[KeithA]

James

I figure another technical Torus question to take you into the weekend

I understand the theory of the design of the Torus presenting a low-impedance source for an amp. I understand that an amp without the Torus can't likely draw peak current from the wall due to contact resistance, etc.

However, did you guys ever measure what the Torus (with an amp hooked to it) was trying to pull from the wall from a peak current perspective? I mean, could it be possible that even the Torus will try to draw excessive peak current from the wall at some point and then performance would be impacted by the same high impedence problem that plagues an amp that is plugged directly?

In other words, does the impedance at the wall outlet ever play into the Torus' ability to get current from the wall? If, say, the amp was looking for high peak current over extended periods of time, does, or would, the Torus run into the same problem as an amp plugged directly into the wall? Or does the storage potential of the Torus all but make this virtually impossible in real world situations.

Keith

[gerald porzio]

Sounds like snakeoil, & I respect Bryston gear. If it's not boosting amperage from the wall outlet, I fail to grasp the pseudo science of the Torus puppy. I'll put a dedicated 20 amp line against any Tori defying anyone to discern differences w/o knowing when the Torus is in use. The bottom line is that it  gives a mfg. anothe4r product to sell - nothing more & nothing less.

[James Tanner]

James

I figure another technical Torus question to take you into the weekend

I understand the theory of the design of the Torus presenting a low-impedance source for an amp. I understand that an amp without the Torus can't likely draw peak current from the wall due to contact resistance, etc.

However, did you guys ever measure what the Torus (with an amp hooked to it) was trying to pull from the wall from a peak current perspective? I mean, could it be possible that even the Torus will try to draw excessive peak current from the wall at some point and then performance would be impacted by the same high impedence problem that plagues an amp that is plugged directly?

In other words, does the impedance at the wall outlet ever play into the Torus' ability to get current from the wall? If, say, the amp was looking for high peak current over extended periods of time, does, or would, the Torus run into the same problem as an amp plugged directly into the wall? Or does the storage potential of the Torus all but make this virtually impossible in real world situations.

Keith

Hi,
 
The answer is, yes, the Torus does have a large energy-storage capacity. 

A Torus always draws current out of the wall in a sinusoidal waveform, whose AVERAGE power is equivalent to the amplifier's power draw.  An amplifier tends to draw power on only the top few degrees of the 60Hz waveform, however.  This means its peak current requirement can go very high, as much as 50 or more peak Amperes on a 300-WPC amplifier, even when the average current to the amplifier is only 10 Amperes RMS. 

The Torus can supply this high peak current from its energy-storage capacity, while drawing much lower peak currents from the wall socket, only about 15 Amperes.  In effect, it operates on an inductive basis to provide a power reservoir for the amplifier's current requirements, and reduces the source impedance at the amplifier's plug to much lower values than the 1 Ohm which is typical for a wall-socket, to values as low as 0.04 Ohms! 

These are normal, verifiable engineering considerations, and absolutely not 'snake oil' in any way.
 
cwr

[KeithA]

Thanks Chris and James

I knew there was science behind the approach.

Keith

[smerlas]

It is interesting to note that my observation is that the design of the Bryston amplifier draws less current than other manufacturer's.  I suspect that this is due to the large transformers and capacitors within the amp itself.  I have my 4BSST running through a Rotel power conditioner.  And can view the current draw and it is lower with the Bryston than other amps I have run.  And the lighting in the room does not vary with the intensity of bass even when driven hard.  I have been considering the Torus product and have been impressed with the amplifier performance without a "reserve" source introduced into the line.

[James Tanner]

It is interesting to note that my observation is that the design of the Bryston amplifier draws less current than other manufacturer's.  I suspect that this is due to the large transformers and capacitors within the amp itself.  I have my 4BSST running through a Rotel power conditioner.  And can view the current draw and it is lower with the Bryston than other amps I have run.  And the lighting in the room does not vary with the intensity of bass even when driven hard.  I have been considering the Torus product have impressed with the amplifier performance without a "reserve" source introduced into the line.

Hi - Which Rotel Power Conditioner?

james
   

[smerlas]

The RLC1040.  It is their newest offering and is manufactured for Rotel by APC.

[James Tanner]

The RLC1040.  It is their newest offering and is manufactured for Rotel by APC.

Thanks - this is a voltage regulation, surge (using MOVs; I believe) and filter device. It is not a "Power Isolation Transformer" unit like the Torus. From the specks it also seems to limit the voltage out to 12 volts.

james

[Tony1]

Hi,
 
The answer is, yes, the Torus does have a large energy-storage capacity. 

A Torus always draws current out of the wall in a sinusoidal waveform, whose AVERAGE power is equivalent to the amplifier's power draw.  An amplifier tends to draw power on only the top few degrees of the 60Hz waveform, however.  This means its peak current requirement can go very high, as much as 50 or more peak Amperes on a 300-WPC amplifier, even when the average current to the amplifier is only 10 Amperes RMS. 

The Torus can supply this high peak current from its energy-storage capacity, while drawing much lower peak currents from the wall socket, only about 15 Amperes.  In effect, it operates on an inductive basis to provide a power reservoir for the amplifier's current requirements, and reduces the source impedance at the amplifier's plug to much lower values than the 1 Ohm which is typical for a wall-socket, to values as low as 0.04 Ohms! 

These are normal, verifiable engineering considerations, and absolutely not 'snake oil' in any way.
 
cwr

[/quote]



James

Does this mean that even though I have a 15 amp dedicated line that I can use a Torus to run say two 20 amp amplifiers?

Thanks

Tony

[James Tanner]

Hi Tony,

No the difference is Instantaneous Power vs Average Power. You still want the total amount of power the amp can draw to match the Torus rating.

