More output with no double down vs less output with double down

[SomeGeoffGuy]

My Coda Continuum #8 v2 produces up to 150 amperes of current output. Are you saying I need to have an electrician on retainer because of this rating??

I am just saying if you run big power, don't just add a big powerstrip to whatever outlet was there when you moved in. When I first moved into my house, the living room was all on one circuit and for some reason it had a wall switch that controlled it. I finally bypassed the switch, but was horrified at the giant wire nutted bundle that was literally powering my entire stereo system TV, power chair, etc. So I put in a circuit by the stereo - just one outlet although I probably should have cut in two. I was thinking that if I ever went with some big mono amps, I would run a circuit to each one, too.

Also, you can buy special outlets that make better contact. A lot of people say "Hospital Grade" outlets are fine, but you can spend as much as you want on this stuff as is the usual in our hobby! Most of the big power conditioner manufacturers also sell a line of outlets. At the minimum, I would run at least one dedicated circuit to my stereo system with a hospital grade outlet. But yea, if you are putting in a home theatre - seven seems like a good number!

-Geoff

 

[ttocs]

^^^^ +1 about the hospital grade outlets. They have a VERY strong bite on whatever is plugged in, and that's the only reason I use them.

 

[wink]

I have six of these PS Audio Soloists throughout my audio system.

 

[Robert D]

I went a little nuts on outlets when I updated the electrical 5 years ago. There are seven 20A circuits for the audio/video system. The lessor items are plugged into a couple Panamax M-5400PM and both are using one 20A outlet. And the higher wattage stuff, amps, subs, Expressions, are distributed amongst the rest.

I have the distribution setup such that when listening to two channel music the items that are being used have the most amperage available to them.

You can't have too much service in a room, but at what point are you just throwing away money? I'd hate to spend on something needlessly. I like the idea of being over the minimum needed though! Can see myself doing that in a new build, but wondering if there is a good way to know how much you need.

 

[Robert D]

I have six of these PS Audio Soloists throughout my audio system.

What qualities do those have that make them good? I know nothing about this stuff.

 

[Leporello]

Theoretically, which amplifier drives best, to low or medium listening levels, a ML hybrid (e.g. Spire, Summit, Montis, Expression etc.) (sensitivity: 91dB, Impedance: 0.8/20kHz);
a) An amplifier that doesn't double down, but delivers 300W/8Ohm, 430W/4Ohm, stable at 2Ohm loads (like the Mark Levinson 532H), or
b) An amplifier that delivers 135W/8Ohm, 270W/4Ohm, stable at 2Ohm loads (like the new Mark Levinson 5302)?

Notice that in both cases the amp manufacturer doesn't state exact output at 2Ohm, and doesn't say anything about <2Ohm loads. Actually, the 532H which I've been using for the last 5 years to drive my Spires, is stable with them. However, I am not happy with the reproduction of high frequencies, which seem to be faint and weak.

Comment: Traditionally high quality manufactures like Mark Levinson, Krell, Parasound, Electrocompaniet, Simaudio, PassLabbs etc. that used to manufacture power amplifiers that doubled output down from 8 to 2 Ohm, do not make new models with this specification. I think this is becoming a common issue to ML owners or future owners, who need to know the amp output in very low loads.
Theodore

I believe the criterion of doubling power for each halving of impedance is widely misunderstood. If you consider an ideal voltage source--one of many useful fantasies constructed by electrical engineers that don't exist in the real world--the voltage V remains constant under any conditions, so the power V^2/R doubles as R is halved. If your amp does that at 8 versus 4 ohms it approaches the behavior of such an ideal voltage source. But say you played your amp at a level just below clipping into 8 ohms, then put a crowbar across the speaker terminals. Then one of a few things might happen: the protection circuitry kicks in, or the speaker fuse blows, or the output devices--and probably a bunch of stuff connected to them--act as speaker fuses, or the power supply sags to near zero volts, or the power supply fuse pops, or the house breaker trips. Something has to give, at any rate.

Now suppose you take your super amplifier that doubles its 8 ohm power at 4 ohms and again at 2 ohms, and connect a 4 ohm high wattage resistor in series with your speaker. If you only plan on listening at low levels, you may not care about the amount of power wasted across the 4 ohm resistor. But the fact remains that with a speaker whose impedance varies wildly with frequency such as an electrostat, the frequency response is going to be radically different compared to the amp driving the speaker straight, with no series resistance. If the speaker is designed to have a certain frequency response at constant voltage, it's going to be altered significantly. This will be true regardless of how loudly or softly you are playing the speakers.

It may well be that the speaker was not designed for a constant driving voltage but rather, for a real world amplifier, which may not deliver the same V^2/R at 8 and 4 ohms. And anyone who knows anything about loudspeaker design knows that a speaker designed to have a flat frequency response from 20 hz to 20 khz on axis in an anechoic chamber will sound terrible. And regardless of what the "all amplifiers sound the same" nerds say, other factors like nonlinearities they claim are insignificant do make a difference. Which is why I added the Yogi Berra disclaimer to my original comment.

Speaking personally, I recently bit the bullet and bought a pair of used Parasound JC-1 monoblocks to drive my CLS II's (the new JC-1+ is too rich for my blood right now). These amps do inf fact double their power at 4 ohms versus 8, and are guaranteed stable into 2 ohms. I love the CLS II's, and have never heard them sounding better. So the amp case is closed for me.

 

[wink]

What qualities do those have that make them good? I know nothing about this stuff.

https://www.crutchfield.com/S-vgnO3pFQECD/p_681SOLOIST/PS-Audio-Soloist.html

 

[SomeGeoffGuy]

https://www.crutchfield.com/S-vgnO3pFQECD/p_681SOLOIST/PS-Audio-Soloist.html

Those look pretty nice! Too bad they are discontinued...

 

[JonFo]

I generally subscribe to the notion that the quality of power is more important than the connectors and plugs (assuming they are not garbage), so I run a Balanced Power rig driven by a 5KVA Equitech transformer connected to a 30A 240v source. Zero noise and huge current reserves in the 200+ lbs transformer.
Did have to engineer my own power distribution and sequencing though: https://www.avsforum.com/threads/power-distribution-unit-with-relay-controlled-outlets-–-build-thread.3028892