The Audiophoolery Thread.

[wd40addict]

Time for a resurrection of the Auxetophone!

http://www.douglas-self.com/MUSEUM/COMMS/auxetophone/auxetoph.htm

https://youtu.be/J7SV65DFNy8

[Craig Sawyers]

Originally Posted by Refugee

Hydraulic acoustics are real.
They do a few Hz to about 300Hz and are used for geological surveys.
The rams that act as voice coils are about 6 foot long and are mounted on an eight wheel drive truck.

Yup - I knew that before I posted my tongue-in-cheek about hydraulic amplifiers ;-)

Craig

[Craig Sawyers]

Originally Posted by wd40addict

Time for a resurrection of the Auxetophone!

http://www.douglas-self.com/MUSEUM/COMMS/auxetophone/auxetoph.htm

https://youtu.be/J7SV65DFNy8

Good heavens! That is a serious beast of a technology. "Audible for four miles". Almost makes you want to build one.

Hey - it would make a really daft car horn!

Taking that as a lead, a guy from Australia who was posting on a Jaguar forum I was admin for, described his younger self installing a locomotive horn under the bonnet of his old Holden. Apparently when he pressed the horn button it took so much current the car slowed down.

Craig

Craig

[stacman]

Earth shaking bass then....and the ‘home’ version, the Buttkicker.

[Radio Wrangler]

How long before someone brings out special audiophile-grade hydraulic pipes?

David

[Al (astral highway)]

I’ve just found a giant gap in the market! Yay! £££& coming my way! With such ‘dirty’ and underpowered 240V AC colts coming in to your fine rhodium/platinum power lead, what’s needed is something more robust.

I will be boxing up and badging as ‘audiophile’ a fantastic new power- supply which — wait for it- runs from three-phase and provides clean and powerful power where it’s needed. A group of 100A-capable bridge rectifiers is followed by a bank 12,000 uF of EPCOS capacitors, providing a crystal clear and yet fully muscular energy to the amplifier. Why, you could even DJ at Glastonbury with this wonder.

And this beauty will retail for only £999 monies.

[bikerhifinut]

Originally Posted by Radio Wrangler

I think the key to understanding audiophiles is that they seem to take all movements of energy and information as being mechanical. They just haven't made the transition to electricity at all.

Speaker cables need to be made as if they were carrying literal vibrations to the cones.

It explains why even amplifiers with no moving parts have to be stood on individual stands with spiky feet, and those thingies for standing cables on, made of exotic woods.

Everything has to look right to them and their viewpoint is mechanical.

David

As I understand it, the argument goes that vibrations transmitted via the ground or air or whatever medium the protagonists suggest, deform the wire and insulation combination/interface thus generating an electrical signal that interferes with the music signal, which in turn causes "smearing" of the sound whatever that means.
And again theres the ones who say that certain conductor and dielectric/insulation interfaces and constructions deform under the applied music signal and this also alters the timing of different frequencies arrival at the speaker or amp input.
It's a belief system and as long as you accept it as such I dont mind.


I figure the poor souls can't win......................

Andy

[bikerhifinut]

Originally Posted by astral highway

I’ve just found a giant gap in the market! Yay! £££& coming my way! With such ‘dirty’ and underpowered 240V AC colts coming in to your fine rhodium/platinum power lead, what’s needed is something more robust.

I will be boxing up and badging as ‘audiophile’ a fantastic new power- supply which — wait for it- runs from three-phase and provides clean and powerful power where it’s needed. A group of 100A-capable bridge rectifiers is followed by a bank 12,000 uF of EPCOS capacitors, providing a crystal clear and yet fully muscular energy to the amplifier. Why, you could even DJ at Glastonbury with this wonder.

And this beauty will retail for only £999 monies.

I bet someone's already beaten you to this. and 12000uF of Epcos (fairly normal standard brand) is about what you'll find in a quad405. You'll have to sell it a bit harder al sorry, i'd suggest a hand polished tropical rosewood case for its non magnetic and low accoustic resonance properties and beeswax encapsulation around the rectifiers. Or something else equally organic to get an "organic" sound.
This also has probably already been done by someone, I ceased to be surprised a long time ago.
A.

[Radio Wrangler]

There was a Swedish chap de-canning electrolytic capacitors and fitting them in exotic wooden cases.

It looked like he had no knowledge of the relationship between keeping the H2O component in.... or maybe he did?

It looks like the beginning of the exoticified capacitor.... those that didn't start life exotic enough.

David

[Refugee]

I can remember those wooden capacitors.
He used wax that was strikingly like the stuff used on capacitors we change on sight.
I never bothered to keep a link to what he did.

