Ed's Knob

[spaceace76]

that's another big maybe. doesn't mean it was the same mod, or even that there was a hole there. maybe that's a color code so Ed/Jose would know which amp had certain specs without opening it up.

[plexified]

Its interesting he has the 50 watt choke and the Dagnall OT rotated 45 degrees away from stock . Thats just for starters . I find it AMAZING that the detail concerning Frankie clones goes beyond what should be addressed to the Main Marshall ! I've put alot out there concerning that amp and to date NOBODY has addressed those details or tried to replicate that amp . LOOK at the VHII studio picture . It shows the inside of the back of the amp . What do you see ? Its so obvious !

Next , take the Mark Cameron photo of the preamp from the gut shot . LOOK , what do you see ? I will start a Christmas Present thread if need be , but come on gang , I'm even surprised George hasn't offered a kit yet . I know alot of really , REALLY , talented builders and designers have to know what I am talking about and , hey its time to just get CSI and get 'Sticky Wit It'.

Just the above mentioned details are not going to get you the tone , its going to need playing skills and a cabinet . Ed started with the 20 watt Celestion cabinets with the Dagnall . And it sounded great ( I've done it too ) . BUT , that stuff is so rare , and they always blow up with that kind of power , their is a progression . Ed continuously morphed with his gear . Their was no absolute . But the main thing to keep in mind was he had the technique , the fire AND the desire . He tried many things , but to get the Main amp nailed we gotta go CSI and start from 1970 . The effects , the slaving and the evolution are very obvious as you look at the timeline .

Just remember he had the tone early on ( 1970-1973) and then started making mistakes and losing components along the way . He eventually got help (Jose)and learned alot . He was not stupid as a young kid . He was as in tune with his gear as he was with his playing . It was his life . And do you think after his main amp , his lifeblood ,was lost by PAN AM for 6 MONTHS ! he would take it on the road ? Hell no . It recorded in the studio only . He may have used the headbox for other stand in amps , but no , after a while he learned his lessons and he used similar amps to experiment with . What you see in the VHII picture is what he was left with . Mark Cameron gave us a gut shot of the pre amp . What do you see there ? Come on guys , the 'Stock' amp was progressively worked on . Camerons pre amp shot is profound !

Am I alone here ? , if so , why has a Frankie replica taken more concern ? I'm just amazed at why these puzzle pieces are SOOOOOO out in the open and just ignored . That is just for starters . The rest of the truckload of evidence to tune a 1959 within the schematic is mind numbing .

I love a conversation on the cascade , and the cascode , which I think is stellar material . But before we get to that , lets iron out a stock circuit .

The final element is that the speakers are no longer a viable variable to consider . So therefore , you cannot use them in a new build . You need to utilize existing speakers and components and break them in to realize the end result . Its all design and engineering . How to adjust these variables to meet the end results .

I'm really wondering about the primary Impedence portrayed from the Dagnall to the Drake . Remember Ed ran the 8 ohm tap on the replaced output transformer . Here he doubled the Primary impedence , hence doubling the end result . The adjustment from Dagnall to Drake .

Lastly he always loved to say the amp had 'BALLS' !

Do you think Balls meant Dagnall into a straight cabinet loaded with 20 watters ?

Sounded freakin godly , but thats not balls .

Balls was a Metal Panel into a single cab .

That cab would be dancing on the floor .

I would suggest Siemens EL-34's .

[vanhalen5150]

Plexified..you mean 90 degrees, correct?

[Good Guest]

Well I'm not a marshall expert but that 3 rd transformer on the back of his amp to the left isn't your stock choke, that's for sure. It could be another output transformer or a seperate power transformer or a high voltage / high current type choke. The angle of the output transformer could be either way....after looking at some 12000 series chassis pics..

The Cameron pic clearly shows a cascade type circuit where there is no volume for the first stage , it's hard wired to the second where there is a volume with the 470k mixer going to ground , consistent with the ralle one wire mods except there are no volume controls on the back of the amp. It looks to be a randy rhoads type , bypassing the 1st volume tho. The coupling cap sequence is opposite to how I would think. Fromm .022uf too a cap that looks to be in the range of .001uf..just look at the size in relation to the 470pf.

The way it is setup looks like a slaved signal could be injected at the cathode follower pre volume or the preamp cascade could be picked off for furthur processing.

As there is no indication of a white knobbed control in the pic I seen, this evidence will probably be shot down instantly by the white knob police.

[spaceace76]

There are many problems with the M.C. photos, and the lack of a knob isn't really one of them. First, there's nothing solid to indicate this is THE amp. The photos are heavily cropped and don't show much of the inside walls of the chassis which would help us figure out if it's the right amp. Second, this might not be the original spec of the amp, and if these shots were taken by Cameron himself they would be how the amp is today, not really how it was 30 years ago. Plus, there are no notes to tell us what the values are, so we can't even experiment to see if the specs pictured are any good.

Photos of Bigfoot are nice, but a live Bigfoot would be better.

[plexified]

Plexified..you mean 90 degrees, correct?

