Shielded hook up wire
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PAS?
Percussive Arts Society?
Pediatric Academic Societies?
Parental Alienation Syndrome?
Physician Assisted Suicide?
Population Analysis Spreadsheets?
I have some RG-174, and I consider it perfectly suitable for anything except a phono cable (capacitance is too high for my tastes).
http://www.allelectronics.com/make-a-store/item/RG-174/RG-174-MINI-CO-AXIAL-CABLE/-/1.html
http://www.dxing.info/equipment/rg_174_coax_bryant.dx
Percussive Arts Society?
Pediatric Academic Societies?
Parental Alienation Syndrome?
Physician Assisted Suicide?
Population Analysis Spreadsheets?
I have some RG-174, and I consider it perfectly suitable for anything except a phono cable (capacitance is too high for my tastes).
http://www.allelectronics.com/make-a-store/item/RG-174/RG-174-MINI-CO-AXIAL-CABLE/-/1.html
http://www.dxing.info/equipment/rg_174_coax_bryant.dx
bhamham
Super Member
All of the above, especially the Population Alien-nation Suicide one
... sorry, meant to say a Dynaco PAS-2 preamp. RG-174 probably wouldn't be good for the phono input.Thanks for the links.
signal-dude
Just one good watt.......
"What do you guys use? Does anyone use coax like RG174?"
Yup, I used it to wire up my Rod Elliot P97 Preamp board and it works nice.I used the Carol 95% shielded stuff from Digikey. Solders very easy and nice to work with.
"I'm thinking of rewiring my PAS to eliminate some crosstalk."
Should work fine, I have no cross talk whatsoever that I can measure. Or hear.
I like the RG174 so much that I just replaced all my interconnect cables that used twisted pair and shield,read directional cable, with RG174.
I used metal RCA connectors and the coax to make a simple cable. The 174 just sounds better to me, don't know why though. At 30 pf. per foot its not the lowest capacitance cable but its really easy to make a bunch of cables in one evening.
Yup, I used it to wire up my Rod Elliot P97 Preamp board and it works nice.I used the Carol 95% shielded stuff from Digikey. Solders very easy and nice to work with.
"I'm thinking of rewiring my PAS to eliminate some crosstalk."
Should work fine, I have no cross talk whatsoever that I can measure. Or hear.
I like the RG174 so much that I just replaced all my interconnect cables that used twisted pair and shield,read directional cable, with RG174.
I used metal RCA connectors and the coax to make a simple cable. The 174 just sounds better to me, don't know why though. At 30 pf. per foot its not the lowest capacitance cable but its really easy to make a bunch of cables in one evening.
If the runs are short (10" or less), the added capacitance isn't a big deal, especially since the PAS-2 doesn't have a cap at the phono input.
whoaru99
Epic Member
Higher capacitance tends to create high frequency rolloff, afaik. A slightly softer/warmer sound, perhaps?
signal-dude
Just one good watt.......
"Higher capacitance tends to create high frequency rolloff, afaik. A slightly softer/warmer sound, perhaps?"
One would think so, Who, but I checked the loss with my generator and scope at 40Khz. on my longest cable which is 6 feet long. The loss was undetectable at 5 millivolts per division on my scope. 40Khz. is the highest freq. my HP 200AB generator will go. My scope is a 100Mhz. HP 1740A.
Maybe its the old placebo effect or new clean contacts on the RCA plugs.I used Switchcraft 3502A metal plugs from Digikey, very nice.
But for me and my system these super cheap interconnects sound great.
One would think so, Who, but I checked the loss with my generator and scope at 40Khz. on my longest cable which is 6 feet long. The loss was undetectable at 5 millivolts per division on my scope. 40Khz. is the highest freq. my HP 200AB generator will go. My scope is a 100Mhz. HP 1740A.
Maybe its the old placebo effect or new clean contacts on the RCA plugs.I used Switchcraft 3502A metal plugs from Digikey, very nice.
But for me and my system these super cheap interconnects sound great.
signal-dude
Just one good watt.......
So, today I pondered how to accurately test for loss of the RG174 cable. Could not see much loss on the scope at a low signal level. I have a DMM that can do AC volts but can also count frequency up to 4 Mhz. Along with this it can measure AC and display the level in Dbm's.
There is 16 feet of 174 left on the spool that I have so I used this piece for testing. I used a Marantz MA-500 amp as a low impedance source to simulate the output of a pre amp or CD player etc. Put a 48K ohm resistor at the other end of the cable to simulate the load end.
