power line conditioners...

Bicycleman,

What bikes do you ride? I keep a Seven and Serrotta in my garage.

As for the power conditioners. First, no energy/power is stored in a transformer, so that isn't it. You likely are seeing the fact that you are now less influenced by interference in the line, but transformers can hummm so they aren't used in many (some do) power conditioners. A transformer also can't do anything to control or eliminate spikes or drops in the power, it will simply reproduce them on the output side.

Also when using a 500Volt-Amp transformer, you are limiting yourself to ~4 Amps of power @ 112 Volts, so I am surprised the bass is better and the dynamics too, but every system is different.

I live in florida and we have horrendous power here thanks to all the A/C's and such, so I have been using power products for years. I always liked the Chang Lightspeed units (TIP, I am selling these now) but once I tried the PurePower APC 700 I stopped using them, the PP's regenerate your electricity to perfect sine waves and have a battery backup so it can actually deliver more power instantaneously than the line itself, and keep you from suffering from power sags or surges. They aren't cheap, but they improved the sound so much in my system, I will likely never be without one or two again.

Well put questions. My intuition as an EE is that the improvements you noted revolve around the fact that you are using a very early preamp and amp (even if they have been modified/upgraded). I suspect your findings would be different with newer electronics.

I would think that although energy stored in the inductance of the transformer may be a factor, it is more likely that the transformer's most significant effects are due to filtering of high frequency hash that may be on the ac line (the filtering being provided by its limited bandwidth), and also to the ground isolation that it provides.

I suspect that your preamp and amp have less than ideal isolation between their chassis (which are probably used for signal ground) and ac neutral, due to component degradation that has occurred over time. That would have sonic effects that are hard to predict in both character and magnitude, but would almost certainly be negative. Likewise for the effects of incoming hash/noise/rfi on the ac line. The transformer very conceivably would help in both areas, but would have different and probably lesser effects with modern gear, due to the modern gear probably having components which are in better condition, as well as perhaps better overall power supply design, and components such as capacitors which are better quality to begin with.

I'm not experienced with plc's, but I've seen a lot of comments here from experienced people that with modern, quality, gear they usually do more harm than good. Not sure why that would be so. Most of them, I'd imagine, provide inductive and capacitive filtering of high frequency garbage, as well as isolation.

There are one or two very expensive models that actually convert the incoming ac to dc, then use the dc to power an ac oscillator and amplifier, thereby providing a really pure ac source. I have not seen any assessments of those units.

Regards,
-- Al

BTW, I want to make sure that nothing in my previous post is construed as being pejorative of older tube gear. I've had several pieces of 1950's and 1960's gear in my main system over the years, and still do in the case of the fm tuner, and I have great respect for the sound quality they can provide if in good condition.

Regards,
-- Al

Thanks for the replies! Very interesting information. And, it seems very reasonable about the hf hash being filtered out.

Kennyt, perhaps because the power supply in my st70 is the original the quad filtering cap is so far gone that filtering out garbage and fluctuations helps even with such limited current availability. I am currently modifying the ps with the SDS Labs power supply board.

By the way, I ride a 1981 Eddy Merckx with full Campagnolo Super Record. I sometimes swap the derailleurs out with Nuovo Record. I recently had it restored by Tom Kellogg in the Molteni paint scheme. He did a wonderful job on the bike! I do my own mechanics, and build my own wheels. Brazing in a new headtube was beyond my capabilities, so off it went to Mr. Kellogg.

Thank you, again, Kennyt and Al for your thoughtful replies!