the AxeFX with a plexi sim. So I slapped a 100 watt Plexi on the grid and went from there. While I had a good time and learned a few things along the way, it just wasn't sounding anything like the Brit Brown or similar amps. I think the missing ingredient is the lower voltage that the variac provided. I remember reading some threads on this or a similar topic. I'll go dig these up.

Thanks for the replies guys.
 

levipeto

Fractal Fanatic
Hints and homework:
- He used dummy cabs and separate power amps. So think about what could happen to Xformar Match and the Resonance Frequencies.
- Change the high cap to around 220.
- He used 2 amps for VH1.
- What would he do to the preamp bias and poweramp bias to achive his tone?
- He could have used EQ boost, which he denies. If he did use, why did he use it or what for if it wasn't for boosting back in his time?
- Final tone was done in the studio. What did the engineers did there? What equipment were hot at the time?
 
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Cagey

Veteran
Why does nobody sound like Jimi Hendrix? Or Robin Trower? Or, Stevie Ray Vaughn? Or, Eric Clapton. Or, for that matter Eddie Van Halen?

Hint: it's not the equipment.

Those guys have a touch. That's why they're famous. Not everyone can pull that sound off. Buy all the equipment you want, even the exact same stuff all those guys use - you still won't sound like them. In fact, if they showed up in your basement to play your Behringer V22, they'd sound like themselves while you sucked hind tit.

There's a story out on the 'net somewhere that talks about Ted Nugent wanking on EVH's rig, then hearing EVH wank on it, and they were worlds apart. Ted sounds like Ted, and Eddie sounds like Eddie. The gear doesn't matter - technique is the thing.
 

R.D.

Forum Addict
Here's some information that I've seen posted around the webz on the specs of Ed's # 1 ....


Eddie’s Plexi # 12301 ( VH 1 to Carnal Knowledge ):

· Split cathode V1a 250uF / 820,V1b .68 / 820
· All coupling caps are 0.022uF, Bright channel coupling cap is 0.0022uF
· bright cap on vol pot 0,005uF
· 470k mixer resistors
· 470pF mixer bypass cap
· Bypass cap on V2a is .68uF
· 33k / 556pF tone stack combo
· 47k NFB resistor at 4 ohm tap
· 220k bias splitter resistors
· uF cap on presence control
· 47pf on PI


John Suhr ( v2 fat cap and other mods ) – 1[SUP]st[/SUP] restoration:

· Split cathode V1a 250uF / 820,V1b .68 / 820
· All coupling caps are 0.022uF, Bright channel coupling cap is 0.0022uF
· bright cap on vol pot 0,005uF
· 470k mixer resistors
· 500pF mixer bypass cap
· Bypass cap on V2a is .68uF and a 220uf to 470uf
· 33k / 500pF tone stack combo
· 100k NFB resistor at 4 ohm tap
· 220k bias splitter resistors
· uF cap on presence control
· .022uf output couplers
· 47pf on PI


Dave Friedman ( latest restoration ):

· Split cathode V1a 250uF / 820,V1b .68 / 820
· All coupling caps are 0.022uF, Bright channel coupling cap is 0.0022uF
· bright cap on vol pot 0,005uF
· 470k mixer resistors
· 500pF mixer bypass cap
· Bypass cap on V2a is .68uF ( back to stock )
· 33k / 500pF tone stack combo
· 100k NFB resistor at 4 ohm tap
· 220k bias splitter resistors
· uF cap on presence control
· .022uf output couplers
· 47pf on PI


Here’s what “we think” we know:

· The Power Supply Sags …. In fact, Dave Friedman said that in Eddie’s # 1, the power supply sags about 70+ volts with normal wall voltage dimmed, and 50 some volts with a variac on it” ….

· B+ and Plate Voltages drop …. Mark Abrahamson ( Rockstah ) said the B+ in the amps he’s measured were around 363 dcv, and while he evidently didn’t take the 120v measurement, he estimated that they would normally run between 410 dcv and 500 dcv ?

· Tube Bias drops …, which is why everyone who uses a Variac says to “crank the bias” ! Again Dave Friedman’s comment was: “Now I have said this before, the amp is biased to like 85ma with normal wall voltage and then dropped with a variac to 90 volts. This will bring the bias down to around 50ma.” Of course “the” amp he was referring to was Eddie’s # 1 ….

· Don't underestimate the contribution of the 6CA7 Power Tubes ....

The EL34 is a pentode, while the 6CA7 ( which delivers a similar range of power output ), is a beam tetrode which RCA referred to as a beam power tube. Although power pentodes and beam tetrodes are based on different principles of operation and have different internal constructions they are functionally closely equivalent.

That being said, they both sound different. The EL34 for the most part has a creamy sound with a little grit ( crunch ). The 6CA7 has a tight bottom end and good mids with articulate highs. A lot of people call them a small version of a 6550.


I’m guessing that the frequency response of the Power Transformer gets restricted somewhat too ? But I’ve never been able to find any specific measurements on that ?