Set my audio generator for 44Khz. most it will do, and set a level at the amp output at +25.0 Dbm's as read on the DMM. Moved the meter leads to the other end of the 174 and measured +25.0 Dbm's. Also tried this test by just using my audio generator which has a higher output impedance and got the same result.
And this tells me that 16 feet of RG174 at 44Khz. has basically no loss. Tested the cable at a few other frequencies in the audio band with the same results. I did not expect this result at all as I theorized that my first test at low levels was flawed and at a higher voltage level and longer length of the cable some loss would be evident. At least a couple of Db's at 44Khz. I thought.
So my conclusion is that the RG174 is not bad as an audio cable and makes a dirt cheap IC for Stereo equipment.
There is 16 feet of 174 left on the spool that I have so I used this piece for testing. I used a Marantz MA-500 amp as a low impedance source to simulate the output of a pre amp or CD player etc. Put a 48K ohm resistor at the other end of the cable to simulate the load end.
Set my audio generator for 44Khz. most it will do, and set a level at the amp output at +25.0 Dbm's as read on the DMM. Moved the meter leads to the other end of the 174 and measured +25.0 Dbm's. Also tried this test by just using my audio generator which has a higher output impedance and got the same result.
And this tells me that 16 feet of RG174 at 44Khz. has basically no loss. Tested the cable at a few other frequencies in the audio band with the same results. I did not expect this result at all as I theorized that my first test at low levels was flawed and at a higher voltage level and longer length of the cable some loss would be evident. At least a couple of Db's at 44Khz. I thought.
So my conclusion is that the RG174 is not bad as an audio cable and makes a dirt cheap IC for Stereo equipment.
JBL GUY
Addicted Member
I is good to see AKers doing tests...
My post is a little off topic from the original post...but since the thread has gone to interconnects and types of cable...
But one thing to consider is...It is not only the "Loss" but what effect the complex impedance of the source/cable/end device had on the actual signal.
I would be interested to know what a 44Khz square wave looks like.
When cable is used for phono interconnects it is the inductance (complex impedance) of the phono cartridge along with the complex impedance of the cable that has an effect on the signal.
And this is frequency dependent...So it is not just what happens at one specific frequency...In your case 44Khz...but the relationship of all the frequencies from the lowest to the highest.
That said I do not believe you will see much difference from the low frequencies to the high frequencies with your particular test methodology.
Here is a great link that explains it in depth...
http://www.hagtech.com/loading.html
Scroll down the page a little way an enter the inductance of your phono cartridge and the total capacitance of your interconnects and the input of your phono stage.
For example a Shure V15 has about 500 mH of inductance and 6 ft of your RG 174 would have a total capacitance of about 185 pF. Of course you have to add in the capacitance of the RCA connectors also.
But with these numbers you would have a resonance at about 16Khz.
And of course this is not counting the input capacitance of the phono stage.
A low capacitance audio interconnect might only have about 70 pF total and that would put the resonant frequency out of the audio pass band at somewhere around 26 Khz.
Of course the affect of this is not so great when your are talking about interconnects used at line levels between things like tape deck, tuner and preamp to power amp...
But then again look at all of the differing opinions on the "best sounding" interconnects.
Now back to topic...If RG 174 is used for internal wiring of a tube type amplifier where the cable length is going to be less than 1 ft (Less than 30pF of capacitance) all should be good.
If one is really concerned one could use low capacitance "audiophile" audio cable..at a higher cost of course. As long as the voltage rating is high enough it should work ok also.
signal-dude
Just one good watt.......
"It is good to see AKers doing tests..."
Agreed, there should be more testing going on to trim out the "Snake Oil".
"But one thing to consider is...It is not only the "Loss" but what effect the complex impedance of the source/cable/end device had on the actual signal."
Spot on, Old chap! My setup only checks the resistive domain..
"I would be interested to know what a 44Khz square wave looks like."
Ahhh, now that sounds like a more realistic test. I have a pulse generator also with variable pulse width and rate. And of course square wave. More HP stuff..
"And this is frequency dependent...So it is not just what happens at one specific frequency...In your case 44Khz...but the relationship of all the frequencies from the lowest to the highest."
I used 44Khz. cuz' higher frequencies is the worst case scenario.
"That said I do not believe you will see much difference from the low frequencies to the high frequencies with your particular test methodology."
Agreed.
