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I use a different kind of test. It's called a listening test, and it separates the good form the bad real easily.
So you’d be able to pick out a cable in a double blind listening test?
I don't think it's a good idea. Read the following link to better understand why there are issues with this approach:[size=78%]http://lightharmonic.com/blog/2015/07/24/power-supplies-and-noise/[/size]
These test as well as the ones Audio Precision includes with their $30,000 analyzers:Audio 2000s E02101P2 XLR Male to Female 1 Feet Microphone Cable (2 Pack) https://www.amazon.com/dp/B00O5UBK5U/ref=cm_sw_r_cp_api_i_0y7eDbEDBBKCE
Tommy, I know you are science guy and measurements are an interesting angle to consider, but they don't tell the whole story. As a listener, I am much more interested in how a product sounds than how it measures. I've heard well spec'd amps that sound like crap and poorly spec'd amps that sound amazing.
Running from batteries is less likely to cause a sonic difference with Maraschino amplifiers because of great PSRR. Since the Maraschino also has a floating ground on the other side of isolation from the AC line, it's almost like running from batteries already. In fact, it's better in that batteries aren't regulated, but the Maraschino's power supply (whichever type/voltage) is regulated. Then there's the argument about noise on the power supply, which, in the case of Maraschino, is way out of band, so it's filtered out nicely by the Maraschino's built-in filtering.
Is there a 30V-60V (through regulated DC/DC conversion) battery powered supply already available from somewhere? It's easy enough to try this out if so.
SO, it stands to reason that powering the Maraschino DIRECTLY from batteries would be preferred, since that way, there's no DC/DC output voltage ripple.
So, would Danny's three 12V 100 amp-hour batteries chained together to get him to 36V with enough juice on tap to not have to worry about voltage drop or lack of current for at least a reasonable while even if the battery bank were left completely off the chargers to isolate just the batteries alone for testing purposes get where we need to be to give the maraschinos a good run for comparison with power output to the speakers similar to a stock wall power supply? If so, Danny just needs a pair of amps as-is with a couple pigtail wires for the battery connections to the DC power inputs on the amps.Unless I've missed something in the conversation here, it sounds like this test is good to go as soon as Danny can get his hands on a pair of amps (or a STM)?
Are the HF noise issues mentioned not easily controlled? 30 years ago I was running my microphone preamps off 2 pairs of nicad batteries to get ±18V and I had a small pair of capacitors across the output to short out the HF noise that I had read that nicads generated. This is not recent news. As far as I know all rechargables generate some kind of (typically HF) noise when being drained.Also, I wonder if contemporary designers of domestic DC powered audio are experimenting with what car audio designers have employed for decades: huge electrolytics inline between amp and speaker to provide instantaneous power for brief transients, beyond what the amp is capable of delivering without clipping. The rule of thumb appears to be 1 Farad per 1000W.
Okay, keeping the topic on batteries.......Send me a couple of your amps. I'll try them with whatever power cable that you send with them and with various other power cables that I have.
Someone on here mentioned that you have batteries that might work. Can you send them? Alternately....
We can’t afford to send free amps out very often. Our margins are low, and we build to suit. Demos are reserved for sales to supplement cash flow. Are you able to purchase a pair? I can provide the information you need to carefully apply the battery supply (see “ramp up” elsewhere in this thread)....
First, thanks to those who took the time to respond!To be blunt, I’m skeptical of any system that’s sensitive to minute differences in cables, assuming they are low enough resistance to realize the full potential of the amps (speaker cables, power cords), or of decent quality (interconnects) to get the signal to them. This is a sign that something’s wrong, such as improper grounding, impedance too low at the destination, impedance too high at the source, inadequate shielding, bad connectors, etc.A legitimate double blind test (adequate sample size, controlled environment, only one change per iteration, multiple sessions) is the only way to prove a repeatable difference.If I choose to build some battery powered Cherry Amps, I want to hear them myself first. I want to measure them as well. I don’t believe tremendous available current is necessary. It’s not as simple as just hooking up batteries, in the case there’s no DC/DC between them and the amp, but not rocket science either. Anyway, I’m still wondering if it’s worth the trouble because the Maraschino, for example, is a very high performance amp as-is, and we’ve tested (including lots of listening, of course) with several different power supplies already. So, if only 2 people will ever buy a battery based power supply, it doesn’t make sense to spend the time/money to develop what will be yet another option, thus complicating the product line. We went through something similar with a linear power supply for Maraschino amps. We sold a few, but interest was light, and it wound up fading away. It was a good power supply, and super heavy for its size, but resulted in lower power output. Other specifications were the same, and so was the sound, except when large peaks while driving difficult speakers (Mags) were too much to handle. Meanwhile our standard 60V 1kW switching supply powered though the same tracks without a sweat!
