Thoughts on Jimmy Page’s Super Bass Marshall?

[Mark]

Hi, I was wondering if anyone had any clues on the Tony Frank modified Super Bass Marshall used by Jimmy Page. I have included two pictures on the Royal Amp MSG-100. It’s worth pointing out that I don’t know if the circuit is accurate per Page’s amp.

As shown in the links the Super Bass has the 250pF treble cap and a 56K slope resistor. However the MSG amp has a 33K slope resistor. I assume the amp uses KT-88’s as Page’s Marshall did. To be honest, I don’t see the advantage of using KT-88’s as they would have to be biased so cold as the power supply and probably the output transformer couldn’t handle the full current draw of these valves.

https://www.thetubestore.com/lib/thetub ... ematic.pdf

https://www.drtube.com/schematics/marshall/1992mk2u.gif

IMG_1056.jpeg

IMG_1055.jpeg

[Roe]

serial no is SB A10053. it looks like a late 68, early 69 amps with filter caps on top

these mods are typical 70-80s mods for a main amp with a line out that drives other amps. The line out is dubbed slave and it has its own volume pot. It also has some kind of effect loop apparently.
the line out is clearly tapped from the preamp, not the power amp, since it is combined with an effects loop (which hardly makes sense once the power amps breaks up considerably)



Transformers look fairly standard. The PT is a Drake 1203-80 with a fatter stack than the later Dagnalls. But the output transformer seems like a Dagnall c1998. a least some Drake 1203-80s reportedly had extra high voltage (600ish volts) due to a faulty 115v primary

[Mark]

serial no is SB A10053. it looks like a late 68, early 69 amps with filter caps on top

these mods are typical 70-80s mods for a main amp with a line out that drives other amps. The line out is dubbed slave and it has its own volume pot. It also has some kind of effect loop apparently.
the line out is clearly tapped from the preamp, not the power amp, since it is combined with an effects loop (which hardly makes sense once the power amps breaks up considerably)



Transformers look fairly standard. The PT is a Drake 1203-80 with a fatter stack than the later Dagnalls. But the output transformer seems like a Dagnall c1998. a least some Drake 1203-80s reportedly had extra high voltage (600ish volts) due to a faulty 115v primary

Thanks for the picture and the information.

EDIT I noticed Page has released his amp onto those with deep pockets and is calling it the Super Dragon.

“the amps feature carefully recreated transformers, New Old Stock GE 6550 tubes, Iskra and Allen Bradley resistors and Phillips “mustard” capacitors as well as specially designed speakers and cabinet that recreate the response and feel of Jimmy’s original.”

https://www.sundragonamps.com/

[Reeltarded]

The early sound of this amp is early rotation volume, as if it has a 5kp bright cap over the volume. This means it's basically run around 4-5 without smashing gain if it's true. The ones I had with 2000p-5000p don't have a bedroom setting. lol

We should try to find 70s images with settings clues. There should be a few..

[Reeltarded]

EDIT I noticed Page has released his amp onto those with deep pockets and is calling it the Super Dragon.

https://www.sundragonamps.com/

haha and Page can go eff himself.

If you want to get to a great starting place, KT88 a 50w plexi. Cascade the preamp. The first stage is big bypass (820r and 100u? you decide) with 4700p coupler, second stage is plain old bright 2k7/.68. .22u coupler. Both have gain controls. The amp has a common Marshall 800 master setup, variable slope or fix at 47k minimum with 330p treble cap. The peaker over the 470k splitter to the third stage is 2200p. Third stage is 820r with medium huge 25u bypass. You decide.. early presence, .1/5k

First stage has a 220k on the input side of a 1M pot.

Output coupling is .1u. I use 150k grid leaks here.

The trick is in the settings now. The first stage is set anywhere from 2-3 to around 8 (100-250p bright cap) and the master is between 5 to 7.

Now you use the second gain stage to set volume. I have a similar amp to what I described here that I called Black Dog. By turning the tone controls and moderating the presence it sounds like pretty much anything Pagey. If you turn down the master and crank gain 2 it's a heavy metal horn.

[cdemike]

I fell down this same rabbit hole not long ago and ended up building an amp basically to try to find the configuration that sounded most like The Song Remains the Same and How the West Was Won. The direction I took came out of suggestions from this thread: https://ampgarage.com/forum/viewtopic.p ... 88#p453488

Admittedly, I didn't think it was likely straight ahead Super Bass based on similarly looking closely at MSG100 gut shots; the demos of that amp sound so similar to me that I was fairly certain they got it right. As a result, the amp could be set up as Super Bass-adjacent, but leaned heavily toward Super Lead. An additional point of departure is that my amp is 50w rather than 100w. A schematic of the amp is in this post: https://ampgarage.com/forum/viewtopic.p ... 45#p460845

With the setup shown in that schematic, I thought it sounded pretty close with the lead-spec tone stack, 0.68uF V1 cathode bypass caps on both the first and second gain stages, and 2.2nF first coupling cap.

