[guf]

I have  a Pass Labs x150.5 demo and it's replacing my wyred 4 sound sx1000 mono blocks. After months of researching I went against what I thought would be best and followed the suggestion of the dealer and took the entry level amp. I "knew" it would be underpowered for my  Salk SS8's that are 87db at 4 ohm.  I only had it up and running for 24 hours and it's plenty loud and I'm quite impressed. If I hadn't been reading for months about how I needed the most power I could afford to be completely happy I'd be content.  I trust what I read and others opinion so I figured there must be something wrong with my listening ability.  I was easily listening at the same levels I was with the amps with more power.  I know there are other factors. My room is a well treated , 13x19x, 9 and I sit about 6 feet from the speakers.

Is this a situation where I wont know what I'm missing until I hear the better more powerful amps?

[rollo]

  Yes and no. Nothing wrong with what you hear. Period. some speakers like current meaning a powerfull amp. Panel speaker love wattage. The Pass amp has plenty of power for the Salks. What is more important is the sonic character of the amp and its synergy with the character of the speaker. Your room is the biggest factor. A good room trumps all.
   Well learn by trying different components. There is no rule to follow only your ears. I' ve heard Maggies with Dynaco amps a 70W/ch a supposed bad match [ power wise ] However the sound was glorious.
    Trust your ears not opinions. With Salk's my only advice would be stay away from bright sounding amps.



charles

[Photon46]

Rollo's right, trust your ears and emotional reaction to the music. Unless you're listening to thrash metal at 105db. in a large room, your Pass should be plenty adequate. I tend to think audio reviewers and car reviewers are alike in that they often have an insatiable desire for "more power" to a degree that seems dissociated from real world driving/listening.

[Folsom]

The reality is you just typically need available current. I've put under 20w on some 87db 4ohm speakers without an issue. It was a smaller room, but still, the reality is available current is what makes things good. You can have a lot of available current with low wattage amplifiers, but typically you don't. It's coincidental circumstance, you're going to need a big power supply for 600w output, say class AB, but you're going to use 10w, like, most the time in small to medium rooms. The robust available current is what makes it fun to listen to at low watts.

The Pass amplifier you are using I'm sure is like other Pass models, it uses a constant current power supply so it pretty much always has tons of current on tap. All amplifiers like this tend to function real well at most wattage and speaker. Now move to most class D etc, and it just isn't going to cut it to your ears.

I think you'll find class A and AB will tend to fit the bill, most the time.

[Elizabeth]

Nothing wrong with your listening abilities. What is wrong is endless 'Gurus' spouting off about endless things most of which is only hot air.
Pontificating is cheap.. like passing gas it gets the creator a tiny bit of attention.
Where, on the other hand, your dealer knew you, your system, and what the actual amp he sold you could do.

[Freo-1]

Nothing wrong.  The issue could be now that you have high end speakers and amp, you may be hearing the limitations of the preamp and source.  This happened to me along the way of upgrades.

I solved the issue by getting a tube Oppo player, and a tubed Wavelength Audio DAC, along with a matching Pass Labs Preamp.

[jd3]

I felt the same way as you when I had SS8's...the more power the better.  I had the INT-150 and then the 250.5 with SS8's and the difference really is negligible.  In fact, I really liked the INT-150 with them.  Be happy!

[bladesmith]

I would give it ample time to settle in.

(IMHO)

[Freo-1]

I felt the same way as you when I had SS8's...the more power the better.  I had the INT-150 and then the 250.5 with SS8's and the difference really is negligible.  In fact, I really liked the INT-150 with them.  Be happy!

+1.  The INT-150 is a great product.

[sts9fan]

If it sounds good to you then it sounds good. Period.

[Don_S]

[watercourse]

Guf - that's a nice amp that puts out 300wpc into 4 ohms (and you know I know because you heard it at my place!). Sitting 6 feet away, seems you wouldn't need all that much juice to kick it up to very loud levels.

As others have said, if it sounds good with nearfield listening, IT IS GOOD.

[guf]

Guf - that's a nice amp that puts out 300wpc into 4 ohms (and you know I know because you heard it at my place!). Sitting 6 feet away, seems you wouldn't need all that much juice to kick it up to very loud levels.

As others have said, if it sounds good with nearfield listening, IT IS GOOD.

yeah i was wishing i had bought yours! Now i want the xa, and a pre. we'll see.

