Plexified reveals Eds Plexi , again for a sticky

[plexified]

Ok , for many years I have lived and breathed plexi life . Its the baddest amp on the planet . With its matching 4x12 pair its a monster , Hendrix drove that home . Ed took notice and saved his pennies and bought one . Not just one , a sample from practice stable from the Rose Palace . Here its lifeblood had an immense amount of A+ players plugging in tuning up and rocking the house for thousands before him . He got the amp and tried to play this monster in his house with parents and neighbors and being immigrants , AL and Ed were concerned with the fury of this massive volume compliment . So Al played softer although he outplays a Plexi and Ed was introverted with his early playing so he used a wall dimmer to turn down the volume as he thought it was a solution . It got great sounds this way , however this is the first misconception . Live during the parties and such he was wide open trying to keep up with the beast that AL is . He is one of the loudest drummers on the planet and his skills are mad .
Next we get into the Jose zone . Jose was Eds first experience when his stuff blew up . He was experiencing what we ALL do , a line voltage from the wall that is sometimes as high as 130 volts . Here you have an amp that is designed to see 110 volts and 130 is going to melt things , like transformers and tubes and other parts in the chain . It happened and here you have Jose .
During the early seventies , the factory replacement was a larger transformer for the output . Fortunately , Ed blew the output and not the power transformer . The Power transformer as with the output transformer were very limited runs during the 12 series run . Not many around and not many alive let alone parts . Here his amp was prior to the 'A' series and pre 69 . The replacement in his amp was an A series or 69 unit . Much larger with a lower primary impedence and that means more drive , grind and balls . I was also installed rotated 45 degrees and the edge of the transformers orientation effected the way the output tube compliment reacted . So this is unique and note worthy here .
In addition the power transformer is under rated . It was a huge step down from the big stacks of iron from days prior . Marshall was mindfull of the 20 watt Celestions and under rated it to keep from going down the warranty road by having to answer to blown speakers . They had already experienced that from Hendrix road tests and Hendrix was upgrading to 6550 output tubes and higher wattage speakers . They were constantly reacting to the live show artists blowing stuff up .
So Jose advised Ed to use a variable ac transformer or variac as we know to drop the voltage supply . Here a few things happen . The Ed 12 series had already a low power supply rail supplying the pre amp and this means more dirt and the magic happened with the larger output transformer heavily driving the results . The lower filtering being stock was a classic . Large first stage ripple control and lower values feeding the pre amp . Here the control over the cones or the 'ring' of the cones or tightness became critical and the prescence control became very important . The stock prescence control employed a 27k resistor to the negative post . Meaning whatever impedence you selected it was constant regarding if you chose 8 ohms with two cabinets or one cab at 16 ohms . Ed had his slightly modified to best attain the tightness he liked . Probably a larger resistor and off the positive terminal . Here it worked when he wanted to slave the amp or just use one cabinet . It was about the bottom end . Tighness with that silky milkshake bottom end that 'Thumped' and also was very velvet like . Like George , velvet , no harshness . Its the signature . It was also enhanced with a large second stage pre amp cap of a large value . Second stage later Plexi is a .68 . Here it was a 330 in parallel to allow more bass to flow through the pre amp and give a more enhanced bass and a bit of wool here .
So to conclude , a T1221 Celestion was the center in the straight cab . Ed eventually used the 014 cone and heavy mag 30 waters into the single 4x12. It was louder with crisper highs and beefier lows . This was to compliment the small output transformer that sagged like a situation between a tube rectifier and a solid state rectifier creating its own sound . This is the component that I spoke of so many times that it was never realized . Chris Merran and I are scratching out heads as to why the community has missed it all this time . Its the most important archetype . It probably would not get UL laboratories approval its so on the edge that's probably a consideration by designers . SO , the cats out of the bag here .
Its a very happenstance hybrid circuit that needs much closer consideration . Myeself and others have put it on the table and its always missed . I own a plexi a few numbers prior to Eds and I speak from not only experience buy real world application . I own the amps , cabinets, and tubes and have learned the skills to understand this stuff . So with my utmost respect for George and all he has done for us to allow this massive exchange of information , I felt it was time to set this straight for the skills to shine with great tone . In my 'Grail' post , it was heartfelt to deliver a mind set that to play at this level you need a zone that is attainable . And we all have this ability , I cannot stress it enough that we have this in us and I hope their is no shortage of great tones to come , because when you get it , it consumes you and allows you to free your mind and the rest will follow .
So cheers my fellow Metro Mates and like I said before , Nobody touches the tone that the Metro Board gets . Its like the show Street Outlaws . I am a massive motor head . I love cars . One of my best songs I wrote is called Fast Guitars and Mean Guitar . That says it all . The outlaws push against the laws , despite rules and the outcome is magic . That's what we do here , we push the rules , dissect the scenario , plug in and let it out !

