Cable for my amp.


Hi,

how do i find out whether my amp takes 15A or 20A power cables??

I have a Mark Levinson 27
thx
yingying99

Showing 8 responses by nsgarch

First, to answer your question, the ML 27 takes 15A (smaller truncated) IEC connectors. I'm pretty sure all ML amps do, even the new models.

A somewhat associated issue, which has come up before has to do with whether or not certain aftermarket PCs can be called 20A cords if they only have 15A IEC connectors, even if they have 20A AC plugs on the other end and are made from 10AWG (or larger) conductors.

I think the answer is "no" and I'm sure Underwriters Laboratory would think so. Though there is nothing illegal about making a PC with "20A -sized" conductors and 15A plugs on each end, it's not a 20A cord unless it has 20A plugs on each end as well.
.
YY -- do not lump all power devices into the same category. There are basically 4 kinds of devices:

1. Regenerators
2. Conditioners
3. Isolation transformers
4. Balanced power units

The first device to try is really not a device: dedicated circuit(s) with or without isolation (transformers)

1.) REGENERATORS: If you can't install DCs for some reason, the next best thing is a power regenerator. Basically a PR takes wall current -- dirty, noisy, fluctuating, inaccurate wall power -- and "re-manufactures" it into perfect, theoretically ideal AC power. The best (most electrically efficient) one currently on the market IMO is the ExactPower EP-15A.

2.) CONDITIONERS: Power conditioner/surge protector units, including a very well respected one named after one of the Greek Furies, are basically an assemblage of chokes and other filters plus some fast acting diodes. They can filter and cancel most line noise, but they do not improve the quality of the wall AC itself, and they do not offer meaningful protection against voltage spikes. The internal components they use can greatly slow down energy transfer (especially important for amps) rendering even the biggest power cords useless. I totally pass on these devices, and so should everyone (in my ever-so-humble opinion!)

3.) ISO TRANSFORMERS: These can be used with regular wall AC, dedicated circuits, regnerators or balanced power units. They are most often found with dedicated circuits and no other devices. They offer excellent protection from ground spikes (lightening) line noise and some powerline irregularities. They need to be large capacity to work with big amps, and can be expensive, but seem to be most popular with audiophiles who are also electrical engineers -- they must know something ;--)

4.) Balanced power units are an excellent way to provide quiet -- really quiet! -- power to source components. They represent a "finishing touch" after you have done dedicated circuits and/or 1 or 3. They usually do not improve amplifier performance, so buying one with sufficient capacity to handle an amplifier is not cost-efficient.

Your electronics and speakers are a nice combo, regardless of what other ppl use. If you ever have the chance to score/upgrade to a 26s and/or a 27.5 or 23.5 do it, and keep the speakers.

The 390S is in the top ten. It's not in the top three, but would have good synergy with your 26 -- use the balanced interconnects with it -- either Madrigal CZ GEL or PAD Venustas. Also use balanced PAD Venustas ICs between the 26 and 27 and for the spkr cables.

Get rid of the cheap power conditioner but don't spend money on an expensive one! If dedicated circuits can be installed DO IT before spending money on ANY power devices. If they can't be installed, then get an EP-15A and plug everything into it. That may be all you ever need.
.
Sam and YY, the Shunyata Hydra is one of the most popular power conditioners. Please re-read my comments on these devices. Even though it's very expensive, the Hydra is still just a conditioner, and therefore in my opinion, not the best use of your money. And when used with amps, can actually degrade performance. I guess their power cords are OK, I've never tried one.

YY, you would be best served with an EP-15A. I don't think they are switchable but I'm sure you could get a 220V version. Check with Brent Jackson at the factory:

TECHNICAL SUPPORT:
800-773-7977 toll free
818-886-5364 outside USA
818-886-0504 fax
info@exactpower.com

I forgot to mention that the Exactpower units (both the regnerator and the balanced power unit) also have a couple of outlets with filters to trap digital noise your DAC or CDP power cords can send back into the power lines. This is a really good thing, and why people who install dedicated circuits often put in an extra one just for their digital gear.
.
Samzx12, no, I must admit I never auditioned a Hydra. However, all power "conditioners" like Hydra, Monster, Panamax, PS Audio, etc., are variations on the same circuitry, and use the same kinds of components. They all present the same problem too, which is that in using passive circuits and devices to reduce noise, they slow down energy transfer.

Nobody realized this problem at first. Amps were less powerful and/or they didn't have detachable cords. Everybody was happy to have surge protection (they hoped!) and less line noise. Then, with the introduction of large conductor aftermarket power cords, folks began to realize that these power conditioners were choking their amps, which sounded better plugged right into the wall. In addition to that, today's components often already have built-in surge protection and some noise filtration.

Power REGENERATORS compare what's coming out of your wall (in terms of noise, sine wave accuracy, and voltage stability) with the ideal AC power profile, and corrects the wall current to match the ideal, using active amplification and feedback. The Exactpower unit does this very efficiently by "fixing" only the distorted parts of the incoming AC power and leaving the rest alone -- it doesn't throw out the whole signal and start over, which would waste energy and is how some other regenerators work.

Power "conditioners", regardless of brand, are IMO a thing of the past for serious audio. To quote a friend who designed the first line of super high-end DACs, "they do more harm than good."

And balanced power units, although they can be used as "stand-alone" devices (right from the wall) end up being unnecessarily large capacity if you want to plug everything, including your amp, into them. This might be OK for a recording studion, but completely unnecessary for a home audio system.

So basically that leaves the following options:

1. Dedicated circuits with or without a power regenerator or isolation transformer(s). A regenerator is necessary with dedicated cts. ONLY if your utility power fluctuates a lot or has noise in it before it even gets to your house (a common problem in New York for instance) With dedicated circuits alone, you get no lightening protection so unplug everything during T-storms.

