Chassis material and tone...anyone TRULY know?

[iknowjohnny]

Thru your own experience that is? has anyone built the same amp in both aluminum and steel, and if so what was the tonal difference? There are a lot of guys who swear theres a considerable difference in a non magnetic tele bridge and a magnetic one due to the way it interacts with the pickup. That being the case it would stand to reason a steel amp chassis should have a huge difference in tone over a aluminum one. But i think the only way to know is to do what i mentioned, so has anyone done that ?

[paulster]

I predict you'd find more difference between the two sets of components than between a steel and aluminium chassis so to do a true test you'd have to move all the boards between the two chassis and record a reamped track through each.

Otherwise it isn't a fair comparison.

[iknowjohnny]

I built 2 amps the exactly same except for layout differences and they sounded so close i could never tell the difference in a blind test. So unless theres not much difference between steel and alum, then i agree. But if it's at all significant then it should be obvious. I just can't imagine how it could NOT be considerable if teles change as noticeably as is said by many between magnetic and non magnetic bridges.

[Zippy]

Thru your own experience that is? has anyone built the same amp in both aluminum and steel, and if so what was the tonal difference? There are a lot of guys who swear theres a considerable difference in a non magnetic tele bridge and a magnetic one due to the way it interacts with the pickup.

1) A Tele is not an amp...

2) Are they actually comparing magnetic properties or are they comparing metals of varying mass/density that happen to have different magnetic properties?

[iknowjohnny]

Exactly, thats the point. A tele should see far far less change than an amp given you are only talking about the pickup's tonal change due to it's interaction or lack thereof with the bridge. (yes, mag vs non mag all else being equal) In a amp you have 2 to 3 trannys and who knows what else could be affected, tubes etc. I have a steel chassis amp, and granted it's different than my other ones but it's been thru a million changes and the others have even at one time or another been played with the same OT's and tubes and the entire preamp has been the same. But that amp always has a very different tone...different ballpark altogether. I DO believe there is *likely* a difference in steel vs aluminum. I'm not sure, but if i had to wager thats how i'd bet.

[Andy Le Blanc]

With HI-FI its more like the resolution of a picture, is it black and white newsprint
or is it full spread color glossy.

Its the chassis material, if its the only ground.

There's never a perfect ground.

[Cliff Schecht]

Whether or not you'll hear a difference really depends on the grounding scheme you use in the amp. If you're a chassis-based grounding scheme then the resistivity difference between aluminum and steel might be noticeable. Otherwise you probably won't notice a difference.

Steel amps with chassis-based grounding schemes I think are typically noisier because the higher chassis resistance equates to larger voltage noise induced in the ground. I've had problems in the past with this type of grounding scheme with a higher gain amp. Noise is a problem if you aren't careful about grounding (especially in the first stage)..

[Zippy]

Exactly, thats the point. A tele should see far far less change than an amp given you are only talking about the pickup's tonal change due to it's interaction or lack thereof with the bridge.

In a guitar pickup you are dealing with a magnetic transducer. The magnetic baseplate changes the shape of the flux field that is interacting with the movement of the string.

What is the analog in an amplifier?

[billyz]

Besides the grounding effect of Aluminum vs Steel chassis, there is a magnetic effect difference as well. Whether you hear it or not. Aluminum is more transparent to the many magnetic fields created inside an amplifier.

[Zippy]

What components are affected by this "magnetic effect difference"?

If it's real, I'd like to understand it.

[billyz]

http://en.wikipedia.org/wiki/Charged_particle

http://books.google.com/books?id=y0d9VA ... ts&f=false

http://sprott.physics.wisc.edu/demobook/chapter5.htm

food for thought.

I did not say you could hear it, maybe you can or can't. Maybe someone else does. Might depend on many factors, like frequency, volume, Effects( distortion, delay etc), speakers, room, your hearing.
Just because one person does not hear it, does not mean it does not exist. Even though the earth appears flat, it is a fact that it is not.

Also, you might prefer the sound of a steel chassis or copper for that matter, or all beer tastes the same.

[Zippy]

Do you have any information regarding the "magnetic effect" as applied to guitar amplifiers?

I understand the basics of magnetism and electricity - that's not at issue. My first degree was in applied physics, my graduate degrees are in materials science.

No wiki nor HAD, please. I'm looking facts, not just random reading material.

[paulster]

Whether or not you'll hear a difference really depends on the grounding scheme you use in the amp. If you're a chassis-based grounding scheme then the resistivity difference between aluminum and steel might be noticeable. Otherwise you probably won't notice a difference.

I'll add a big +1 for this and I should have mentioned it in my first post. If you want to hear the difference the materials make as a chassis then you want to ensure that you don't use a chassis grounding scheme, so you are comparing like with like.

As soon as you use a chassis grounding scheme the significantly different resistances of steel versus aluminium make the grounding scheme a component in its own right, so you'd be comparing the differences in resistance in your grounding scheme as well as the chassis material, rather than just the effect the chassis material has on tone.

[Zippy]

As soon as you use a chassis grounding scheme the significantly different resistances of steel versus aluminium make the grounding scheme a component in its own right, so you'd be comparing the differences in resistance in your grounding scheme as well as the chassis material, rather than just the effect the chassis material has on tone.

Or, that IS the effect that the chassis has on tone...

[Jana]

It's all about the Eddy currents (not the Eddie currents )