The Marshall amplifier gave birth to Pete Townshend’s power pop jangle with The Who, Eric Clapton’s voice-like electric blues with Cream, Duane Allman’s country/rock hybrid with the Allman Brothers Band, Slash’s dirty and mean streets of Los Angeles tone with Guns ‘n’ Roses, and perhaps most famously, the psychedelic shaman of the electric guitar himself, the original user and abuser of the “Marshall stack,” Jimi Hendrix.

Marshall amplifiers are the great equalizer of rock and roll. From dirty basement clubs with a dozen people in the audience to tens of thousands of people packed into the biggest stadiums in the world, chances are good that if you walk away with a ringing in your ears it’s because someone turned their Marshall up to “11.”

The Marshall sound is inimitable their look is classic. Without shadow of exaggeration or embellishment, it can be said that Marshall amplifiers are the voice of rock and roll electric guitar. Without Jim Marshall’s amps the sound of rock and roll would not be the same. The Marshall amplifier is the muscle of rock and roll.

Let’s pause for a moment of silence to remember ‘the father of loud,” Jim Marshall.

Now, let’s turn it up. That’s what Jim would want. He would want us to turn up the amps, and lost in the sound of the almighty Marshall amplifier.

James Charles Marshall.
1923 – 2012.

By Damian Master

Frank Werner, owner of On Stage Services, was fortunate to have met Jim at the 2002 NAMM show.

Gin Blossoms and Tonic, Val Du Lakes, MI

Gin Blossoms sound check, Val Du Lakes, MI

Val Du Lakes at night

Electric Junkyad Gamelan, One Trick Pony, Grand Rapids, MI

Dublin Irish Festival

Tiesto, Electric Forest Festival

Tripolee Stage, Electric Forest Festival

Tripolee Stage, Electric Forest Festival

Dog Look A-Like Contest, Laugh Fest

Pat Benatar

Paul Rodgers

REO Speedwagon

Secondhand Serenade, Art Prize 2011, Grand Rapids, MI

Loading in backline, National Catholic Youth Conference

The main stage, National Catholic Youth Conference

The main stage, National Catholic Youth Conference

New Year's Eve, Grand Rapids, MI

New Year's Eve, Grand Rapids, MI

New Year's Eve, Grand Rapids, MI

Fender Super Reverb Restoration

When tubes go bad.

This is not a good tube.

Marshall JCM800 in for repair.

Tung Sol EL34 power tubes.

1965 Fender Pro-Reverb

Packing for a big rock show.

What brand of tubes are the worst? This shows defective tubes that where pulled out of tube amps over the course of one year. They are mostly out of guitar amps.

6L6 Power Tube Types

We found that the Groove Tubes were mostly out of Fender amps and the tubes themselves had many more years than the other brands. These were typically the tubes that the guitarist had in their amp since they bought it. The Groove Tubes GT6L6B are Sovtek 5881WXT.

EL34 Power Tube Types

The Winged C tubes were all labeled Marshall and were the original tubes that came with the Marshall amps.

6550 Power Tube Types

These are mostly from Ampeg SVT bass amps. Winged C 6550 tubs were a very popular choice for replacement tubes. Note that there aren't any defective Winged C tubes in the list. Electro-Harmonix was also a popular choice.
Sovtek, Groove Tubes, Fender, or Mesa-Boogie?
Notice the white debris, that's from the plate. It's time to change your tubes when you see this.

I get this question quite often. Although we don’t mind the business we would rather have our customers understand how to not blow up their equipment.

The Problem: Blown Highs
Why does this happen? A simple answer is excessive heat…we see a lot of burned voice coils. Excessive heat on a voice coil is the result of distortion or clipping in an amp or mixer. Usually we find that the customer has not matched the amp to the speakers. I know this is a common mistake; even the sales guy at the music store doesn’t know how to match an amp to your speakers…a good reason to do some homework before you buy a sound system. Improper gain structure is also to blame in many situations. When you have poor gain structure starting at the mixer then everything else in your chain is going to get an ugly signal. The speakers are the last component in the signal chain and therefore will suffer the most. The woofer is a bit sturdier than the high frequency diaphragm so that is why it probably didn’t blow…yet. If you are coming close to the clip light coming on then it may be time to reconsider your current setup.

