The sound of chassis? - Page 18

DF96 · 16th December 2011, 07:12 PM

Might do. Aluminium might be OK too. You can think of steel as acting like a pipe to transfer magnetic flux from here to there, thus coupling circuits which are separated in space. Reducing loop area at both ends will help too.

Magz · 16th December 2011, 07:20 PM

I'll probably end up doing what I should have done in the first place, which is build a separate power supply box using a real center-tapped transformer and diode bridge to supply the +/- 18V required, instead of the wall wart/ voltage doubler setup that came stock.

misok · 13th January 2013, 04:48 PM

I'd just like to briefly contribute with my little experience.

The preamp i've made was firstly done on a wooden frame with relatively thin copper top plate. Then i changed the top for a thick pine board as the copper and was very touch sensitive (microphonics) and not very stiff because it was thin.

Change in sound was quite apparent and i cannot describe it in terms or good/bad. Surely the first one sounded more metallic with shimmering highs. Not necessarily bad, for example trumpets were amazing, so real. Pipe organs were 'ringing' more. The wooden version removed this bite and made everything more smoothed out and 'theoretically correct' soundwise, more universal, balanced.

Oh and i'm talking about near field listening, no ground shaking stuff.

GoatGuy · 13th January 2013, 05:12 PM

Of interest - research we did at the materials science lab in the 1970s showed that one of the single most effective dampened plate designs was a pair of thin high-tensile aluminum sheets, as the outer sandwich having a filling of clay-impregnated silicone (setting) putty. Clay about 1/3 by weight. We mixed it using a glazers trowel directly on the bottom plate, then spread it (by trowel) out to about 1 mm thick, as uniformly as possible. To apply the top plate, it was alcohol and methyl-ethyl-ketone cleaned first (as was the bottom plate, MEK from ACE hardware), and very slightly bent into a curved form. Doing so allowed one edge to be clamped down, then the other (curved up a few centimeters) pressed down and again clamped. To cause the silicone to cure, just before clamping, we sprayed it with a woman's perfume atomizer, with ordinary water. Very little. 1/50th the amount of the silicone.

The plates of course overnight were bonded. They became as "dead as lead", yet had the strength and resilience of the aluminum.

Mercedes Benz, Boeing, McDonald-Douglas, Toyota and quite a few Japanese elevator manufacturers consider it now to be their "proprietary/patented" technology. This doesn't prevent it from being used for OTHER purposes though, especially microphonics reduction.

GoatGuy

Loren42 · 13th January 2013, 09:45 PM

Aluminum makes a more ringing sound.

Steel, even more so.

Wood makes a dull thud when hit.

Glass makes an interesting sound, but only once.

Kay Pirinha · 14th January 2013, 10:53 AM

The most ringing, even chiming sound undoubtedly can be expected from bell-founding brass :-).

Best regards!

misok · 14th January 2013, 02:16 PM

indeed. there is no universal system that can do everything the best. people often talk about 'fidelity', original information on the medium etc.. and it all becomes irrelevant once we want to transform it to mechanical waves.

long ago i experimented with cheap stick-on transducers. in general the complex sound was rubbish of course, but when i put it on acoustic guitar and played Paco de Lucia or even solo violin tracks, it was unbeatable since my guitar physically played it. im still planning to make some dedicated speakers for wooden acoustic instruments as well as for brass, just for special occasions. to some extent its the same for chassis as i see it. but of course, there are many things that 'matter' more for sure.

Kay Pirinha · 16th January 2013, 03:38 PM

Well, this is not what I meant.

Talking about the "sound" of certain chassis materials sounds more than eccentric, even esoteric to me, as I bet that no physical or chemical parameters related to chassis materials are reliably (!) proven to have any influence on the "sound" of an amplifier at all. A chassis' only duties are to provide mechanical stability and electro-magnetic screening.

Best regards!

misok · 16th January 2013, 03:55 PM

Quote:

Originally Posted by Kay Pirinha

Well, this is not what I meant.

Talking about the "sound" of certain chassis materials sounds more than eccentric, even esoteric to me, as I bet that no physical or chemical parameters related to chassis materials are reliably (!) proven to have any influence on the "sound" of an amplifier at all. A chassis' only duties are to provide mechanical stability and electro-magnetic screening.

Best regards!

hi Kay,
i was thinking like this for years and i still accent importance of another factors contributing to sound, but we cannot overlook the phenomenon of microphonics, especially with tubes and capacitors. I realized it on my chassis rebuild described above and i wasn't expecting anything sound-wise (i just wanted more rigid chassis) so no mind programming took place. I'm not over-emphasizing it though..

