Looking for a sound

[jckid649]

I spent way too much money buying, selling, building, and selling amps to find this simple basic tone that I want.

I am looking for a build or modification for a circuit that will produce that basic raw clean, clear overdrive found in Jimmy Page's live tone and Jimmy Hendrix's tone on Voodoo Chile (Slight Return). Very raw, clean punchy overdrive.

Everything I've read up to this point says that you need big bottles like the KT88 with tons of clean headroom but I cannot find anything to tell me really what circuit and what exact mod's it takes to attain this basic tone.

Does anybody out there have layouts or schematics for this?

What Marshall amp is the best foundation for this?

[xtian]

My 1987 and 2203 Marshalls KILL at driven-single-coil tones. LOVE. A JTM would be cool, too, but I must have master volumes in my amps. PPIMV work great for me.

As I recently discovered, throwing any random tone stack and presence caps in is not a recipe for success. When I replaced my Mallory 150s and old Astron presence cap with Vishay polypropylene, my 1987 sounded MUCH better.

[roberto]

Vishay 1813 caps sound goo in those amps.

[jckid649]

My 1987 and 2203 Marshalls KILL at driven-single-coil tones. LOVE. A JTM would be cool, too, but I must have master volumes in my amps. PPIMV work great for me.

As I recently discovered, throwing any random tone stack and presence caps in is not a recipe for success. When I replaced my Mallory 150s and old Astron presence cap with Vishay polypropylene, my 1987 sounded MUCH better.

I've sampled 1987's and owned a 2203 but they both sound too 80ish for me. I also owned a JTM-45 and after rewiring the tone stack i got a really good clean sound but ultimately it didn't produce the overdrive tone I'm looking for.

I realize that Hendrix used the JTM45/100 before the Plexi and Page also used similar amps. But it appears the consensus goes with late 60's Plexi's as the basis for this tone but there are modifications in there that ultimately are needed to achieve this sound.

My question is, "What mods?"

[Colossal]

One thing to note on descriptives...the earlier classic tones where you hear what is referred to as "rawness" (I think KISS, I...(thunk)...wanna rock n' roll all night...), that can be achieved with a couple of warmer biased gain stages. The smoother, crunchy more modern sounds are typical of cooler biased stages cascaded.

For the Page tones, that is the realm of classic '68-71 Plexi but not a lot of gain. Stays warm and clear with that super-musical clank and punch. Don't forget HiWatt too.

[jckid649]

One thing to note on descriptives...the earlier classic tones where you hear what is referred to as "rawness" (I think KISS, I...(thunk)...wanna rock n' roll all night...), that can be achieved with a couple of warmer biased gain stages. The smoother, crunchy more modern sounds are typical of cooler biased stages cascaded.

For the Page tones, that is the realm of classic '68-71 Plexi but not a lot of gain. Stays warm and clear with that super-musical clank and punch. Don't forget HiWatt too.

That's what I'm talking about. But everyone I've talked to swears that you'll never get that sound out of a stock Marshall. Most of us are not gonna be able to own an original Plexi but I want to know what can I build and with what schematic, tube combo, bias setting, etc will achieve this.

[Colossal]

That's what I'm talking about. But everyone I've talked to swears that you'll never get that sound out of a stock Marshall.

"Everyone" is misinformed! Page played with high volume and not much gain. You can hear the fat, warm, woody knock of the cabinet. For his sound, one of the tricks is having that 5000pF bright cap over the Bright channel volume. Also, there was a difference in Plexi topologies:

Version 1 (earlier)
Bright Channel - 820R/680nF cathode -> 2n2 coupling cap
Normal Channel - 820R/250 or 330uF cathode -> 22n coupling cap

Version 2 (later)
Bright Channel - 2k7/680nF cathode -> 2n2 coupling cap
Normal Channel - 820R/250 or 330uF cathode -> 22n coupling cap

There is an audible difference in these. 820R is warmer biased, where the later version 2k7 is cooler and gives a slighter smoother, crunchier sound. You could certainly put these two values on a switch so you can switch from the '68 to '71 configuration. Then, set it and forget it as desired.

Most of us are not gonna be able to own an original Plexi but I want to know what can I build and with what schematic, tube combo, bias setting, etc will achieve this.

No need for an original, they are too much money for one worth having. To keep it clear, you don't need a lot of gain stages. Plexis just have the two followed by a cathode follower off V2a (820R or 820R/680n...make the 680n bypass cap switchable.

Getting a good transformer set is very important. It all starts there if you want to get the sound right.

[Reeltarded]

It's easy to get all these sounds from all of these amps at more volume.

Lots more.

[Colossal]

It's easy to get all these sounds from all of these amps at more volume.

Lots more.

Very true.

[jckid649]

But if you don't want a lot of gain then why a 5000pf? Wouldn't that make the gain more extreme like this video comparison of bright caps demonstrate?

https://www.youtube.com/watch?v=N1_P07w0RlY

[Colossal]

Yes, that cap will let a lot through, but just turn down the Bright Volume a little and there you go: Page tone. I put that cap on a pull-pot switch.

[Reeltarded]

The big HUGE bright cap and that channel is on between 3 and 4 and the tone controls are moderate and the sustain is all volume shaking the guitar and the amps are built like non-UL Majors with lots more headroom.

On a 2203 the master is on ten and the gain is on about 5 and the guitar volume knowb is lowered a lil.

[jckid649]

So is there an ideal schematic out there for a Plexi that would be good? What would be a good set of trannies for the build?

Also, what tubes are we talking? KT88's, EL34's

[Reeltarded]

69/70 era schematic with el34s. I am loathe to use other tube types for my own reasons.

[Colossal]

I would look into a set of Heyboer, Mercury, or Magnetic Components Plexi transformers. Stock Plexi voltages are around 460-475V on the plates. If you want a little more squish and compression, reduce that significantly. Definitely EL34s.