LONG TERM: The Robert Koda K-10 Preamplifier

Living with a hifi component for a long period of time is either a wonderful or dreadful thing. Features that seemed annoying at first can really be problematic after a time and magic that wasn’t always apparent at first really shines after about a thousand albums.

When you truly commit to a component, it’s almost like a long term relationship with a person; you either grow together or you grow apart. You need look no further than the recent court docket of divorce decrees or Audiogon to see who’s become tired of their spouse or their preamplifier.

Happily, after three years of using Robert Koda’s K-10 preamplifier, I still feel as if I’m on a honeymoon. After listening day in and day out, sometimes from sunrise to sunset and beyond, it remains one of, if not the finest preamplifiers I’ve had the privilege to own for a number of reasons.

The gold faceplate is reminiscent of Conrad-Johnson gear, but the one affixed to the K-10 is finished to a much higher standard. The only other gear I’ve seen with this level of quality in the machine work is Burmester. This extends to the control feel as well, there is a vault like solidity and security to using the K-10, and because it lacks a remote control, you will be using these fine controls regularly.

The understated aesthetics and lack of remote control may not be to the liking of those preferring more bling, but it will thrill the purist. Aesthetics aside, the sonic purist will be instantly transported as so many of my friends and acquaintences have been when listening to the K-10. This preamplifer does an incredible job of getting out of the way to just let you enjoy music. It doesn’t sound like a solid state or a tube preamplifier. It has no sound at all, and music merely unfolds, with an effortlessness that few components at any price can deliver in this manner. Acoustic instruments retain tone and timbre in a way that the right recordings will convince you that you are seated in front of the real thing and not a stereo system – if this is your idea of the absolute sound, look no further.


In my initial review of the K-10 (above), I said there was no limit as to how far you could peek into a recording with this preamplifier, and this has only gotten better with time. Now that I have listened to thousands of tracks through it, I continue to be amazed at the resolution, effortlessness and complete lack of sonic signature that it provides. Music simply unfolds from the K-10, and now that Mr. Koda has built a K-15 model, I can’t even imagine at how he could have improved upon this design. Maybe one will make it our way for a comparison someday? Every time I swap a different preamplifier in the place of the K-10, I find myself missing it, and that is the highest compliment I can pay any component.

As one who loves the physical look and feel of the K-10 as much as its sonic attributes, I put this preamplifier in the same league of classic creations like the Eames Lounge chair or a Porsche 911 – it is beautiful to listen to and beautiful to behold. Its subtle, understated elegance is something I never tire of and contributes a sense of peacefulness to my listening sessions.

However, the K-10 does have a few minor idiocyncracies that a potential owner does need to be aware of. The K-10s 6db of gain may not be enough for a few system configurations utilizing  low output moving coil phono cartridges or a modest gain phonostage,. With the high output of most DAC’s, (usually 4V) gain should never be a problem in an all digital system. When pushing the limits, I still would like a bit finer range of adjustment at the higher end of the volume scale, but again never enough to be annoyed.

For some, the lack of a remote will be an issue. Honestly, I thought it would drive me crazy, but forgoing the remote brings me back full circle to the beginning of my high end audio experience, when they did not exist! Let’s face it, most of us can use the exercise to get up and adjust the volume anyway! But most of all, the lack of a motorized or digital volume control makes for a quieter, more pure signal, I feel it forces you to focus more intently on the loudness level of the listening session instead of fidgeting with the volume control. Set it, relax and get into the music I say!

Three years later, the Robert Koda K-10 preamplifier still gets my vote for one of the world’s finest audio creations. I’m guessing three years from now I’ll still feel the same way. This one is a bit off the beaten path, but if you are looking for the ultimate audio Zen experience, in a preamplifier that makes a major statement by not making a statement, this is your final destination. Unless of course, you pony up for a K-15!


Symbol Audio Tabletop HiFi

Symbol’s new Tabletop HiFi offers a refreshingly attractive alternative to the more traditional form factors of audio equipment.  In essence, the HiFi is a powered music playback system, but the console’s unique nuances make it so much more than that.

The HiFi, which measures 28.75 inches long by 9.5 inches high by 8.5 inches deep, offers an absolutely clean and modern-looking appearance free from visible knobs, controls or indicators.  All the owner sees from a listening position are two 4-inch, full-range drivers set widely apart on the HiFi’s face.  A built-in Class-D amplifier provides 8 watts to the front drivers and 15 watts to the 5.25-inch subwoofer.  Symbol hides the down-firing woofer beneath the cabinet, which has dual rear ports.  With so much hardware crammed into a small space, the HiFi tips the scales at a substantial 30 pounds.

