Reviewed by: Paul_Bui, Audio Enthusiast, from Milpitas, CA, USA

Price Paid: $674 at Decware Factory Direct

Product Model Year:

This report refers to an upgraded ZSLA-1 built with signal path of pure silver litz, Decware signature grade WIMA coupling caps and a 20 step Alps carbon volume control. The unit is being used between the EVS DAC II and Decware SV83M monoblocks, driving the Horn Shoppe full range speakers with the Zero Autoformers and CAT5 speaker cables.

First off, its "sound" is very similar to that of the passive EVS unit (mentioned below). The ZSLA-1 doesn't add extra warmth or do anything to alleviate your system's glare. What it does is faithfully bring more information fed from the front-end to the amplifiers. It does it better than the passive unit by matching the amp/source impedance using a tube buffer stage and an extremely simple circuitry. It doesn't beautify the sound IF the beauty doesn't exist in the recording, and I imagine this could be a tough pill to swallow for many people.
My roughly $2K digital front-ends ( Redbook transport+ 24/96 upsampler DAC) is far from state-of-the-art gear but reasonably good for the time being, and the ZSLA-1's telling me that, too. With the active line stage in the system, any change down to the power cord, or input tubes on either preamp or amp, or speaker cables, even ICs and digital link, has no where to hide. Admittedly, I was initially bothered with this new behavior of the system (easily sensitive to any small change) after "adding" the ZSLA-1 to the audio loop. True, the sound was getting more robust, warmer, bigger (sometimes huge) image sige, well extended in bottom and top ends when called for, meanwhile more detailed to the point where even the noise floor buried in the recordings was also brought to the surface. Mind you, the 20-step ALPS pot (7 AM to 5 PM positions) is as quiet as the EVS wherever it is (min. or max. idle position). Only gradually later on, I became more appreciative of its "chameleon" nature as well as its "magnifier" capability.

To describe how the ZSLA-1 sounds, Steve Deckert the designer has put it in his Designer Notes, accurately and completely, as you see in the Strengths section below. I'd only like to add a few personal comments: The unit shipped and arrived in excellent condition, as Decware's (a few others) tradition. The latest price is $475 stock (refundable with 6.5% re-stocking fee), optinally plus $199 for silver litz signal path, WIMA cap, and 20-step ALPS pot (non-refundable). The upgraded ALPS potis a very good sounding and invaluable piece - I find my favorite volume levels IN BETWEEN the STEPS, not necessarily right on the steps. My DAC output voltage is over 4 volts, so I most often listen to music with the volume pot at the 10:30 AM to 12:30 (max, rarely). Your mileage may vary.

For under $700, I feel this line stage is a giant killer, a no-brainer winner. Considering its "weaknesses", highly and unconditionally recommended!

Well balanced ~ 100% Grain Free ~ Holographic Imaging ~ Beautiful Sound!
No noise, hum or hiss
ZERO negative feedback
Lifetime warranty to original owner
Never gets hot - can be left on indefinitely.
Removable power cord which is a critical factor in its good sounding
Excellent detail during low level listening with plenty of bottom end
Excellent non-fatiguing high level playback without the glare
Has the tube in easy reach so that the owner can plug in his choice of 6N1P, 6922 or 6DJ8.
It will drive long lengths of cable without problems


But if I'm forced to be nit-picking:
- Unity gain, so probably won't work with a phono stage
- Extremely simple look, not having the preamp bells & whistles (remote control, various function knobs, fancy plate, etc.)
- Ruthlessly revealing the audio components up and downstream (including tubes, power cords, speaker cables and interconnects), so the owner may have to re-evaluate his system's weakest link and/or find a reasonable balance.

Similar Products Used:
- EVS passive stepped attenuator (owned)
- Decware ZTPRE signature preamp (home auditioned)
- Bottlehead's Forelay (home auditioned)

In addition, the ZSLA-1 let me, for the first time, appreciate the REL subwoofers that have been in my room for over a year.  It also forced me, without mercy, to throw my expensive speaker cables (Analysis Plus, Kimber Monocle XL) to eBay and adopt the costing-next-to-none CAT5.  It is also whispering into my ears, "If you think your digital gear is THIS GOOD, go get an SACD player!"

The effect of "adding" the ZSLA-1 to the system is almost like transforming the 4" Fostex HornShoppe into an 8" Lowther Fidelio that Alex kindly brought in my room a short while back.  The room is now easily filled up with music that is full range, warm yet detailed, well extended, and incredibly holographic.  I keep asking myself, "How could I live without such a good active line stage?"

Oh yes, it "sounds" spooky sometimes, and explosive some other times too.




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