[JLM]

The rough numbers say you'll reach 111 dB with the Pass vs. 117 dB with the Wyred making either more than adequate to reproduce realistic sound pressure levels.

But we don't listen to numbers do we?  In my experience, the power supply capacity is more of a relevant measure.

And I agree that reviewers push amps/speakers hard (that's part of what they're supposed to do) but that they get somewhat 'addicted' to the high sound pressure levels.

IMO the only thing that might be wrong with your critical listening is your mental need for wattage.

[Big Red Machine]

You are getting all bad advice here.  1000 wpc is what you need.  Come on!  Flea amps are for fleas.  You've got SS8's and they love power.  ha   

Actually, if you measure the watts of power your amps draw it will be very low as mentioned.  My entire system only draws about 3.6 total amps when running at listening levels.  My amps are rated at 500+ watts into 4 ohms but I use very little of that.  Headroom for dynamics and the reserves built into the amp that allow that seem important.  My amps have relatively small transformers but the same large coke-can caps the Dude has in it.  That must be how dynamics are handled.

My own experience with Pass amps were they seemed very mild mannered and not un-governored to me.  Just my own experience.  I don't feel my Samsons are beasts like Krells so not much more open than I experienced the Pass amps.  The 4 ohms of the 8's is easy to drive.


But seriously, 150 watts is kinda low.  Personally, I am never comfortable with less than 250 wpc in my house.  Because I want the headroom, not because I cannot get my desired db levels with even just 50 wpc.  I'd rather have an overpowered truck than an underpowered truck so when the bed is full I can still pass grandma going down the highway in 10 seconds versus 50 seconds.

At RMAF last year, Frank V remarked that the very efficient Salk Exoticas sounded nice on the small tube amp he makes but when they put the large solid state amp on them the speakers really shined and they were very impressed with that. 

What is your preamp? 

Why do you sit so close in that size room?  My old room was about that size and I was 9 feet from the tweeters and the speakers were 8 feet apart.

[Delacroix]

Nothing wrong with your ears, All things being equal, more power is nice to have. But your comparison amps are not equal, in my opinion. No amount of power increase in the Wyreds would matter to me,  a sufficiently powered Pass amp will just sound better to my ears (and it sounds like you hear the same). Now, a higher powered Pass mono set up might be nicer still, but by then, it's because other things are equal. Enjoy your music, you have a nice rig.

[watercourse]

As with everything, there are trade offs between the X and XA amps. I think the XA are a better match with my speakers, but I'll bet that wouldn't necessarily be true across the board. Also depends on what sonic characteristics you value most.

Are you running with the BH pre, or something else? Bet a tube pre would sound really good with that amp!

The near field listening would allow you to hear distortion easier, whether at soft or super loud volumes - so if the amp/speaker combo is not revealing this problem, I think you've got as much power as you need.

[macrojack]

Maybe you need to take the "critical" out of your listening. A man hears what he wants to hear. If you are looking for problems, you will find some. Just turn the thing on and play it without worrying about anybody else's opinion. Despite assertions to the contrary, my experience has shown me that I am quite adaptable. I can get used to anything if my mind will get out of the way and let me. And krikey, don't we all have gear that far exceeds realistic minimum standards?

For what it's worth, you are addressing the wrong end of the spectrum - high efficiency speakers are the key.

[woodsyi]

One thing not being mentioned is the type of music you listen to.  Big symphonies require a lot of head room for the dynamic changes.  Small ensembles don't.  Loud compressed hard rock don't really need any headroom either.    I am with BRM in having more power if you listen to dynamic music but your x150.5 should be just fine for the crooners. 

[CSI]

... After months of researching I went against what I thought would be best and followed the suggestion of the dealer and took the entry level amp. ...

Is this a situation where I wont know what I'm missing until I hear the better more powerful amps?

I spent several years managing a high end audio store back in the day. People still ask me for system pointers. I always tell them to read forums like this one if they are so inclined but try to find a good dealer (much harder these days) and follow their advise. It's not that dealers are brilliant or that some won't try to sell you things you don't need. But if you can find a good one you have found someone who has a vested interest in recommending stuff that he knows from his own experience should work well in your situation. You instantly confirmed with your own ears that your dealer was right. The rest is audio nervosa. Relax and enjoy the music.