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Thread: Some stuff about Ed`s old Marshall

  1. #1
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    Some stuff about Ed`s old Marshall

    Most might have sean this anyway,

    (1) By Mark Cameron by pictures taken in the early 80'S.
    There ARE small tone altering and/or gain altering mods.
    I do have pic's so I CAN physically see that the amp has a split cathode arrangement.
    ...the cap on v2(330uf) cathode.
    ...its a 2.7k/.68 and the resistor looks like the stock part(but I don't think it is)but the cap is one of those yellow square type from the 70' Marshall's. From the circuit card It looks like it came stock with this arrangement. The post that is pressed in looks stock too witch tells me more than anyone could.In the pics the serial # is 12301.


    (2) By Cerrem. 1980.
    To try to wrap up is ED thing...
    His head was a 67/68 and he had the first stage valve with BOTH cathodes tied together sharing the same 820 ohm resistor that was bypassed with a 330uF blue cap...

    His treble cap was a round shaped ceramic that was a 250pF that said MURATA ... With 56K on the tone circuit feed..

    One of the 470K mixer resistors was bypassed with a round hollow tubular MURATA cap 500pF... If memory serves me right on the value, or it was a 330pF..I will check my notes....

    The real kicker, his phase-inverter "get-rid-of-the-FIZZIES" cap was a 100pF instead of the normal 47pF ....and this my friends is how the "brown sound" with that added compression happens..

    Oh, BTW those 820 ohm resistors were carbon-comp and drifted in value up about 1.1K and make the amp much more gainy and warmer, since these re-bias the 12AX7 valves in a bit more non-linear region..

    I am pretty sure the feedback resistor was a 47K ...I will have to check my notes...

    The filter cap in the center of the board was a dual 16uF gray RS cap...

    The screen filtering was 2 DALY 32uF light-blue caps in series... The voltage doubler were 2 100uF DALY royal-blue caps...

    Rear cap on top of chassis was a royal-blue HUNTS 32uF or 16uF...need to check notes..

    The value of the coupling cap between V1 and V2a....022uF.

    At least that was what it was in 1980...


    (3) Plaap (a friend of Peter Van Wheelden who restored Eddie's amp.)
    Edwards amp's internal measurements were as follows:

    1.The first 820 ohm resistor (carbon type) measured a little over 1K. It was bypassed with a blue 330uF resistor. can

    2.His treble cap was a 250pF Murata flat ceramic one. The cap across his 470K was a Murata hollow round 330pF. cap

    3.His second stage 820 ohm (which also measured a little over 1K, was also bypassed with the exact same type 330uF blue colored cap that was on the first cathode resistor.

    4.The filtering caps for the middle of the board were gray colored RS caps that had dual 16uF values.

    5.The screens were 2 blue caps in series (DALY 32uF's).

    6.The voltage doubler were two big blue caps (100uF DALY's). The one on the outside was a blue Daly - and was a single 32uF.

    7.The feedback resistor was a 47K of unknown origin.

    8.His power transformer was the smaller one of that era. His OPT was also the smaller one with 1.5" stack.

    The amp was either left stock into a load resistor or, a big Ohmite(or other) power resistor was placed somewhere in the circuit to cut the power of only the output stage meaning Sylvania 6CA7's were the only valves to hold up to this.

    If this is true - doesent this kinda dispel the whole 'special' 67 slp 100 myth ...as almost all amps of that year had pretty much identical configurations (with the small exception of the 330uf cap on the second preamp stage?

    Dankuwell !(dutch for many thanks)
    Plaap

  2. #2
    Senior Member R.D.'s Avatar
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    Here's the rest ....

    Plaap's specs are C e r r e m s specs.
    Plaap got them from C e r r e m or more specifically an old Usenet post of C e r r e m s.
    Plaap has probably never been near Peter Van Wheelden who worked on Ed's amp after John Suhr did in the early 1990s.
    Plaap has zero credibility and C e r r e m s specs are well who knows, I think C e r r e m s specs are a "guess" by C e r r e m.

    C e r r e m s specs (and the so called Plaap specs) mean nothing really.

