Mc2300 Peak Limiter Theory - REVISITED

[strumminsix]

Very cool, Brad! I still think you need some cab & mic & air modeling in that sweet preamp of yours!

PS - did you ever get our question answered?

[mijknahs]

Brad,

Why not just make a clone of an old MC-50?


Jim

[jdsmodulus]

If were going to ask for clones, I will just say that Brad if you make a MC2300 clone for under 1000$ I will place my order now.

[Rusty the Scoob]

If were going to ask for clones, I will just say that Brad if you make a MC2300 clone for under 1000$ I will place my order now.

Me too! 600 watts is right about where I'd like to be. I'm using every inch of my 350 right now just to keep up as a stage monitor. But please, please don't sell them to guitar players! Especially now that we know we have to push them hard to get the sound.

[Mick]

I remember reading somewhere about the US military freaking out because it needed MC2300s but the Grateful Dead had reserved them all for the Wall of Sound and wouldn't part with any of them.

That's nothing. I think it was in '78, I ran into some cats from the planet Floopular in the parking lot of a show in Andover and they told me Jerry had stolen all of the good solos from their planet and they were there to try to get them back. Freaky stuff man...

[mijknahs]

Check out this '84 clip. I love the tone of the solo. This is the clipping sound we're talking about. No effects. Just "clean" guitar.

http://www.youtube.com/watch?v=RJcGldd2Z2I

Jim

[waldo041]

the drummer kit swap is pretty cool also! never seen(noticed) that before, happens towards the end of that video.

peace,
waldo

[SarnoMusicSolutions]

That definitely is the "clean dirt" that interests me the most. I spent the better part of last week in the shop doing all kinds of tests; clipping my little Mc250 and analyzing the distortion, playing a Mc2300 loud but lean, running the tube preamp clean AND dirty, Dimarzio Dual Sounds and Super II's, etc.

One conclusion I keep coming to time and time again is that it's gotta be the sound of his transistor Mac being overdriven. If I generate any significant tube clipping in the preamp section, the sound just isn't right. It loses that crisp percussive punch and presence and gets too gushy and soft and a bit dark and "messy" in the high end. Preamp clipping sounds to "splatty" and soft. It has me convinced that this sound we're hearing is very much about the preamp running clean with headroom and mostly providing that sweet and warm natural "clean" tube harmonic distortion, but not the kind you get from overdrive. I'm still holding pretty firm to what Healy has said, that the McIntosh was driven into clipping and hitting the JBL's pretty hard. That dirt you hear in this '84 link, I think, is coming from a VERY driven Mac. '84 for some reason seems to be about the dirtiest Jerry tended to get with that rig. '83 and '85 too. He cleaned it up a bit in the later '80s and onward. I think it's just a matter of him cranking things up and making that Mac get dirty. It's like he used the Mac as if it was a tube amp and just cranked it up and beat on it. With my gear, that's the closest I'm able to get. I think we're hearing power transistors distorting, and also maybe the JBL's giving off some character from being pushed a bit. The E120's which he apparently had in '84, should have easily handled his approximately 250 to 340 watts. I wonder if the extra dirt in this mid/early '80s comes from the E120's being able to handle more power and distortion from the Mac where the weaker K120's would have more easily blown. And Jerry knowing that the E120's could handle it gave him the confidence to push things harder and dirtier than he used to. I also wonder if Jerry's extreme usage around that time had something to do with the loudness. Those were dark times as I understand it. Killer jams and great playing though.

Brad

[mijknahs]

It's a killer sound however he got it.

[SarnoMusicSolutions]

No doubt! But I can't help wanting to know how he did it. Beyond, of course, his fabulous guitar playing.

Brad

[jdsmodulus]

I want to know as much as possible on this subject! Thanks already for the incredible whealth of info.

[tdub]

Terrific discussion. While I wait giddily for my SMS pre and McIntosh MC 250, I am pondering what it may take to achieve the grit and hair---without being tossed out of a mid-size club or the practice room. So many vexing theories... It sounds as if Jer's was acheived by pushing the JBLs pretty hard WITH his masterful pick attack and technique and the Mc going pretty full on.