2. Regenerator in lieu of dedicated cts. Even with decent utility power, this is the BEST way to insure an adequate power resevoir for your amp, plus quiet noise-free power and spike protection for your other equipment.

If you want, you can plug a (modest capacity) balanced power unit into the regenerator for the ultimate in quiet power for your source equipment. Another benefit of balanced power is it eliminates (cancels) the hum caused by ground loops. (It doesn't necessarily eliminate the ground loops themselves, but who cares!) Therefore, you don't have to worry about lifting the ground pins on any of your components' AC plugs -- thus improving both safety and performance.

Regenerators (NOT conditioners) are the ONLY logical solution for condo and apartment dwellers for whom dedicated circuits are out of the question.
.
Samzx12 -- your choice of words:

do a nice job cleaning up the power

tells me I'm not being clear enough. Power conditioners "clean up" power (power regenerators don't need to) by filtering EMI and RFI out of wall power. Add a (current limiting) circuit breaker to protect from lightening strikes (yeah right!) and it's a finished product. For example, here are the specs for the Hydra 8, their best unit:

Trident Defense System
1.) • Shunyata VENOM noise-reduction filters (16 elements):
These are wire-wound chokes to take out line noise from refrigerator motors, etc.
2.) • Patented FeSi-1002 noise-reduction compounds: These are nothing more than ferrite chokes for RFI. Patented iron? I don't think so ;--)
3.) • 8 cryogenic treated Shunyata SR-Z1 outlets: Must be why it's Hydra 8! What, Ever, there's outlets and there's outlets!
4.) • Four isolated individually filtered circuits: Code for 4 duplex outlets, the 8 outlets (total) already mentioned
5.) • Massive cryogenic grade CDA-101 copper buss array: So they froze 2 copper strips and attached the 4 duplex outlet to them. Whoopee!
6.) • Advanced hydraulic electromagnetic circuit breaker: I'm not sure what the hell this is. Maybe it just makes a SOFT pop when it blows because it's hydraulic! CBs are like fuses and they limit current. They belong in your electrical panel, not in your audio chain. Your equipment already has fuses in it (unfortunately) so you don't want any more!
7.) • 2400 watt / 20-amp power rating: Only if it's attached to a 20A wall outlet with 20A AC and IEC plugs. In fact, the Shunyata PCs have 15A AC plugs on them standard, otherwise they wouldn't work in most folks homes.
8.) • Dual chassis -- all aluminum case: Thats nice, I guess.

OK, so my point is, the only parts that are doing anything are items #1 and #2. Item #6 it would be better to leave off. The rest is just fluff and cool-sounding copy. A massive rip-off IMO.

Regenerators, by comparison, don't CLEAN up the power. They CREATE new power, which is clean to begin with. So they don't really need all these little beads, and coils and filters. And although they all must be fused to meet UL requirements, they don't require circuit breakers or diodes to protect your equipment. When the AC-matching amplifier feedback loop senses a voltage spike, it simply tells the amplifier to shut down. Instantly. No muss, no fuss, no continuous current limiting.

By the way, just for general info, one reason some equipment (like the Hydras) aren't sold with PCs (or with just junk PCs) is that to get UL approval, any shielded PCs sold with electronic equipment must have the shield attached to the ground pin at both ends of the cord. Do you know what that means? It means INSTANT GROUND LOOP! So most manufacturers hope you'll just go out and buy a 10AWG PC with a floating shield.
.
YY, I bought my EP-15A and my SP-15A used for $1075 and $930 respectively (great deals both of them ;--) There are 2 used EPs for sale on the Gon right now. The higher priced one is a newer model which comes with 2 digitally filtered outlets (for your CDP.) The cheaper one could be sent back to the factory for a no-charge upgrade. (my advice: offer $1100 for the cheaper one and send it to Chatsworth CA for the upgrade. It's a light weight unit and won't cost much to ship.) MSRP is around $2500 I think.

Here's an AgoN discussion on the Exactpower units:

http://forum.audiogon.com/cgi-bin/fr.pl?aamps&1123946553&openfrom&1&4#1

Except for the 33H (still in production) the best amps Mark Levinson has made so far are:

20.5
20.6
23.5
27.5
33

The 20, 23, 27 are good units, more like today's 300 and 400 series. But they don't use teflon PCBs and upgraded components, and just don't have that special sparkle and effortless presentation of the ".5" versions. I use my 23.5 with CLS electrostats, and they sound allllllmost as good as they did with ARC tube amps ;--)
.
I agree that a 331 (might) sound better than a 27 (certainly not worse). However I'm of the opinion (along with many others, I might add, just search the threads) that a 27.5 will sound better than either one of them, in a number of important areas: soundstage, midrange openness, bass articulation, headroom, high end smoothness, and not dark sounding like the new stuff.

In fact, the only recent amps by Mark Levinson that equal or exceed the performance of their "Golden Age" amplifiers (the 20.5, 20.6, 23.5, 27.5) are the 33 (no longer in production) and the 33H -- primarily because of their amazing "power regenerator" type power supplies (not in the 300 or 400 series) and even better (than Teflon) printed circuit boards and newer component devices.

If you're searching to buy brand new SS amps, I'd look elsewhere if I were you. Sadly, because I've loved Levinson equipment for a long time. But today, there are much better choices in that price range. Pass, Lamm, Rowland, Boulder, darTZeel, Goldmund, FM Acoustics, etc., if you really want to spend that kind of money and buy new stuff.
.
Sam, the Powervar is simply an isolation transformer with some noise filters, an on/off switch, and a few built-in outlets. If you have good reliable power from your utility company, and you can install dedicated circuits, this would be a nice finishing touch.

It is not a power regenerator. Nor is it a balanced power unit.
.