    Dave Friedmans specs are the same as John Suhrs specs and John Suhr has also given the serial number which happens to be the serial number of the white knob Plexi, so all is hunky dory.
    Steve Fryette had the amp just before John Suhr in the early 1990s and his basic specs agree with Dave Friedman and John Suhr.

    So Dave Friedman, John Suhr and Steve Fryette are all saying the same thing, basically a split cathode input 12 series Marshall originally with a .68uf on V2.

    Steve Fryette says this

    "I might add, and this is just from memory, but I recall that the circuit was actually closer to a 70 JMP than it was to a plexi, something I attributed to this possibly being a transition model, seeing as how it had a plexi panel, but apparently the newer input (ie split cathode) and feedback configuration."

    The main changes that happened to Ed's amp that we know of are

    1: output transformer change to probably a 2 inch Drake in the VHII 1978 photos.

    2: Fat cap across V2's cathode installed in ????, maybe post VH1.

    The white knob mystery which could be a standby switch and the white knob would probably have something to do with something in the circuit past V2 because John Suhr has said the original solder joints were intact when he looked at the amp in the early 1990s except for the V2 cathode Fat Cap solder joints and a few other solder joints further down the circuit in the power section, I think some cap solder joints.

    John Suhr bits and pieces

    "I believe the amp also had a standby jack in the back that disconnected the power tube cathodes."

    All solder joints were original up to the treble pot except for a more bass mod which was a 470uf + .68uf on the V2 cathode which was later changed to just a 330uf capacitor, so there was no cascade.
    There was also a minor change in the feedback circuit as well.

    The screen resistors and the wires to the output transformer and the power supply capacitors were not original solder joints.

    Quote Originally Posted by Ralle
    The powersupply capasitors... does all the filter caps count as powersupply caps, or is it only the two 100u's in the main?
    Don't know, all I can find that John Suhr said about the caps is this

    "OK , The bottom line for me is when I saw it the amp was 100% untouched except for filter caps and 1 added part which I prefer to keep to myself (the Fat Cap on V2's cathode)."

    Dave Friedman says

    "it was a stock 12 series amp with 2 changes the 470uf on v2 (Fat Cap) with a .68(uf in parallel with Fat Cap)). Filtering of that era and a slight change in the feedback circuit."

    "Filtering of that era"

    So it might be that the caps needed to be replaced and they were replaced with the same values.
    Long Time Listener ..., First Time Caller ....


    From member Bruce Lychee @ TGP ....
    Fractal's slogan should be ..., "If you don't like it, Frac You."

  3. #3
    Senior Member RDeraz's Avatar
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    WOW!you guys seem to know your stuff.i thought this was finally put to rest that there was really nothing that special about Ed's amp,except ED plugged into it.i know,once a tone chaser,always a tone chaser.i'm always disappointed when i find the truth though.went through the same thing trying to figure out Saraceno's Plaid tone.after some research and finding Vic Steffens(engineered and mixed Plaid in West Haven,CT.) on a forum board,come to find out all the solo's were cut with a 100W Marshall and a single 4x12 in Blues' garage!go figure.

    point being,we got the AFX,we can get Ed's sound in spades!

  4. #4
    Senior Member R.D.'s Avatar
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    First of all, let me say that up until very recently I’ve never really chased after Edward Van Halen’s tone …. What changed ? Well I was recently experimenting in the Axe-Fx with panning my amps & effects into a Dry/Wet configuration, and I stumbled ( by accident ) on a tone that was very close to what Eddie used on VH’s first two recordings. I guess I got bit by the same bug that has plagued others for many years ! Oops !

    Anyway I set about to get as close as I could, and I wondered if it would be possible to use the Advanced and Amp Geek parameters to do a better job of simulating a Variac ?

    So …, I read as much information as I could get my eyes on, and I even sent E-mails and messages to people who seemed to be “in the know”.

    I’M IN NO WAY A TECHNICIAN, AND IN MOST CASED I DON’T EVEN UNDERSTAND WHAT I’M TYPING …. BUT …, here’s what I gleaned from reading well in excess of 250 pages from various forums and web pages ! They are too numerous to list, with the exception of the MetroAmp Forum which is where the bulk of what seems like accurate information was coming from !

