System assembled; only a final decision about speakers remains

Hilde45,
Thank you for the heads up. I appreciate it. 

@hshifi I read recently that even with a whole house protector, one should retain something for protection at the wall outlet. Maybe you're just doing an experiment?

Hello,
I thought coax was better than toslink. I have tried it myself and in my system it holds true going into the same DAC from my Oppo 205. I have to try the amp straight into the wall when I get a chance. If I like it I will put a whole house surge protector on my breaker box. I use the Furman Stable Power Regulator-SPR 20, but I will still try the wall outlet for the amp. 

^^^ Good move!

I can tell you, btw, that Professor Kingsfield (as played by John Houseman in "The Paper Chase") was a softie compared to some real-life law professors :-)

Best,

-- Al

@dill  D'oh! Newbie mistake. I shall channel Professor Housman and conduct a shrouding.

@atmasphere Thanks for your post and I'm copying a bunch of this into notes. I moved from a Salk 83 db speaker up to a 90db speaker after a conversation with Jim. The cost of the speaker went up, but my required amplifier power went down — and so did the cost. I thought I'd be safe with 60watts tube. At this point, I'll just have to try the 90db speaker and hope Jim was being conservative. Otherwise, it will go back and I'll keep in mind that figure of 93 db and the other good details about the 4 ohms, double woofer, and various ways of tackling the math.

OP, remember rule #1 ...

@kenjit I could ask Jim what makes his speakers better, but my guess is he'd do what anyone who makes good equipment would do — shrug and tell me to try them and return them if I don't like them. And I suppose if I ask for evidence of perfect phase coherence, I should use all caps — just to let him know I'm "on to his little scheme"? [I mean, dude — didn't I already say, right at the beginning — that this is simple? Buy, try, keep, or return? I can explain that to you, but I can't understand it for you.]

IF: you have a 60w tube amp with a damping factor of 20,
THEN: make sure you get a speaker that is, at least:
___ sensitivity
___ ohms nominal
___ ohms curve that looks like [insert description]
___ other metric(s)?

Having a rough and ready chart like this could help me rule out of bounds any number of speakers.

A lot depends on the room- a bigger room will mean that you need greater efficiency. A chart would be nice but you don't really need one.


A flat impedance curve is nice but not mandatory. What's important for a tube amp in the bass is that the impedance is benign. As a general rule of thumb I avoid speakers with dual woofers as they tend to be nominally 4 ohms, and that's going to be a lot harder to drive. You need to make the most of the watts you have; a 4 ohm woofer array for a tube amp is like using a poor lubricant in an engine- it won't make as much power and the tubes will wear out faster.


The more feedback the amp has the more peaks it can tolerate in the impedance curve. If the amp has no feedback then the speaker has to be designed to accommodate that. Since the ear tends to favor tonality induced by distortion (brightness of solid state, 2nd harmonic warmth of tubes) over actual frequency response, this can be important. There is more information about that at this link:
http://www.atma-sphere.com/Resources/Paradigms_in_Amplifier_Design.php

IME 50 watts is a bit lean in the power department if the speaker is only 90dB. My speakers are nearly 98dB and I find 50 watts is pretty nice on that; that would be like running a 300 watt or so amp on a speaker that is only 90dB. Now you can see how important speaker efficiency actually is!

One further note- since the industry has gone over to voltage measurements rather than power, you can run into important issues when trying to suss out speaker efficiency! In the old days a speaker was measured at 1 watt/1 meter to get a certain output (Efficiency). Nowadays a voltage measurement is used (Sensitivity) which is 2.83 volts/1 meter. 2.83 volts into 8 ohms is 1 watt but 2.83 volts into 4 ohms is 2 watts. The difference there is 3dB, a doubling of amplifier power. Now tube amps don't double power as impedance is halved; this is why Efficiency is a more important and useful spec when sussing out speakers. But since Sensitivity is used you always have to do that math. For example, if a 4 ohm speaker is 90dB, subtract 3 dB off the Sensitivity to get the Efficiency value; its actually 87 dB 1 watt 1 meter. Conversely if a 90dB Sensitivity speaker is 16 ohms, add 3 db to get the Efficiency.


So beware of that! IMO, in most average American rooms, 93dB and 8 ohms is a good place to start if your amplifier power is 50-60 watts. One other thing to watch for is some speaker manufacturers are more conservative about these ratings than others, depending on what part of the efficiency curve (bottom or top) the speaker's rating is derived.

I wouldn't plug a power conditioner into a power strip.

Steve, that is not what he will be doing.  This particular conditioner/surge suppressor mounts directly on the wall outlet.  It in turn provides only two outlets.  He will plug a power strip into one of those two outlets to provide up to ten outlets he can use for the components in the system.  The power strip will contain nothing other than wires and outlets.