[Pfraser]

Ages ago, I read of 'the singing, dancing arc' in a book on radar R&D. A fun project to lighten the wartime grimness, it employed crude modulation of a HV arc! (What else?)

The lab gents played classical music through this contraption. 'Reproduction' was surprisingly clear, and quite powerful. I think this was at Metropolitan-Vickers.

Could go down a storm at an eventual new normal hi-fi exhibition. No speaker cables to hinder fidelity...

[Al (astral highway)]

Originally Posted by bikerhifinut

[

You'll have to sell it a bit harder al sorry, i'd suggest a hand polished tropical rosewood case for its non magnetic and low accoustic resonance properties and beeswax encapsulation around the rectifiers.

Ahah, that sounds perfect for a three-phase power supply!

As for the capacitors, I'll remember to think of a value and then add an extra order of magnitude for maximum phoolery!

[jjl]

I have a friend who used to work at the BBC's Daventry short wave transmitter station.
On a visit there in about 1988 I was shown the modulation transformer for one of the late '50s vintage Marconi transmitters there. This thing was roughly the size of a sub-station transformer and sat in the middle of an otherwise empty locked room. When I saw and heard it, the transformer was very clearly and very loudly producing the sound of the Housemartins song "Happy Hour".

John

[GrimJosef]

Originally Posted by Pfraser

Ages ago, I read of 'the singing, dancing arc' ... Could go down a storm at an eventual new normal hi-fi exhibition ...

Acapella have been making and selling them for years https://www.acapella.de/acapella-2/?lang=en#ionen-hochtoener. Quite by chance I wandered into a room at a hi-fi show where a pair were being demonstrated. They sounded very, very good indeed. But then they should, given what they cost. I have a friend who has a pair. Once in a while the plasma electrode needs replacing, and some effort is made (I can't recall the details I'm afraid) to stop the ozone being an issue.

If you ever get the chance to hear a pair then I strongly recommend that you take it.

Cheers,

GJ

[mark_in_manc]

We had a 'Magnat' plasma tweeter in work for a while, which was used in scale-modelling for auditoria design (before numerical methods really took over, and instead of a spark source which was the other way to do it via impulse response and Fourier transform). It smelt funny

Scale modelling using ultrasonic signals is fun - if you want to try to scale the speed of sound (a bit) you can fill them with nitrogen. Well, I guess you can fill them with other gasses too, but sometimes not with a spark source

[Beobloke]

Originally Posted by GrimJosef

Acapella have been making and selling them for years https://www.acapella.de/acapella-2/?lang=en#ionen-hochtoener. Quite by chance I wandered into a room at a hi-fi show where a pair were being demonstrated. They sounded very, very good indeed. But then they should, given what they cost. I have a friend who has a pair. Once in a while the plasma electrode needs replacing, and some effort is made (I can't recall the details I'm afraid) to stop the ozone being an issue.

If you ever get the chance to hear a pair then I strongly recommend that you take it.

Cheers,

GJ

The Lansche loudspeakers featuring plasma tweeters aren’t too shabby either.

https://www.lansche-audio.com/en/

[bikerhifinut]

What about the "Ionofane" tweeter? I think they worked by modulating a plasma arc.
I remember a friend having a set.
And I am sure you can do something similar by passing an Ac current through a bunsen Flame, I guess any hot gas will work once ionised.
Neat trick if it could be contained and at normal room temps, a virtually massless driver?
A.

[Craig Sawyers]

There is a decent summary of the various versions of the ion plasma tweeter by numerous manufacturers worldwide.

Although the transient response and frequency range are extraordinary, alas so is the distortion, typically not much less than 1%

http://www.roger-russell.com/ionovac/ionovac.htm

Craig

[Pfraser]

Good Lord! I thought 'twas no more than a lab curiosity! To borrow a tagline: 'I never knew there was so much in it!'

[Radio Wrangler]

I'm used to plasma sound.

I have a function generator which can generate DC or sine or squarewaves of variable frequency and mark:space ratio, which modulates several kW of plasma. It's rather satisfying from a vintage radio point of view in that the plasma is generated from a thoriated tungsten electrode - water-cooled, no less. 210 Amps with the waa-waa pedal floored.

It can go quite loud.

It just doesn't sound good at all. A loud barking sound. squarewave much worse than sine.

It's a bit bright. Not only do you need the ultimate in peril sensitive sunglasses, you can't leave any skin exposed to the UV.

It's made a nice tubular steel hifi rack and a fancy aluminium swing-down bracket
arrangement for the antenna mast on the house.

The hefty mains cable would make an audiophile very happy indeed and you need something a bit better than an ordinary 13A plug if you wish to turn it up to 210 (199 more than spinal tap)

I think I read that some plasma tweeters needed a supply of bottled gas. Argon isn't safe in an enclosed space without good ventilation.

David