    ( Oh …, and by-the-way …. Before I get too deep into this, Dave Friedman said simulating a Variac isn’t really possible with the current parameters Cliff has exposed for us to manipulate ) …. Based on his work directly w/Cliff on the Friedman BE & HBE ( formerly the Marsha ), I have no choice other than to believe him ….

    Here’s the summary of EVH’s # 1 Marshall SuperLead ( as well as the possible spec changes to the Amp during its life span ) ….

    Eddie’s Plexi was # 12301 and below is the spec from serial # 12267 Plexi ( 34 ‘units’ prior to Eddie’s ) ….

    - split cathode V1a 250uF/820,V1b .68/820
    - all coupling caps are 0.022uF, Bright channel coupling cap is 0.0022uF
    - bright cap on volume 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
    - 0.1uF cap on presence control
    - 47pf on PI

    - Stock Output Transformer: 1.5 inch Dagnall ….

    Next, when John Suhr saw the amp in 1991, it had a fat cap electrolyte ( probably 470uf ) in parallel with the stock .68uf on V2. So, since 1991 is a long time after 1977 …, take away the fat cap on v2 that John Suhr saw in 1991, and we get this:

    - split cathode V1a 250uF/820,V1b .68/820
    - all coupling caps are 0.022uF, Bright channel coupling cap is 0.0022uF
    - bright cap on volume pot 0,005uF
    - 470k mixer resistors
    - 500pF mixer bypass cap
    - bypass cap on V2a is .68uF
    - 33k/500pF tone stack combo
    - 100k NFB resistor at 4 ohm tap
    - 220k bias splitter resistors
    - 0.1uF cap on presence control
    - .022uf output couplers
    - 47pf on PI

    At this point, the amp probably still had the stock Dagnall 1.5 inch output transformer …, although there’s absolutely no way to confirm that.

    Transformer notwithstanding …, this is most likely the spec that the amp had when Eddie ( & Co ) recorded VH I …. And is also most likely prior to any supposed “modding” by Jose Arredondo… !

    But in between VH I & VH II it’s generally accepted that Eddie’s tone changed ever so slightly. I can’t speak for everyone, but to me, it seems just a tad warmer …? And based on what I’ve read, this just might account for Jose’s involvement ?

    It’s rumoured that if someone came in to his shop and complained that their amp was too bright, one of the first things he did was the “fat cap mod” ( cap on V2a is .68uF and a 220uf to 470uf ), which is what John Suhr saw when he worked on the amp in 1991.

    Also, keep in mind that before John Suhr saw the amp, it may have already been to Steve Fryette to have the output transformer changed …,

    …, “probably” to a VHT ( or maybe a Drake ) 2.0 inch output transformer ….

    O.K., you’ve probably also noticed that there are a couple of other small differences:

    1.) a 500pF mixer bypass cap instead of a 470pF mixer bypass cap
    2.) 33k/500pF tone stack combo instead of a 33k/556pF tone stack combo
    3.) 100k NFB resistor at 4 ohm tap instead of a 47k NFB, and …,
    4.) 022uf output couplers that the earlier Plexi doesn’t seem to mention ….

    These differences are most likely supported by Steve Fryette, John Suhr and Dave Friedman who all commented that the Amp was stock, but that “some” of the values were different than other Plexi’s from the same general date(s). For a short time there was even an argument over John Suhr’s statement that “most” of the solder joints were in fact un-tampered with ….

    Fryette, Suhr and Friedman all seem to agree that these are just standard Marshall production variations. In fact, some people ( although not Fryette, Suhr or Friedman ) have even referred to the amp as “transitional” from the Plexi, to the Metal Panel era(s) ….

    And keep in mind that both the 470uf and .68uf were replaced by a 330uf electrolyte at some point too. But, I don’t t list them in any of the specs above or below, because it’s generally accepted that they have now been changed back to what’s listed. And since it can’t be confirmed that he ever recorded with that configuration I left it out !

    One other thing that is known and accepted is that Eddie sent the amp to Holland to Peter Van Wheelden to have it reconditioned. When that was being done, everything was re-wired with Teflon wire. Again, that’s all been reversed now by stripping another Plexi with a close serial number of all its original wiring and using it to once again re-wire Eddie’s # 1 …. That’s why none of that is listed in the specs either !