Kay Pirinha · 16th January 2013, 03:58 PM

Yes! This is exactly what I meant with "mechanical stability".

Best regards!

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16th December 2011, 07:12 PM	#171
DF96 diyAudio Member Join Date: May 2007	Might do. Aluminium might be OK too. You can think of steel as acting like a pipe to transfer magnetic flux from here to there, thus coupling circuits which are separated in space. Reducing loop area at both ends will help too.

16th December 2011, 07:20 PM	#172
Magz diyAudio Member Join Date: Oct 2009 Location: New Jersey, USA	I'll probably end up doing what I should have done in the first place, which is build a separate power supply box using a real center-tapped transformer and diode bridge to supply the +/- 18V required, instead of the wall wart/ voltage doubler setup that came stock.

13th January 2013, 04:48 PM	#173
misok diyAudio Member Join Date: Oct 2012	I'd just like to briefly contribute with my little experience. The preamp i've made was firstly done on a wooden frame with relatively thin copper top plate. Then i changed the top for a thick pine board as the copper and was very touch sensitive (microphonics) and not very stiff because it was thin. Change in sound was quite apparent and i cannot describe it in terms or good/bad. Surely the first one sounded more metallic with shimmering highs. Not necessarily bad, for example trumpets were amazing, so real. Pipe organs were 'ringing' more. The wooden version removed this bite and made everything more smoothed out and 'theoretically correct' soundwise, more universal, balanced. Oh and i'm talking about near field listening, no ground shaking stuff.

13th January 2013, 05:12 PM	#174
GoatGuy diyAudio Member Join Date: Dec 2012 Location: SF Bay Area	Of interest - research we did at the materials science lab in the 1970s showed that one of the single most effective dampened plate designs was a pair of thin high-tensile aluminum sheets, as the outer sandwich having a filling of clay-impregnated silicone (setting) putty. Clay about 1/3 by weight. We mixed it using a glazers trowel directly on the bottom plate, then spread it (by trowel) out to about 1 mm thick, as uniformly as possible. To apply the top plate, it was alcohol and methyl-ethyl-ketone cleaned first (as was the bottom plate, MEK from ACE hardware), and very slightly bent into a curved form. Doing so allowed one edge to be clamped down, then the other (curved up a few centimeters) pressed down and again clamped. To cause the silicone to cure, just before clamping, we sprayed it with a woman's perfume atomizer, with ordinary water. Very little. 1/50th the amount of the silicone. The plates of course overnight were bonded. They became as "dead as lead", yet had the strength and resilience of the aluminum. Mercedes Benz, Boeing, McDonald-Douglas, Toyota and quite a few Japanese elevator manufacturers consider it now to be their "proprietary/patented" technology. This doesn't prevent it from being used for OTHER purposes though, especially microphonics reduction. GoatGuy

13th January 2013, 09:45 PM	#175
Loren42 diyAudio Member Join Date: Sep 2008 Location: "Space Coast" Florida, USA	Aluminum makes a more ringing sound. Steel, even more so. Wood makes a dull thud when hit. Glass makes an interesting sound, but only once.

14th January 2013, 10:53 AM	#176
Kay Pirinha diyAudio Member Join Date: Oct 2011 Location: Tauberbischofsheim, Germany	The most ringing, even chiming sound undoubtedly can be expected from bell-founding brass :-). Best regards!

14th January 2013, 02:16 PM	#177
misok diyAudio Member Join Date: Oct 2012	indeed. there is no universal system that can do everything the best. people often talk about 'fidelity', original information on the medium etc.. and it all becomes irrelevant once we want to transform it to mechanical waves. long ago i experimented with cheap stick-on transducers. in general the complex sound was rubbish of course, but when i put it on acoustic guitar and played Paco de Lucia or even solo violin tracks, it was unbeatable since my guitar physically played it. im still planning to make some dedicated speakers for wooden acoustic instruments as well as for brass, just for special occasions. to some extent its the same for chassis as i see it. but of course, there are many things that 'matter' more for sure.

16th January 2013, 03:38 PM	#178
Kay Pirinha diyAudio Member Join Date: Oct 2011 Location: Tauberbischofsheim, Germany	Well, this is not what I meant. Talking about the "sound" of certain chassis materials sounds more than eccentric, even esoteric to me, as I bet that no physical or chemical parameters related to chassis materials are reliably (!) proven to have any influence on the "sound" of an amplifier at all. A chassis' only duties are to provide mechanical stability and electro-magnetic screening. Best regards!

16th January 2013, 03:58 PM	#180
Kay Pirinha diyAudio Member Join Date: Oct 2011 Location: Tauberbischofsheim, Germany	Yes! This is exactly what I meant with "mechanical stability". Best regards!