Grateful Dead Music Forum

RiverRat wrote:

tigerstrat wrote:

SarnoMusicSolutions wrote: Also, Healy said that it's likely that another factor in Jerry's sound is not only the McIntosh being pushed, but also the speakers themselves being pushed real hard, magnets and coils beginning to saturate and even perhaps distort a bit too. All that alchemy will be hard to exactly duplicate, but maybe we can get something so close that it's good enough for most of us.

I get more of a sense or a hint of some slight speaker loading when running the octave fx and the Mutron.

The load does not change. You are hearing either an increase in gain, or some distortion in the source signal. The load is the speaker, the pedal is just part of the source chain. signal flow source to load, so loading is the reverse... You load the source.

Right, I wasn't talking about impedance changes (or claiming to be able hear them), simply misusing the word "loading" when I really meant being "pushed", as Brad had put it. And of course when you do start engaging FX like the Mu, or Octo-what-have-you or both, it becomes pretty difficult to try to pinpoint the sources of distortions elsewhere in the rig!

SarnoMusicSolutions wrote:According to Roger Russell, the autoformer is there to match impedances so that full power can be delivered to various loads. While the amp at its core (with no autoformer) may be designed to drive 2 ohms, the autoformer allows for full power matching to the other load options.

Roger said: "Full continuous amplifier power could be delivered to each of these loads."

The consistent loading allows for best ratio of output power to dissipated power.

"As power is reduced, efficiency is also reduced, and output device dissipation increases until a critical point is reached, after which it again falls with falling output power."

The autoformer allows for maximum efficiency, dissipating fewer Watts as BTU's and allowing for more Watts to Db SPL.

Most modern solid state amps reflect this, you see that as the impedance increased by a factor of 2, the output power typically decreasing by a factor somewhat great than 2. The additional power loss is dissipated heat.

This may not be based on the McIntosh, but my friend TC Furlong in Chicago, who is also the region's largest Meyer Sound dealer, also happens to be a steel guitar enthusiast. TC has been making powered speaker cabinets for pedal steelers to go in conjunction with my tube preamps. More recently he's developed these combo cab's that house my preamp as well as his high-end, audiophile class-D switching power amps. These things are 500 watts into 4 ohms, and 300 watts into 8. Very, very light weight combos. With the SMS Classic, they sound like a cleanly run Twin or Deluxe on steroids.

This is the 15" K130 version, but he now makes a smaller 12" combo that's just a hair larger than a Deluxe Reverb.

Brad