* Finally, don’t forget that Ed used a lot of cord ( extra capacitance ) in front of the Amp, as well as an Echoplex EP-3 as a slight booster …

And both Dave Friedman & John Suhr have been quoted as saying, the Amp was "stock" ( ie; no Jose Mod ), but there was one thing that neither will comment on ?

It 'might' have been John Suhr that said the amp was a very bright beast with a little more gain than a stock 12,xxx Plexi.


IMHO- It all comes down to what the Variac contributes ? Here's what John Suhr had to say about it over @ HRI ....


Posted by: Suhr -
8/1/2013 @ 5:09 pm

Here is the thing though.

Lowering the plates is one thing but lowering the heater voltage also changes the tone and is the way Ed's was run. You can safely run the heaters on the low side it is a major component of the "brown sound".

There are other amps with low plate voltages like that, Fargen’s Marshally amp. That is only like 25W but uses two EL34's as well which equals low plate or screen voltage.

To my ears, as well as last time I talked to Dave Friedman though it isn't 100% the same unless the heaters come down a bit as well ( the SL68 does drop the heater voltage too ). Of course there is a voltage drop that is acceptable and in some audiophile circles believed to extend tube life, you can also go too far and hurt tube life. For that reason it should not be adjustable.

Posted by: Suhr - 8/2/2013 @ 12:51 pm

Heaters in a plexi are AC there are no diodes.

Take a variac and run a stock plexi amp with 500V plates at 120VAC at 95~90V, around 435 B+ is what I read on his, rebias the power tubes for the B+ you are reading and you are good to go. I wouldn't go lower than 5.5. You might be able to drop them independent of the B+ a little with a larger wattage resistor but it will get real hot and the value will be real small.

Remember though you cant variac an amp that has any switching or regulators in it.

I remember Ed's conversation clear as day when I picked his brain while working on his amp in 91’. He brought the original light dimmer he used too.

The amp was stock ( almost ) but the OT was replaced and there was a small mod to increase bass response.

The Marshall was a little hotter circuit than typical though, there were a few versions Marshall would use that had slight differences.

He used the variac to turn the volume down until the pilot light dimmed when he played a note on the G string. He said that was the main amp used on all records until F.U.C.K. He said everything else was engineer and the pedals he may or may not have used, the Echoplex, EQ and said he honestly just didn't remember and never knew it would be such an iconic elusive tone or he would have documented it all. IMO it had everything to do with his attitude and engineering. I heard him play through that amp with and without the variac and surprise ! ..., it all sounded sick and was Ed's tone in a box. In fact I doubt anyone could really tell a difference when he is playing it. It was more of a loudness and feel thing. When I played thru it, I sounded nothing like him, it just sounded like a freaking loud Marshall.
 
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Strumzilla

Forum Addict
This stuff can be academically interesting, but Ed is using stock EVH gear that anyone can buy now, and although the last album doesn't sound like VH1, it still sounds like Ed and it still sounds fantastic. Any tone chasing I need to do involves practicing the guitar.
 
this reminds me of when i was lurking around the metroamp forum going through pages and pages of discussions (putting it mildly) on eddie's gear.
i was also drawn into a discussion at halen.com on whether his frankenstrat was actually a fender..
it's just amazing that after all these years we are still trying to figure out who shot jfk..
anyhoo, i love his tone in this clip montage (even if it's youtube):
 

Narzugon

Forum Addict
This stuff can be academically interesting...
And this is my interest. Something fun and something academic. As far as I'm concerned there are a slew of amps in the Axe that get close enough on their own. Then play the parts right and you got it. So this isn't a "quest for the holy grail" kinda thing. Just having some fun. :)
 

Dimebucker

Veteran
Hey

I have hear that Halen was only take preamp distortions for her Marshall Plexi heads ,and H & H transistor power amp he was use poweramp stage. In first records ,and live situations. BTW doctor Feelgood was use ,same H & H amps. If that is true it kind of weird because ,lots of peoples was say that Eddie was cranking her marshalls poweramp tubes very hot. To get that amazing tone. But if he was use transistor poweramp ,and bypass Marshall poweramp stage. There was not then ,those hot poweramp tubes in her tone.
 
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Sixstring

Axe-Master
For the guitar I'm using the Plexi 100W Jumped works well for me. I look at his tone in 3 steps... 1st is the amp and cab types, 2nd are the effects used in the songs I want to learn, 3 are his techniques and tunings. I think the one thing the that people over look far to often is tuning down a 1/2 step. It's a major factor for the first few albums.
 

barhrecords

Axe-Master
And how he tunes his "B" string differently. You can't play Running With the Devil or Unchained properly unless you tune it like he does.
I always thought he was talking about being 1/2 step down?

in that tuning the B string is Bb but the other strings are all down 1/2 step too.

Some believe that 1/2 step down tuning gives a more consonant third interval.
 

svl

Forum Addict
Never heard about a particular way he tuned his B. What does he do, specifically?
 
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