John Suhr Provided Details Regarding the SL68 (JMP SL clone)

[Tone Slinger]

Listen to the 'Golden West Ballroom' gig from 3/77 (it is mistakenly labeled as '76 alot, though some boots mix some stuff from '76 with it). THAT tone, imo, is Ed's best. Listen to 'Last Child', extreme tone and whammy and stretched legato licks just flying all over the place. Love the transformer 'sag' he's getting from just totally cranking his amp and running through a variac.

[stef]

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[projectx102]

That doesn't explain him getting almost the exact first album tone live on that last Pasadena Civic show in '77.

yep! and he did not sound bright and shrill at all - actually it sounded a tad warmer and fuller than VH1

Exactly

[jnew]

Isn't the sag also realized through the low mains filtering? 50uF or so? I thought that a variac on 90 or so, would make any power transformer sag but the filtering also has to be down low.

[johnnybgoood]

The '77 Pasadena show and the '76 Ballroom show were recorded using tape. I listened to it again last night and the sound is muffled even with digital mastering. Great bootlegs nonetheless! Listening to a show live and listening to shows recorded on tape are two different things.

Kate Upton is smokin' hot on the SI cover. But, ...even with her beauty her imperfections are still photoshoped out. Friedman said it best. "You guys are trying to get your amp to sound like the recorded tone. Well just to let you know a lot of eqing was done after the fact in mixing. Your chasing a ghost." http://forum.metroamp.com/viewtopic.php ... 99#p316781" onclick="window.open(this.href);return false;
Ed's amp is bright. There is too much evidence in favor of that.

Van Halen fumbled on the difference between european and north american voltages when he plugged his 220v amp into a wall socket at his folk's Pasadena home. Eventually, that discovery helped him tame his 100 watt shrill beast and gave the rest of us the variac-to-amp application.

To believe that Ed's plexi is stock then the 12301 amp has the 5000pf bright cap on the volume 1 knob. The harshness was taken down slightly by the cranked bias and the variaced wall voltage. But then he brought the highs back in by placing the Echoplex into his effects chain. Suhr knows how bright a Marshall is with that .005u cap and that is why he left it off his SL68 amp altogether.

We know what the EP-3 preamp does to the sound and there is much discussion of that in forums everywhere. See Pete Thorn's vids where he was peddling (pun intended) the Clinch-FX EP-Pre which "fattens" up the sound but also adds brightness. Thorn, in his quest for the brown, noted that a "bright and brash" sizzle is a must to get close to VH. Suhr also knows this and that is why he is selling his ISO boost pedal. The Echoplex preamp is a simple and cheap circuit ($30) but you need to get the right voltage flowing (i.e. charge pump) to get it to work right if you want to build it yourself.

Pete Thorn/Sinas
http://www.youtube.com/watch?v=5HlmLdsqXZc#t=14m19s" onclick="window.open(this.href);return false;
http://www.youtube.com/watch?v=LderEFqby4A#t=1m12s" onclick="window.open(this.href);return false;
http://www.youtube.com/watch?v=LderEFqby4A#t=5m23s" onclick="window.open(this.href);return false;
staalhoofd
http://www.youtube.com/watch?v=KGeJsMdBrzw#t=0m02s" onclick="window.open(this.href);return false;

Happy Easter!

[johnnybgoood]

low mains filtering?

Low filtering was generally normal at Marshall in the '60's.
50uf Main
16uf Screen
32uf Preamp
100uf PI (not really low)

[jnew]

Yeah. I'm trying to figure out how to do 100uF on the PI and 16 on the screens. I'm talking about in the case of my amp. Its the JTM that I converted to a 50 watt and I have only the one cap on the inside that does the screens and PI and it's a dual 16uF. I don't think I have the room to put another cap in the chassis. It's a small chassis. Have to figure out something though.

