[AmpDesigner333]

Yeah, that brought them back in line. Good thinking.

Vampire's best 8.17 ohms.
Eachman Copper 8.20 ohms.
Some cheesy looking Copper binding posts from something 8.19 ohms.
Some imported binding posts from EP 8.19 ohms.
CMC pure Copper 8.18 ohms.
Some pure Silver coated Copper binding posts 8.18 ohms.
Tube connector with male tube connector end 8.16 ohms.

The tube connectors still have less resistance and it was the only one in the group that I used a connector with. And I used them hollow and not with high gauge wire inside of them.

I'm guessing you mean mΩ, not Ω.  Is this correct?

[jtwrace]

The tube connectors still have less resistance and it was the only one in the group that I used a connector with. And I used them hollow and not with high gauge wire inside of them.

So you're saying that .01 Ohm is > the calibrated range of the instrument that you're using to measure these at? 

[keantoken]

Did you measure the drop across just the 8ohm resistor so we can subtract that from the measurements? I would guess that resistor is at least 8.1ohm. Even 8.15 ohm is probably not large enough.

14ga wire has 0.0025ohms per FOOT, I would expect a good connector to not have a lot more than that.

[Danny Richie]

I'm guessing you mean mΩ, not Ω.  Is this correct?

No, that's ohms. I used an 8 ohm resistor.

[Danny Richie]

Did you measure the drop across just the 8ohm resistor so we can subtract that from the measurements? I would guess that resistor is at least 8.1ohm. Even 8.15 ohm is probably not large enough.

14ga wire has 0.0025ohms per FOOT, I would expect a good connector to not have a lot more than that.

Okay this is interesting. I measure 8.2 ohms of resistance for the resistor itself. And if I add a jumper and the tube connector then it drops to 8.16 ohms.

[keantoken]

Hmm, it sounds like your tester may have a voltage offset problem. If you are using a DMM you can reverse the leads. You get 2 different voltages, then add them together and that cancels out the offset. If it's inside your resistance tester then you might want to invest in a new tester.

That measurement taken literally means the Electra tube connectors have negative resistance. If that's true then expect a knock on your door and very serious discussions with the military. I personally could find some great uses for a negative resistor.


EDIT: Also, if your resistor is hot during the measurement, and the tester leads are touching different metals (say copper on one, steel on the other), you may be getting offset from a thermocouple effect. Just shooting from the hip here though.

[Danny Richie]

Hmm, it sounds like your tester may have a voltage offset problem. If you are using a DMM you can reverse the leads. You get 2 different voltages, then add them together and that cancels out the offset. If it's inside your resistance tester then you might want to invest in a new tester.

That measurement taken literally means the Electra tube connectors have negative resistance. If that's true then expect a knock on your door and very serious discussions with the military. I personally could find some great uses for a negative resistor.

Yeah, I know there is something going on that's not right. That's why I said, this is interesting. And the measurements are consistent. And this is using my Clio (computer based) measuring system.

[keantoken]

Are you measuring with an AC signal? If so then it might make sense if the connector inductance is swamping out the resistance. You could see that with a frequency sweep. To get around that you would lower the test frequency.

[AmpDesigner333]

Hmm, it sounds like your tester may have a voltage offset problem. If you are using a DMM you can reverse the leads. You get 2 different voltages, then add them together and that cancels out the offset. If it's inside your resistance tester then you might want to invest in a new tester.

That measurement taken literally means the Electra tube connectors have negative resistance. If that's true then expect a knock on your door and very serious discussions with the military. I personally could find some great uses for a negative resistor.


EDIT: Also, if your resistor is hot during the measurement, and the tester leads are touching different metals (say copper on one, steel on the other), you may be getting offset from a thermocouple effect. Just shooting from the hip here though.

The technique (known current through the DUT) I described earlier in this thread allows use of a “modest” voltmeter (just needs to have a mV setting) and will still produce reasonably accurate measurements.

[AmpDesigner333]

Are you measuring with an AC signal? If so then it might make sense if the connector inductance is swamping out the resistance. You could see that with a frequency sweep. To get around that you would lower the test frequency.

Use DC current!

[AmpDesigner333]

Did you measure the drop across just the 8ohm resistor so we can subtract that from the measurements? I would guess that resistor is at least 8.1ohm. Even 8.15 ohm is probably not large enough.

14ga wire has 0.0025ohms per FOOT, I would expect a good connector to not have a lot more than that.

You shouldn’t need to measure across the resistor at all. The only reason for the resistor is to keep the power supply from cutting out (thinking it’s shorted).  Yes, the result should be milli-Ω!

[Danny Richie]

I'll see what I can figure out to get some actual resistance readings on this stuff. But back to what I said earlier. The audible difference is not due to the difference in resistance.

[jtwrace]

The audible difference is not due to the difference in resistance.

What is it objectively related to?

[Danny Richie]

What is it objectively related to?

Specifically it is hard to say. There is a big difference in mass, type of conductive material, different masses and types of material and coatings, the dielectric material, etc. But it is not about resistance. If resistance was all that matters we could just use a 1/2" thick steel bolt.

But unquestionably there are audible differences. 

[AmpDesigner333]

I'll see what I can figure out to get some actual resistance readings on this stuff. But back to what I said earlier. The audible difference is not due to the difference in resistance.

Resistance is the only factor that it could be since there is not enough capacitance or inductance to make a difference. This is why I’m interested in measurement of the actual resistance before/after.  Proper equipment is a must for design verification.  I’d elaborate, but....   Let’s resume this discussion after AXPONA, which is what I need to focus on at the moment.

[jtwrace]

Specifically it is hard to say. There is a big difference in mass, type of conductive material, different masses and types of material and coatings, the dielectric material, etc. But it is not about resistance. If resistance was all that matters we could just use a 1/2" thick steel bolt.

But unquestionably there are audible differences.

What were the design goals when the product was developed?  Usually there is something that one is trying to solve which leads to research.  So, how was that achieved? 

[Danny Richie]

Resistance is the only factor that it could be since there is not enough capacitance or inductance to make a difference. This is why I’m interested in measurement of the actual resistance before/after.  Proper equipment is a must for design verification.  I’d elaborate, but....   Let’s resume this discussion after AXPONA, which is what I need to focus on at the moment.

No resistance is not a factor. Like I said, "If resistance was all that matters we could just use a 1/2" thick steel bolt."

Why not Brass and just use a larger size if it is only about resistance.

[S Clark]

Resistance is the only factor that it could be since there is not enough capacitance or inductance to make a difference.

Seeking clarification--are you saying that all wires and connections that have the same RC&I are going to sound the same?   

[Danny Richie]

What were the design goals when the product was developed?  Usually there is something that one is trying to solve which leads to research.  So, how was that achieved?

The given or known element was that using no binding post at all, with no break in the wire, yielded the best sound. And all binding posts (no matter the type) caused a noticeable loss in sound quality in various or multiple areas.

So the goal was to provide the least disruption to the signal and maintain close to the performance of having no break in the signal path yet still allow a removable speaker cable. So it was necessary to redesign that connection.

And this is the result of how that was achieved: http://gr-research.com/electracabletubeconnectors.aspx

[jtwrace]

The given or known element was that using no binding post at all, with no break in the wire, yielded the best sound. And all binding posts (no matter the type) caused a noticeable loss in sound quality in various or multiple areas.

So the goal was to provide the least disruption to the signal and maintain close to the performance of having no break in the signal path yet still allow a removable speaker cable. So it was necessary to redesign that connection.

And this is the result of how that was achieved: http://gr-research.com/electracabletubeconnectors.aspx

OK, so it was all "measured" subjectively with your ears?