I continued tweaking the amp especially to try to get a similar "rubbery" transient response, though, so that schematic isn't as the amp stands now. I tweaked the power rail and think it sounds closest with the following B+ rail:
32uF (reservoir) > choke (3H) > 32uFv (screens) > 8.2k > 64uF (phase inverter) > 22k > 32uF (2nd gain stage + cathode follower) > 16uF (1st gain stage)
This setup, per Miles' suggestion in the first thread, provides very high preamp voltages and sounds appropriately bright and dynamic. Saggy filtering on the screens node is especially important for the right transient response, which is accentuated by the low reservoir value. I chose 32uF for those nodes since a 100w amp ostensibly requires 2x the current as a 50w amp with the same B+ values, so they were the standard values closest to equivalent 50uF reservoir and 50uF screens nodes in a 100w amp, i.e., the typical values for a 1969-spec 100w as well as the values I see in Royal MSG100s.

Since none of the Royal MSG100 gut shots I could find had bright caps, I ended up trying a version very similar to their setup by removing the bright caps, compensating by increasing the effect of the peaking network after the volume control (reducing the 1M to ground immediately prior to the second gain stage's grid to 470k), and eliminating the parallel triodes in the first gain stage. To my ears, this sounds closer than having a bright cap. Second place falls to the 4.7nF bright cap, and I didn't think the 100pF bright cap with the less aggressive peaking network sounded very close since it lacked the honk I associate with Page. Presently the amp sounds very close to what I hear in the recordings: lots of honk, vowel-like transient response, and strong bass response despite the squishy transients. I think the KT88s are responsible for at least some of the bass response, FWIW, since the EL34 amps I have don't feel as well-controlled in the bass register at similar settings.

Here are clips of the amp in the latest configuration:
https://www.youtube.com/watch?v=uPHMmYPKx2Q
https://www.youtube.com/watch?v=Qq2H_jgpkac

This setup provides plenty of overdrive, especially with an echoplex style preamp. For reference, these were recorded with the volume around 6/10.

[Mark]

EDIT I noticed Page has released his amp onto those with deep pockets and is calling it the Super Dragon.

https://www.sundragonamps.com/

haha and Page can go eff himself.

If you want to get to a great starting place, KT88 a 50w plexi. Cascade the preamp. The first stage is big bypass (820r and 100u? you decide) with 4700p coupler, second stage is plain old bright 2k7/.68. .22u coupler. Both have gain controls. The amp has a common Marshall 800 master setup, variable slope or fix at 47k minimum with 330p treble cap. The peaker over the 470k splitter to the third stage is 2200p. Third stage is 820r with medium huge 25u bypass. You decide.. early presence, .1/5k

First stage has a 220k on the input side of a 1M pot.

Output coupling is .1u. I use 150k grid leaks here.

The trick is in the settings now. The first stage is set anywhere from 2-3 to around 8 (100-250p bright cap) and the master is between 5 to 7.

Now you use the second gain stage to set volume. I have a similar amp to what I described here that I called Black Dog. By turning the tone controls and moderating the presence it sounds like pretty much anything Pagey. If you turn down the master and crank gain 2 it's a heavy metal horn.

Thanks for your advice Miles. It turns out that I saw the amp when I was in NYC purely by accident. A nice accident to have. I notice there are no back shots of the Super Dragon amp, I’m sure there is a reason for that.

[Mark]

I fell down this same rabbit hole not long ago and ended up building an amp basically to try to find the configuration that sounded most like The Song Remains the Same and How the West Was Won.

Thanks for your advice and the links to your amp, I think it sounds pretty good.

[Roe]

I guess the originals and clones have extra high plate voltage and some way to control the screen voltage and current. Custom transformers are made by Merren, who knows the specs obviously.

To some extent, this amp is similar to the west coast hendrix mods, which involved 6550s, high voltages and increased Z (rougly like a jtm45/100)

[Reeltarded]

To be so treble forward but not act like it.. to be so clean but to play dirty..

It is a weird sound to want, but who wouldn't? Jimmy Page is weird!

I love the Plant Page Unplugged thing. The air around that little AC almost make my mind print the drum pedal squeak from studio version.

[Mark]

To be so treble forward but not act like it.. to be so clean but to play dirty..

It is a weird sound to want, but who wouldn't? Jimmy Page is weird!

I love the Plant Page Unplugged thing. The air around that little AC almost make my mind print the drum pedal squeak from studio version.

Yeah, I listen to black dog and the guitar sits well in the mix, but on its own it’s not a pleasing sound. I have thought the same about the tone of some of Brian May’s dubs is recordings.

[Reeltarded]

If you hear the stripped tracks you wonder how Queen ever got on the radio. The drums are criminally poop.

[Mark]

If you hear the stripped tracks you wonder how Queen ever got on the radio. The drums are criminally poop.

Definitely.

[rmroza]

Here is the back pic of the Super Dragon and then a back pic of Jimmy's actual #1:

Super Dragon - output / output / impedance / IEC / fuse / fuse
No 1 - return / slave / foot switch / slave volume / output / output / impedance / power / IEC / fuse / fuse

[Roe]

the phase inverter uses a 12au7 here (both the original and the recraeations).