Mains Blocks / Conditioners / Regenerators

[ifor]

Another question (which may reveal my ignorance, but there it is): is this hum/buzz/grumble the same thing as I notice using a dimmer for the light switch? Or is that something completely different? Or the same result from a different cause?

(I never had a humming amplifier, so I can't compare...).

That is a question that interests me. I'm never had a buzzing amp or any interference that I've noticed (I sometimes wonder whether things always sound as good as they can all the time) and this seems to be exactly the sort of problem that a lot of these products claim to overcome.

 

[matt49]

Another question (which may reveal my ignorance, but there it is): is this hum/buzz/grumble the same thing as I notice using a dimmer for the light switch? Or is that something completely different? Or the same result from a different cause?

(I never had a humming amplifier, so I can't compare...).

I took you to mean that the dimmer itself was buzzing, not that the dimmer switch was causing the amp to buzz.

Like this?

http://home.howstuffworks.com/dimmer-switch5.htm

Matt

 

[ifor]

Ah, maybe I was jumping to conclusions.

 

[Daveperc]

Toroids are especially prone to buzzing in that way, but a DC blocker will fix it. It's a simple thing to make if you have the ability. Cicuit below.

With great respect that circuit will do absolutely nothing to the DC component!! It may be 40 odd years since my degree but a GCSE pupil should be able to tell you that if you put two diodes in parallel facing in oposite directions then they will pass whatever is sent their way! :doh:

 

[Covenanter]

Toroids are especially prone to buzzing in that way, but a DC blocker will fix it. It's a simple thing to make if you have the ability. Cicuit below.

With great respect that circuit will do absolutely nothing to the DC component!! It may be 40 odd years since my degree but a GCSE pupil should be able to tell you that if you put two diodes in parallel facing in oposite directions then they will pass whatever is sent their way! :doh:

I agree that this seems a silly circuit. The power of Google? As the sainted Jeremy says "10 billion facts on the internet and all of them are wrong".

Anybody with lots of money might look at:

http://www.mains-cables-r-us.co.uk/mains-cables-/140-the-excelsior-dc-blocker-.html

Chris

 

[a91gti]

Why spend money? My 303 buzzed and hummed like a one man acapella group. A firm rap with my knuckles soon silenced it for the evening though.

 

[TrevC]

Toroids are especially prone to buzzing in that way, but a DC blocker will fix it. It's a simple thing to make if you have the ability. Cicuit below.

With great respect that circuit will do absolutely nothing to the DC component!! It may be 40 odd years since my degree but a GCSE pupil should be able to tell you that if you put two diodes in parallel facing in oposite directions then they will pass whatever is sent their way! :doh:

I agree that this seems a silly circuit. The power of Google? As the sainted Jeremy says "10 billion facts on the internet and all of them are wrong".

Anybody with lots of money might look at:

http://www.mains-cables-r-us.co.uk/mains-cables-/140-the-excelsior-dc-blocker-.html

Chris

Each diode junction drops 0.6 to 0.7 volts of DC, so the circuit will happily remove 1.2 to 1.4 volts of DC in either direction, which is as much as is usually encountered. The expensive lead will have a similar circuit built into the box.

 

[ifor]

Anybody with lots of money might look at:

http://www.mains-cables-r-us.co.uk/mains-cables-/140-the-excelsior-dc-blocker-.html

Chris

That's cheap! Check out Vertex AQ's Jaya Shunt Fliter and their other stuff.

 

[davedotco]

I feel that several different issues are being rolled together here which is confusing.

DC, half wave rectification etc visibly distort the sine wave that is household current, you can see that on a 'scope. I can see how a well constructed amplifier power supply will isolate the audio side from these variations.

However one issue that remains unresolved in my mind is that of high or radio frequency interference entering the amplifier through the mains. RF in particular appears to be able to get into the active circuits of an amplifier despite the normal isolating effects of the power supply.

I have detailed, in another thread, my experience of using a filtered power supply to feed a high quality but modestly powered system. Conditions were extreme, hi-fi show with a hell of a lot of equipment on the same supply. The power supply removed a level of 'grain' or 'haze' that could be heard in the system in that specific situation.

Entirely subjective evaluation of course, but several people heard the improvement without knowing what it was, including my non enthusiast boss who was happy to buy the filter after the show. Not conclusive by any means, but this was the one and only time ever, that I was convinced that any mains product produced a definite benefit.

 

[Covenanter]

Toroids are especially prone to buzzing in that way, but a DC blocker will fix it. It's a simple thing to make if you have the ability. Cicuit below.