Your brother in arms , necks and the hair standing on the audiences bodies , Plexified aka ~Crowd Dancing

[fivecoyote]

Tx mang! Wish I had the time to build amps...maybe when the kids get off to college, but then I'll be to poor? Great read tho, can't wait to see what guys do with it....

[plexified]

fivecoyote ,
as always thanks for the kind words and gang don't forget to visit woodytone.com for insane interviews , fun and factoids . Yeah man , I was trying to compact the whole game here , because I do not like to read about guys and gals struggling to chase this very unique tone here . You can get it in different ways , however , lets face it , even Ed is chasing it . I'm sure Dave Friedman is taking care of him , but like I said the power transformer is in between a solid state rectifier and a tube rectifier in its reaction and tone creating that spongy bottom end character that is also very tight and focused with balls . Find another amp that does that . You won't . It goes into the 3-D plane of where the parts are located and why they react the way they do and the influence they receive . For instance the tubes from the magnetic pattern of the transformer , rotated the way it was . The lack of using the tube covers in the pre amp . The board mounted filter capacitors and even the style rectifier . It all plays into the collective and its important to understand what does what not only from a designer or a repair person , but someone trying to figure out what is actually happening .

When that Van Wheelden dude was spoken of by that charlatan Fliegler I was pissed . Because they talked so much smack like we were all collectively idiots to sell a magazine . That right their gets me enflamed . I was spitting blood out of my eyes mad . Because people were actually believeing that penmanshit and calling this charlatan to do actual work on their stuff . Its wrong .
So here you have an outline of what happened and why and not a six hundred post thread to weed through that essentially gets you confused . So , I hope somebody posts something and this does not go to the bottom and rot . Because if you can understand what Is going on in the power transformer and the power rail with the capacitors and the 3-d plane , you got a shot and you can tune an amp and know what you need . Other wise , just get a digital modeling amp or board , save the crane or brain and just practice . I get mega tone out of my zoom g9 2 tt . its a digital modeling pedal board with a few 12ax7 tubes for fun or ha ha's and you can take over the world with it . If you can learn how to program the robot . But the first time you hear real Plexi Tone , their is no going back , you could care less who's louder. Yes you finally out power the drummer . Yes trinkets fall off the shelves at home . Yes, the whole house shakes , BUT , with a little recon , you can find out how far that sound carries and at what time its not good to do so , when somebody else plays your rig and you can recon the area OR you have a wireless and can walk around it a few hundred feet . I find it effective to use the wireless to do so , FIrst you can test daylight Db and second if you are seen by chicks its a very effective tool . Stop the car and make up some bullshit like you lost your dog and your trying to provide familiar tones for them to find their way back . Bust out some stellar lead work and guys and gals its like you just told them you A. have your own place , B. have concern over another life form you miss , and C. well their is opportunity defining this c strategy , maybe pretend your shaking down the live rig for the upcoming tour of Europe and then ask if they want to go ,( for example purpose only ).
Ok , back to our regularly ignored information .....

[awangotango]

I envision a time soon where guys who know how to play a plexi without pedals or mods or 19k pups, yet still get enough gain out of it to play rock music or in my case old skool metal, will be seen as a wonder from a past age. Because it will be a rare thing. It's been going towards a lost art for decades now and soon there will be less and less of us around as we dieoff. And since the smithsonian can't call ed in to demonstrate how to play a plexi, they'll have to call one of us. We'll be in a glass case like at the museum or a freak carnival and onlookers will marvel at the historic and ancient relic technique and sound being achieved. 'Look johnny, back then guitarists had to use their picking hand and arm to create gain and overdrive before we had invented ginormous amounts of preamp gain'. ' I see dad, that explains why all those old records you had sounded so different and old school. That must have been a hard life playing through amps like that and at such loud volumes, i'm so glad we don't have to struggle like that any longer'.

2 gain stages 'till the end rock brethren!

[Ralle]

It feels sooo good to see that this surface... I've been on this since I first got my tone out of my head... actually since I converted to stock head ( non-cascade )... I would like to seccond that of the tone quallity and how it caries through allmost any lineup... I've been playing with guy who have both jvc heads and 5150 heads, EVH peavy heads... allthough they might have had a tad more gain than me, they never came up the the level of tone I did... When I play in the band, the sustain is insain... feedback and harmonics... and yet it's fairly clean in a way... But the raw power is ABSOLOUTLY amazing... It might not be louder than the others but the tone carries through in a way that's astonishing...
Don't know if what I have in my head is what Ed had, but it sure works in the same manner; b+; 460v with a c1998 ot... the PT is a 1203-80... I swapped to the stock T2562 pt, but I blew the ot atfer a while, so I changed it back to the 1203-80 pt... not only does the ot survive better, but it sounds a lot better as well...
So I totally agree that the pt has a huge impact on the sound...

