Review: Silver Circle Audio PP1 v 3.0 high current AC filter

Category: Accessories

Silver Circle is a relatively new / small / unknown mfg of select audio products. For this reason, I'll offer up a lengthy review, as its a company worth watching for.

The 3.0 is a massive (got to go 70lbs +) power conditioner, @ 20" * 15" * 10"---its not easily hidden, nor is it something that you can simply throw 70lbs, its too damn heavy, and its bulk means it can't simply be ignored. This thing is bigger than almost all amplifiers. But I bring up the weight again, as that's where the action is. Externally, the unit is not that special, but then again the Mac 501s have spoiled me on what an audio component should look like. With the 3.0, there's no triple anodized faceplates that are so reflective I can shave using their reflection, and the lovely side wood panels are hardly noticeable when the unit is in place. What you pay for is what's inside: in this case, a massive 3.0kVA toroid transformer, which, along with some other proprietary passive filtering inside, is where the performance comes from. Now, while I'd never buy a passive conditioner (nothing but caps / inductors / resistors, which i can do myself), I've always been leery of isolation often manufacturers of amplifiers or active power conditioners push to meet a price point and skimp with tranny size or put the $ for materials into a prettier box---this is bad juju. The 3.0 unit isn't about the uber-pretty box of the 1st generation Shunyata Hydra, or the radiant chassis of the Isoclean isolation transformer. Its relatively spartan, simplistic, and its easy to dismiss its appearance, but Dave Stanard (Mr. Silver Circle) made the right choice by putting the $$ into the tranny's size rather than the chassis. The oversized tranny in theory should ensure no compromises in dynamics---and IME it is dynamics that ultimately separate the home experience from live music. Any undersized power supply, whether in the preamp, CDplayer, amplifier (!), or power conditioner, will rob music of the leading edge transient and bass depth required to get the home closer to real. Its still impossible to make the illusion real, but no sense starting behind the 8-ball.

Other points of note: its a 20a unit, and comes with a supplied power cord with a 15a AC plug and a 20a IEC connector (Wattgates). The back panel is replete with four 20a hubbell outlets. While these things have an admirable grip, it is worth noting that their construction is solid brass. And IME, brass offers a distinct sonic signature (warm / musical / not the last word in detail) relative to gold (very musical / warm / more pronounced midrange coloration ala a SET amp) or silver (extended / fast / hyper detailed). I'd love to see Silver Circle offer outlets to order based on your config...tubes go best with silver, SS gear best with gold / brass. As is, the unit's outlets would lead me to expect a sonic signature erring on the side of warmth, but at the expense of the last word of detail.

Prior to this unit, I was not using any active power conditioning, for the very reasons I articulated earlier---so often active units are underbuilt in their tranny size, or passive conditioners (hydra among others) represent terrible value for the $$. However, i was using 4 dedicated lines using 12ga romex in a twisted pair, various high quality AC outlets (including isoclean, acme, and pass / seymour hospital grade) along with passive power conditioning I'd built into each line level component (a 1uf Auricap across + and - after the IEC, and a bybee after the cap on +). I honestly didn't expect much improvement, but I gave the unit a shot.

Glad I did.

In quick AB tests using Modest Mouse "Bulkowski" (lots of very quiet passages), it became easy to hear that the noise floor was dramatically lower with the 3.0 in the system. AC noise is a funny don't know you're listening to it until it goes away. Without the 3.0, the system had a very fine upper frequency haze, which could either be ignored (easy to do without a point of reference), incorrectly identified as high-frequency transient decay, or reasoned away as tape hiss on the master. Its only upon inserting the 3.0 did I see the noise floor drop and this haze evaporate. With the 3.0 in series, there was a black background, one that I thought was impossible in the context of my very small (and as such, lively) room. Right there, the unit delivers in a BIG way, but that's not all. There's also a much-improved retrieval of micro-detail and separation between notes, but this extended all the way to the bottom octaves---bass depth, definition and transient attack are all substantially improved, and this was not at all expected (perhaps if my line level gear had over-built power supplies, this improvement wouldn't have been audible, but its hardly as if my line level gear is mid-fi). With the noise floor now gone, I am now picking up the corners of the recording studio, info that I'd have not known was present otherwise. ---Lots of info on a well recorded disc, and I am always pleased when I get more of it through my speakers. This is the effect of the Silver Circle in the system---black backgrounds, more info, more of the wholesome audio goodness that we each strive for..

