Redecorate, rejuvenate, reoscillate

I'M NOT a great believer in the many tweaks that proliferate our audio market place. A large number are, quite frankly, based in the realms of black magic rather than in cold, hard scientific principals -- not to mention the over-inflated price that accompanies most of these upgrades.

So when Sujesh, our esteemed editor (he makes me say stuff like this) asked me to head on down to Octave Electronics to check out the latest in revolutionary quick fixes for your CD player, this sceptic went along and got the shock of his life!

Unannounced, I dropped in on Michael Loke at his Petaling Jaya Old Town shop, with folder in hand and ears prepared to experience the effects of these CD player modifications that are keeping him quite busy these days. Naturally I started by asking him, "so what's the deal?"

"At the moment, we are performing two upgrades to customers' CD players. Both of these are relatively easy to do, inexpensive ... and our customers have been extremely happy with the final results," said Loke.

LClock XO promises to revitalise your old CD player.

The first upgrade, he added, consists of replacing the internal clock circuit with a small, credit card-sized circuit board called the LClock XO Precision CD Master Clock Generator from a Danish company called LC Audio. This reduces jitter in the player. The next step is to replace the operational-amplifiers with the much higher quality AD825.

Now, before I go on and explain in detail what all of this means, you don't need to understand any of the technicalities to appreciate the difference. And let me say that the difference is amazing!

Also, if the very thought of opening your CD player and taking to it with a soldering iron makes you dizzy, Octave Electronics will be happy to complete the whole procedure for you -- and given the number of these modifications they have successfully performed, they've got that reassuring edge of experience to back them up. Best trust the experts, eh?

Extrapolations on jitter

Right! Let's get down to some jitter nitty-gritty.

Instead of using the term jitter, let's call it errors in timing. Timing is a critical part of digital, much more critical than I'd like it to be. You see, it's with a great sadness in my heart that I have to tell you that digital is not just "1"s and "0"s.

Actually, flying about in your CD players digital circuits are analogue waveforms. That is, the 1s and 0s are represented by a (hopefully) squarish, but decidedly, analogue waveform. So your CD player's digital electronics must decide above which voltage becomes a one and below which voltage becomes a zero -- this is a relatively trivial exercise. The big problem here is, when does this decision occur?

Various op-amp options from LC-Audio

Imagine if you will, a square wave, but due to inferior internal electronics, this square wave has become more of a triangle wave (it would never get this bad, but just humour me for a minute). Now, we've got a digital one, represented by the peak of the triangle, and the next bit is going to be a digital zero, which would be at the base of our triangle. At a precise moment in time, that digital one, on its downward journey, crosses the decision point (at around the half-way mark) and becomes a digital zero.

Everything is cool at this point as long as the CD player makes the decision at the exact right moment -- at the decision point if you will. If the CD player looks at the waveform too early in time (i.e. a timing error), the worst possible case scenario would be that a digital zero might become a digital one, as the waveform hasn't crossed the line yet. Welcome to the deadly effects of jitter.

Of course, this example is simplified and highly unrealistic, but I hope you at least understand why timing is so important. Tiny errors in timing result in subtle, but audible errors in the bit stream, essentially destroying low-level detail. The next scary part is how accurate does this timing need to be?

Most CD players (including expensive ones) use cheap, noisy, multi-purpose CMOS crystal oscillators, which introduce timing errors. They are still accurate enough, but their timing typically varies by about 200pS (0.000000000200 of a second) or more.

The LClock XO Precision CD Master Clock Generator can reduce this to around 2pS (0.000000000002 of a second). The audible difference? A tremendous increase in detail across the entire frequency spectrum, especially in subtle things like reverb trails. You get a proportionate increase in bass detail and clarity, and the list goes on.

Unfortunately, not all CD players use the same oscillator frequency, which is measured in MegaHertz (MHz). Common oscillator frequencies are 8.4672, 11.2896, 16.9344, 22.5792, 33.8688 and 45.1584MHz. If your CD player uses one of these (which it probably does), then the upgrade might be for you.

CD players where modifications and technical details are well-documented include Accuphase, Arcam, Cambridge, Copland, Denon, Kenwood, Marantz (including the famous CD63), Micro Mega, Onkyo, Parasound, Pink Triangle, Pioneer, Proceed, Quad, Rega, Rotel, Sony, Sugden, Teac, Technics, Thule and Yamaha.

For CD players not on the list, for example, my own Nakamichi that I now want to upgrade, it becomes a process of investigating what the frequency of your oscillator is by ripping the lid off and checking out the main crystal. (How jitteringly funny! -- Ed.)

A surgical symphony

Phase two in the process involves upgrading the operation amplifiers (op-amps) in your CD player to a much better version, the AD825 from Analog Devices. The AD825 is an ultra high-bandwidth (41MHz), ultra-fast (125 V/us), ultra-low distortion (0.00012% THD @ 1KHz) amplifier -- as compared to the standard op-amps in your CD player, which can have specifications as low as 3MHz, 9V/us and 0.0006% THD respectively.

Fundamentally, this is a straightforward transplant -- out with the old, in with the new. These components are essentially baby amplifiers (they look like tiny computer chips) that drive the analogue stage in your CD player. Ironically, you can buy a handful of these devices (your CD player usually has from one to six) for a ringgit or so down at Jalan Pasar (in Kuala Lumpur). Scary, eh?

The AD825 is mounted on a tiny circuit board in four versions to accommodate the different pin configurations; see the sidebar piece for details.

Once again, it's just a matter of ripping the lid off your CD player and checking the numbers on the tiny chips to see if they match any of the above. If so, you can consider the upgrade.

Be wary of doing this particular modification yourself, as most of the op-amps are soldered directly onto the CD player's circuit board. So you'll have to de-solder the existing op-amp, extract it, solder in a new socket and place the appropriate AD825 module in the socket. Once again, if you've got any doubts, go see the experts.

Sonically, you'll get a significantly reduced noise floor, further increase in detail across the frequency spectrum, tighter bass (due to the AD825s speed) and better imaging (both width and depth). The full list of improvements is too lengthy to mention here.

So, Im upgrading ... how about you?

Keeping old faithful

For such a small investment (only a few hundred ringgit, depending on the model of your CD player), I've never heard anything that can produce such a massive improvement. You'd really have to be deaf to miss this one!

I can't urge you strongly enough, go visit Octave and check out the difference for yourself. You might just end up keeping old-faithful for a long time to come.

Retail prices for LC Audio products:  LClock C2: RM350 LClock XO: RM520 Op-amps: RM110 per module Available: AD825 Type 1 Dual DIP for NE5532, AD712, NEC2114, JRC4570, OPA2132, OP275 and OPA2604 AD825 Type 2 Dual SIL for Teac VRDS10, VRDS10SE, Yamaha, Kenwood CD players AD825 Type 3 Dual SIL for Marantz CD63 series, CD67 series, Rotel RCD971, most Sony models. AD825 Type 4 Single DIL for NE5534, AD811, AD844, AD711. Installation charges for LClock XO: RM60 For more information, call Octave Electronics (03-7783-7939). The company is located at 81 Jalan 1/12, 46000 Petaling Jaya, Selangor. E-mail: info@octave-electronics.com. Website: octave-electronics.com