So if I put a 220 pf. cap at the end of a 6 foot RG174 cable and put some sine waves into it and then a square wave I should see the cable behaving different. I really was not interested in using this stuff as a phono cable only interconnect cable.
"Tuning" the cartridge-cable-preamp load signal chain is an excercise in patience and ear listening.As I have no interest in LP records and TT's I will leave that testing to someone else.
Agreed, there should be more testing going on to trim out the "Snake Oil".
"But one thing to consider is...It is not only the "Loss" but what effect the complex impedance of the source/cable/end device had on the actual signal."
Spot on, Old chap! My setup only checks the resistive domain..
"I would be interested to know what a 44Khz square wave looks like."
Ahhh, now that sounds like a more realistic test. I have a pulse generator also with variable pulse width and rate. And of course square wave. More HP stuff..
"And this is frequency dependent...So it is not just what happens at one specific frequency...In your case 44Khz...but the relationship of all the frequencies from the lowest to the highest."
I used 44Khz. cuz' higher frequencies is the worst case scenario.
"That said I do not believe you will see much difference from the low frequencies to the high frequencies with your particular test methodology."
Agreed.
So if I put a 220 pf. cap at the end of a 6 foot RG174 cable and put some sine waves into it and then a square wave I should see the cable behaving different. I really was not interested in using this stuff as a phono cable only interconnect cable.
"Tuning" the cartridge-cable-preamp load signal chain is an excercise in patience and ear listening.As I have no interest in LP records and TT's I will leave that testing to someone else.
signal-dude
Just one good watt.......
Tried a 50 Khz. square wave today on the 16 footer. No change in fidelity that me or my scope can see. Then tried a 220 pf cap at the far end and it skewed the load signal as well as the source signal. Still looks like good IC cable to me. Phono is another story that I have no clue for.
JBL GUY
Addicted Member
Not saying that it is not ok for line level interconnects...But if you can see a visible change it the signal then you have an audible change also...And of course you do not have any inductance in line either. With inductance and capacitance you will have a "tuned circuit" that may have a greater affect on the signal.
And this is where the debate on "Interconnects in general, including speaker wire" starts and then goes on and on.
And there is another thread here on AK about being able to measure what we hear vis a vis all the hardware involved including interconnects.
Glad to see you are continuing to experiment.:thmbsp::thmbsp:
It is fun and interesting stuff. (At least for me)
I'm surprised that you hear cross talk with the PAS-2. I had one for years and never had that problem at all. I"m quite sure that the PAS-2 if properly built, has better channel separation than any phono cartridge or FM tuner when set to the maximum separation. Shielded cable should be completely unnecessary and superfluous. Perhaps there are some leaky bypass capacitors on the power supply lines in your unit.
signal-dude
Just one good watt.......
".But if you can see a visible change it the signal then you have an audible change also...And of course you do not have any inductance in line either. With inductance and capacitance you will have a "tuned circuit" that may have a greater affect on the signal."
Yeah, totally agree. Whats weird to me is the cable capacitance measures out at about 500 pf. Which is calculated also. But adding another 220 pf at the load resistor end caused a skewing or angling of the square wave. You would think that 500 pf. alone would cause that unless I turned it into a tuned circuit with the 220 pf.
"And this is where the debate on "Interconnects in general, including speaker wire" starts and then goes on and on."
Oh no, not getting involved in THAT vortex!!!!!!!!
"And there is another thread here on AK about being able to measure what we hear vis a vis all the hardware involved including interconnects."
I've been watching that one and keeping a safe distance,heh-heh.....
"Glad to see you are continuing to experiment.:thmbsp::thmbsp:"
"It is fun and interesting stuff. (At least for me)[/QUOTE]"
Yup, me too.
Yeah, totally agree. Whats weird to me is the cable capacitance measures out at about 500 pf. Which is calculated also. But adding another 220 pf at the load resistor end caused a skewing or angling of the square wave. You would think that 500 pf. alone would cause that unless I turned it into a tuned circuit with the 220 pf.
"And this is where the debate on "Interconnects in general, including speaker wire" starts and then goes on and on."
Oh no, not getting involved in THAT vortex!!!!!!!!
"And there is another thread here on AK about being able to measure what we hear vis a vis all the hardware involved including interconnects."
I've been watching that one and keeping a safe distance,heh-heh.....
"Glad to see you are continuing to experiment.:thmbsp::thmbsp:"
"It is fun and interesting stuff. (At least for me)[/QUOTE]"
Yup, me too.
