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Reviewer: Jeff Day
Licorice Disc Source: Garrard 301, Cain & Cain plinth, Denon 103 cartridge, Origin Live Silver arm [in for review], Pete Riggle Audio VTAF (Vertical Tracking Angle on the Fly), Auditorium 23 moving coil step-up transformer [in for review], Monolithic Sound phono stage
FM Source: Vintage early 1960s Scott 370 FM vacuum tube tuner supported by Yamamoto ebony audio bases, Magnum Dynalab ST-2 Vertical Omnidirectional FM Antenna
Digital Source: Meridian 508.20 CD player used as a transport with the Audio Logic 2400 vacuum tube DAC crunching the digits
Preamplifier: Tom Evans Audio Design Vibe, Tom Evans Audio Design Pulse power supply [in for review]
Integrated Amplifiers: Almarro A205A EL84 single-ended pentode; Sonic Impact Class T digital
Amplifiers: Fi 2A3 single-ended triode monoblocks with Tung-Sol JAN-CTL-6SF5GT (5842) inputs, Sovtek 2A3 outputs and Phillips 5V4GA rectifiers
Speakers: Avantgarde Duo 2.0, Omega Super 3 & matching Skylan Stands
Cables: Nirvana S-X interconnects between DAC and preamplifier; Nirvana S-L interconnects between preamplifier and amplifiers; Nirvana S-L speaker cables between amplifiers and speakers; a custom Nirvana wiring harness to connect the Duos midrange and tweeter horns and woofer module; Nirvana Transmission Digital Interface [on loan]; Cardas Neutral Reference digital cable; Auditorium 23 speaker cable [on review]
Stands: Atlantis Video Reference equipment rack, Billy Bags 2-shelf rack
Power Line Conditioning: none
Room size: 15' x 25' x 8', short-wall setup
Review Component Retail: $99.95 or call 908-754-1479 to order in Plainfield/New Jersey
"Hey guys, I'm in need of a little speed control."
While working on the Garrard 301 Restoration Project, I asked my audio pals what I should do to calibrate the speed on that grand old transcription table. With one voice they shouted "K-A-B!" Given that unanimous recommendation, I thought I'd better google up KAB USA and find out a little more about their Speed Strobe. KAB's Kevin Barrett responded positively to my subsequent review inquiry so now you get to hear all about the Speed Strobe. The goodies from KAB arrived in perfect condition in a sturdy shipping carton. It contained a nicely packaged Speed Strobe kit in a cardboard box that you'll want to hang on to store your new analog goodies. The kit comes with a sturdy and nicely finished black PVC calibration disk with white silk-screened numbers that range from 33 to 90; and a battery-powered 60Hz quartz calibration strobe light that is 99.99% accurate (battery included). In the order of 33, 45, 70, 72, 73, 75, 76 and 78, the marker numbers progress in circles from the outer band towards the inside and correspond to speeds of 16.66 RPM for the outer band and 33.33, 45.00, 70.59, 72.00, 73.47, 75.00, 76.59, and 78.26 for the numerical markers using the 60Hz quartz strobe light.

According to KAB, the calibration disk and quartz strobe light allow you to measure speed accuracy of your turntable to 0.03% while noting that a speed error of 6% "will alter pitch a full sharp or flat." As any musician will tell you, that's a severe

offset from true. You had better have your table's speed dialed in properly if you really want to hear the music as intended. KAB makes it a point in their instruction pamphlet that theirs "... is the only optical disc measuring system. Any strobe can set speed; only the KAB Speed Strobe can actually measure it!" KAB goes on to say that the industry standard for broadcast accuracy is 0.3% whereas the Speed Strobe can measure it by a magnitude of 10 more accurately.

How does it work?
KAB has a really nice description of how the strobe calibration principle works. I'll briefly summarize it here. The strobe light gives the illusion of freezing the motion of the calibration numbers passing under it as the table's speed is adjusted so that the rate of numbers passing through the strobe beam is the same as the flashing frequency. When the numbers for a given speed stand still, your table is running at the speed indicated by that number.