However, I am very curious abut that nfb; " The stock prescence control employed a 27k resistor to the negative post. Meaning whatever impedence you selected it was constant regarding if you chose 8 ohms with two cabinets or one cab at 16 ohms . Ed had his slightly modified to best attain the tightness he liked . Probably a larger resistor and off the positive terminal "... What's up with that?

[Strat78]

Running the purple wire to the speaker jack instead of either the 4,8 or 16 taps. I actually like it best this way (with a 47k which I think some amps came stock), it's like keeping the impedance set at 8ohms which is cool when running it into a 16ohm cab. I think it was you Ralph that turned me on to this.

[vh junkie]

I feel like I must be getting slower in my old age... what are the "negative post" and the "positive terminal"?

[Ralle]

I feel like I must be getting slower in my old age... what are the "negative post" and the "positive terminal"?

If I'm not misstaken it means; negative post is the 100nF input of the piv stage, and the possitive terminal is simply the speaker jack lead tip...
And keeping the " impedance constant " is having the purple wire at one of the ot seccondary taps... correct me if I'm wrong

I have mine at the 16 ohm tap... with 47k...

Regarding the NFB, there's two ways of forming the sound ( or tightness if you will ); the nfb resistor, and the purple wire attachment... assuming we're talking about the 100nF/5k presence pot... This is probably the one point in the whole amp where you can change the sound/gain more than any other place, without affecting the basic character of the amp... I've spent more time in working with the nfb circut than any other place in the amp... and so far I think the best combo is 16 ohm/47k... that's my personal take on it, but having 100k/16 ohm is to my ears more EVH than anything...

[mightymike]

"This (NFB CIRCUIT) is probably the one point in the whole amp where you can change the sound/gain more than any other place, without affecting the basic character of the amp"
Ralle

So much bang for your buck here.. Lots of impact can be made in the NFB circuit; be it the amount of NFB (gain), or the Presence (treble focus) and its opposite Reasonance (bass focus). The reason I say focus because it does adjust the feel/tightness as well as the frequency response.

I really like the simple resonance mod on the Atomica called "Thump". It reminds me of the PEAVEY Meat Control.

One of these days I'm going to try the Depth/Punch reasonance circuit like on the CCV and just make a 2 knob module of it.

[rgalpin]

...
Ed eventually used the 014 cone and heavy mag 30 waters into the single 4x12. It was louder with crisper highs and beefier lows .

This was to compliment the small output transformer that sagged like a situation between a tube rectifier and a solid state rectifier creating its own sound .
...

The "small" OT ... you are referring to the stock OT from 12 Series? I'm a little confused. The PT and the OT were stock right? Trying to get my head completely around this point.

[Strat78]

...
Ed eventually used the 014 cone and heavy mag 30 waters into the single 4x12. It was louder with crisper highs and beefier lows .

This was to compliment the small output transformer that sagged like a situation between a tube rectifier and a solid state rectifier creating its own sound .
...

The "small" OT ... you are referring to the stock OT from 12 Series? I'm a little confused. The PT and the OT were stock right? Trying to get my head completely around this point.

Yeah, the cats out of the bag all right. Seriously, I think he meant a weaker PT and a stronger OT if you go by what he is driving at in the beginning of the post. An OT that sags similarly to a tube rectifier? More screen (rail) resistance? Changing the NFB resistor or putting in the fat cap....sounds like he is describing some of the things that van wheelden did and what is later referred to the "Friedman spec"? "This is the component that I spoke of so many times that it was never realized" What component? If it is a weaker OT, than I guess we are talking about 1.75k vs. 2.2k? 30watters drawing more current? I don't know, why speak in riddles but just show us what we are supposed to "realize". Still, most of us have done all these things over and over and had allot of fun dipping into that wonderful realm of tone. This isn't 2004-2009, we don't posses special powers knowing how a 12xxx works, much less how to produce a good VH tone with these old circuits. Those days are gone.

[plexified]

So , I actually flipped the script here , its the power transformer I meant to accentuate . Yeah , the output transformer stuff still stands , but the output is the main issue here .

[Strat78]

I did a measurement of the OT in the VHII shots, seems to be standard size there.

[vanhalen5150]

That lay down PT is magic. I don't know why, but it is.

[rgorke]

That lay down PT is magic.

do you mean Ed's? Or another specific one?