Has my mains cable ruined my amp?

[lesmallett]

I am just wanting to know if the Chord Superscreen mains cable is strangling my Marantz SR7005 amp?

I have just replaced the standard cable which was a particular poor European effort with a cheap adaptor plug to make the Euro plug fit UK sockets. Since changing though I'm having to use more volume and it is lacking punch.

Is there a better cable I should be using?

I'm not looking for people to tell me to use the standard or they don't make a difference as I believe they do.

 

[hammill]

I won't recommend a cable nor try to convince you to leave well alone. I do wonder if anyone could explain how a mains cable could make an amp quieter unless it has an unusually high resistance ( perhaps due to an almost broken wire somewhere?). Although I would not expect the cable to improve the sound surely it must be broken if it is reducing volume?

 

[chebby]

Just go to your local electrical supplies/wholesaler place and buy a normal lead (with no Euro adaptors) or cut off the European mains plug/adaptor from your supplied lead and fit a good quality 3 pin plug top (like an MK Toughplug for about £3).

Or go to Tesco with a tenner.

 

[robjcooper]

perhaps the cable has a knot in it.....

 

[lesmallett]

Quieter my not be accurate as I haven't measured the decibel levels but the bass now lacks punch and the surround effect is less prominent. I find myself turning it up to try and get some of these qualities back.
I didn't really expect to notice any difference to be honest as I haven't with amps in the past (I have noticed a good improvement with my TV and source equipment though), so I bought this lead used.
Maybe I should just stick to the belden cables I've always used.

 

[lussen]

mine also got same issue just bought chord supersceen connect to avr 1910 the bass now not tight as before but it make the sound very clean n detail.tonight will turning my sub n recalibrate hope it will work

 

[lesmallett]

That is interesting. I will try swapping it with my TV mains cable and see if that helps. It seems the Chord Superscreen isn't good with AV amps.

 

[MUSICRAFT]

Hi lesmallett

As you're now not as comfortable with the performance of your Marantz amplifier i'll recommend that you should take as step back and go back to using the original standard mains cable.

Fwiw, i use standard mains cables with multichannel AV amplifers such as the Plinius Odean and Chord Electronics SPM3005 as these standard mains cables enable components to breathe

Keep it simple. Simple is best.

All the best

Rick @ Musicraft

 

[CnoEvil]

I would recommend talking to Darren of Clearer Audio, as he's very helpful and I rate their products (which have a trial period): http://www.cleareraudio.com/

The best measurements that may indicate how better mains cables work, is provided by research from Shunyata:
http://www.shunyata.com/Content/DTCD.html
http://www.shunyata.com/Content/DTCD-meas.html
http://www.shunyata.com/Content/DTCD-indepth.html
http://www.shunyata.com/Content/DTCD-whitepaper.html
http://www.theaudiobeat.com/visits/shunyata_visit_interview.htm

 

[lesmallett]

Problem solved. Swapped the TV cable I bought from Mains Cables R Us with the Chord Superscreen and amp is now behaving again.

Had to turn the brightness up in the TV but all good.

 

[MajorFubar]

Sounds to me like it's now under-performing on your telly

 

[lesmallett]

Possibly but not keen to spend anymore money on power cables now and the picture still looks good.

Something to get at a later date I think.

 

[bigboss]

The best measurements that may indicate how better mains cables work, is provided by research from Shunyata: http://www.shunyata.com/Content/DTCD.html http://www.shunyata.com/Content/DTCD-meas.html http://www.shunyata.com/Content/DTCD-indepth.html http://www.shunyata.com/Content/DTCD-whitepaper.html http://www.theaudiobeat.com/visits/shunyata_visit_interview.htm

This "research" cannot stand to scrutiny, & hasn't been peer reviewed. There's also a clear conflict of interest here. I would like to see a research done by a cable manufacturer saying that their products do not show any improvements, or that's peer reviewed.

As I doctor I read many medical papers. If such a study was performed to support a medicine, it would never be accepted, neither by peers nor by the public in general.

 

[lesmallett]

There's an old saying, if it ain't broke don't fix it and I really should listen to it. Amp sounding boomy with music this morning using my Squeezebox so going back to its original cable.

Then again I also changed a cable into my Squeezebox so who knows.

I know what I'm like though so will probably keep fiddling until I've spent a new amps worth on mains cables. What I need is one cable to fix them all.

 

[CnoEvil]

This "research" cannot stand to scrutiny, & hasn't been peer reviewed. There's also a clear conflict of interest here. I would like to see a research done by a cable manufacturer saying that their products do not show any improvements, or that's peer reviewed.

As I doctor I read many medical papers. If such a study was performed to support a medicine, it would never be accepted, neither by peers nor by the public in general.

BB, you are of course quite correct, which is why my use of "may indicate" was very deliberate.

I have heard the improvements that M/Cs can make, and this is the best empirical evidence that I've come across which could explain it.