I must admit I have a tough time getting a read on what the hubbells are doing. I'd need to put them on as dedicated AC outlets and compare to find out definitively. My system, by design, was never one to cause listener fatigue--I am always able to sit & listen all day without getting tired even without AC conditioning. I will simply say that, if anything, the tonal balance of the system is now a wee bit mellower and more relaxed with the 3.0 in series. Is this consistent with the use of brass (hubbells)? I'd guess yes, as IME every outlet has a signature, and the further tonal relaxation is the influence of a brass connection. If your system is warm to begin with, this could take it too far on the sonic spectrum, in which we all try to balance detail & speed vs musicality. Given the preponderance of tubes in my front end gear, I'd have liked to try a zippier outlet to see if my theories / prejudices hold true. I also expected a loss of detail via the brass, but I got just the opposite and more details emerged with the unit in the circuit---is this b/c of hubbells or despite them? I don't know.

When its all said & done, I'd have not bought the unit if dynamics suffered. So often I've spoken to audiophiles who buy active conditioners who live with the tradeoff of cleaner power / black background / more detail but with degraded dynamics; this is a tradeoff I'd never make. Happy to say, the 3.0 does not compromise dynamics in any way on line level gear---as noted earlier, it actually got better, especially in the bass. Maybe its a function of a large source of power so close to the line gear's power supplies, but all I know is that once I ascertained this effect, there was no going back. Again using Modest Mouse "Bury me with it", the transient attack of the drums and the aggressive guitar was not compromised at all---in fact, the drums were enhanced as the improved micro-detail retrieval allowed recognition of the skin of the drum and not simply the striking action. It takes a good system to get both leading-edge transients and microdetail at the same time, and with the addition of the 3.0, this is the first time my system has done so.

So to wrap up, yes, I bought it; hell, even with the 30 day demo, there was no chance it was going back once I got a good feel for it. While I readily admit I've not compared it to other offerings in the $2.5m range, I will say that, given the weight and the componentry inside, it represents excellent value for the money (esp. relative to the empty-box hydra 6 as seen on audiogon's recent threads, or the uber-pretty but exorbinantly-priced isoclean gear). Is it perfect? No, its too large for my room (the size of a large closet), and I'd have preferred a bit zippier outlets (or a choice among outlets), as my system was already tonally relaxed; but as so few systems are voiced like mine its likely that the design choice of a warmer presentation will be preferable to 90% of the users--I suspect this unit will be ideal for those with solid state componentry that sounds like solid state, or any system suffering from digititis and in need of a more analog type tone. Is there better conditioners out there? I don't know. I simply approach this hobby by putting my hard-earned cash into products that deliver exceptional performance at a price I can live with (which is why I'd never by Wilson speakers new, but bought em used in a heart-beat). This audition has been instructive in that, given where I started from, I never thought I'd need power conditioning. What I've found is that, much like demo'ing AC outlets and various footers, the AC conditioning that the 3.0 provides has been an epiphany in my system's performance and I'll be keeping this thing for as long as I'm in this goofy hobby (and if I ever get the room, you can bet I'm going to try a few more on my monoblocks).

Kudos to Silver Circle for bringing a fine product to market. Definitely worth a listen.

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1. Perhaps I am missing something, but I can't tell if you are plugging the Mac amps into the silver circle or not- I would like to hear your thoughts on how they sound with/without conditioner.

