[jimbones]

my listening area is a section of a larger room (basement) the listening area is approx 13' x 18'. I listen mostly to jazz (critical listening) and rock when just casual listening. I crank sometimes but don't listen as loud as i used to. I think a pass 150 would be more than enough given that it has decent headroom.

[Tyson]

Pass 150 is about as good as it gets, till you get to stupid level $$.  If you can separate out the bass section and amp it separately, then the First Watt F5 would be a great match for the mid/high section of your speakers. 

[jimbones]

Yes that Pass 150 seemed to be the sweet spot for me in terms of price/performance. Just for fun my friend measured the heatsink temp on his plinius at 168 degrees. OOOWWWEEEE

[RDavidson]

You'd have a hard time going wrong with Pass Labs. You might want to consider getting the INT150. You'd upgrade your amp and preamp in one big shot.
Note also that the XA series actually have tons of power on tap. The big difference between the X and XA series is that the XA series is high bias class A, but still switches to A/B once it's specified class A power is tapped out. The X series is not deeply biased into class A and operates more like a conventional class A/B amp. It's horses for courses, sortof. I have an XA30.5 on a pair of KEF LS50's (which are the most difficult speakers to drive that I currently own) and only when playing very loud, dynamic, music have I seen the needle jump over to the class A/B side (which is to the right of the 12 o'clock position). As you have multi-driver speakers, with likely a somewhat complex crossover network, you're MAYBE better off with the versatility of the 150. When the XA series crosses over the the A/B side, the transition is noticeable if you're paying close attention. It is subtle, but it turns somewhat hard and sterile. The 150 will maintain it's primary character regardless of playing soft or loud. I find the Stereophile reviews to accurately describe the XA30.5 and INT150. Their measurements also help to clear the air regarding their power specs and technical performance.

[jarcher]

An alternative suggestion : optimize what you have with a better / more judicious cable selection, primarily the MIT + PS Audio, which can be improved on substantially.  Also try different tubes for your AR SP preamp. The Mondial group amps (Acurus + Aragon) I think tended to be voiced darker (at least early Acurus was), but nonetheless, with the right cable selection & some judicious selection of quality NOS tubes for the AR SP8, you'd be surprised what a difference can be achieved towards the greater clarity you seek.  I'm not going to claim that cables + tubing along are going to make a mediocre system fantastic, but you have very solid gear that with right associated equipment should sound very good.  Don't also discard the notion that your pre + amp going on 20+ years may need a "tune up" whether re : the tubes or even the bias (yes, even of a SS amp). 

One example : for a fellow AC member who shall remain nameless, recently with the proper biasing of his amp + some cable swaps, the sound went from a dark and muddy mess, to very clear, engaging and improved on every level.  Now aside from perhaps some future greater power wishes, he doesn't feel the need to change components. 

Guess what I am also trying to say : the temptation when dissatisfaction sets in is to remove + replace one or more components, when the real problem may lie elsewhere.

[jimbones]

Thanks jarcher. Understood. My system doesn't sound bad. But it's like that saying, you don't know what you're missing until you get to that higher level?

My pre was retubed last year, but with standard grade replacements from the Tube Store. I shall consider NOS, but i have always shyed away from that because I have to know which brand and all the nuances (long vs short plate, year of manufacture, country of origin, etc) that make a difference that I am no expert in.

Bias? ha ha I have never touched my Aragon. Solid reliability. I only upgraded with fancy schmancy fuses ha ha.

I did audition a pair of cabledyne speaker cables. They were ok but not significantly better than my MIT 750. Note that the PS Audio is a power cable not an interconnect.

I really appreciate all the advice. I am in a local audio club there are a couple of tube heads that can steer me in the right direction there and on cables, well thats hit or miss.

[jarcher]

For clarity you might want to try RCA clear tops, Siemens, Tesla or Telefunken (pricey). Better yet - have one of your audiophile / tube-phile friends lend you some to try.

