Jim Marshall, RIP

Gratuitous (and anonymous) Leo Fender bashing. But here is the prize sentence:

"After several false starts, the pair hit upon a remarkably powerful design with unprecedented distortion, volume, and a characteristic tone that had never been heard before."

Unprecedented distortion -- just what I look for in an amp.

Maybe just poor wording but in the 60's it may mean just what it says.

Tom

It's that "toob" sound ;-) ...Jim Thompson

--
| James E.Thompson, CTO                            |    mens     |
| Analog Innovations, Inc.                         |     et      |
| Analog/Mixed-Signal ASIC's and Discrete Systems  |    manus    |
| Phoenix, Arizona  85048    Skype: Contacts Only  |             |
| Voice:(480)460-2350  Fax: Available upon request |  Brass Rat  |
| E-mail Icon at http://www.analog-innovations.com |    1962     |
             
I love to cook with wine.     Sometimes I even put it in the food.

I once had a guitarist ask me, "Is there any way to get that cool sound all the time without always cranking up the volume?"

In a guitar amp? That's what makes Rock rock.

--
My liberal friends think I'm a conservative kook.
My conservative friends think I'm a liberal kook.
Why am I not happy that they have found common ground?

Tim Wescott, Communications, Control, Circuits & Software
http://www.wescottdesign.com

In the "boom-box" phase of my engineering career, I had requests for solid-amplifiers that sounded like a tube amplifier ;-) ...Jim Thompson

--
| James E.Thompson, CTO                            |    mens     |
| Analog Innovations, Inc.                         |     et      |
| Analog/Mixed-Signal ASIC's and Discrete Systems  |    manus    |
| Phoenix, Arizona  85048    Skype: Contacts Only  |             |
| Voice:(480)460-2350  Fax: Available upon request |  Brass Rat  |
| E-mail Icon at http://www.analog-innovations.com |    1962     |
             
I love to cook with wine.     Sometimes I even put it in the food.

You're obviously not guitarded.

-- Les Cargill (is guitarded)

Celestion drivers had small voice coils owing much to the Marshall sound.

Greg

Distortion is not (necessarily) a bad thing in rock amps. In fact, they use deliberate clipping to achieve the sound of an overdriven amp at (relatively) lower volumes. So that sentence may not have been a typo.

--
Hope not, lest ye be disappointed.
		-- M. Horner

ne

If the voice coil height was the same as the gap height, such that the number of lines of flux the coil intercepted was continually changing for large excursions, that would add quite a bit of distortion.

Tom Biasi wrote in news: snipped-for-privacy@4ax.com:

Rock guitarists overdrive the input to create distortion for a particular sound. for transistor amps,they used a "fuzzbox",with a footswitch for activation. transistor amps did not overdrive the same as tube amps.

--
Jim Yanik
jyanik
at
localnet
dot com

"spamtrap1888"

** The story in the " tinyurl " above is entirely false.

Wiki is a lot closer to the truth.

As a long time repairer of guitar amplifiers, I can safely state that at no time did the Marshall company ever show any sign of any expertise at either design or manufacture of value guitar amplifiers. This is still true today.

The original model was cobbled together by a drummer and two service techs - it was pretty horrible.

Later models incorporated several changes that made the design worse and very prone to self destruction.

Marshall's success in the marketplace was DESPITE the actual product, not because of it.

Endorsement from Jimi Hendrix and others was the main reason for any sales success.

AFAIK, Jim Marshall never took any credit for the designs nor accepted any blame for their many shortcomings either.

... Phil

This is arguably the finest thing I have read today. It's 100% true*. In a way, it's the ultimate tribute to Jim Marshall. But they were persnickety, temperamental beasts. Just the impedance switch mess alone

- one guitar player I knew kept no less than *three* in his kit bag - was some of the worst I've ever seen.

*and I lack Phil's exposure to the guts of one - this is just from knowing people who used them as tools.

If a Marshall could have leaked oil, it would have. Still, the 100 watt nonmaster volume models moved air in a very interesting way.

The first time I played with someone who had one is still a watershed.

The good ones make an *amazing* sound, for those of us who like that sort of thing. there's really nothing else like it.

i think a lot of what they got right wasn't so much the electronics as the cabinet/speaker combinations. 'Course, fender had pioneered the closed back cabinet before.

Interesting! Very astute of him.

-- Les Cargill

"Jim Yanik"

Tubes have a gradual saturation characteristic which makes for even harmonics. Solid state amps tend to brick wall saturate which give odd harmonics - that are much more harsh sounding. That's the way it was explained to me.

An electric guitar is a music instrument with two equally important parts, the human interface unit with strings attached and a signal processing unit (often with glowing tubes inside :-).

The signal produced by the human interface unit is very dry. and consists of 1-6 simultaneous tones.

The signal processing unit adds at least harmonics to these tones and also some intermodulation distortion, which usually falls on some pleasant notes due to the way the strings are tuned.

Using this electric guitar signal processing unit for vocals or even all signals from a band in a PA arrangement, is going to produce unpredictable and nasty sounding intermodulation products between all the input signals.

"Oppie"

** Completely WRONG !!!!!!!!!!!!!!!!

Push pull output stages ALL give odd harmonics, the even ones are all suppressed.

Stupid, stupid MYTH !!!

.... Phil

"Les Cargill"

** The famous "Marshall Sound" as achieved with the early JTM45 model was entirely due to the use of four 12 inch, 15 watt rated Celestion "guitar" speakers in a closed, un-lined plywood box of a good size.

The acoustic resonance effects with such a large box combined with a generous cone area and very efficient drivers meant it made a whole heap more noise than the Fender Bassman ( 4 x 10 inch, open back ) model that had been copied.

In the mid range, the cab would have output about 110 dB SPL for each watt of input.

When two such cabs are stacked with a 100 watt amp on top, you have the famous Marshall roar.

** Common sense really.

... Phil

At the same time, the Bassman evolved into a stiffer amplifier against a closed back box. As I've seen the story, the interesting thing was the "arms race" between what Fender and Marshall could do over a short span of time.

They still more or less do.

I always found that people playing with the edge of that roar were more interesting.

Common sense is most uncommon. Here's to Jim Marshall.

-- Les Cargill

Not what I would look for in an op-amp, but certainly it can be a positive thing in a guitar amp. In that application, the amp is part of the instrument, and "straight wires with gain" don't add much to the sound".