On the rear of the unit, the HiFi offers a master volume knob as well as a separate control for the subwoofer, allowing the owner to tailor the sound to his or her preference.  The rear-facing controls require the user to lean behind the unit to visually locate them, until the placement of the controls becomes familiar, but the volume knob is easy enough to reach over the top of the unit.  The HiFi offers only one input, a 1/8-inch minijack.  If a user intends to switch between multiple sources, a cable splitting adapter or other manual intervention is needed.

When ordering a HiFi, soon-to-be owners have the opportunity to customize the appearance of the face and cabinet.  Options for the front include a walnut or oak finish, or a clean white or gray; cabinet finish options include walnut wood grain or a minimalist black, white or orange.  For families with young children, it’s probably a good idea to go with the protective, poke-proof metal grille option for the drivers.  The grilles match whatever finish you chose for the rest of the unit.  The many custom options allow the HiFi to be either a striking visual element for a room, or a chameleon blending into the background.  Either way, those houseguests who do notice it will find both its aesthetics and its sonics appealing.

Symbol Audio’s HiFi is available for $1,800, regardless of finish choices.  Given the unit’s single-box, single-input design, it’s clear that the Symbol Audio solution is a purist one that’s not trying to complete directly with full-blown component stereo systems.  It’s designed to fill a room with sound from a single source, and do that job very well.  Those audio enthusiasts seeking multiple input options, pinpoint stereo imaging and a broader soundstage may be served better by more traditional stereo equipment.  But for those who prioritize the appearance of a beautiful, stylish and unobtrusive audio system, and who also want good sound to complement it, the HiFi is an elegant solution.

Symbol Audio Tabletop HiFi

MSRP: $1,800


Mini Watt Amplifier: Take a Fresh Look at HiFi

No matter what your position in the audiophile game, you need a MiniWatt. This is one of the most fun pieces of gear I’ve seen in about fifteen years. (The last time was when the Antique Sound Labs Company sold their $99 tube monoblocks…) The MiniWatt is a 2.5-watt per channel tube amplifier that weighs a couple of pounds and only takes up about a 6 x 6 inch footprint on your desk, about 15 x 15 centimeters for our friends in the rest of the world.

It uses a pair of 6J1 and 6P1 tubes and a self contained AC power supply. The rear side of the transformers have banana jacks wired directly to them for your speakers and there is one set of RCA jacks to plug in an analog source. ALOAudio and their retail store 32 Ohm Audio is the exclusive American distributor for these little jewels, and when I stopped by their store last week, they weren’t even open and people were already buying them. “Wanna take one home?” Ball asked me as I was surveying the new store. Look, shiny thing!mini watt rear

Hurry up and plug it in

I wasn’t even half way to my car when I thought of hooking the MiniWatt up to my Zu Essence speakers that have a sensitivity of almost 100db. Knowing the luck I’ve had with Zu’s and 2A3 amplifiers in the past, I knew that this would be a rocking combination. The minute I hit the door, the MiniWatt was plugged in to the living room system, with the tubes warming up.

For the nerdtrons in the audience, I hooked the MW up with a pair of Zu’s Libtec speaker cables and a pair of Furutech Reference III interconnects to my Marantz Pearl SACD player. You think I’m crazy hooking up about $4k worth of ancillaries? It didn’t stop there, I had a spare Shunyata Python CX power cord, and so I was now ready to roll with the whole setup plugged into a Running Springs Haley power conditioner.

FYI, for those considering the MiniWatt to be the hub of a “budget” system, it works great that way too. Later on, after the amplifier was fully evaluated, I broke out the $50 Pioneer 563 Universal Player and my favorite $100 Polk Audios and was still very impressed with the performance.mini watt top

2.5 watts can accomplish a lot

Powering the Zu’s the MW was able to blast. I zipped through some of my favorite metal discs and was amazed at how loud I could play Van Halen with this tiny amplifier. TONEAudio writer Jerald O’Brien stopped by for an adult beverage and thought I was using the Lavardin integrated amplifier that is also in for review. He was pretty surprised when I told him it was just the MW. “I thought that was a new headphone amp!” he remarked.

We proceeded to spin more discs and after some jazz and vocals, it was evident that this tiny tot was no mere toy amplifier; it delivered the goods. Because this amplifier has the tubes driven in ultralinear mode and those are some pretty small output transformers, it’s slightly grainy, but that’s judging it against my Bottlehead 2A3 monoblocks, which are silky smooth and with some upgraded 2A3’s will set you back a couple thousand bucks. You’ll never touch tubey goodness like this for $229.

