Mike Currie, Atma-Sphere S-30 amp and Quad ESL-63 speakers:
"I guess I have been among the most skeptical in thinking that ZEROs would do nothing for my Quads given that speaker's impedance curve. Though I've had them set up for only a couple of days now, it is apparent that I was quite mistaken. The most profound difference is in the mid and upper bass, which has both tightened up and has become more 'organic'. I never have figured out what the latter term really means in sound reproduction, but I guess you know it when you hear it. Deep cello and double bass simply sound more real - and they sounded pretty damn good to begin with. Two days do not a long term partner make, but I can say right now that unless some strange deleterious effects show up unexpectedly, this is the best 'tweak' money I've ever spent. Congratulations, Paul!" Mike

"The more I listen to the system with the ZEROS in, the more I like them. Please note that this applies to my new M-60s just as much as my former S-30. This is a great product and a true bargain."

Jay Min (California), Tenor 75WP OTL Amplifier and Amati Homage Speakers (4 ohms):
"Dear Paul, Got the ZERO-Boxes. Talk about return on investment. It just has to be the best $1K I've spent considering all the money that I have blown in the past 30 years. I only played with them for about 5 hours and can't wait till they are fully broken in. I am still debating between 3X and 4X and at the moment I am inclined to use the 4X despite that the mid bass is just a hint drier than I would like. I have the Amati Homage (nominal 4ohm with a dip of 1 ohm at about 400Hz) driven by Tenor 75WP. The Zero really brings out the best of the OTL, of Tenor in term of airiness and openness while retaining excellent control of the bass. I was inches away from dumping the Amati but the ZEROs sorta save its day. I believe I have talked a few of my fellow audiophiles into giving it a shot. Thanks.... Jay"

Gary Susott (Kansas), Cary V12 (Push-Pull) amplifier and Magenpan 1.6 speakers (4 ohms):
"Paul, Just thought I would let you know the ZEROs arrived yesterday and I'm a happy customer. I didn't have much time to experiment or listen last night, but the initial results were very impressive. I set up my amp and the ZEROs to double the damping factor because the Cary amp has a high output impedance, a little more than half the tap value, I understand. A whole new world of bass clarity appeared. This was not at all subtle. I was hearing surprising bass depth, space, air, and delineation I never heard before. The overall listening experience was quite improved. I'll have more time to experiment over the weekend. It's been a pleasure."

Tim Kirkpatrick (Georgia), Atma-Sphere MA-1 Mk II.2s and Spendors speakers (8 ohm):
"Well, Paul, I was skeptical. I really wasn't sure that the ZEROs would improve my nominally 8 Ohm speakers. Boy, was I wrong! I'm using the 2X tap to make the MA-1s think they are driving 16 ohm speakers. The ZEROs are everything you advertised them to be--tighter more defined bass, improved mid-range detail, and extended highs. All in all, the ZEROs just provide a much more realistic reproduction of the recorded event. I am a thoroughly satisfied customer, and I will pass the good word along. Thanks again for a great product! By the way, the ZEROs in the cherry case match my Spendors perfectly and actually look to be part of the original speaker. Take care!" TK

Gerald Rankine-Galloway (District of Columbia), Conrad-Johnson Evolution 2000 amp (SS) and Infinity Kappa Speakers (4-6 ohms):
"Dear Paul, The ZEROs did arrive yesterday, I have them connected, and they sound quite wonderful at 3x. The best way to characterize them at this early stage is to say that they impart a remarkable sense of meaning and intelligibility to the musical message. Suddenly voices and instruments breathe as they should, and the system disappears." Gerald

Joe Ranium (Hong Kong):
"Paul, I am very impressed with the ZERO-Autoformers and will be taking two more for my two other systems, but will defer the purchase for 2 months as I have spent quite a lot on hi-fi this month. Will be in touch in due course. Best regards, Joe"

Manuel Vidal (Puerto Rico), Transcendent OTL and Soliloquy 5.3 Speakers (90dB, 8 ohm):
"If you want to know what difference a 16 ohm impedance speaker sounds like with our OTL's give Paul Speltz' Zero's a try. I tried various taps and found that the X2 impedance multiplier sounds the best. My speakers are the Soliloquy's 5.3, which are an easy 8 ohm load, thus making it a 16 ohm load. This set up was sounding perfectly well, I thought, until I heard the Zero's. My preamp is a GG built from scratch and the Bel Canto Design DAC driven by a Sony 7700 DVD/CD player. After evaluating the Zero's I am not sending them back. Every aspect of the reproduction is enhanced, specially in the smoothness department. All the resolution,detail retrieval and dynamic aspects are kept but with much more refinement. The stage is also bigger. I don't really know if this is exactly as driving a 16 ohm speaker, but I am pretty sure it's very close. According to the designer, adding this device does not defeat the OTL's prime design purpose of not having an OPT, though this device works differently to an OPT."

