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Chat about Equipment Info

 #44836  by jenkins
 Tue Jun 10, 2008 8:58 am
[quote="jeffm725"]dont forget.............the following....people who are much more versed in the inner workings of the Mac and preamped twins than Iam swear by the notion that an often overlooked ingredient of Jer's rig/sound was that he was driving the Mac at 2.66 ohms instead of 4, by using 3 8 OHM JBL's wired in Parallel.

quote]
I think it is the macintosh's limiter circuit which was one of the key's to garcia's tone. He was driving the mac to the point of clipping which was causing the limiter circuit to be activated, which is basically a hi-fi compressor-limiter.
What I've read it seems like this had a way bigger effects on is tone than the fact taht his speakers were mismatched.

The mac have an autoformer circuit which means you can plug any ohm speakers into any ohm taps. On my mac I run 8ohm speaers attached to the 4 ohm tap. The only reason I do this is because the way my speaker wire is configured it makes it easier. Beside, it has an autoformer so matching up the ohms really isn't taht important at all.
I hear absolutly no difference in tone when I am plugged into the correct tap or the wrong tap. Same volume, same lack of distortion, same everything.

But when I get the volume up so that the clip lights are firing when I hit my loud notes, thats when mcintosh really shines.

 #44990  by RiverRat
 Sun Jun 15, 2008 6:20 am
x
Last edited by RiverRat on Tue Feb 22, 2011 10:06 am, edited 1 time in total.

 #45005  by tigerstrat
 Mon Jun 16, 2008 9:53 am
RiverRat wrote:Jeff may be right about the impendence of Jerry's rig but you could easily achieve a similiar load by using an Attenuater or Dummy load (MY, I think I had a discussion with you about this a couple years ago. when you were building your smaller rig and were concerned about tone and performance)
There could be something to the impedance of 3 JBL's creating a certain sound, but that would mean Garcia got different signature Garcia tones when using 4 JBLs (late 70's/early 80's) or 2 JBLs (1991).

 #45011  by jenkins
 Mon Jun 16, 2008 11:34 am
in the mcintosh owner's manual it clearly states taht you can mismatch speaker loads with no bad effects. That is waht the autoformer is for.
The way im running it, using a 8 ohm spekares in the 4 ohm tap is completly fine. It sounds great

 #45024  by RiverRat
 Mon Jun 16, 2008 1:03 pm
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Last edited by RiverRat on Tue Feb 22, 2011 3:55 pm, edited 1 time in total.

 #45031  by tigerstrat
 Mon Jun 16, 2008 3:35 pm
RiverRat wrote:The key points:
The amp is designed for an optimal 2.1 Ohm load... Probably why the 3 JBL's were utilized initially during the Wall of Sound era, then increased post Wall as the road crew got familiar with how the amps performed on the road,
Can you clarify that statement? Especially "3 JBL's were utilized initially during the Wall of Sound era" ? Because afaik, at the onset of WOS-era, three B-12(2x12) cabinets were used. By the time the WOS was "official" Jerry was using 9 or 10 B-12's, a freekin skyscraper of 20 JBL D-120's. The 3x12 cabinet became standard for him in late 82 or early 83 iirc

 #45032  by tigerstrat
 Mon Jun 16, 2008 3:51 pm
Interesting site Roger has. Couldn't find any references to the GD or Wall of Sound. Did enjoy this page- some clever, very dry humor: http://www.roger-russell.com/notone/notone.htm :lol:

 #45321  by tigerstrat
 Mon Jun 23, 2008 7:53 am
tigerstrat wrote:
RiverRat wrote:Jeff may be right about the impendence of Jerry's rig but you could easily achieve a similiar load by using an Attenuater or Dummy load (MY, I think I had a discussion with you about this a couple years ago. when you were building your smaller rig and were concerned about tone and performance)
There could be something to the impedance of 3 JBL's creating a certain sound, but that would mean Garcia got different signature Garcia tones when using 4 JBLs (late 70's/early 80's) or 2 JBLs (1991).
Perhaps the implication is that during the 4x12 cab years of 77-83, one of the JBL's wasn't wired? Which would jibe nicely with that one crazy 1983 picture with the reversed driver ... and perhaps during 1991, a dummy 8ohm load was added to the 2x12 to keep the Mac at the magical 2.66ohm?
 #45349  by hard truckers co
 Tue Jun 24, 2008 4:21 am
Hey Guys....

Most of the time that Jerry ran his 3x12 cabinet there was a 4th speaker in a 1x12 cabinet that was running behind the stage so that Steve, Ramrod and everyone else would have their own Garcia Monitor backstage. While this wasnt a hard and fast rule it was true more often than not. According to Big Steve it had nothing to do with running at 2.6 or 2.0 ohms. The crew just wanted to hear Garcia clearly. They had no reason to believe one ohmage ran better than the other.

Straight from the horses mouth...
peace
glenn
 #45356  by tigerstrat
 Tue Jun 24, 2008 12:26 pm
hard truckers co wrote:Hey Guys....

Most of the time that Jerry ran his 3x12 cabinet there was a 4th speaker in a 1x12 cabinet that was running behind the stage so that Steve, Ramrod and everyone else would have their own Garcia Monitor backstage. While this wasnt a hard and fast rule it was true more often than not. According to Big Steve it had nothing to do with running at 2.6 or 2.0 ohms. The crew just wanted to hear Garcia clearly. They had no reason to believe one ohmage ran better than the other.

Straight from the horses mouth...
peace
glenn
Thanks Glenn. And that's really neat to think the crew would add extra gear to the equation just so THEY could hear The Man during the show.

 #45357  by Tennessee Jedi
 Tue Jun 24, 2008 12:29 pm
I always wanted to be one of those guys up in the lights controlling the spotlights and stuff ...
Just smoking and jamming to the Boys ....
Great seat .....
:smile: