# Townsend Isolda cable

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#### solderdude

##### Major Contributor
We don't need the reference as we now have a graph showing voltages. Input voltage 55.5mV, and 1.1mV cable loss @ 10kHz. What's the formula that gives 23dB cable loss using these input parameters?

(There might be some error margin on the 55.5mV input voltage, but that error would need to be really huge to get a 23dB cable loss).
There is no reference as the 2i2 input pot can be in any position. Also the 55.5mV is not accurate.

Let's say the 55.5mV is correct. Then at 200Hz the impedance of the load = 8 Ohm.
55.5mV over 8 Ohm = 6.9mA. Do note this is the total signal containing the entire frequency band.

at 200Hz the used cable has a voltage drop of 90uV (the small 10uV bump is mains hum)
90uV / 6.9mA = 13mOhm and given the fact that his cable is 8.4 mOhms per meter (so the measured side 4.2Ohm/meter) would mean the cable is 3meter long.
The article states 7m long so something is fishy and the reference is not correct, the 7m is not correct, the Ohm/meter is incorrect, the load is incorrect.
Acc to mr. Townshend the 7m Isolda is 2.45uH, 65.8nF, 189mohm (= 13.5 Ohm/meter for 1 conductor and not the 4.2 Ohm per meter).

Apples and pears, no reference.

To really be able to tell something you need the sweep also with 2i2 of the input signal. Certainly because the RMS value is measured over the entire frequency range (a total, well not total as >500Hz it doesn't register correctly) and the 90uV value is (most likely) not calibrated and is only part of the entire 'energy'.

You really cannot use the data as there is no actual reference.

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#### mansr

##### Major Contributor
Guys, you can't compare the RMS value to spectral densities at specific frequencies.

#### solderdude

##### Major Contributor
Indeed so the 55.5mV is no reference in this case.
mr Townshend should have made a plot of the input signal as well. For more than 1 reason as we have no idea if the 2i2 voltage is actually correct as well.
The calculations above from the uV in the plots are meant to show you can't compare apples and pears.

#### SIY

##### Major Contributor
Technical Expert
And the big ol’ loop.

#### Cbdb2

##### Active Member
Well done Alt.
You actualy believe that guy? Your further gone than I thought. How can we have a technical discusion when one of the participants believes in magic and thinks his cable has it.

#### Cbdb2

##### Active Member
All hes found is a way to exagerate the miniscule differences in level at 20khz but dosnt understand how.Then imagines something else is going on even thou theres zero proof ( blind testing) and zero physics to back him, so always back to the wrong idea that characteristic impedance matters in audio.

#### Cbdb2

##### Active Member
I have measured the voltages in these two images. Input 55.5 mV and set the y axis to volts. Driven from the monitor speaker output of the 2i2 set to maximum. View attachment 95762 View attachment 95763 View attachment 95763
What happened to ohms law? That should NOT be a flat line. Its the current thru the speaker times the impedance of the wire. The current follows the impedance curve of the speaker which is not flat. If asked this before and even posted sims to show the effect. No answer.

#### Cbdb2

##### Active Member
And, by the way these kind of straw clutching measurements, across a wire have been done before and have been posted on diyaudio's website. Same response.

#### Speedskater

##### Addicted to Fun and Learning
I'm not at all sure that he measured the Resistance, Capacitance & Inductance of the cables that he actually used. I think that some of the info was derived from generic charts & graphs and other from mechanical measurements.

#### Cbdb2

##### Active Member
What came first, the cable or the test. Was the cable designed to fix a problem discovered while testing cables or was the test designed to show an improvement in this one cable? I think we all know which. And the test fails.

What exactly is this cable trying to fix?

#### southall-1998

##### Member
I'm not an engineer these other guys/gals are doing a good job of trying to get technical answers I am just wondering why the end of your cable is plain copper wire and cheap terminators?

View attachment 95786
It's a thing called snake oil and getting ripped off.

S.

#### Cbdb2

##### Active Member
I'm not at all sure that he measured the Resistance, Capacitance & Inductance of the cables that he actually used. I think that some of the info was derived from generic charts & graphs and other from mechanical measurements.
Was that a reply to me? No measurements neccesary.

#### mansr

##### Major Contributor
What exactly is this cable trying to fix?
Perceived lack of funds in the seller's bank account.

#### ahofer

##### Addicted to Fun and Learning
Forum Donor
You actualy believe that guy? Your further gone than I thought. How can we have a technical discusion when one of the participants believes in magic and thinks his cable has it.
Well, you probably aren’t generating enough alpha brain waves to understand.

#### Cbdb2

##### Active Member
Just lost all respect for this "engineer". These cables are cryo treated. It really bothers me when someone keeps calling them selves engineers but have no idea about physics. I guess a 50% is all you need to pass and the other half you can just make up.

http://www.townshendaudio.com/isolda-speaker-cables/

#### Cbdb2

##### Active Member
That zoom call will be censored.

#### Max Townshend

##### Active Member
Manufacturer
You actualy believe that guy? Your further gone than I thought. How can we have a technical discusion when one of the participants believes in magic and thinks his cable has it.
I was taking the piss

#### mansr

##### Major Contributor
I was taking the piss
Are you saying your entire cable operation is just a giant pisstake? I could almost believe that.