The Solution: Match the amp to the speakers.
There are other scenarios that can blow your speakers but we’re going to focus on amp and speaker matching in this article. This problem seems to be the biggest one.

The incorrect way… you buy a speaker that is 800 watts program and a 700 watt amp and you figure the extra 100 watts is a cushion. Well, I thought that too at first, but your amp will clip long before the speaker reaches its peak power handling. The peak power handling of a speaker is usually twice the program watts. So this speaker that is 800 watts program and 1600 watts peak will handle peaks of up to 1600 watts. Back to the amp: it is clipping at 700 watts. Whether the clip light is on or not you may be sending peak signals to your amp causing clipping. That will start to overheat the voice coils in your speakers.

The correct way is to find out the program watts and peak watts of the speaker. Then multiply the program watts times 1.5 or 2 to find out how much amplification you need.

Speaker Program Watts x 1.5 = Amplifier Watts

For example: 800 watts program (at 8 ohms) x 1.5 = 1200 watt amplifier (at 8 ohms)

The impedance or ohms is extremely important. If you can’t find the specs on a speaker, don’t buy it. I get my info from the people who make the speakers, they do tons of research. Here is some info from JBL on this subject.

“All loudspeakers are capable of sustaining short peaks of power much higher than they can sustain on a steady, continuous basis, and the proper choice of amplifier is quite dependent on the loudspeaker’s ability to do this.”
– Speaker Power Requirements by JBL Pro

Some real world examples:

Peavey SP4 - 2000 watts program/4000 watts peak
2000 watts program (4 ohm) x 1.5 = 3000 watts
This means you will need a 3000 watt per channel amp if you have two speakers. The Peavey CS3000 produces 3100 watts at 4 ohms in bridged-mono.

JBL SRX722 - 1600 watts program/3200 watts peak
1600 watts program (8 ohm) x 1.5 = 2400 watts
This means you will need a 2400 watt per channel amp if you have two speakers. The Crown XTi 4000 puts out 2400 watts at 8 ohms in bridged-mono.

It’s no surprise that the amps match up so nicely, they are designed this way. If you run your speakers with the correct amp they will sound better too. Here are a couple places that have good information and advice for powering your speakers effectively:

JBL Professional has very good information on this subject.
Danger: Low Power (PDF File) (PDF file)
Speaker Power Requirements (PDF File) (PDF file)

Peavey also has some great info on this subject and many others.
Top 10 Ways To "TOAST" Speakers and Diaphragms

Crown Audio has some great online calculators for this as well.
Crown Audio Design Tools

I’m sure anyone with a television or computer has been watching the devastating floods in Nashville this past week. Fortunately for us , our family that lives just outside of the city was on high enough ground that the only effects it had on them was the inconvenience of traffic jams , and longer lines at the grocery store. For many others within the flood plain itself, we’ve seen images of everything from flooded homes, heroic rescues in make shift boats and on the lighter side, younger folks wake boarding behind SUV’s. You gotta love that!

Beside the obvious loss of property and mental anguish, and being that this is happening in Nashville or Music City as it is known to most industry peeps , the entertainment business has been greatly affected as well.

I watched a CNN interview with Keith Urban this morning and he pointed out how his people “couldn’t get trucks in” to the facility that stores his stage gear. The facility he’s speaking of is Sound Check and is also known for its sound stages and entertainer support services.

Sound Check is located near LP Field where the NFLs Titan’s play. Situated on the east side of the Cumberland river , Sound Check is just down the street on the same side of the river.

Please see this story that came out today. http://www.comcast.net/articles/music/20100505/US.Tennessee.Floods.Musical.Mess

Sound Check also stores equipment for some familiar names like Vince Gill, Brad Paisley and Little Big Town as Urban points out in this conversation. It is noted that Urban may have lost his road equipment that includes vintage guitar amplifiers and many guitars seen on his tours.

In the wake of this emotionally turbulent and tragic situation, On Stage Services is making a trip down to Nashville this weekend to offer our resources to our friends in our industry. We all feel like we need to do something to help our industry brethren. Please say a prayer for those whom have suffered so greatly during this very unfortunate event.