What impressed me the most about the MW was the amount of bass power and control it had, which wasn’t limited to the Zu’s. Going through another cache of tracks from Pink Floyd, Genesis and Spock’s Beard, we were convinced that the MW could really get down. I also had a ton of fun using it as a desktop amplifier with a pair of KEF XQ20’s that feature their Uni-Q driver and are very coherent. Soundstaging on my desk between my 30” Apple Cinema Monitor was wide, wide, wide and dynamics remained excellent, even with speakers only having an 88db sensitivity. Near field listening has its benefits.

Pondering the Zu’s again, which have a nominal impedance somewhere around 14 ohms, I thought the MW just might be a good headphone after all and gave my Sennheiser 650’s a try. Again, excellent luck, so this could also work as a headphone amplifier for some phones. I didn’t get a chance to give this configuration extensive testing, so it might not work with every situation, but if you buy a MW I suggest giving your phones a test drive while you are at it. It’s small enough to carry into the bedroom for some late night listening with your iPod and favorite phones.

More performance

I suppose you could get crazy and mod the heck out of the MW, (and this could be a future article because I have a hard time leaving well enough alone) but an easy upgrade is to spend another $45 and get the “upgraded tube set” from ALO which includes a pair of Russian tubes to replace the 6N1’s on the outer left and right, while the two middle tubes are replaced with a pair of vintage Western Electric 403, which is a 7 pin mini pentode tube.

This made a big difference in the overall sound, increasing the soundstage about 25% and eliminating some of the grain that was present in the upper midrange/lower treble range. This is definitely the best $45 upgrade you will ever hear, so I suggest just ordering your MW from Ken with the better tubes, you won’t regret it.Mini watt upgrade

Award winning fun

I am happy to give the MiniWatt amplifier our Product of the Year award in the “Budget Audio” category. This is a great amplifier, period. If you are just starting out in HiFi, you can make a pair of single driver, high efficiency speakers, add a source and be digging music on a pretty tight budget that you will really enjoy and our world definitely needs more products like this. And I can’t think of a more fun way to enter the world of vacuum tube audio if you haven’t yet.

This little amp is the real deal folks. Highly recommended.

– Jeff Dorgay

The MiniWatt Amplifier

MSRP: $229, updated tubes, $30 additional

USA Importer:

Ken Ball/ALO Audio, www.aloaudio.com

MiniWatt home page: www.miniwatt.com.hk

MartinLogan Purity: HiFi with ease!

Purity_Dark_Chery_Lifestyle_2In the last few years, MartinLogan has received a lot of praise for their hybrid electrostatic designs, mating their legendary electrostatic panel to a dynamic woofer. In the case of the Purity, it’s a pair of 6.5-inch woofers in a very compact package that will only take a 10 x 15 inch patch of your living area.

What makes the Purity special though, is the fact that these are powered speakers, so you only need a source component and a pair of fairly long interconnects to build a complete system! These speakers feature a 200-watt, high resolution, switching amplifier built in, so if you want high quality HiFi, but don’t want a rack full of gear to go along with it, the Purity is for you. You can even run them with an iPod or Squeezebox and have the ultimate minimalist system. The Purity can be customized for different color options, at a base price of $3,295.

Small sources

That’s exactly where I started my journey with the Purity. In my small (11 x 17 foot) living room with my iPod full of Apple Lossless files and a pair of 8 foot Radio Shack interconnects. Worth noting when you set the Purity up for the first time, there is a hard plastic base on the bottom of the speakers that will tilt the speakers’ electrostatic panel back somewhat or keep it straight up.

Pay careful attention to this adjustment, because tilting them back gives the speaker a better overall tonal balance if you are going to be listening to the speakers primarily walking around the room or mostly standing. If you are going to be more of a traditional audiophile, listening in your chair, stand them straight up. Note, that with either of these positions, you will lose some of the high frequency and focus when you are not in the optimum listening position.

Tech info

If you’ve got a high quality source, you will be floored at how good the Purity sounds and how much music comes out of these relatively small speakers. I’m guessing you will be in one of two camps: A legacy MartinLogan owner that needs another pair for a different room in your home or office or someone new to the MartinLogan way of doing things.

If you are new to the electrostatic speaker experience, you’ll be surprised at how open and airy these speakers sound compared to a lot of box speakers, and that’s MartinLogan’s trademark. The diaphragm inside the panel assembly weighs close to nothing, so it can accelerate instantly. Thanks to the crossover frequency being so low (450hz) this panel handles most of the critical musical information and the two small woofers give you the same amount of bass you would get with a larger woofer, but in a smaller space. Those two small woofers also move faster, to keep up with the panel, adding to the overall transparency of the sound.
If you’re already a MartinLogan owner, you know all this stuff and you probably want to know how the Purity compares to the larger speakers you already own. The actual panel in the Purity uses the same materials and construction as the rest of the MartinLogan line (all the way up to the flagship CLX, which is one of my reference speakers), featuring their 2nd generation electrostat panel technology.


