Debate on Eddie's Plexi

[rgorke]

Here are the John Suhr bits I have found around the net about Ed's 12301 serial white knob Plexi.


The 2 non typical parts in this amp contribute to the gain in a very minor way. They were not major parts and the amp Already had the 680n at the cathode of the cathode follower."

i was told by bogner and john suhr that the amp was a stock 12series super lead,they both even told me what filter caps values the amp had in it.there stories match up with each other stock super lead with a .68uf/820ohm rather than the later circuit.


yes and also the .68u instead of a 330u on v2a


i was told by a member on this board a few years ago,and i wont say who,that he talked to john suhr about the EVH amp.john told him that it was bone stock but instead of the 2.7k on the v1b it had a 820ohm.he also said that the preamp filtering caps where replaced as well as the screens.


John Suhr has made the split cathode argument too IIRC.....he was a little vague in that thread (ampage?)

Ah..I see..yes there are some descrepancies there. Mark said that the serial # was 12301...which is what John said he had. My 12364 is split cathode. It sounds like Mark and John saw the 12301 amp and ****** and Plaap saw something else.
The amp I saw WAS 12301 I wrote it down in my book on the schematic, if that hole was ever anything it was a Master.
The first stage was split cathode Most definitely NO 250pf treble cap, no on the 100pf across the PI plates and nobody has mention the alternate Marshall parts that made a difference.
Ed must be laughing his ass off if he is reading all this stuff, You should hear him play thru his line 6 ! Also how many of you play with a thin pick?
Damm I wish I had a good digital camera back then !

Trust me, I never cared that much about THE AMP but I did write the number in my book as being 12301 next to all the specific voltages and parts marked in all red pen along with "Ed's amp" as Ed stood by me and dialed it in with the variac (light dimmer) and the amp open. All of the red paint on the solder joints was original and untouched except for one added part up until the Treble pot which could indicate a master at one point. Also if it wasn't "the amp" why would Matt his tech contact me out of the blue about 5~6 years ago to ask if I had done a schematic since I was the last one to see "the Amp" in it's original state? I'm not obsessed about this amp since it takes a specific type of player to play it, it is not a friendly amp and you need authority and chops to make it sound right but as Marshalls of that era go it is definitely my favorite. Piss ass loud amp too even when variac'd. Ed was sincere with me, where he was fuzzy was what he had plugged in to the amp between his guitar and the amp. I'm not shitting anyone, the amp was VERY close to stock but were not the typical values you find in a GT schematic book, it had more gain (stock alternate values) and a tweak for more bass which also increased the gain which was the only non stock value. Anymore than that I cant say without their blessing. It also "sounds" to me like VH1 had the variac turned up even though Ed said it was always down and used for volume issues, basically turned it into a 50W and would also clip faster in the output section due to lack of headroom. Bias could have been wacked as well since he didn't adjust it when he demoed it to me.


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All of the above pretty well matches serial 12267 which is 34 serial numbers before Ed's

At least John Suhr doesn't BS.

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
0.1 uF cap on presence control

Ok, my friends, this spec has been verified and recorded and will get you the VH1 tone. How can I say such a thing? Please read this post...in its entirety.

http://forum.metroamp.com/viewtopic.php?f=3&t=11549" onclick="window.open(this.href);return false;

Here is what our very own Rockstah says in the second post:

check list to evh:

330u/820 - .68u/820 split cathode
.0022u bright channel coupling cap
330u/820 v2a
33k/500p tone stack - 500p on the bright channel mix resistor
.1u in the phase inverter ( output coupling caps)
47k feedback resistor on the speaker tap ( 16 ohm feedback )

dual 16u preamp
32u PI cap
16u screens
50u mains

with everything on ten this is a real good start in evoking the dutch treat

Mark

Then on page 19 you get to the fifth modification (.68 on V2A):

http://forum.metroamp.com/viewtopic.php ... &start=270" onclick="window.open(this.href);return false;

This "fifth modification" is nearly identical to what Mr. Suhr and Mr. Fryette say is the spec of THE AMP. This is the spec I have been using for several months now. Since I put these change in, I have put the amp in the box and not touched it...with a soldering iron, that is.

[vanhalen5150]

+1

[plexified]

+1

But still those changes will be no where near the impact of the choke softening the ac rail and the massive later otx .
Now your voltages go from 460 to 560 .

Oh why the variac? , to get back to 460 .

Oh why the 8 ohm tap ? To simulate the earlier otx impedence.

BUT now he has so much more power to drive the snot out of a single cabinet .

Thats the crazy tone you hear . Celestions begging for their life .

[Good Guest]

So the bass is added at the phase inverter input...instead of a .022uf it's a whopping .1uf....that fits the description and I think it was Suhr saying that it appeared the only solder joint that was worked on was one connected to the treble cap in the tone stack, leading him to believe it was a master that was installed once and removed....maybe it was the .1 uf going to the phase inverter installed. Adds bass

This seems to also follow the pic of Ed's amp that Mark C. posted ..where it looks like a rather huge cap at the input of the phase inverter..split cathode...also. If I remember correctly Rockstash was pumping Mark C. for more info on the values in that pic...especially the cap going to the phse inverer. Big huge fat chocolate cap.

I think we all better start looking at that Mark C. pic again.

[StuntDouble]

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[vanhalen5150]

That M.C photo, other than a split cathode, and some resistor values, say's what?