There is pressure on companies like Shunyata to prove the claimed benefits, and this at least is a step in the right direction.....if there are repeatable measurements, others should be able to confirm the results.

IMO The research (from such a respected company) is worthy of a second glance, despite the conflict of interest and the obvious marketing slant...which is of course why I linked to it.

 

[BenLaw]

I would recommend talking to Darren of Clearer Audio, as he's very helpful and I rate their products (which have a trial period): http://www.cleareraudio.com/ The best measurements that may indicate how better mains cables work, is provided by research from Shunyata: http://www.shunyata.com/Content/DTCD.html http://www.shunyata.com/Content/DTCD-meas.html http://www.shunyata.com/Content/DTCD-indepth.html http://www.shunyata.com/Content/DTCD-whitepaper.html http://www.theaudiobeat.com/visits/shunyata_visit_interview.htm

Isn't the purported relevance of these measurements utterly undermined by this comment? -

DTCD tests are an extreme test of the limits of power cord performance and do not represent normal operation into a power supply

 

[lesmallett]

Spoke to Darren at Clearer Audio and he is sorting me out. Will let you know if it makes me happy.

 

[bigboss]

I would recommend talking to Darren of Clearer Audio, as he's very helpful and I rate their products (which have a trial period): http://www.cleareraudio.com/ The best measurements that may indicate how better mains cables work, is provided by research from Shunyata: http://www.shunyata.com/Content/DTCD.html http://www.shunyata.com/Content/DTCD-meas.html http://www.shunyata.com/Content/DTCD-indepth.html http://www.shunyata.com/Content/DTCD-whitepaper.html http://www.theaudiobeat.com/visits/shunyata_visit_interview.htm

Isn't the purported relevance of these measurements utterly undermined by this comment? -

DTCD tests are an extreme test of the limits of power cord performance and do not represent normal operation into a power supply

That's the problem. I'm yet to see a research done under 'normal home conditions'.

 

[BenLaw]

I would recommend talking to Darren of Clearer Audio, as he's very helpful and I rate their products (which have a trial period): http://www.cleareraudio.com/ The best measurements that may indicate how better mains cables work, is provided by research from Shunyata: http://www.shunyata.com/Content/DTCD.html http://www.shunyata.com/Content/DTCD-meas.html http://www.shunyata.com/Content/DTCD-indepth.html http://www.shunyata.com/Content/DTCD-whitepaper.html http://www.theaudiobeat.com/visits/shunyata_visit_interview.htm

Isn't the purported relevance of these measurements utterly undermined by this comment? -

DTCD tests are an extreme test of the limits of power cord performance and do not represent normal operation into a power supply

That's the problem. I'm yet to see a research done under 'normal home conditions'.

And it's a similar thing that Russ Andrews got in trouble for IIRC.

 

[CnoEvil]

Spoke to Darren at Clearer Audio and he is sorting me out. Will let you know if it makes me happy.

That's good to hear. I hope he was as I described.

Looking forward to your findings

Cno

 

[CnoEvil]

I would recommend talking to Darren of Clearer Audio, as he's very helpful and I rate their products (which have a trial period): http://www.cleareraudio.com/ The best measurements that may indicate how better mains cables work, is provided by research from Shunyata: http://www.shunyata.com/Content/DTCD.html http://www.shunyata.com/Content/DTCD-meas.html http://www.shunyata.com/Content/DTCD-indepth.html http://www.shunyata.com/Content/DTCD-whitepaper.html http://www.theaudiobeat.com/visits/shunyata_visit_interview.htm

Isn't the purported relevance of these measurements utterly undermined by this comment? -

DTCD tests are an extreme test of the limits of power cord performance and do not represent normal operation into a power supply

Good point, but I suspect that they wouldn't have spent thousands of hours and hundreds of thousands of Dollars, developing a machine that was fundamentally flawed from the off.

In the FAQs, somebody asked something very similar (I think) - "Why is the amperage in the graph so high?"

The answer - "You may be thinking your CDP only pulls 1 Amp and your amplifier 12 Amps. So how can a test be valid that shows the cord drawing hundreds of Amps of current?

Read the DTCD white paper. Power supplies only pull current for 5% to 10% (or less) of the AC duty cycle. During the conduction period, the instantaneous current could be hundreds of Amps, but the long term average is only 1 to 20 Amps, depending on the device. Nb. If a power supply is drawing 20A (as measured by a current meter), then the peak current would be 100A to 200A instantaneous current"

So it would appear that this device is designed to" test a single current pulse".....so it needs to "simulate the AC electrical power grid, with its characteristics as a constant voltage source" as well as "mimic the action of a typical power supply when the rectifier turns on and off to fill the power supplies storage capacitors."

I'm not sure if this answers your query satisfactorily, but it's the best I can do.

Apparently "comparative subjective listening tests have been conducted spanning several years, under controlled conditions using blind and double blind tests, that repeatedly confirm the connection between system performance and DTCD. The results will be published along with more detailed information, in a series of supporting FAQ documents."