Regards,
-- Al

I wouldn't plug a power conditioner into a power strip.

you also need to demand EVIDENCE of this perfect phase coherence in the crossover region. 

need to ask jim what makes his Speakers better! he claims perfect flat response on website but there was never any evidence that is needed for perfect sound!! 

@atmasphere Thanks for returning me to the original (and most important) unanswered question.
There are some basic facts I know to pay attention to with my amp (e.g. it’s monoblock tubes, w/ damping factor is 20, putting out 60 watts), etc.
When I look at potential speakers, some facts are given — their sensitivity, nominal impedance.
I realize, too, that different speakers have different power requirements at higher and lower frequencies, and that often one needs to know the nominal and minimum impedance — or, better, the impedance curve of a speaker.

I have read a lot of articles and even tried a spreadsheet as shared by Hans at this video:
www dot youtube dot com/watch?v=itKqSWH07_Y

What would help me is to have some basic information as to what a speaker’s specs should look like in order for an tube amp of X power to drive it comfortably.

Something like:
Assuming these specific variables (about listening distance, loudness, music type, room size, etc.)…
IF: you have a 60w tube amp with a damping factor of 20,
THEN: make sure you get a speaker that is, at least:
___ sensitivity
___ ohms nominal
___ ohms curve that looks like [insert description]
___ other metric(s)?

Having a rough and ready chart like this could help me rule out of bounds any number of speakers.

The Salk SS6m speakers I ordered mention/show their "ruler flat response" and note that they are "phase coherent in the crossover region." Then, the site gives the usual (pretty vague) specs as

• Sensitivity 90 db
• Impedance 8 ohms
• Amplification 50 watts

www.salksound.com/model.php?model=SS+6M

Jim S. told me that his speakers are driven comfortably with even 30 wpc in a room larger than mine. So that put me at ease. But if I entertain other speakers, it would be great to have a chart to suss them out.

With regards to the OP:
Since you are using tubes, its in your best interest to get a speaker that is at least 8 ohms (especially in the bass region) and easy to drive (no difficult phase angles, higher efficiency well into the 90s at least). Tube power is expensive, and to get the most out of it its a simple fact that high impedance speakers allow the amplifier considerably better performance.

In the case of amplifiers that use output transformers, the lower the impedance of the speaker, the less efficient the transformer becomes. This can actually result in a loss of bandwidth on the bottom end- in some cases by as much as an octave! You'll also find that the transformer runs cooler when driving a higher impedance load; the heat comes from the power made by the output tubes turned to heat. Its better when its turned into sound by the speaker :)

An often over-looked issue is the speaker cable- with higher impedance loudspeakers (such as 16 ohms) the speaker cable is relatively non-critical; with low impedance speakers the speaker cable is really important as is its length.

@djones--gotcha. Receptacles. Yes, I think I found my conditioners' answer. Thanks!

I just didn't understand if by power outlets you meant receptacle or something to do with the power strips, conditioners you were discussing. Hospital grade receptacles are very good at gripping the plug. A good one will cost about
$40 -$50.

Why do I want a receptacle? I guess mainly because for a small amount of money I can just cross that factor off my list. I have good power cords, and now a good filter/suppressor from Audience. My outlet might be just fine, but dollars to donuts it could stand some improvement. I could spend $10 I suppose or $50. At this point, it’s so fractional -- and I just negotiated a $50 price break on a half-price used version of the Audience -- a savings of about $425. SO...if there is a chance it could make a difference, I could simply spend $40 and then dismiss "the outlet question."

You mean receptacles? Go to Lowes or Home Depot and get hospital grade or industrial grade.

P.S. Anyone want to weigh in on power outlets that are not crazy expensive (e.g. under $100)?

Thanks, Al. I just bought one online -- 2016. First, I wrote to Audience and found out (a) warranty is still good for 6 more years and (b) warranty will be honored even if I'm not the original owner. Good product, good company. Done. (Just need to get that power strip.)

Q1) My strong instinct would be to not use anything other than a pure power strip/outlet multiplier in series with a quality conditioner/surge suppressor.  (The Shunyata Venom Defender in my setup is not in series; it is in parallel with the outlets on the power strip).

Q2) Various published reviews of the aR2p go back at least seven years.  But since the surge protection it provides is described as non-sacrificial my guess is that you probably wouldn't go wrong buying an older used unit.  But of course if a very nearby lightning strike ever occurred when it was in use it might be a different story.

Best regards,
-- Al 

Thanks to you both. Good accounts which give me enough confidence for a modest investment.

