“Audiophile Power Cable” results

[Cbdb2]

An amp that changes gain with supply voltage (the reason electronic feedback was invented) is a bad design and all bets are off.

 

[fpitas]

An amp that changes gain with supply voltage is a bad design.

Lol well, I'm not arguing.

 

[egellings]

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.

The age of the cord won't change its performance if the copper does not oxidize significantly. If you have access to a milli-ohm meter, measure the DCR of the two cords, and that is where the difference will lie. Reduced power output of the amp can be caused by voltage drop in the AC power feeding the amp, and cord resistance directly affects that. There's no magic; it's only 50/60Hz AC voltage. I can jump up and down that fast with a beer in my hand.

 

[fpitas]

I can jump up and down that fast with a beer in my hand.

Pics or it didn't happen!

 

[egellings]

Pics or it didn't happen!

It's hyperbole. Obviously, beer would be splashed all over the place. The athleticism needed to operate at that frequency is also above my ken. Aso, things can happen without a picture being taken. That tree falling unseen in the forest is an example of that.

 

[fpitas]

It's hyperbole. Obviously, beer would be splashed all over the place. The athleticism needed to operate at that frequency is also above my ken.

It would be a lot of Hertz!

 

[egellings]

It would be a lot of Hertz!

Ouch! Ouch! My poor knees!

 

[Cbdb2]

An amp that susceptible to supply voltage would need a regulated supply to avoid modulating the gain by the supply variations, the PSRR would be terrible. You'ld have bigger problems than the power cord.

 

[RayDunzl]

I checked this twice by swapping the cords and measuring peaks with my sound level meter

Was the meter stationary between tests?

 

[hothwampa]

Was the meter stationary between tests?

Handheld so no, but same result with both “tests”. Will try with the boom or just measure with the multimeter later this week.

 

[GXAlan]

Did you have equal time for tube warmup?

You should invest in a nice ADC measure and try to find out what is causing it.

 

[GXAlan]

Handheld so no, but same result with both “tests”. Will try with the boom or just measure with the multimeter later this week.

Don’t need the boom. Just put it on a shelf or chair where it’s not handheld.

Your body (physical position) will also diffract the sound.

 

[SIY]

Don’t need the boom. Just put it on a shelf or chair where it’s not handheld.

Your body (physical position) will also diffract the sound.

It is not the right tool to use. Period. A simple voltmeter will give massively more accurate and repeatable results.

 

[GXAlan]

It is not the right tool to use. Period. A simple voltmeter will give massively more accurate and repeatable results.

Agree 100%.

I just suggested putting the SPL meter on a fixed surface since I expect the difference to disappear and the OP said it would take “later in the week” to find his multimeter.

 

[Blumlein 88]

Handheld so no, but same result with both “tests”. Will try with the boom or just measure with the multimeter later this week.

I'm repeating what others are telling you. Stop with the SPL meter. Use a voltmeter and test signal. Accurate, simple, quick and you'll clearly know if there is a difference. Don't try and clean up a dirty procedure when a super clean one is available and easier to do.

 

[Mr. Widget]

I'm repeating what others are telling you. Stop with the SPL meter. Use a voltmeter and test signal. Accurate, simple, quick and you'll clearly know if there is a difference. Don't try and clean up a dirty procedure when a super clean one is available and easier to do.

And another repeat. Regardless of how careful you were in your technique, the likelihood of measurement error is just too great based on your results.

For there to be a 3dB change in output, your amplifier would have had to double it's power output. This seems highly unlikely unless there is something very wrong with your amplifier.

 

[OldHvyMec]

I'm glad you found the bad power cable, and replaced it. Pretty simple. Weather it's a bad connection or just a crappy aluminum cable with cheap terminal ends,
I'm glad your 27 dollars was spent well. Yes a bad cable can SOUND bad (the WRONG shielding or RF/EFI) and can cause a voltage drop.
Yes voltage drops effect volume output on many power valve amps. It's not a bad design, it's "A" design. I use a variac to bring up my MC30, & 60s. At about
60-70 they start to increase in volume. 90-100 VAC

Tube rectified is why the volume is affected, by a voltage issue. I'm guessing.

These are stereos, not Saturn 5 rockets. Occam's razor is in full swing, the simplest answer is usually the answer.
My only question is if the batteries are new in the DMM and can you repeat the results? If you can, it's the PC and what it was made from, how it was made or the connections. Either cable to terminal end or terminal end to receipticals. Not all cables are equal for the same application.

Spliced cable will give you spliced cables, another possible place for failure. I had ONE cable drop in my life it cost 8K and a MC275 is still broken.
I couldn't have planned it better with a bomb site.

If money is an issue, I got no problem with it. If you're saying it won't affect the performance it most certainly will. Don't squeeze on the 3M electrical
tape either. . I raised kids and cooked a lot of beans and cornbread. LOL My attic is wired with Romex # 14 for speakers. No splices though.
For the HO railroad sound.

You cannot make chicken soup out of chicken shit. Use what you can afford and take care of what you have. Keep your cables off the floor and routed (no touching)
Cables are easier to clean and the floor noise will drop. THAT'S FREE!! It won't cost a dime to do it either.

Skunk trying to get in the hen house, gotta go.

 

[Blumlein 88]

Keep your cables off the floor and routed (no touching)
Cables are easier to clean and the floor noise will drop. THAT'S FREE!! It won't cost a dime to do it either.

Skunk trying to get in the hen house, gotta go.

Care to explain floor noise? I do smell a skunk for sure.

 

[SIY]

I'm glad you found the bad power cable, and replaced it. Pretty simple. Weather it's a bad connection or just a crappy aluminum cable with cheap terminal ends,
I'm glad your 27 dollars was spent well. Yes a bad cable can SOUND bad (the WRONG shielding or RF/EFI) and can cause a voltage drop.
Yes voltage drops effect volume output on many power valve amps. It's not a bad design, it's "A" design. I use a variac to bring up my MC30, & 60s. At about
60-70 they start to increase in volume. 90-100 VAC

Tube rectified is why the volume is affected, by a voltage issue. I'm guessing.

These are stereos, not Saturn 5 rockets. Occam's razor is in full swing, the simplest answer is usually the answer.
My only question is if the batteries are new in the DMM and can you repeat the results? If you can, it's the PC and what it was made from, how it was made or the connections. Either cable to terminal end or terminal end to receipticals. Not all cables are equal for the same application.

Spliced cable will give you spliced cables, another possible place for failure. I had ONE cable drop in my life it cost 8K and a MC275 is still broken.
I couldn't have planned it better with a bomb site.

If money is an issue, I got no problem with it. If you're saying it won't affect the performance it most certainly will. Don't squeeze on the 3M electrical
tape either. . I raised kids and cooked a lot of beans and cornbread. LOL My attic is wired with Romex # 14 for speakers. No splices though.
For the HO railroad sound.

You cannot make chicken soup out of chicken shit. Use what you can afford and take care of what you have. Keep your cables off the floor and routed (no touching)
Cables are easier to clean and the floor noise will drop. THAT'S FREE!! It won't cost a dime to do it either.

Skunk trying to get in the hen house, gotta go.

This is a perfect example of a post to ignore in its entirety.

 

[IAtaman]

This is a perfect example of a post to ignore in its entirety.

I keep seeing this stream of consciousness style of writing that is peppered with obscure references and weird puns in these types of posts. I wonder if it is an indication of something that underlies this kind of mindset.