 

[Soopafly49]

I bought the Chord superscreen and it arrived today. Did some testing and I dont think I can hear any difference so in short I can't. Think I will send it back and get my 60 quid back. Am glad that I tried it. Think I will try pluging straight into the wall as the conditioner I have coould be killing dynamics apparently according to another thread on here.

 

[BenLaw]

I would recommend talking to Darren of Clearer Audio, as he's very helpful and I rate their products (which have a trial period): http://www.cleareraudio.com/ The best measurements that may indicate how better mains cables work, is provided by research from Shunyata: http://www.shunyata.com/Content/DTCD.html http://www.shunyata.com/Content/DTCD-meas.html http://www.shunyata.com/Content/DTCD-indepth.html http://www.shunyata.com/Content/DTCD-whitepaper.html http://www.theaudiobeat.com/visits/shunyata_visit_interview.htm

Isn't the purported relevance of these measurements utterly undermined by this comment? -

DTCD tests are an extreme test of the limits of power cord performance and do not represent normal operation into a power supply

Good point, but I suspect that they wouldn't have spent thousands of hours and hundreds of thousands of Dollars, developing a machine that was fundamentally flawed from the off.

Well, it's not necessarily fundamentally flawed, as it may well have achieved exactly what they want. As they have control over the amount of power it seems to me they could probably simulate realistic conditions. Which probably means they have. Although they haven't published those results.

In the FAQs, somebody asked something very similar (I think) - "Why is the amperage in the graph so high?"

The answer - "You may be thinking your CDP only pulls 1 Amp and your amplifier 12 Amps. So how can a test be valid that shows the cord drawing hundreds of Amps of current?

Read the DTCD white paper. Power supplies only pull current for 5% to 10% (or less) of the AC duty cycle. During the conduction period, the instantaneous current could be hundreds of Amps, but the long term average is only 1 to 20 Amps, depending on the device. Nb. If a power supply is drawing 20A (as measured by a current meter), then the peak current would be 100A to 200A instantaneous current"

So it would appear that this device is designed to" test a single current pulse".....so it needs to "simulate the AC electrical power grid, with its characteristics as a constant voltage source" as well as "mimic the action of a typical power supply when the rectifier turns on and off to fill the power supplies storage capacitors."

I'm not sure if this answers your query satisfactorily, but it's the best I can do.

Fair enough. I quoted what they put, it wasn't my assessment. It seems to me they say 'up front' it isn't really valid, perhaps to avoid the sort of Russ Andrews liability, and a bit deeper try to row back from that. Seems inconsistent, at the least.

Apparently "comparative subjective listening tests have been conducted spanning several years, under controlled conditions using blind and double blind tests, that repeatedly confirm the connection between system performance and DTCD. The results will be published along with more detailed information, in a series of supporting FAQ documents."

These would be very interesting to see, please post as and when you become aware that these have been published

Also on this section of the site:

These results represent a solid, empirical foundation for continued research into the relationship between AC delivery and pro-recording or A/V system performance.

This seems like a reasonable statement to me.

OTOH I can see no support for the conclusions they claim to have reached, in the first FAQ, which also seem to be inconsistent with the part I've just quoted:

1. There are audible and visual differences between power cords (and other AC power products).

2. Some of these differences can be directly attributable to Dynamic Transient Current Delivery.

The main thought that occurs to me with this is that no objective testing appears to have taken place prior to the manufacture and distribution of their products. And as they claim this is the first machine of this type developed, the implication is no other manufacturer has ever measured their products. This does not seem an impressive approach to me.

I should say, I am as yet an agnostic with mains products, and in particular would like to get the chance to try a good mains regenerator, although I don't expect to get the chance for a long time.

 

[CnoEvil]

@ Ben

I think your assessment is reasonable and well considered. If you read through their blurb, it explains how this device came into existence. Check out the section called "White Paper" and scroll down to the paragraph starting "We used a high power audio amplifier" (opposite the first graph). It describes how getting their results "indirectly" was inefficient.....so this device was conceived.

 

[BenLaw]

@ Ben

I think your assessment is reasonable and well considered. If you read through their blurb, it explains how this device came into existence. Check out the section called "White Paper" and scroll down to the paragraph starting "We used a high power audio amplifier" (opposite the first graph). It describes how getting their results "indirectly" was inefficient.....so this device was conceived.

They also say this:

After many months of testing we found that the results of the test comparisons were not always consistent and repeatable. The input voltage from the wall outlet to the amplifier could vary based upon time of day and other loads within the building. The test could vary depending upon the load on the amplifier and the specific heat that the amplifier was generating.

This could actually be used as an argument for mains regneration, which in a sense is designed to do what their machine does. But it rather seems to disprove their philosophy that (in the real world) all can be solved with after market mains cable and that doing so is an entirely different 'philosophy' from mains regeneration.