PS Audio power cables are ok and definitely a step up from stock, but you can certainly do better without having to spend a lot. Eg Wireworld stratus or Electra powercords, or if you can find them, XLO ultra plus powercords will all give you greater clarity vs PS Audio.

Interconnects and powercords can go many ways. Overall though XLO cabling is very clean and dynamic. Sadly they just went out of business so you'd have to source used.

In the end I suggest demoing cables via a good dealer or even with the Cable Company online.

[RDavidson]

Not a bad suggestion jarcher. I personally don't like the idea of tuning a system with cords and cables. I try to get the most non-invasive / neutral / least damaging cables I can find (without getting near the stupidly priced stuff). This can make a system sound revealing (for both the good and bad), but at least with this approach you know what your components are doing and can then work on getting the synergy between components right. I think Wireworld is a great suggestion in general. Kimber also makes some good, honest, cables such as 8tc. I don't like their use of multi-strand conductors for use in IC's though. Anyway.....In order of importance, I'd go with IC's, then speaker cables. I tend to find power cables to be more of an icing-on-the-cake component.

I agree, the Cable Co is a great resource to try before you buy. Hard to go wrong there.

[jarcher]

Few if any cables are going to miraculously improve a system, but the WRONG cables can certainly make it a lot worse.  That & having tube gear out of bias or with the wrong tubes. 

I'd actually suggest going to the other way for the OP : try / replace the PS Audio PC's first, then the MIT SC, then investigate the IC's.  Don't want to turn this into a cable thread, but I've frequently found, particularly w/ amps, that PC's can make a bigger difference than IC's. 

[Folsom]

While everyone here is right in one way or another...

What are you looking for? You can say "upgrades" HOWEVER I've got to point something out to you, you're seeking the desire for upgrades for a reason!

What I'm always saying is you'd like to achieve more emotional attachment so you listen more often. You'd like to listen more, or enjoy it more.

What's the answer? Well it doesn't start with another W. The corner stone to any and all system that I can rank as truly good for the user, and not just on the little note counts like on EnjoyTheMusic's reviews, is a power conditioner. They aren't all equal, but with a good one you should find yourself having a harder time pulling away from the experience.

[jimbones]

While everyone here is right in one way or another...

What are you looking for? You can say "upgrades" HOWEVER I've got to point something out to you, you're seeking the desire for upgrades for a reason!

What I'm always saying is you'd like to achieve more emotional attachment so you listen more often. You'd like to listen more, or enjoy it more.

What's the answer? Well it doesn't start with another W. The corner stone to any and all system that I can rank as truly good for the user, and not just on the little note counts like on EnjoyTheMusic's reviews, is a power conditioner. They aren't all equal, but with a good one you should find yourself having a harder time pulling away from the experience.

Well, I used to think my system was detailed, until I heard the same cut at someone elses system and my system sounds veiled by comparison. So I would say I was more refinement, detail and just open up the sound.

[Tyson]

The biggest obscurer of details is the room.  What treatments do you have, and how far are your speakers from the wall, and how far is your listening chair from the speakers?

[jimdgoulding]

While everyone here is right in one way or another...

What are you looking for? You can say "upgrades" HOWEVER I've got to point something out to you, you're seeking the desire for upgrades for a reason!

What I'm always saying is you'd like to achieve more emotional attachment so you listen more often. You'd like to listen more, or enjoy it more.

What's the answer? Well it doesn't start with another W. The corner stone to any and all system that I can rank as truly good for the user, and not just on the little note counts like on EnjoyTheMusic's reviews, is a power conditioner. They aren't all equal, but with a good one you should find yourself having a harder time pulling away from the experience.

Recommend one, good sir.  I use a PI Audio uberBUSS based on recommendations here at AC and haven't compared it with anything nor do I understand a PC's influence really other than blacker backgrounds.  What else?  Thanks.