With great respect that circuit will do absolutely nothing to the DC component!! It may be 40 odd years since my degree but a GCSE pupil should be able to tell you that if you put two diodes in parallel facing in oposite directions then they will pass whatever is sent their way! :doh:

I agree that this seems a silly circuit. The power of Google? As the sainted Jeremy says "10 billion facts on the internet and all of them are wrong".

Anybody with lots of money might look at:

http://www.mains-cables-r-us.co.uk/mains-cables-/140-the-excelsior-dc-blocker-.html

Chris

Each diode junction drops 0.6 to 0.7 volts of DC, so the circuit will happily remove 1.2 to 1.4 volts of DC in either direction, which is as much as is usually encountered. The expensive lead will have a similar circuit built into the box.

You certainly can devise circuits to block any DC on a mains supply. I just don't think this one works.

Chris

PS This circuit has come up on at least one other forum and has been pilloried there too.

 

[DocG]

Another question (which may reveal my ignorance, but there it is): is this hum/buzz/grumble the same thing as I notice using a dimmer for the light switch? Or is that something completely different? Or the same result from a different cause?

(I never had a humming amplifier, so I can't compare...).

I took you to mean that the dimmer itself was buzzing, not that the dimmer switch was causing the amp to buzz.

Like this?

http://home.howstuffworks.com/dimmer-switch5.htm

Matt

That is what I meant indeed. Thanks for the link. "If you hook up a really cheap dimmer switch...". It's a relic from my student years, so yes indeed!

 

[ifor]

I feel that several different issues are being rolled together here which is confusing.

DC, half wave rectification etc visibly distort the sine wave that is household current, you can see that on a 'scope. I can see how a well constructed amplifier power supply will isolate the audio side from these variations.

However one issue that remains unresolved in my mind is that of high or radio frequency interference entering the amplifier through the mains. RF in particular appears to be able to get into the active circuits of an amplifier despite the normal isolating effects of the power supply.

I have detailed, in another thread, my experience of using a filtered power supply to feed a high quality but modestly powered system. Conditions were extreme, hi-fi show with a hell of a lot of equipment on the same supply. The power supply removed a level of 'grain' or 'haze' that could be heard in the system in that specific situation.

Entirely subjective evaluation of course, but several people heard the improvement without knowing what it was, including my non enthusiast boss who was happy to buy the filter after the show. Not conclusive by any means, but this was the one and only time ever, that I was convinced that any mains product produced a definite benefit.

Thanks Dave. I now recall your earlier post.

 

[ifor]

You certainly can devise circuits to block any DC on a mains supply. I just don't think this one works.

Chris

PS This circuit has come up on at least one other forum and has been pilloried there too.

Chris, don't be ridiculous! It must work; he's got a degree in electronics.

Sorry Trev! Rude of me, but I couldn't resist it.

 

[matt49]

"If you hook up a really cheap dimmer switch...". It's a relic from my student years, so yes indeed!

I thought you'd like the "really cheap dimmer switch".

For your new house you will want to have good quality dimmer switches fitted. I hear the Shunyata Dark Field dimmer is excellent. Inky blacks.

8)

Matt

 

[TrevC]

The circuit will work. I would like to draw a slightly different one but I don't know how to post it. This is similar and looks better because there is no possibilty of a reverse voltage on the electrolytics. From http://sound.westhost.com/articles/xfmr-dc.htm

 

[DocG]

"If you hook up a really cheap dimmer switch...". It's a relic from my student years, so yes indeed!

I thought you'd like the "really cheap dimmer switch".

For your new house you will want to have good quality dimmer switches fitted. I hear the Shunyata Dark Field dimmer is excellent. Inky blacks.

8)

Matt

Inky black lighting? No need for dark rooms in our new house! :stare:

 

[Covenanter]

"If you hook up a really cheap dimmer switch...". It's a relic from my student years, so yes indeed!

I thought you'd like the "really cheap dimmer switch".

For your new house you will want to have good quality dimmer switches fitted. I hear the Shunyata Dark Field dimmer is excellent. Inky blacks.

8)

Matt

Inky black lighting? No need for dark rooms in our new house! :stare:

Are those Black Ravioli dimmers?

Chris

 

[Covenanter]

The circuit will work. I would like to draw a slightly different one but I don't know how to post it. This is similar and looks better because there is no possibilty of a reverse voltage on the electrolytics. From http://sound.westhost.com/articles/xfmr-dc.htm

That looks more sensible.