[StuntDouble]

...

[Good Guest]

That M.C photo, other than a split cathode, and some resistor values, say's what?

Says Big huge fat chocolate cap...feeding the phase inverter...among other things like it says ...a metal film cap for the lead channel coupling cap..superior quality and tone in the high registers than paper foil etc...that's what you want in that position of the amp for high gain frequency performance...says it looks like a reworked solder joint right where Suhr says it looks like it was tampered with...little bit of measling that's for sure.

Says this could be THE amp just like Mark C. says . Says lots to the trained eye

There is another pic from the left side angle but I can't find it...it is says lots too.

[vh junkie]

So the bass is added at the phase inverter input...instead of a .022uf it's a whopping .1uf....that fits the description and I think it was Suhr saying that it appeared the only solder joint that was worked on was one connected to the treble cap in the tone stack, leading him to believe it was a master that was installed once and removed....maybe it was the .1 uf going to the phase inverter installed. Adds bass

This seems to also follow the pic of Ed's amp that Mark C. posted ..where it looks like a rather huge cap at the input of the phase inverter..split cathode...also. If I remember correctly Rockstash was pumping Mark C. for more info on the values in that pic...especially the cap going to the phse inverer. Big huge fat chocolate cap.

I think we all better start looking at that Mark C. pic again.

This is the pic, that based on the info from JS I was trying eliminate as being the amp.
JS apparently said:
1) 820 in the first stage (we can't see it, but maybe)
2) .68 on v2a (this pic show a much larger cap)
3) A mod to add more bass(could be the .1uf feeding the PI)

But he was adamant that no solder joints had been changed except for the #3, the bass mod.
If that's the case, what the heck is that little blue cap doing there?

Could the pic have been taken after JS saw them amp? Anyone know the timeline?

[vh junkie]

So the bass is added at the phase inverter input...instead of a .022uf it's a whopping .1uf....that fits the description and I think it was Suhr saying that it appeared the only solder joint that was worked on was one connected to the treble cap in the tone stack, leading him to believe it was a master that was installed once and removed....maybe it was the .1 uf going to the phase inverter installed. Adds bass

This seems to also follow the pic of Ed's amp that Mark C. posted ..where it looks like a rather huge cap at the input of the phase inverter..split cathode...also. If I remember correctly Rockstash was pumping Mark C. for more info on the values in that pic...especially the cap going to the phse inverer. Big huge fat chocolate cap.

I think we all better start looking at that Mark C. pic again.

This is the pic, that based on the info from JS I was trying eliminate as being the amp.
JS apparently said:
1) 820 in the first stage (we can't see it, but maybe)
2) .68 on v2a (this pic show a much larger cap)
3) A mod to add more bass(could be the .1uf feeding the PI)

But he was adamant that no solder joints had been changed except for the #3, the bass mod.
If that's the case, what the heck is that little blue cap doing there?

Could the pic have been taken after JS saw them amp? Anyone know the timeline?

Looking at the solder joints...
the following have changed(at least):
the blue cap
treble peaker
v2 (big black) cap
tone stack
preamp cap
PI input cap (big brown)

I don't thing a guy would brag about his ability to inspect solder joints, and say there had only been one change... unless he saw the amp before this pic... or it is a different amp...

[vanhalen5150]

That M.C photo, other than a split cathode, and some resistor values, say's what?

Says Big huge fat chocolate cap...feeding the phase inverter...among other things like it says ...a metal film cap for the lead channel coupling cap..superior quality and tone in the high registers than paper foil etc...that's what you want in that position of the amp for high gain frequency performance...says it looks like a reworked solder joint right where Suhr says it looks like it was tampered with...little bit of measling that's for sure.

Says this could be THE amp just like Mark C. says . Says lots to the trained eye

There is another pic from the left side angle but I can't find it...it is says lots too.

I guess what I mean is we know nothing of those values that we cant see. The fact they are brown doesnt tell you the value. Same with the mustards.
Looks to me like there is lot more than just a few new soldering joints.
That Xicon is most likely a .68uf.
Browns are Cornell Dublier?

Or did you mean it actually is made of chocolate?

[StuntDouble]

...

[vh junkie]

That M.C photo, other than a split cathode, and some resistor values, say's what?

Says Big huge fat chocolate cap...feeding the phase inverter...among other things like it says ...a metal film cap for the lead channel coupling cap..superior quality and tone in the high registers than paper foil etc...that's what you want in that position of the amp for high gain frequency performance...says it looks like a reworked solder joint right where Suhr says it looks like it was tampered with...little bit of measling that's for sure.

Says this could be THE amp just like Mark C. says . Says lots to the trained eye

There is another pic from the left side angle but I can't find it...it is says lots too.

I guess what I mean is we know nothing of those values that we cant see. The fact they are brown doesnt tell you the value. Same with the mustards.
Looks to me like there is lot more than just a few new soldering joints.

Or did you mean it actually is made of chocolate?

Not following here... you can get pretty close on the values of mustards from the size... probably same with an experienced eye with the brown fellows...

I pointed out tons of new solder joints... what we need is a timeline from someone...

[StuntDouble]

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[vanhalen5150]

ahhhh....Dude! You guys just need to use your ears...F***k photos and timelines. Bump 820 up to 1k on V1 and it's perfect. Try this; it's all there!

I'm with you!