Yes 90 degrees .

That is compared to a later layout where the Drake is orientated differently . When you think about this the transformer is radiating magnetism . The bigger trans is radiating alot more and imposing on all the parts around it , including the caps under it and the half side of the tube compliment throwing a balanced pi theory out the window . The chassis is also raw steel not plated . The plating done later in the run would effect the ground plane and the magnetic radiation .

The choke could be another transformer as you can use a resistor to replace a choke internally . It appears to be from a later 50 watter , but a rare unit itself . Usually the 50's had the very small U frame or the larger open frame with the exagerated end bells

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But interesting to imply it would be anything other than a choke ! It is also rotated 90 degrees regarding its origional layout .

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Lastly ALL the output tube sockets have been replaced . They should be brown bakelite , but they are CERAMIC . Ceramic is notorious for introducing vibration and resonating . In addition replacing all those sockets would take more effort than it would to build the amp from start to finish . But thats just a clear indication he had blown a few transformers and took some octal sockets with it as collateral damage .

While on the tubes , notice he used tube shields , yes they do affect the way the tubes interact . Use em if you are going after this tone . Gain is an excercise in multiplication . Earlier in the signal chain , it becomes magnified in regards to the end result .

[Good Guest]

I'm beginning to wonder if he used a choke myself. I figure a seperate transformer because I have done that to run extra heaters that suck lots of current while operating the voltage at differant levels without changing the heater voltage.

Seeing as Ed used the variac tho that kind of makes me wonder if he did that, also as it would change the heater voltages if connected to the same line. It would have to be isolated from the variac'd line.

If he did use a seperate power transformer it would also give some credance to the power switch theory...whether he's is switching it in or out. Perhaps a seperate transformer for the preamp , but I don't see any extra power filter caps which would be necessary. Or he could be running the transformer in paralell for more current availability. Which would make sense if he was playing with the bias and boosting the voltage with the variac. Actually if he was reducing the voltage to extremely low or high levels he would have to adjust his negative bias to an extermely high current consumption level or higher voltage level that would probably go out of the range of his stock transformer.

Ahh haa ..a seperate transformer for his bias voltage. One thing when you look at pcs of 12000 series amps and they have this tiny transformer and you look at Ed's amp...something has definatley changed.

Regarding the M.C. pic yeah....there is no indication whatsoever the amp was Ed's other than his word.....and the fact that he owns Jose's work shop. More than I can say.

[spaceace76]

that choke is bothering me now. it really sticks out...
it would be interesting if Ed started out with the Variac and after blowing a few transformers he went to Jose, who added that extra transformer as well as a larger PT.

has anyone really experimented with different chokes, or no choke at all?

[Good Guest]

I've had limited experience with chokes and presently I don't use one just some extra filtering and some resistors. Some claim tho it's responsible for virtually everything under the sun. I don't see it. In one case the choke caused more hum than anything....simple resistors can replace chokes in a lot of cases. Be prepared to hear words like dark..smooth..harmonic resonance....all hard to stomach. oh and the biggy... sag....which can also be done with a sag resistor and is mostly related to the rectifier. The sole purpose of the inductor is to clean up your B+ and that's it's purpose.

Still leaves the mystery of the possible extra transformer and now I'm thinking ...another OT....that can have many uses regarding impedance matching and mismatching ..and even combined with a power resistor could be a transformer lineout of some kind. The load box was in his amp? Isolating that transformer and locating what exactly it is would be interesting...there's a csi thingy right there...

[vanhalen5150]

with a power resistor could be a transformer lineout of some kind. The load box was in his amp? Isolating that transformer and locating what exactly it is would be interesting...there's a csi thingy right there...

No foolin' on that one GG. Iso transformer to a line out level..."hmmm where would I put a knob for that ummmm.....oh right here would be a good spot."

And what is the second jack there that looks like it has no cable coming out of it?

[Good Guest]

with a power resistor could be a transformer lineout of some kind. The load box was in his amp? Isolating that transformer and locating what exactly it is would be interesting...there's a csi thingy right there...

No foolin' on that one GG. Iso transformer to a line out level..."hmmm where would I put a knob for that ummmm.....oh right here would be a good spot."

And what is the second jack there that looks like it has no cable coming out of it?

The inductor looks like a cross between an open frame and bell version but that could be anything ...(a cross).

I looked carefully at the back too and you'll notice the blue jack does have a line to it it's just that the impedance selector switch blacks it out ..another line is in a loop and looks to go under the amp but doesn't ..however there is this one lead that seems to go under the amp between the chassis and frame looks like it is split (Y cord) with some kind of rca connector at one end the other in the amp then it joins and goes in a loop with a normal jack at the other end ..it's a short cable.

For all we know he has an alligator clip on the one in the amp and he's picking the signal off anywhere. No wonder no one can figure out the thing.

edit: after looking at other pics that small cord just has it's ends split and dangles in the air

To the right of the amp on the bottom is another cable that seems to be going under the amp.Regarding the power tubes...They are the mil spec 6ca7's... Well it does say sylvania on the bottom of one tube ..just like mine do. That's where the simularity ends

[Grosh_Guitars]

Plexified..you mean 90 degrees, correct?