Chris

 

[andyjm]

Toroids are especially prone to buzzing in that way, but a DC blocker will fix it. It's a simple thing to make if you have the ability. Cicuit below.

With great respect that circuit will do absolutely nothing to the DC component!! It may be 40 odd years since my degree but a GCSE pupil should be able to tell you that if you put two diodes in parallel facing in oposite directions then they will pass whatever is sent their way! :doh:

I agree that this seems a silly circuit. The power of Google? As the sainted Jeremy says "10 billion facts on the internet and all of them are wrong".

Anybody with lots of money might look at:

http://www.mains-cables-r-us.co.uk/mains-cables-/140-the-excelsior-dc-blocker-.html

Chris

Each diode junction drops 0.6 to 0.7 volts of DC, so the circuit will happily remove 1.2 to 1.4 volts of DC in either direction, which is as much as is usually encountered. The expensive lead will have a similar circuit built into the box.

You certainly can devise circuits to block any DC on a mains supply. I just don't think this one works.

Chris

PS This circuit has come up on at least one other forum and has been pilloried there too.

Just goes to show you that you shouldn't believe everything you read on the Internet. I wouldn't suggest anyone build it, but the circuit does work, and will remove up to 1.4V of DC offset (using silicon junction diodes). You could increase the offset range by increasing the number of series diodes.

 

[matt49]

We're often told to take notice of what pro sound engineers do, so this article would prima facie seem to be of interest. It certainly does seem quite thorough, though I've no idea how true it is.

http://www.soundonsound.com/sos/jul03/articles/mainsproblems.asp

Cheers,

Matt

 

[DocG]

We're often told to take notice of what pro sound engineers do, so this article would prima facie seem to be of interest. It certainly does seem quite thorough, though I've no idea how true it is.

http://www.soundonsound.com/sos/jul03/articles/mainsproblems.asp

Cheers,

Matt

So I guess the bottom line is: if there is no problem, it needn't be fixed. And if there is a problem, find a qualified electrician to sort out what's wrong, and treat accordingly. No one-cure-fits-all!

 

[TrevC]

Toroids are especially prone to buzzing in that way, but a DC blocker will fix it. It's a simple thing to make if you have the ability. Cicuit below.

With great respect that circuit will do absolutely nothing to the DC component!! It may be 40 odd years since my degree but a GCSE pupil should be able to tell you that if you put two diodes in parallel facing in oposite directions then they will pass whatever is sent their way! :doh:

I agree that this seems a silly circuit. The power of Google? As the sainted Jeremy says "10 billion facts on the internet and all of them are wrong".

Anybody with lots of money might look at:

http://www.mains-cables-r-us.co.uk/mains-cables-/140-the-excelsior-dc-blocker-.html

Chris

Each diode junction drops 0.6 to 0.7 volts of DC, so the circuit will happily remove 1.2 to 1.4 volts of DC in either direction, which is as much as is usually encountered. The expensive lead will have a similar circuit built into the box.

You certainly can devise circuits to block any DC on a mains supply. I just don't think this one works.

Chris

PS This circuit has come up on at least one other forum and has been pilloried there too.

Just goes to show you that you shouldn't believe everything you read on the Internet. I wouldn't suggest anyone build it, but the circuit does work, and will remove up to 1.4V of DC offset (using silicon junction diodes). You could increase the offset range by increasing the number of series diodes.

It looks like the caps are the wrong way round, but the circuit will still work.

 

[CnoEvil]

So I guess the bottom line is: if there is no problem, it needn't be fixed. And if there is a problem, find a qualified electrician to sort out what's wrong, and treat accordingly. No one-cure-fits-all!

That's not a mile away from what I said in my first post.

Let me quote what Plinius say in their FAQ, which can't be written off as marketing propaganda:

"Most mains conditioners or filters act in series with the mains and will starve the amplifier and negatively affect the sound. Look for a brand that works in parallel. If you need this treatment to your mains supply, this is a better option for you."

 

[Chokobolt]

They mainly block the conditioning of regenerators from outer space.

 

[Sospri]

So I guess the bottom line is: if there is no problem, it needn't be fixed. And if there is a problem, find a qualified electrician to sort out what's wrong, and treat accordingly. No one-cure-fits-all!

That's not a mile away from what I said in my first post.

Let me quote what Plinius say in their FAQ, which can't be written off as marketing propaganda:

"Most mains conditioners or filters act in series with the mains and will starve the amplifier and negatively affect the sound. Look for a brand that works in parallel. If you need this treatment to your mains supply, this is a better option for you."

I think that you will find Naim concur with this................