Puritan vs IsoTek vs inakustik

I found in relative esoteric comparisons the place to start is with AI. 

Here’s how these three tend to differ sonically (all system-dependent, of course):

IsoTek V5 Titan (high-current conditioner for amps/subs)

Feel: punchy, dynamic, “unclamped.” Often adds bass grip/weight while keeping transient slam intact.

Why: it’s purpose-built for big current delivery (3 high-current outlets; massive surge protection), so amps don’t sound choked. Many listeners note extra kick in the mid-bass and a cleaner floor without dulling leading edges. (IsoTek, Alpha Audio, Music Direct, Facebook)

Puritan (top tier: PSM156 / PSM1512)

Feel: blacker backgrounds, smoother/“sweeter” mids, and a calmer treble; can read a touch warmer and more relaxed.

Why: extensive multi-stage filtering and DC blocking across many individually filtered outlets. Fans praise hum/noise removal and a more liquid presentation; a few reviews found the effect system-dependent—stellar in some rigs, less so in others. (PSM1512 is a 12-outlet expansion of 156 with the same sonic aim.) (6moons, The Audiophile Man, Steve Huff Hi-Fi, Alpha Audio, AudioVision San Francisco)

inakustik Reference Power Station AC-4500P

Feel: very clean, fast, and transparent; tighter, quicker bass and a focused, deep soundstage—often perceived as leaner/clearer vs. Puritan’s warmth.

Why: high-current parallel filtration and low-resistance busbars aim to avoid current limiting; several evaluations noted better bass control and spatial focus, even compared directly to Puritan’s 1512. (Stereo Times -, Small Green Computer, Mono and Stereo)

Quick pick guide

Want maximum slam & zero dynamic constriction on power amps? IsoTek V5 Titan on the amps, with a separate unit for sources if needed. (IsoTek)

System a bit edgy/bright and you crave ease and “inkier” silence? Puritan PSM156/1512. (6moons, The Audiophile Man)

System already warm/rich and you want speed, clarity, stage focus, and taut bass? inakustik AC-4500P. (Stereo Times -)

Setup notes that affect the sound

Keep high-current amps on high-current outlets (IsoTek Titan or inakustik do well here); put sources on the multi-filter banks (Puritan excels). (IsoTek, AudioVision San Francisco)

Expect room and power quality to swing results; the same unit can sound transformative in one system and subtle in another. (Alpha Audio)

If you tell me your system (amp/speakers, room size, what you’re hoping to change), I’ll tailor a recommendation and ideal outlet layout.

If you have your amplifier plugged in to IsoTek start with trying the amp plugged into the wall directly. Keep the isotek for source components only. I would even plug the ARC preamp directly into the wall as well. Try it. 
If you insist on using power conditioner I’d give Shunyata a try. Bypass puritan. Not good at all. TOL Audioquest is worth trying as well. But again the amp and preamp most likely don’t need power conditioning. Especially if on dedicated circuit. 

Thoughts about using Equitech balanced power?  I assume it would be the same good for sources but avoid amplifiers, preamps.

I have used Equitech 2Q with excellent results, both pre & power (200 amp). Benefit for both. Absolutely no power limiting, feels like the opposite. I have measured my power use in the amplifier. Never above 5/6 watts :)  I enjoy classical, chamber, solo instrument, jazz-- and of course older rock :) 

I had the Puritan and now have a PS Audio P15.  The Puritan had a subtle negative effect on my system, I loaned it to a friend and he had the same experience. I ran it for a a couple months and it was a breath of fresh air when I removed it.
 

The effect of the P15 was a subtle improvement across the board. What it gives me is consistent sound any time, day or night. What I call Sunday night sound, now 24/7. I have two direct lines to my breaker box, and pretty clean power to start with I think. For someone living in a noisy power zone, I suspect it would make a significant difference. I ran my power amp through it for a couple months, but switching it directly to the wall was an improvement. Everything else has benefited from the P15. 
 