From here in the realm of the great unwashed, I am pretty damned sure I will never have his dynamic sense down, but wondering what may work best with this setup. Obviously working on technique, but how to push a JBL without killing myself or anyone else. Starve the pre a bit and push the Mc into the JBL? Or push the pre and go moderately on the Mc and JBL.

I know, I know... I'll know it when I hear it, no doubt. Lots of factors in play.

Thanks for the insight, though.

[NeebruM]

The early 2300's did have sentry guard, but NOT power guard. I had one for 30+ years, bought around the same time as Jerry's. Sentry guard was a circuit breaker.

From McIntosh:

Power Guard, a McIntosh circuit innovation, maximizes sound quality at high power levels while our Sentry Monitor feature provides continuous short circuit protection of the amplifier and connected loudspeakers.

The amp didn't clip per the lab tests until output of over 480 watts per channel!

I think much of Jerry's sound was from a mostly clean Fender put through all those watts into at most 4 JBL's and usually 3!

The amp was designed for 8 12's, 2 mid ranges and 2 tweeter arrays for the ML4 speaker system.

I think most of what you heard was the MAJOR amplifying of the preamp tubes, for the most part, but I stand to learn otherwise...

Oh, and the order that the CIA (or whoever) was beat out of was for the even MORE massive 2500's, I think they were called, though the "Navy" got some 2300's too...

Here is ton's of McIntosh info. You probably have this already but some may not:
http://www.roger-russell.com/aboutmc.htm

Oh, and from 1st hand experience back stage AND front, the Mac's were always on 3:00 or higher AND each one had names: bertha, sally, cindy, etc...

[waldo041]

The early 2300's did have sentry guard, but NOT power guard. I had one for 30+ years, bought around the same time as Jerry's. Sentry guard was a circuit breaker.

this we know, and have stated in our discussions, but those are maybe in the other threads. the mc2300 was the last line of macs NOT to get the power guard.

and the sentry monitor is not a circuit breaker, It is a common VI current limiter.

The amp was designed for 8 12's, 2 mid ranges and 2 tweeter arrays for the ML4 speaker system..

this is how the GD used the 2 mc2300's in jerry's Wall of Sound rig. just Prior he only used one for the 8 -12"

I think most of what you heard was the MAJOR amplifying of the preamp tubes, for the most part, but I stand to learn otherwise... .

this is without doubt a correct statement. but the talk here is about the removal of said Sentry Monitor, which would allow Jerry to actually reach the clip point and saturate those transistors. with the Sentry Monitor, it is current limited to a threshhold as that is the function of a VI current limiter. Although mcintosh states this is only for severe shorts during operation, but it does do something to those transient peaks that clip that threshhold. HEALY stated that there was no limiter on the driver cards they used. he also hand matched the transistors to include the drivers on the heatsinks of the driver cards and the emitter resistors. these were not stock mc2300 they used during the WOS, and jerry's was the same one he used from the WOS.

Oh, and the order that the CIA (or whoever) was beat out of was for the even MORE massive 2500's, I think they were called, though the "Navy" got some 2300's too...

actually this is all wrong, it was the MC3500 tube amps the navy tried to get from the GD. later as healy stated, it was the gd that had to wait for the military to get there production runs over for the mc2300 as well as spare parts. i guess a lessoned learned by not letting them get a couple of the mc3500's when they asked. LOL

Oh, and from 1st hand experience back stage AND front, the Mac's were always on 3:00 or higher AND each one had names: bertha, sally, cindy, etc...

this must be from the WOS days, as jerry ran his rig with the single mc2300 a tad or 2 higher. i wonder which one jerry kept!

peace,
waldo

[mijknahs]

Maybe when Healy said the MC2300 didn't have the Sentry Monitor he really meant to say it didn't have the Power Guard. His is getting old ya know. Why wouldn't McIntosh build a MC2300 without the Sentry Monitor anyway? Is there any confirmation from McIntosh that they released any MC2300s without the Sentry Monitor circuit or did Healy say that they removed it after they got it?

Jim