“Audiophile Power Cable” results

[hothwampa]

Ok, so I have a question. Not trying to troll or start a flame war. I consider myself halfway between the objectivist and subjectivist camps, and I love my 300b tube amp for music and my Denon 3700h for movies. I’ve returned DACs after A/B-ing and found zero difference (as expected). I also have found to my ears noticeable improvement from upgrading some tubes and possibly capacitors, but with caps it certainly could be placebo. I don’t believe speaker wire can make a difference, and I use lamp cord that has been spliced with screw caps in my theater system.

Anyhow, I had some Amazon bucks and dropped $27 on the cheapest “audiophile grade” power cord I could find on the site. Really just out of curiosity since this hobby is all about tweaking. The cord is nice and thick and seems well made. I swapped out the stock cord on my Wilsenton R300 (tube rectified) truly expecting zero difference. I found it subjectively louder without having changed the volume knob. No subjective difference in tonality, separation etc. I checked this twice by swapping the cords and measuring peaks with my sound level meter, and on the same track (Bo Diddley), with the volume knob static, the peaks were clearly over 80 db with the new cord, and peaks were around 77 db with the stock cord. So any idea what may be going on here? I’m able to listen with with volume at a nice loud clip at 9:00 where previously I would be closer to 10:00 for “loud”.

 

[fpitas]

Sounds like your old cord was going bad and dropping voltage.

 

[hothwampa]

Thanks for the reply, I guess that makes sense, but it wasn’t old, basically new. Bought the amp new about a year ago. Maybe poor quality or defective somehow.

 

[fpitas]

Thanks for the reply, I guess that makes sense, but it wasn’t old, basically new. Bought the amp new about a year ago. Maybe poor quality or defective somehow.

Must be. You measured a greater output, so...

 

[jae]

There's a possibility the cord or connection could have been bad, or something totally unrelated resolved itself or changed when you moved the setup or changed the cord. There's a lot of threads picking apart the audibility of cable spec and what specifically you should look for when choosing a cable. If it is good quality copper with a large enough gauge, low enough reactance etc., once it is in your system the cable is nothing anyone should worry about since it will have no further potential impacts on audibility (if it even did in the first place).

 

[SIY]

Using an SPL meter without VERY careful setup and attention to detail is unlikely to give you good measurement repeatability. 5 or 6dB variances are not unexpected.

You'd do MUCH better using a voltmeter.

 

[Ricardus]

Anyhow, I had some Amazon bucks and dropped $27 on the cheapest “audiophile grade” power cord I could find on the site. Really just out of curiosity since this hobby is all about tweaking.

IS IT?

I haven't changed much in my rigs at all once I've purchased them. This idea that minor changes will make changes in the audio is just silly and anti-science.

 

[diddley]

Bo Knows!
Well thats some test track you got!

 

[sarumbear]

Really just out of curiosity since this hobby is all about tweaking.

We have different hobbies, it seems…

 

[hothwampa]

IS IT?

I haven't changed much in my rigs at all once I've purchased them. This idea that minor changes will make changes in the audio is just silly and anti-science.

 

[hothwampa]

I find it fascinating that two people took the time to nitpick a throw away comment without bothering to address my actual question. The anonymity of the internet really is something.

There's a possibility the cord or connection could have been bad, or something totally unrelated resolved itself or changed when you moved the setup or changed the cord. There's a lot of threads picking apart the audibility of cable spec and what specifically you should look for when choosing a cable. If it is good quality copper with a large enough gauge, low enough reactance etc., once it is in your system the cable is nothing anyone should worry about since it will have no further potential impacts on audibility (if it even did in the first place).

thank you for the thoughtful reply

 

[fpitas]

I put shorty power cords on my rack stuff to reduce clutter. Would you believe the soundstage widened 100% and the veils were lifted? Well, none of that happened. It did all still work, though.

 

[fpitas]

I find it fascinating that two people took the time to nitpick a throw away comment without bothering to address my actual question. The anonymity of the internet really is something.

thank you for the thoughtful reply

The internet is for nitpicking!