Even using my iPod as a source, I was very impressed with the sound of the Purity. Think of the Purity as a bite-sized serving of what the CLX has to offer. When sitting in the sweet spot, it’s easy to be fooled at first listen that you aren’t hearing something much more expensive than the Purity and that’s it’s best attribute.

Granted, a switching amplifier has some limitations and because of the two 6.5 inch woofers, these speakers will reproduce solid bass down to about 40hz, where MartinLogans’ larger speakers will go all the way down to the mid 20’s, the overall balance is excellent.

As a MartinLogan owner, I was excited at just how much sound I could coax out of these speakers. After quite a bit of iPod listening, my next task was to investigate the limits of performance these speakers were capable of, so my next task was to drag out some better interconnects, power cords and source components to find out if this was a serious HiFi speaker after all.

Upping the ante

Again, the Purity passed with flying colors. Now, my “budget” system consisted of the Audio Research SP-17 preamplifier that we had in for review along with the Marantz K-A1 Pearl CD/SACD player. Both of these components cost almost as much as the Purity, and I did upgrade from Radio Shack interconnects to two pair of ED422 interconnects from Empirical Design, valued at about $500 each. I swapped the stock power cords from the Purities for a pair of Shunyata Venom cables ($125 each) and plugged the whole system into a Running Springs Haley power conditioner.Purity_Front_3Quarter

Bottom line, the Purity is up to the task of being the cornerstone of a real “audiophile” system too, so even if you start out just using the Purity with an iPod, you can rest assured that if the upgrade bug bites, you can grow with these speakers.

The Sound

The sound is pure MartinLogan. Open, airy highs, walk through midrange and tight punchy bass. I kept going back and forth between my dedicated listening room where the CLX’s make up a six-figure system and the Purity in my living room with the ARC/Marantz combination, playing the same CD’s on each.

The Purity did a fantastic job with everything I played. My favorite rock records had plenty of body and of course, vocal records really let these speakers shine. At times, you could definitely hear the limitations of the switching amplifiers present in the Purity, but that was only when comparing the system to my reference system. I think MartinLogan has done a great job with integrating the amp and speakers.

When playing musical selections that did not possess huge dynamic swings or subterranean bass notes, it was easy to be fooled when going between rooms. I was surprised at how good the speakers’ bass response was, considering the printed spec lists the LF response at 41hz. Yep, the driving bass line in “In-A-Gadda-Da-Vida” came through loud and clear. Speaking of loud, these babies did a great job with my favorite Mastodon, Tool and Metallica cuts, so they should be able to play anything else that interests you after this torture test.

While the Purity does not have the full scale of dynamic range that the more expensive Vantage or Spire possess, it does one thing better than most of the speakers in the MartinLogan line; top to bottom coherency. Those small woofers are fast and articulate. So much so, that you might be fooled into thinking this is a full range electrostat!

The only real limitation to the Purity is that the sweet spot for critical listening is small. If you have them angled back, the sound is very good all over the room, but the best sound will only be in one spot. Same thing if you have them optimized for your chair; that will be the only place you get all of the magic. Keep in mind you would have the same limitations with a small pair of mini monitors in this kind of space too, so I don’t see this as a limitation.

I also made it a point to run some fairly long interconnects to these speakers, as they only have RCA line-levelinputs. While I didn’t have any trouble with 20 foot interconnects, it might be a good idea for the next version of these to have balanced XLR inputs as well. Those with a budget source only possessing speaker level outputs can connect via the speaker level inputs as well.

In the end, convenience

Thanks to the internal power of the MartinLogan Purity, they make a great place to put a high quality sound system, where you might not have in the past. In five minutes you can have them set up and playing music and that’s what it’s all about. Though some of you might get grumpy that a powered speaker doesn’t give you the flexibility to choose amplifiers, speakers, etc., you’re missing the point; the Purity is the perfect speaker for someone who doesn’t want to bother with all of that! Plug em in and enjoy.

Because the Purity offers this level of performance, style and simplicity in one package at such a great price, we are awarding it one of our Publishers’ Choice awards for 2009.

The MartinLogan Purity
MSRP: $3,295


Sources: iPod Touch, Audio Research SP-17 preamplifier, Marantz K1 Pearl SACD player

Cable: Empirical Design ED 422 interconnects, Shunyata Venom Power Cables

Accessories: Running Springs Haley power conditioner