2. Is the Silver Circle a balanced unit like the BPT products? Have you tried BPT and/or compared it- i.e. did you consider BPT first before you bought the Silver Circle?
1) i did try my mac 501s on the 3.0, and i noticed minor dynamic compression. a more appropriate scenario would be to use 1 PP1v 3.0 for each mono, and a 3rd for the line level gear.

unfortunately, my counterfeiting printing press is on the fritz.

2) it is not balanced. no, i did not try the BPT products. might be a good product, but do take note of transformer size (balanced is just 60/60 vs 120/0, and if the tranny is undersized, it will limit dynamics, regardless of 60/60 or 120/0).

I a very early version of the 3.0 that I picked up from one of the dealers for Silver Cirlce. The problem I have had with it is when you turn it on it blows the fuse! Even in a dedicated 20 amp curciut- POP!!!!
Draws some current HUH?
I like my amp direct into the power with nothing in the way, I don't have those big 501's but I am running two MC352's as mono's and each has its own 20 amp outlet and they sound better to me at least direct into the wall. I also like my Wadia direct into the wall.

Thanks for your review
i'd contact the mfg, as the early units may have been without the soft start circuit (mine has one, and i never had that problem).

i'm not surprised the 3.0 doesn't work for amps; seldom do active conditioners. but FWIW i gather Silver Circle is working on a passive conditioner for amps.

or, just get a 5.0, which is as big a conditioner as i've heard of.

curious that you liked the wadia better into the wall (though that's what they recommend). what was the differences b/w the PP1 vs direct to the wall?

"Rhyno- i'm not surprised the 3.0 doesn't work for amps; seldom do active conditioners. but FWIW i gather Silver Circle is working on a passive conditioner for amps."

Reply- You misunderstood, never used it with an AMP!- Plugged it into the wall, turned it on- POP!!!, reset breaker and worked fine. It even went back to them- we are talking about 2-1/2 yrs or so.
Once it was up and running it was fine, I guess it needed the electric in the transformer to run.

Quote- Rhyno “curious that you liked the wadia better into the wall (though that's what they recommend). what was the differences b/w the PP1 vs direct to the wall?”

Reply- To my 50 yr old ears, the sound stage is much larger, wider and more precise. I was using a EMM LABS SACD player which I liked better via a Shunyata Hydra 2 with an Anaconda VX PC. Nice player but as soon as I plugged the Wadia 581 SEi in (which I ran to the wall with stock PC) it rocked! PERIOD- then I tried it with the Shunyata set up and it was nice, but with the Anaconda VX direct to the 20 amp dedicated circuit it just opend up and kick the crap out of the EMM.

Next move is to hook up my AudioValue Challenger Mono Blocks via the Wadia for 2 channel very soon. Still doing some tweaking 1st.

Back to subject however- you really seam to have gotten more from the Silver Circle than I. Mine has been boxed for over 1-1/2 yrs and maybe one of these days I will list here on A-gon. It just doesn’t move me, but that is why there are so many products out there.
maybe you have good power to begin with (always a possibility); i've never owned a component that didn't benefit from AC conditioning (amps require passive conditioning, but front end does well on the PP1).

i gather the 581 is the ticket these days; FWIW the EMM gets *much* better if you're willing to tweak a few things (hint: my biggest gripe was w/ dynamics, which i was able to improve via one part substitution), to the point that i found it a "pick em" contest vs the esoteric xo1-d2.
"maybe you have good power to begin with (always a possibility);"

NOPE I sure don't hell I live in Florida probably the worst power out there. My Theta, Wadia and Mc stuff all want passive line products. Anything other than that is adding to the signal.

Just my take. Thanks for your insight
Silver Circle Audio makes a 5.0 KVA conditioner that is more capable of supplying larger amplifiers with their huge transient demands without restricting dynamics at all. In fact both macro and micro dynamics were improved with my 1000 watt mono blocks.
The lowered noise-floor and improved detail and clarity were the icing on the delicious cake.
I removed the pp1 5.0 from my system just to double check my own hearing and was totally shocked at the sound quality that I used to listen to and previously thought was very good. The pp1 just made everything perform better. Much better.