Yes 90 degrees .

That is compared to a later layout where the Drake is orientated differently . When you think about this the transformer is radiating magnetism . The bigger trans is radiating alot more and imposing on all the parts around it , including the caps under it and the half side of the tube compliment throwing a balanced pi theory out the window . The chassis is also raw steel not plated . The plating done later in the run would effect the ground plane and the magnetic radiation .

The choke could be another transformer as you can use a resistor to replace a choke internally . It appears to be from a later 50 watter , but a rare unit itself . Usually the 50's had the very small U frame or the larger open frame with the exagerated end bells

The attachment OPEN_FRAME.jpg is no longer available

The attachment C1999.jpg is no longer available

But interesting to imply it would be anything other than a choke ! It is also rotated 90 degrees regarding its origional layout .

The attachment BellChoke.jpg is no longer available

Lastly ALL the output tube sockets have been replaced . They should be brown bakelite , but they are CERAMIC . Ceramic is notorious for introducing vibration and resonating . In addition replacing all those sockets would take more effort than it would to build the amp from start to finish . But thats just a clear indication he had blown a few transformers and took some octal sockets with it as collateral damage .

While on the tubes , notice he used tube shields , yes they do affect the way the tubes interact . Use em if you are going after this tone . Gain is an excercise in multiplication . Earlier in the signal chain , it becomes magnified in regards to the end result .

That is a choke. it's the same choke I have in a 1970 Super Lead which is totally stock.

[Ralle]

Well I'm not a marshall expert but that 3 rd transformer on the back of his amp to the left isn't your stock choke, that's for sure. It could be another output transformer or a seperate power transformer or a high voltage / high current type choke. The angle of the output transformer could be either way....after looking at some 12000 series chassis pics..

The Cameron pic clearly shows a cascade type circuit where there is no volume for the first stage , it's hard wired to the second where there is a volume with the 470k mixer going to ground , consistent with the ralle one wire mods except there are no volume controls on the back of the amp. It looks to be a randy rhoads type , bypassing the 1st volume tho. The coupling cap sequence is opposite to how I would think. Fromm .022uf too a cap that looks to be in the range of .001uf..just look at the size in relation to the 470pf.

The way it is setup looks like a slaved signal could be injected at the cathode follower pre volume or the preamp cascade could be picked off for furthur processing.

As there is no indication of a white knobbed control in the pic I seen, this evidence will probably be shot down instantly by the white knob police.

Not if that knob is a pre PI master... I find this very interesting... I've come to the conclution that the 470k mixer is in there somhow... but the coupling cap thing caught my eyes Do you mean that the couplings were placed the other way around; the lead had .022u and the normal had something between .001u and 470pF?
I'm using thet "white knob" to be able to adjust the gain into the seccond stage, and because of that, it fits perfectly to say that the pot was in there for that purpose... but if there's another possibillity of handeling the gain... man this never ends... hard, but great fun

[IloveMyMarshall]

Not if that knob is a pre PI master... I find this very interesting... I've come to the conclution that the 470k mixer is in there somhow... but the coupling cap thing caught my eyes Do you mean that the couplings were placed the other way around; the lead had .022u and the normal had something between .001u and 470pF?
I'm using thet "white knob" to be able to adjust the gain into the seccond stage, and because of that, it fits perfectly to say that the pot was in there for that purpose... but if there's another possibillity of handeling the gain... man this never ends... hard, but great fun

Hey ralle try a .047 and also the PI input put a .047 and get back to me on it I have run in to some killer stuff with your mod brother thank you!!! The pot is just controlling the grid gain correct? My amp I'm getting some clean detailed gain it was HI to much treble until tried the .047 she worked for me, sounds awesome amp to cab as well as lining out from the Rockstah load line box.

[StuntDouble]

with a power resistor could be a transformer lineout of some kind. The load box was in his amp? Isolating that transformer and locating what exactly it is would be interesting...there's a csi thingy right there...

No foolin' on that one GG. Iso transformer to a line out level..."hmmm where would I put a knob for that ummmm.....oh right here would be a good spot."

And what is the second jack there that looks like it has no cable coming out of it?

I've got a transformer isolated lineout box that was patterned after an old Jose modded Marshall where it was installed in the amp, extra transformer and all, with the knob in the same spot...accordering to Trace Davis. This would be my guess as to what it is, although who knows for sure? When you're slamming the front end of the 1st amp, slaving yields more than enough gain to get Ed's early sound. The JBL's added high end and sizzle also kind of fool you into perceiving more gain than is really there as well as adding headroom.

These cascade mods sound good, and if Ed didn't slave early on, then I think it's at least a good possibility that he used one in his main Marshall...but, if he slaved...and I think that Templeman and Landee reamped his sound into a slave setup from the board...just my .002, then I don't think he would need a cascade mod. I actually had to pull the sliders back on my MXR 6 band EQ from where I normally have them, when I slaved cause I was getting too much gain.