Two further questions:
1. Would my Panamax 1500 "surge suppressor/line conditioner" be able to simple serve as the power strip? If so, then all I’d need is the Audience?
2. Also -- how old is too old for these Audience units? I see one for sale for $345 but it’s date of mfr is indeterminate.

Do you think that you lose any benefits by attaching a $71 dollar power strip to a high quality filtering unit like the Audience?

Hi David,

Well, what I can say is the following:

1) As you realize, that power strip is purely an outlet multiplier, containing nothing more than wiring and outlets.

2) It appears to be well made.

3) For many years prior to acquiring it and the other pieces I mentioned I was using this BrickWall eight outlet surge suppressor/conditioner, which provided comparable functionality in a single unit, at a much lower price than the combined prices of the three pieces I described.  I was pleased with the results it provided during those years.  I made a number of other changes to the system at around the same time as I made the change from the BrickWall to the Audience/Wiremold/Venom Defender combination, so while I noticed substantial improvements I can't say to what degree, if any, the improvements resulted from the change in power conditioning/distribution.  But I certainly was not disappointed with the results.

Now, might a much more expensive audiophile-oriented power strip have provided even better results?  Perhaps, but my technical instincts combined with the results I have been getting cause me to be uninterested in pursuing that possibility.

Best regards,
-- Al
  

Thanks, @almarg  A good solution to varied requirements.

One final question -- because I'm really tempted to just copy your solution:

Do you think that you lose any benefits by attaching a $71 dollar power strip to a high quality filtering unit like the Audience? I realize that you've economized, but I know you must have confidence that that power strip is not compromising the Audience unit. That $71 strip passes muster?

Yes, David, the main reason for selecting that approach was simply that alternatives I found to be appealing were much more expensive. Also, since my living room is my listening room it would have been problematical to fit some physically large alternatives into the available space in the setup, in a manner that would be aesthetically acceptable.

Best regards,
-- Al

@almarg Thanks, Almarg. I’m curious — why did you choose to run the two-outlet Audience Adept aR2p unit into a multi outlet power strip and then address that with the Shunyata unit to attenuate noise? As the Audience Adept product notes, "the aR2p can provide power conditioning for an entire audio or video system albeit without component to component isolation featured in multi-outlet Adept Response conditioners."

In other words, why not buy a unit which performed the functions of the Audience and the Shunyata combined — a unit which also separates noise from digital and power equipment? Were you economizing or is this a superior way for some reason? [I think I just answered my own question -- the aR6 from Audience is $3495. So it seems you found a way to get the benefit using the 2 outlet unit with a power strip?]
P.S. I found a good review about the Audience here: https://www.stereophile.com/content/audience-ar2p-adept-response-power-conditioner-sweepstakes

If you think a MOV device degrades the sound you could use something like ZeroSurge. 

FWIW, in my particular case I believe that the quality of my incoming AC is relatively good, as there is no commerce or industry within more than two miles of my house and nearly all of the town is zoned two-acre residential. So I’ve chosen to adopt a "less is more" approach to power conditioning (no regenerators for me!), but without compromising the protection of my system.

What I’ve done is as follows:

-- Installed an Audience aR2p Surge Suppressor/Conditioner ($695).
-- Installed a Wiremold UL210BC Power Strip ($71) to expand the two outlets of the Audience to 10.
-- Plugged a Shunyata Venom Defender ($225) into one of the outlets of the power strip, to attenuate noise that may be generated by digital components and the power amp and fed back into their power cords, from whence it could potentially couple into other components.
-- Installed a single 20 amp dedicated line, which powers the entire system via the Audience.
-- FWIW a "SyCon" whole house surge protector was installed by an electrician at the service panel, when I had him replace the entire panel a few years ago.

As I said I’m in an area that presumably has relatively clean power, so this approach may or may not be a good one in other circumstances. But it works well for me.

Best regards,
-- Al

I have seen that advice and I’ve also seen many people say that they would never take that risk with their equipment especially given the crap that’s on our electrical lines or the possibility of an electrical storm. I would be worried that I would forget to unplug it or that the storm would happen in the middle of the night.

From all the info and advice I gathered here on Audiogon years ago, most all members suggested plugging amplifiers directly into the wall.  
Things may have changed but that was the advice that I was given here on Audiogon years ago!

Thanks @b_limo   
so, you’re comfortable running your amps into the wall without protection?

Hilde45, 
I had great results on a previous setup just using a PS Audio Quintet.  I used a Pangea AC9 on the Quintet.  I used Pangea AC14se’s for my dac, cd player, and streamer whichI plugged into the Quintet.  I then used a Pangea AC9 for my Amplifier which I plugged directly into the wall.  My wall outlet was / is a Porter Port (search Albert Porter here on Audiogon!)