@zlone    Could you please explain the subtle negative effects the Puritan caused in your system?

@dayglow Could you please explain the subtle negative effects the Puritan caused in your system?

I would have to say that it caused an increase in the noise floor overall, how this affected each component and to what degree, I do not know. I just knew after a couple months that I was not enjoying my system as much, and when I pulled the Puritan out, it became very apparent that its effect was negative. Like the proverbial 'veil being lifted', suddenly everything was crisper and more in focus, with blacker backgrounds.

On a side note, but power related, I just resolved a problem in my system that has been dogging me for six months or so. It just did not seem up to the levels of sound I had come to expect. While fiddling about with some cables, I bumped the power cord coming out of my preamp and its power cycled signaling a bad connection in the plug or with the preamp. I popped off the plug and sure enough, the neutral wire was not well clamped anymore. Who the heck put this piece of crap together! Well it was me. I suspect I stressed it too much at some point and it pulled loose. Anyway, my sound has improved by massive amounts, but what is really noticeable is the blackest background I have ever (not) heard. Does clean and copious amounts of power to a preamp matter, you betcha.

I appreciate the quick reply. Have heard nothing but positive reviews on the Puritan makes you wonder how many opinions were bought. 

I love my PSM156. I actually did measurements on mine to make sure it actually worked. It reduced my line noise by almost 75% in addition to providing surge protection.

Kinki Studio/Vinshine TaiHang is very good, esp for the money. Less than $2K.

I read all the glowing reviews of the Puritan as well. It does make wonder if there was something wrong it’s the one that I had.

I have had the exact opposite experience of @zlone. When I removed the P15 and introduced the Puritan, I couldn't believe the impact. Everything got better, making me feel like the P15 was doing nothing.

@lancelock Wow, interesting. Makes me think even more that I may have had a faulty unit. The impact of the P15 was subtle to be sure, definitely not a wow factor. But I think I have pretty good power to start, and it just gives me consistency.

Puritan reduces noise by active filtering. With it though comes restricted current delivery and pinched dynamics. And no it’s not non current limiting. It puked when I connected my Pass Labs mono blocks to it and started ringing like your grandma’s old rotary phone.
 

The initial illusion of reduced noise floor by excessive filtering overwhelms all other effects and it takes time to realize that it does more harm than good. Live with it for a while then remove it completely and run everything direct. If you prefer the sound with puritan may be you have a very dirty AC line or your components power supplies are not up to snuff. None of my components benefited from it. Not even a DAC.
I couldn’t get rid of it fast enough. 

I use 2 Puritan PSM 156. One on each dedicated line. One on all front-end and source components. One one amps and subs. Been very positive for me.

I use the Puritan only for source components. My power amps always go directly to the wall, with a dedicated line to the panel.

I'm surprised by the negative comments I have read about the Puritan 156. I use a Puritan 156 Ultimate which is connected to a Core Power Technologies Deep=Core 1800 that is connected to my wall outlet. The results are outstanding.  All my components are connected to the Puritan 156, including my ASR Emitter 1 Exclusive amplifier which the manufacturer does not recommend be connected to a power conditioner. I have compared the performance with my ASR amplifier connected directly to my wall outlet versus having it connected to the Puritan 156. The improved performance when connected to the Puritan is undeniable - better resolution, soundstage, and bass, and no negative impact on  dynamics.  

Interesting thread.  One thing I rarely see is some type of pre/post measurements of the mains regarding noise, etc., despite the use of some pricey gear in a lot of cases.  Meters like the Trifield or Entech are relatively inexpensive and will display  some type of noise.   

Anyway, my question is whether any of these devices offer any sonic improvement if the power is already pretty clean. In my case, post-treatment using a TriField EM100 meter I get readings varying from about 10-35mV on a 20 amp dedicated line (10 awg). Prior reading were 60-120 mV.  Noting used on the dedicated circuit, but about 8 plug-in G-S filters at various spots in my house.