    Finally, mixing back in in the John Suhr ( v2 fat cap and other mods ) we get this from Dave Friedman ( the most recent of the truly reliable source ) to have seen and worked on the amp.

    - split cathode V1a 250uF/820,V1b .68/820
    - all coupling caps are 0.022uF, Bright channel coupling cap is 0.0022uF
    - bright cap on volume 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
    - 0.1uF cap on presence control
    - .022uf output couplers
    - 47pf on PI

    Drake 2.0 inch output transformer ….

    Dave also is a little more specific on “the filtering”, which is:

    2) 100uf's f & t in series mains
    2) 32uf's f & t in series screens
    1) 100uf lcr phase inverter
    1) Dual 33 x 33 f & t preamp

    * Dave’s last comments are to relate a quote from both Eddie and Matt Bruck, that finally the amp now sounds “like it did, back in the day” !

    What does all this mean to us Axe-Fx-ers that are ( still ) chasing Eddie’s tone ? Well I’ve come to the conclusion nothing really ! There’s no way for anyone except Cliff to compare the latest Specs ( from Dave Friedman ) to the “Brown” amp that was originally modelled ….

    IMHO - It’s very likely that while VERY similar, the specs probably weren’t identical …. Plus there are at least three other “items” that in Suhr & Friedman’s opinion are hardly inconsequential !

    The 6CA7 Tubes ! From everything I read, they NEVER came stock in a Marshall. They’re similar to an EL-34, but different enough that the change in tone would be both considerable and noticeable …. Evidently they’re about as close as you can get to melding a 6L6 and EL-34 ? It’s got the bigger low end ( like a KT77, but not the brittle top end that they have ! ); it stays smoother like the EL-34. They are said to be “quicker” in their dynamic response ( more like a 6L6 ) too.

    Then there’s the whole Variac issue ! When Eddie applied the Variac to his amp and lowered it to 90V, it lowered the B+ ( which we can change ), and he evidently “cranked” the tube bias ( which we can change too ). Friedman seems to think the B+ would be approximately 380dcv and the bias would be between 40 to 50mA. But I’m guessing that’s not all that a Variac changes …?

    In fact, I have NO IDEA everything that it does do ? About the only other thing I’ve been able to ferret is that it lowers the voltage of the tube heaters and some speculate that might be what actually shortens the tube(s) life ?

    Here’s where Friedman said, we have no way of simulating a Variac with the parameters Cliff has currently exposed. You would theorize that his modelling process took all that into account, but based on the defaults of the Brown Amp in the Axe-Fx, I’m not so sure ?

    Last but definitely not least …, Eddie’s effects chain ! We know that prior to the amp ( however it was spec’ed out ), he used his Phaser & Flanger. Plus various EQ’s ( with a frown curve ), and an Echoplex EP-3 ( which provided both some additional mid-&-gain boosting ). And don’t forget the additional highs that would have been tamed by the capacitance of the cable length(s) ! In the early days he supposedly used a 30 footer from the guitar to the first effect …, plus what’s in between each effect, and then from his pedalboard back to the amp ?

    I don’t know about you, but my mind is completely boggled ….

    I guess I’ll quit now and go find another tone to chase for a while !

    If you’re up for it, have fun and let us know how it turns out for ya !

    THANKS for reading ….
    Long Time Listener ..., First Time Caller ....


    From member Bruce Lychee @ TGP ....
    Fractal's slogan should be ..., "If you don't like it, Frac You."

  5. #5
    Forum Baron Sixstring's Avatar
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    Well you guys have done a lot of research on this subject, way more than I have ever done. I would add that I talked with John Suhr a wile ago and he was saying the same thing you have posted. He even had an EVH Marshall chassis sitting on the floor of the shop when I was there.

    I have also spoke with Victor Mason of Mojave Amp works when he had his shop just down the street from where I live now, He basically said the same thing regarding the untouched recorded Marshall of the day.
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  6. #6
    Senior Member EdgE's Avatar
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    VERY,VERY Interesting .

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