Stew Glick (New York), Wright/Sound 3.5 2A3 SET amps, driving Quad ESL63 speakers:
"Paul, I received the ZEROs, thanks! I put them into my system and even though they are not even broken in yet, I heard an immediate improvement in my stereo. I used the 4x setting on my Wright/Sound 3.5 2A3 amps, driving Quad ESL63 speakers. The bass is deep and VERY tight, plucked strings have more of a percussive sound, and the sound is cleaned up overall....it really makes me shake my head in disbelief that I am getting this kind of sound out of a pair of 3-8 watt 2A3 amps. (I do also use a Hsu VTF-2 sub, but any changes I am hearing is coming from the speakers as the sub is driven via the preamp outputs). At this time I have no desire to check out other settings, as 4x is pretty high and I am not hearing any thinness or the like. I feel like I am getting the most out of the ZEROs with no negative effects as they are set up now. Thanks for you help and friendly assistance." Stew

"I'm still very impressed with the sound of my stereo since adding the zeros into the equation. Everything sounds so natural, effortless, organic. Thanks for your help." Stew Glick

Jose M. Rodriguez (Puerto Rico), Naim M1.1 (Solid State) amplifier and Parsifal speakers (8 ohm):
"Hi Paul, Had heard a bit about the ZEROs, but a couple of days ago got a pair on loan and tried them in my system. WOW, never had anything brought so much improvement to it. Work best with 2x setting. Do you have ZEROs  available? Thanks." Regards, Jose

Greg Gresham (South Carolina), Rogue 88 (Push-Pull 6550s) and Inersound Isis electrostat speakers (4 ohm):
"Paul, I just wanted to get back with you on the ZEROs in my setup, they worked GREAT, they sound there best in the 2.75x tap. I could not believe how much better this system is with the ZEROs, you hear all the music that seemed to get lost in the mix before , I have emailed a few people on the web site Audiogon and told them about this product, well done Paul well done." Greg

Andy Timmons (Maryland), Joule Electra VZN-80 amplifier and 4 ohm Magnepan speakers:
"Thanks for remembering me Paul, Since we last talked, I was able to borrow  and then purchase my friends pair of original ZEROs. Once again my Maggies sounded so much better with the ZEROs in-line, but my curiosity still begged the question, how would the ZEROs sound directly connected to my Joule VZN-80. Well, after moving my speakers very close to the amp and re-connecting the ZEROs direct, I got my answer. The system sounded its best with the ZEROs alone. I didn't realize how quick, accurate and focused the ZEROs could be, and with absolutely no degrading of the sonics.  The soundstage is tighter, more natural and the speakers have truly disappeared. For me it's the only way to run my system.

Luis Ponce Leao (Portugal), Atma-Sphere M-50 and B&W N805 4 ohm Speakers:
"The result was very impressive! The sound opened in way I really didn't expect... a huge soundstage, incredible dynamics and FOCUS, something I always missed on my system. This was particularly notorious with orchestras that really didn't seem to "fit" on my speakers." Luis

John Jansky (Minnesota), Audio Research VTM 200 amps and Wisdom Audio Adrenaline D-75's (4 ohms):
"Hi Paul, I am really enjoying the new version of the ZEROs . The improved leads do make a significant difference on my mid-range/ high frequency towers. I have not yet used them on the low frequency drivers. I think I'd like to upgrade one pair for now. I'm using Audio Research VTM 200 amplifiers on a pair of Wisdom Audio Adrenaline D-75's. The speakers are 4 ohm and I'm using the 2x configuration with the 8 ohm output of the amplifiers. The sound is considerably richer with more low level detail."

Bill Layer (Minnesota), Atma-Sphere M-60 amps and 8 ohm speakers:
"I've applied a set of ZEROs to my (very) original Atma-Sphere M-60 MK.II  OTL amps, and felt like sharing my pleasure with these devices. Simply put, the Zero and the M-60 are a match made in the stars.. I never thought that hanging a piece of iron off the back was anything like correct, but I was happily wrong on that point. Though my speakers are a nominal 8-ohm load, and have reasonable efficiency - 94dB - the ZEROs puts more controlled power into this system than I thought possible. With the ZEROs at 2x, not only is the bass notably more authoritative, but every other part of the range seems to derive benefit as well. Not to mention that I am getting about 50% more power, overall - the M-60 really wants to see 16ohm load - and that's what it gets from the ZEROs. With the full tube complement, truly antisocial volume levels are just a volume knob away - gone is the  loosened bass and occasional stridency that I would get in the past, when I really pushed the system to the rails. With half the tube compliment, and the ZEROs at 4x, this system remains extremely musical, while still delivering excellent levels. I can say for a fact, that I will *never* be without a set of ZEROs for as long as I own my M-60s, and it goes without saying that will be for a very, very, long time. In terms of hardware design, quality, etc, the ZEROs are nothing other than a perfect compliment to Atma-Sphere equipment... and that is saying a *lot*. With Paul's very reasonable demo policy, you really have nothing to lose in trying out a set - and so much to gain. I hope these comments will help steer you down the path to more music. -Bill Layer"

Scott Bayne, B&K M200s (SS Mono Blocks) running into Carver AL-III+ speakers:
"Paul, I just installed the ZEROs. I've got to say the improvement is  dramatic. Thanks for a great product."

Robert A. Ettema (Ohio), Decware SET amplifier:
"Dear Paul; The ZEROs arrived yesterday and the first impression is  WHOWWWWWW ! Thanks, Best regards, Robert A. Ettema"

Adam Berusch (Colorado), Atma-Sphere amps and Martin Logan CLS IIz Speakers (1-4 ohm):
"THE SOUND: Incredible!!! Even after a very informal setup, the imaging, detail, transparency (etc) was really something. I had assumed that there would be little or no bass. Well, I gotta tell ya, the bass was very strong down to just under 40hz in my smallish room. I have extensive experience with Magnepan, Sound Lab, and Avant Garde, and this combo blows those others away! This is the kind of pleasant surprise audiophiles look forward to, but rarely get. I did not notice any anomalies in sound with the ZEROs installed. I tested the sound using a variety of sources, including the XLO test disk and The Absolute! Sound space CD. The sound passed all the tests impressively. Paul - You sir are a mad man! It's people like you that make this industry far more interesting. Job well done!" -Adam