[Tone Slinger]

Hey, no argument from me about Ed's tone being bright, it WAS indeed. BUT, it was also pretty darn warm and luscious. Remember, most American dudes were using '73 to new (with new being 1977, in accordance to the timeline of Ed's '77 tone) at that time. Not many American's had PTP pre '73 Marshalls at that point. The BOMBARDMENT of mass produced pcb tops came from mid '73 on. These amps were Darker and harder sounding than the earlier ones. The earlier ones had the .68uf on v2 which made them more upper mid/high endy as compared to the '73's on. Also, the lower filtering of Ed's top (a 12xxx Marshall was more rare in the states back then, than it is today, which is saying something). 12xxx had the 32uf pi can, which contributes to that slight sag needed.

I dont need to record with tape or digital, I know the sound when I'm standing in front of it. It will pretty much sound right being played back on an cell phone, IF the sound is there to begin with. I think that the old analog/tape recording scenario captures what the human ear is capable of hearing optimally, whereas digital recording overshoots what we can audibaly decipher, resulting in MORE frequincies than we can hear, resulting in it sounding sterile, harsh and cold. But here again, if it sounds right coming out of your amp, then NO recording process is gonna take THAT away.

[JimiJames]

I think that the old analog/tape recording scenario captures what the human ear is capable of hearing optimally, whereas digital recording overshoots what we can audibaly decipher, resulting in MORE frequincies than we can hear, resulting in it sounding sterile, harsh and cold.

Generally speaking, Yes.

[Strat78]

For me, the VHI recording process is neither here nor there when it comes to dialing in how the rig actually performed in the studio at that time, and from my experience much of that first album had little significant tone changing post e.q., because those tones are simply what a good (or bad) 12xxx can produce. I don't here anything shrill (to me the Mod5 is shrill), I hear the strings bottoming out on the pickup, but that adds a nice chirp (you hear allot of that in Page's playing too, it's great). I'm The One is a great tone, but is actually a total mess, it's very difficult to control a disintegrating tone like that. 5000pf works in reverse: when the amp is dimed it is bypassed, dial vol1 back and you start mixing the dimed warmth and power with that beautiful sparkle and sizzle (RWTD rhythm tone vs. solo tone demonstrates this). I don't get the EP-3 pre pedals, they don't simulate a real EP-3 at all never-mind the absence of the tape echo. Nothing beats having that big box sitting there churning away with all it's rattles, squeaks and other inconveniences. When the echo is engaged, it can't be beat. I love using NOS parts and I think it only improves the tone much less can make an amp special.

[JimiJames]

...When the echo is engaged, it can't be beat...

I get close like all (EP & echo pedal), but yeah, it ain't the same... I currently use a Strymon/Clinch and is not like my Roland SE-201...and is not a EC-80.
Just listen to those old boot's with his delay. It is already there to begin with.

[rgorke]

5000pf works in reverse: when the amp is dimed it is bypassed, dial vol1 back and you start mixing the dimed warmth and power with that beautiful sparkle and sizzle (RWTD rhythm tone vs. solo tone demonstrates this).

Could you elaborate on this? Are you saying to use a bright cap? I haven't had one on in years. Am I missing something if I pull the volume back 8 or 9?

taking the chassis out again.....

[Tone Slinger]

Roger, watch George's clip '12xxx options' on his Metro build section. He goes over what the bright cap does. Turning vol.1 down to 7 or 8 would leave enough edge to the tone to possibly dial in the 'ol 6 band to warm it up a bit and add the rest of the gain back.
Back to the op,

I was interested enough in this amp to research it a bit (Sl68). The going price is $3900

[rgorke]

Roger, watch George's clip '12xxx options' on his Metro build section. He goes over what the bright cap does. Turning vol.1 down to 7 or 8 would leave enough edge to the tone to possibly dial in the 'ol 6 band to warm it up a bit and add the rest of the gain back.

Thanks, I put in 560pf cap and left it in for about 90 secs, sounded thin and crappy. Is that the wrong value? Nothing ventured nothing gained.

[julkke]

Roger, watch George's clip '12xxx options' on his Metro build section. He goes over what the bright cap does. Turning vol.1 down to 7 or 8 would leave enough edge to the tone to possibly dial in the 'ol 6 band to warm it up a bit and add the rest of the gain back.

Thanks, I put in 560pf cap and left it in for about 90 secs, sounded thin and crappy. Is that the wrong value? Nothing ventured nothing gained.

Try 5000pf and turn volume to 8..