Need help with calculations for a ribbon speaker cable!

planeguy67

Joined Jan 29, 2015
60
Back in the 80's, when I first got interested in hi-fidelity audio, I came to learn the term "audiophile" was somebody who loved great sound reproduction. Therefore, I considered myself an audiophile.

I would continue to do so, but it seems like the term now applies to a dark secret order of mystics who believe in the non-science based unaudible qualities of equipment and components that all share nothing more than the common trait of being at least 4 times more expensive than a similarity performing piece of ordinary gear. :)
 

cmartinez

Joined Jan 17, 2007
8,253
Back in the 80's, when I first got interested in hi-fidelity audio, I came to learn the term "audiophile" was somebody who loved great sound reproduction. Therefore, I considered myself an audiophile.

I would continue to do so, but it seems like the term now applies to a dark secret order of mystics who believe in the non-science based unaudible qualities of equipment and components that all share nothing more than the common trait of being at least 4 times more expensive than a similarity performing piece of ordinary gear. :)
Never underestimate the dark side of the pseudosoundforce...
 

GopherT

Joined Nov 23, 2012
8,009


Yeah, I CAN hear a difference. It's only $20K you said? NICE! :)
I love all the precision pieces and then, the critical piece of unfinished lumber in the center of everything. I'm not sure if this was assembled or photoshopped as a joke or a real turntable, but it is humorous to me!
 

cmartinez

Joined Jan 17, 2007
8,253
I love all the precision pieces and then, the critical piece of unfinished lumber in the center of everything. I'm not sure if this was assembled or photoshopped as a joke or a real turntable, but it is humorous to me!
That piece of wood my friend... is actually a calibrated tesseract of 4-dimensional cellulose that sends all the undesirable rogue acoustic vibro-waves of the device out into hyperspace, where they then harmlessly dissipate into the void...
 

Kermit2

Joined Feb 5, 2010
4,162
I thought it might be an old scroll saw that was modified for the purpose. Or could a rube goldberg device for audiophiles.

Maybe I'm in the wrong business. I should be selling fancy little black boxes to these guys with enormous ears and larger egos, because, they seem to have wallets even larger. And a fascinating willingness to give it away for nothing more than a promise that a superstition actually DOES create a more realistic reality of music reproduction realism.

REALLY
 

planeguy67

Joined Jan 29, 2015
60
That piece of wood my friend... is actually a calibrated tesseract of 4-dimensional cellulose that sends all the undesirable rogue acoustic vibro-waves of the device out into hyperspace, where they then harmlessly dissipate into the void...
However, a change of just 1% relative humidity affects the dynamic range by 0.784 dB.

And Douglas Fir imbues the vinyl with a warmer, more open and organic, tone than common pine.
 

MikeA

Joined Jan 20, 2013
362


Yeah, I CAN hear a difference. It's only $20K you said? NICE! :)
That looks interesting actually. There is a vintage microscope head (Leica?) on the left side, some sort of sliding mechanism under the table. Is there another needle cartridge that is stationary and the table moves under it?
 

Alec_t

Joined Sep 17, 2013
14,314
a change of just 1% relative humidity affects the dynamic range by 0.784 dB.
The new Mk3A version will be available soon for only $25k, featuring a humidistat and micron-resolution servo calibrated to compensate for the Douglas Fir dimensional/relative-humidity profile.
 

Thread Starter

kelpf

Joined Apr 11, 2013
20
Here's a sim you might find informative/convincing/amusing....
It models a 5 Ohm ribbon speaker when driven by a 1V amplitude 25kHz signal (deemed the maximum of interest in the real world) from a 0.5 Ohm source, via ~10 metres of (1) 'normal' cable with a 100 Ohm characteristic impedance and (2) ribbon cable with a 5 Ohm characteristic impedance. The transmission line model in each case is lossless.
As can be seen from the FFT plots, the 'normal' cable plot has a secondary peak at ~3MHZ, some 55dB below the main peak.
The ribbon cable FFT plot secondary peak is at ~2.5MHz, some 60dB below the main peak.
Arguably, the ribbon cable introduces slightly less distortion (obviously the trumpeted selling point ;)), but this is entirely academic because the 25kHz signal, and certainly any signal in the MHz region, is completely inaudible regardless of its level.
View attachment 80046
Here is the LT Spice. Couldn't get QUCS to simulate. My 1st attempt at a spice thing.

Untitled-1.jpg
 

ronv

Joined Nov 12, 2008
3,770
kelpf,
Did you know if you decreased the time step in that simulation it would be even more accurate? -98 db instead of -99!


Oh no! did I say that? :eek:
 

Thread Starter

kelpf

Joined Apr 11, 2013
20
The ribbon drivers. These cables are for the ribbons only. I can't afford this stuff, so I build it instead.

99-06-02 - Wood cabinets completed.jpg 12-10-30-58 - Glammor Shot - GRCs.JPG 13-05-30 - GRC 2 Cables Finished 4.jpg
 

Alec_t

Joined Sep 17, 2013
14,314
Welcome to LTspice-world!
Couldn't get QUCS to simulate
What is QUCS?
The Td value in your first sim implies a transmission line length of ~1metre. Is that reasonable?
Why the inductors in series with the transmission lines in your sims? The transmission line model has inherent inductance and capacitance.
I'm unclear what you're trying to demonstrate in the second sim? Seems to be comparing chalk with cheese, since the transmission line delays are different.
 

Thread Starter

kelpf

Joined Apr 11, 2013
20
Welcome to LTspice-world!
What is QUCS?
The Td value in your first sim implies a transmission line length of ~1metre. Is that reasonable?
Why the inductors in series with the transmission lines in your sims? The transmission line model has inherent inductance and capacitance.
I'm unclear what you're trying to demonstrate in the second sim? Seems to be comparing chalk with cheese, since the transmission line delays are different.
As I read, the Td was the transit time. The Zo was per meter. OK, so no inductors and caps since they are built into the Zo, ? The TL are different types, different delays.
 

bertus

Joined Apr 5, 2008
22,277
Hello,

I have it on my computer, but have not tried it yet.
I have attached the technical manual of qucs, so you can have a look at its capabilities.

Bertus
 

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Alec_t

Joined Sep 17, 2013
14,314
As I read, the Td was the transit time
Agreed. 8.3ns delay is shown for the first sim. That would correspond to ~2.7metres metres in free space. What velocity factor do we assume for the line? If 40%, then the modelled line is ~1 metre.
The Zo was per meter.
Zo = characteristic impedance, which is not length dependent.

Thanks for the QUCS info, Bertus.
 
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