[vklyushnikov]

Hi,
I have an issue with Bryston based system (bcd-1, bp-25, 4bsst): at evening during peak power usage hours the system almost always sounds bad. Highs becomes muffled, bass becomes fat and slow. But voltage is stable - near 220V (Russia). I use stock power cords, connected to standard 10A wall plugs . No dedicated AC line and it is impossible to install.  But no other device on same line causes such impact - I may switch off everything and issue still remains.  I never listen on full power, the issue is clearly listenable on moderate volumes. But at daytime sound is always good, clear and fast.
So I have the following question - what causes sound degradation? Maybe amplifier cannot draw enough current from mains? In such case can Torus RM 8 really help to solve issue? It's hard to make a purchase decision because here in Russia we don't have money back warranty for such equipment.

[Napalm]

Check the power line with an oscilloscope. If the voltage looks roughly like a sine wave and has the required amplitude, then a Torus (or any other device) won't do anything for you. Except maybe some additional trouble.

See below power at my location while contractors are using a bunch of construction power tools across my street (connected to the same transformer as my house). While severely distorted it still does nothing to the amp, it takes much more than this to affect it.

[Elizabeth]

If you live in a residential area, it may be the local transformer is strained to meet demand when everyone gets home in the early evening.
So your power may be 'low' like what (in USA)is called a 'brown out' low voltage..
Checking what the voltage is in the time period when you have issues..
An AC voltmeter (OK for 220v use) is easy to borrow. See is the voltage drops compared to during the day.
If it is low voltage, then a device to maintain the correct voltage would be better than a conditioner.

Here, if the transformer was going bad or overstressed.. we could call the electric co and get it replaced.. Do not know if you could do same?

[vklyushnikov]

Voltage is stable 220V all the time - AVR feature seems to be not required (checked with voltmeter). I'm living in apartment block (200 apartments). So we have large number of power consumers on single transformer. I sure that AC noise level is high at evening. Unfortunately I'm not familiar with oscilloscope to check this.
But it's a common issue in such buildings here. In russian audio forums many people with different systems discuss similar issues. Torus conditioners are new here - there is little info about their benefits in our conditions. I've asked audio shop yesterday - they only told me that they sold two Toruses and feedback is good.

[drummermitchell]

Why not give Torus a call,just look up Torus Power and look under contacts.

[werd]

Check the power line with an oscilloscope. If the voltage looks roughly like a sine wave and has the required amplitude, then a Torus (or any other device) won't do anything for you. Except maybe some additional trouble.

See below power at my location while contractors are using a bunch of construction power tools across my street (connected to the same transformer as my house). While severely distorted it still does nothing to the amp, it takes much more than this to affect it.

Wow nice distortion on your line. No wonder you are so bitter. ...lol

[Napalm]

He can definitely try. However it definitely helps to first understand what exactly the problem is - before attempting to fix it.

Also do not forget what the Torus is - an isolation transformer. It does a fantastic job at breaking ground loops created by equipment where the "engineer" decided to connect together safety ground and signal ground. It will also filter the high frequency components of the power noise. However if the power is severely screwed up, it won't be able to restore it to a sine signal. In that case you're looking at something like an inverter.

OTOH consumer equipment, especially expensive one, is supposed to be engineered to work from regular consumer AC power outlets within its tolerances - i.e. it should not fail or degrade when the power signal is deviating to some extent from a perfect sine of nominal value.

If it does then it was not properly designed.

[Napalm]

Wow nice distortion on your line. No wonder you are so bitter. ...lol

Say Werd why don't you try one on your line, you'll be amazed by your discoveries.

I would also suggest a couple of other very revealing test points:

- the output plug of that 1 inch thick miracle AC cord (selling for $1000 or so)

- the amp's rectifier stage output, with and without load

- the outputs of the CD player, preamp, amp and the speaker connector, with no input signal and with signal (sine and square)

[tim92gts]

Not sure what the voltage range spec of your 4B will be but if the voltage is too low you'll need some form of regeneration to convert the variable mains into a constant 230 or 240 Volts.
If 220V is indicated you may have lower transients?
i couldn't see a Torus product doing quite the right job but there may be one.
If not would something like the Furman P-6900 AR E Voltage Regulator/Power Conditioner (30A) be available within budget?
Could be slight overkill but other regenerators are available.
My Bryston amps do a fantastic job of cleaning up the mains power so the only reason i have to use conditioning is for lightning protection.

[snook2]

The torus avr 20 amp has voltage regulation along with isolation transformer and line conditioning.

This sounds like a wise choice.

Is the Bryston power conditioner a Torus{plitron} in their metal box?

[drummermitchell]

Yep,but has the Bryston faceplate (BIT) matching Bryston amps,components ect.

[Speedskater]

If you think that, that trace is ugly then you should see the current waveform of a typical power amp's AC input.  It's often about 75 % THD.