I'm with Tyson about speaker and seat positions in a room especially if you listen to lots of music recorded on location (i.e. classical).  I use a modest amount of absorbtion treatment to minimize glare at high levels behind my speakers tho they are out 53" from their fronts to the wall behind them and tall open back record cabinets for diffusion behind my chair 48" from my ears to the wall.  My room is 12X15X8' if you care to do the math and compare in your room.  One thing my audio chums consistently comment favorably on is that there is a palpable sense of a stage in the front end of my room which is recording dependant.  Some of these chums of mine have mega dollar systems but show less regard for speaker placement.  I suppose its what you value.  I don't believe that I am losing anything by taking such care, only gaining realistic perspective.  I place value upon the sensation that I am in attendance.

[Early B.]

Well, I used to think my system was detailed, until I heard the same cut at someone elses system and my system sounds veiled by comparison. So I would say I was more refinement, detail and just open up the sound.

You can unveil greater detail from changing virtually any component.

[RDavidson]

Few if any cables are going to miraculously improve a system, but the WRONG cables can certainly make it a lot worse.  That & having tube gear out of bias or with the wrong tubes. 

I'd actually suggest going to the other way for the OP : try / replace the PS Audio PC's first, then the MIT SC, then investigate the IC's.  Don't want to turn this into a cable thread, but I've frequently found, particularly w/ amps, that PC's can make a bigger difference than IC's.

Agree to disagree. But what would be the point of doing things in "reverse?" If low level signals (between source components up to the amp) aren't being preserved as best possible, the effect will obscure everything else down the line (ie speaker cables, speakers, and the resulting sound). I'm not discounting your approach as all have their own experiences and philosophies. I'm just bringing light to what I personally have found to work.

[jimbones]

I auditioned a TWL power cable last week specifically for digital sources. i used it on my DAC. It was a short audition but in my observations it helped. I am getting the cable back to audition again. The only things I won't change in my system are the DAC (because I have it less than a year) and my speakers. Since I am the designer of the speakers, in the future I can always redesign the speakers using higher end drivers, but not right now.
BTW the PS Audio power cord is a lower end model AC-3.

[jarcher]

Agree to disagree. But what would be the point of doing things in "reverse?" If low level signals (between source components up to the amp) aren't being preserved as best possible, the effect will obscure everything else in the down the line (ie speaker cables, speakers, and the resulting sound). I'm not discounting your approach as all have their own experiences and philosophies. I'm just bringing light to what I personally have found to work.

I recommended the PC & speaker change first based on experience or reputation of PS Audio PC and MIT SC not offering the most dynamic and clear presentation - particularly PS Audio PCs. With MIT just heard they can sound mechanical / unmusical. I am not personally familiar or the reputation of the other brands of cabling the OP owns.

As far as PCs vs ICs - I think they both could be considered to be at the beginning of the chain so to speak with respect to sound reproduction.....

[jimbones]

The biggest obscurer of details is the room.  What treatments do you have, and how far are your speakers from the wall, and how far is your listening chair from the speakers?

2 ft from side walls, 4 ft from rear wall. I have 2 corner bass traps and auralex/GIK diffussors in ceiling and some panel absorbers on walls. foolrs are carpeted. It is a dead room. (probably too much so.)

[Early B.]

I recommended the PC & speaker change first based on experience or reputation of PS Audio PC and MIT SC not offering the most dynamic and clear presentation - particularly PS Audio PCs.

With regard to the PS Audio power cords, I agree. They're definitely contributing to the lack of detail that you're hearing.  I don't doubt that the ICs are doing the same thing. Problem is -- good PCs and ICs aren't cheap. Expect to pay several hundred dollars per IC and PC.

[RDavidson]

With regard to the PS Audio power cords, I agree. They're definitely contributing to the lack of detail that you're hearing.  I don't doubt that the ICs are doing the same thing. Problem is -- good PCs and ICs aren't cheap. Expect to pay several hundred dollars per IC and PC.

In terms of price, I don't necessarily think you have to spend A LOT (ie more than $250ish) to glean a significant increase in performance. In terms of IC's and speaker cables, Zen Wave, Darwin, Morrow, all have EXCELLENT entry level offerings that will blow the doors off of more commercialized offerings in the same price categories (and higher). I believe they all have pretty generous trial periods as well.