So for instance a 4B can draw 7 amps so 2 -4B's on a 15 amp Torus is the best possible option. Recognize that most of the time though your not using the total amperage draw from your amplifier so I usually recommend taking the total amperage the amp can draw and getting a Torus that is rated at about 2/3 thirds of that total requirement.

james

[vegasdave]

It is interesting to note that my observation is that the design of the Bryston amplifier draws less current than other manufacturer's.  I suspect that this is due to the large transformers and capacitors within the amp itself.  I have my 4BSST running through a Rotel power conditioner.  And can view the current draw and it is lower with the Bryston than other amps I have run.  And the lighting in the room does not vary with the intensity of bass even when driven hard.  I have been considering the Torus product and have been impressed with the amplifier performance without a "reserve" source introduced into the line.

This is my observation as well. The lighting does not vary even with the air conditioning on, the Bryston 4BSST is stable. Impressive!

[James Tanner]

Hi Guys,

The main thing to be aware of here is that the type of idle or average power that the amplifier is showing on these metered power conditioners is not the main concern.  It is when the amplifier is asked to deliver INSTANTANIOUS current that the Torus comes into its own. Meters etc. are far to slow to show this effect.

james

[KeithA]

I think the othe thing here to remember is that the 4BSST is likely not drawing anywhere near the instantaneous current it would like to from the household outlet. So, the amp will not show any peak surge  (say on the meters of a power conditioner, or causing the lights to dim).

As Chris Russel pointed out in earlier posts, most times this instantaneous current draw is only over 1/2 the cycle, so that just reinforces what James is saying about the peak current need being so fast it wouldn't register.

I have a 6BST and have a dedicated circuit for my system. My system sounded great before. With the Torus, it's definitely up a notch...and if nowhere else, definitely in the bass. The bass now is fast and articulate (even more than pre-Torus). Some people I know use expense power cords, with expensive connectors and expensice outlets to try to achieve a similar thing to what the Torus does, and that's reduce contact resistence at the outlet as low as possible and thus increase current flow potential. The Torus just does it in a different way....it just works.

If it didn't, I'd have no hesitation selling it.

Keith

[smerlas]

James,

If I am following this correctly, a 4BSST could draw 7 amps, 7 amps @ 0.67 = 4.67 therefore a 5 amp Turus would suffice for my 4BSST?  I have reviewed other postings on this and thought I saw anywhere from the RM10 to the RM15 recommended for use with the 4BSST. 

I have been considering using my Rotel "Conditioner" on my preamp, cable box, etc. and acuiring a Torus unit for the amp only.

Smerlas

[James Tanner]

James,

If I am following this correctly, a 4BSST could draw 7 amps, 7 amps @ 0.67 = 4.67 therefore a 5 amp Turus would suffice for my 4BSST?  I have reviewed other postings on this and thought I saw anywhere from the RM10 to the RM15 recommended for use with the 4BSST. 

I have been considering using my Rotel "Conditioner" on my preamp, cable box, etc. and acuiring a Torus unit for the amp only.

Smerlas

Hi Smerlas,

Yes I guess I was not very clear on that. When I said 7 amps I meant that was the 2/3rd draw. Also the draw will be different depending on the impedance of your speakers.

4B-SST Current Draw 120V:
2 channels @ 300W @ 8 ohms   1280 W= 10 amps
2 channels @ 500W @ 4 ohms   2100 W= 17.5 amps

So a 15 amp unit would be perfect with a 4B driven hard into 4 ohms whereas a 4B driven into a more benign load of 8 ohms would only require the Torus 10 amp unit.

james

[James Tanner]

I have a neat story involving Torus.

About 2 weeks ago I had a call from a customer in Vancouver. He had taken a 20 amp Torus home for demo from his dealer and installed it in his system. He called to say that he was not sure if he heard a difference in his system or not. I said give it a few days then take it out and see if he notices a difference.

He called me 4 days ago to say that he removed the Torus from the system and returned it to the dealer. I said that's fine if you could not detect a performance difference then there is no point (other than protection) in keeping it.

Yesterday he called me and said he had returned to the dealer and reinstalled the Torus in his system. Why I asked?  My wife said she could not stand to listen to the system since I removed the Torus!

james

[smerlas]

Bowers & Wilkons literature indicates that the 804s nominal impedance is 8 ohms with a minimum impedance of 3 ohms.

If I understand this next part correctly ............... the speakers impedance varies depending on how the speaker is driven .............. it would be safer to upsize to the 15 amp version for use with these speakers and the 4BSST. 

[James Tanner]

Bowers & Wilkons literature indicates that the 804s nominal impedance is 8 ohms with a minimum impedance of 3 ohms.

If I understand this next part correctly ............... the speakers impedance varies depending on how the speaker is driven .............. it would be safer to upsize to the 15 amp version for use with these speakers and the 4BSST. 

Hi Smerlas,

8 ohms nominal is the 'average' impedance of the speaker.  A small dip to 3 ohms over a small range is not a big issue. Given the quality of your system though and the ability to expand on it in the future I would recommend the 15 amp unit.

james

[smerlas]

Thanks James,

Do you know if Torus plans on a 15 amp unit in the BX series?  The Box style unit would allow more flexability in my installation than the rack mount unit.

Amp @ 62 lbs & Torus unit @ 76 lbs requires one heck of a shelf.

[James Tanner]

Thanks James,

Do you know if Torus plans on a 15 amp unit in the BX series?  The Box style unit would allow more flexability in my installation than the rack mount unit.

Amp @ 62 lbs & Torus unit @ 76 lbs requires one heck of a shelf.

No I am sorry there are no plans for a Box version of the 15 amp - the transformers are HUGE so the do weight a lot.

james