 

[FrantzM]

Hi

I have seen am increase in these newcomers posting things they know would not be well received by the people here. I suppose one joins a forum, at least aware of the forum's philosophy. The OP may prove me to be wrong. but I suspect, and strongly so, trolling.

Mods, feel free to delete my message if you judge it to be inadequate...

Peace.

 

[wwenze]

Try a constant signal instead of music if you're really interested in power testing... which itself has its caveats because a single frequency causes room modes which then causes hand-held SPL meters to shift by 10dB or more between measurements. White noise gets past this problem I guess.

I find it fascinating that two people took the time to nitpick a throw away comment without bothering to address my actual question. The anonymity of the internet really is something.

thank you for the thoughtful reply

Have you tried swapping cables to see if the nitpicking goes away?

 

[VintageFlanker]

The internet is for nitpicking!

ASR, in particular, is.

The anonymity of the internet really is something.

So far, what I do see is members I'm used to read here, responding to a freshly arrived one. So, I'm not sure who's concerned by the "anonymity" in that case.

Anyway, regarding your specific question, I second @SIY about the questioning initial diagnosis. You should first double check your findings with a multimeter. Measurements with a SPL meter in a domestic environment are not reliable.

 

[hothwampa]

ASR, in particular, is.


So far, what I do see is members I'm used to read here, responding to a freshly arrived one. So, I'm not sure who's concerned by the "anonymity" in that case.

Anyway, regarding your specific question, I second @SIY about the questioning initial diagnosis. You should first double check your findings with a multimeter. Measurements with a SPL meter in a domestic environment are not reliable.

Thanks, I’ll go back and check it perhaps with a level signal as someone suggested. Like I said I was surprised. I mean, it’s plugged into a surge protector/power strip. I’m genuinely not trying to troll folks, I’m a long time lurker first time poster type. I’ve appreciated the science based approach here. Hence my question. I agree the initial diagnosis is questionable, although I will say the only reason I pulled out the db meter was it did subjectively sound louder. I do have a multimeter, may Google how to test the two cables (without killing myself).

 

[SIY]

Thanks, I’ll go back and check it perhaps with a level signal as someone suggested. Like I said I was surprised. I mean, it’s plugged into a surge protector/power strip. I’m genuinely not trying to troll folks, I’m a long time lurker first time poster type. I’ve appreciated the science based approach here. Hence my question. I agree the initial diagnosis is questionable, although I will say the only reason I pulled out the db meter was it did subjectively sound louder. I do have a multimeter, may Google how to test the two cables (without killing myself).

Just run a tone at a moderate frequency (say, 400Hz, not critical), adjust volume to a moderate level. Measure the voltage at the speaker terminals or (equivalently) the amp output. Then change power cables and without changing the volume control, measure again. As a basic check on repeatability, go back to the original power cord and repeat to see if you get the same number as before. Easy peasy.

 

[Cbdb2]

Unless the amp is faulty or very badly designed the gain should not change with supply voltage. Dosnt matter if I feed the amp 110vac or 130vac the output level should stay the same. The circuit determines the gain. If it didnt the amp would constantly change volume as the power grid voltage varies, which it does. The only difference with the lower voltage is less total power before clipping, about .1db.
So how can power cords make any audible difference?
Some numbers. A 22 gauge (small) 10' (long) power amp cable has resistance of .3Ω. If the amp is drawing 10amps (1200 watts!) the v drop is only 3 volts. The power grid regulation is +\- 5%. You really think you can hear the difference between 16 gauge and 0 gauge when drawing less than 100watts?

*****dont try this at home, the cable will be burning 30watts, if you want use a .3Ω 50watt power resistor instead

 

[fpitas]

Unless the amp is faulty or very badly designed the gain should not change with supply voltage. Dosnt matter if I feed the amp 110vac or 130vac the output level should stay the same. The circuit determines the gain. If it didnt the amp would constantly change volume as the power grid voltage varies, which it does. The only difference with the lower voltage is less total power before clipping, about .1db.
So how can power cords make any audible difference?

Generally you're right, but the 300B amp may change transconductance with anode voltage, and I doubt it has a ton of NF. In any event SIY set him on a good path to more precise measurement.