The ratio of the square of the strobe light's pulses (F) and the desired speed in RPM equals the number of markers (N) spaced evenly around the calibration disk. Then one marker will pass under the strobe light every time it flashes for the desired RPM and that number will seem to stand still. That is expressed as the equation "N = [(F)(F)/RP)]". Inserting figures into this little math equation for a 33.33 RPM record, you get "N = [(60)(60)/33.33]" = 108 markers in the calibration circle for one marker to pass under the strobe every time it flashes. Lucky for you, KAB has already done the math. All you have to do is...

Give the Speed Strobe a Twirl
After figuring out what made the Speed Strobe tick, I unpacked the calibration disk and strobe light and popped the included battery into the strobe light's black plastic case. In case you need a size reference, it's just about the size of a pack of cigarettes (just for you, Senator Dole - there has to be at least someone who'll get the joke!). In use it's an easy drill: Place the calibration disk on the platter, turn on the motor of the turntable, point the strobe light at the calibration disk and read the speed right off the disk as the speed reading emerges magically like a ghostly red specter from the surface. If the numbers appear to be drifting to the right, the table it running slow, if to the left, it is running fast. If you're a Garrard nut like me, you'll next reach for the transcription motor speed control and change the dial until those same ghostly red speed numbers appear stationary. That's all there is to it unless you want to be analytical about it or own a turntable with a fixed motor. In that case, you can count the numbers going by the strobe beam over 60 seconds. If 10 numbers drift by in the course of one minute, your motor is running at 0.3% accuracy. 3 numbers equate to 0.1% accuracy and 1 number to 0.03% accuracy. As long as the accuracy is 0.3% or better, you're all set.
When I checked my Garrard for one minute, 20 numbers drifted past the strobe to the left. This was clearly too fast, an error of 0.6%. My table reproduced an f-flat as slightly sharp. In my case, this error also happened to be outside the motor control's ability to correct. So I pulled my trusty Variac out of the closet, plugged it into the wall and plugged the Garrard into it. By dropping the voltage from 120 to 110, I was able to get the motor back into the range where the table's speed control could fine-tune final speed. After a little tweaking, I was able to adjust it so that just one number was drifting past the strobe beam in 60 seconds. This now was 0.03% accuracy - an order of magnitude better than the broadcast standard. I didn't know the old girl had it in her. I would have never known without the Speed Strobe. It rocks! If you want to compensate for stylus drag on your table's motor speed, you can place a small 45 record over the calibration disk and set the speed while the stylus is running in the groove.
I didn't have a 45 handy though when I get my hands on one, I'll check to see how much drag my needle puts on the motor. With the industrial strength of the Garrard motor, I'll bet it won't be much.

You're probably wondering what all this speed calibration has to do with music & sound. So was I. In fact, I really doubted that I would even be able to hear how such small differences in speed would affect the sound. To do a quick check, I pulled out one of Chad Kassem's awesome test pressings of Bill Evan's Waltz for Debby [APC 009 A/B1M]. After making sure my table was calibrated to within 0.03% accuracy, I dropped the stylus and grooved to the music. Then I twisted the transcription motor's speed adjustment dial to slow it down to where it was 0.6% below accurate - the exact amount that my table had measured fast when I first calibrated it with the Speed Strobe. "Holy burning Bush!" I thought - the difference was profound. The small change in pitch was dramatic in its effect on the music. And that was at a level ten times below the threshold of a half-step change - music lingo for going from a note to a sharp or flat change of that note, in this case flat by 0.6%. It's like hearing Mickey Mouse talk after smoking a little weed. He's a little slower and lower and it affects the feel of the music. Ditto for when you crank it up faster. You get a Mickey who's wired on Starbucks espresso for a jittery fast-talkin' jive cat with a slight falsetto. It's really ugly. What you want is a cool-dude Mickey with no mood enhancements, just Bill's straight jazz vibe for the real feel at the wheel.


So what else is there to say? The KAB Speed Strobe is intelligently designed, made with quality, so easy to use even I could figure it out, and sells for $100 which I think is a very fair price. Am I going to buy one? You bet!!
KAB website