You can achieve a nice tidy layout of your power cords with a set-up like this.

Another nice thing about this set-up is that when we get one of those nasty afternoon Colorado thunderstorms, I could unplug two powercords from the wall and my entire system was then disconnected from the power.

Lightning striking anything electrical in your home will blow through most (if not all) powerstrips / surge protectors.

And lastly, even if you have zero hiss coming from your tweeters with the volume levels high, you can still lower the musical noise floor.  Having a black background / low noise floor really is apparent with how images appear out of nowhere and allow you to pick up more easily on micro details and ambient cues.  

@zx10 Appreciate your input on speakers — Elac, Tekton.
@twoleftears twoleftears — I didn't know that the Panamax fell into that category. Good to learn that distinction.
@tvad Tvad — who could resist a comfy Eames chair? It might almost cause me to take up pipe smoking.

The Panamax isn't really a power conditioner; it's a distributor/surge protector.  To get noticeable results, you'd need to stretch outside your budget range, to the Inakustik 3500.

I could have sworn the original question was speaker suggestions. Hmmm....On that issue I would suggest value leaders Elac and Tekton Design, especially TD as I thoroughly enjoy my OB Sigmas with Hsu Research subs. Eric @ TD will be more than happy to allow you to sample anything in his lineup...you probably won't be disappointed.

Thanks, guys. Without OCD (and not to make light of that condition, so I'll stop using it, now), I like the idea (a) of protecting gear throughout the house, and (b) having something just for my audio gear that I can point at and say, sotto voce, "my bodyguard."

That’s the way they work look at Home Depot or Lowes they sell them. I've been thinking of adding one.

I suffer from a touch of OCD and I think about running a dedicated  circuit but in my situation it would cost about 3K - 4K and my OCD isn't quite that bad for what would probably turn out to be a placebo improvement. 

Thanks. I couldn't tell from the EP2050 website's photos HOW that surge suppressor protected the whole house. At least, the photo I saw connected with that product seems to be affecting just one breaker or two. 

Even if you use whole house surge protection you can still use a power conditioner.  There are other good ones besides panamax it's just what I have always used. I didn't  mean don't  try different things like removing the conditioner as has been mentioned. If you try it and don't notice a difference  I would still use the panamax. You can get whole house surge protection and it's not a bad idea because it protects more than your stereo. Refrigerators, washing machines, stoves, TV,  AC units a lot of household items use electronic circuits that could be damaged from a surge. 

@djones51

Don't borrow trouble — including OCD! Exactly.
Do I have problems now with noise? Not that I can tell, though some here suggested that I might easily discover an improvement by just plugging things in without the conditioner. Easy enough to test. (Like making a dish without X amount of salt; it can improve by simple subtraction. Not OCD to try that, for sure.)

My goals are simple.

• Protect my gear. (overall value is not strataspheric: $13k or so)
• Run reasonably clean power.
• Not break the bank doing this. (In other words: try to keep this below $1k)

The gist of what has been recommended to me is:
1. Dedicated line.
2. Whole house surge suppressor à la Environmental Potentials EP-20503.
3. Power conditioner.

Because advice comes in bits and pieces and from different people, I do not know if 1, 2, 3 are ALL necessary. For example, if I got a whole house surge suppressor, then wouldn't I just need a multi-outlet for plugging in gear down the line?

@djones It sounds like your new listening room is fine without a dedicated; you just plug your stuff in to protect it, don't have noise — so you're good.

I moved to a patio home a couple of years ago after retiring. My room now is my living room and I'm using one of the outlets on the living room circuit. I have a newer panamax I bought when I moved in. I can detect no noise issues, the background is black, when I hit play it remains black no distortion, no noise I can hear. I moved from a house with a dedicated room , equipment on it's own circuit the whole works and I don't have any more of a problem with noise now than then. You may have a problem if you do the first thing is figure out what's causing it and go from there don't  borrow trouble is the way I view it.

With a power condition you are removing mains noise which will show up as a hiss or static sound. Turn your volume up with nothing playing to see if you have a problem. Panamax also sells service entry surge protection if you want to go that route. I've  been using Panamax products for 20 years. Lowering the noise floor will have more to do with your entire system, speakers will usually produce the most distortion in your case the tube amps would run a close second. Since ambient room noise runs about 30dB but I believe yours is in a basement so when any HVAC is off it might be as low as 15 - 20dB it's  possible you will hear an improvement in noise floor but unless it's something that pops out at you like acoustic and vocal recordings sounding off, strange like a guitar sounds like a digeredo and vocals slightly helium induced I wouldn't worry to much about it. Noise in a system usually is easily apparent no need to get OCD over it. 

Gotcha. Will try.