December 2004

Audiolics Anonymous Chapter 63
Blue Note Best Of 2004 Award
Article By Bill Gaw

  Welcome to another meeting of Audiolics Anonymous, the place for the insatiable tweaker. Hopefully your Thanksgiving went well, and you've bought all your Christmas gifts for the loved ones. Why? Because I've decided to present my products of the year a month later than usual. First though, I'd like to discuss a tweak I've been playing with for several months that is good value for the money, especially when you build some of their iterations yourself like a good tweaker should. I'm referring to...

Bybee Quantum Purifiers  
Several of Mr. Bybee's products have been reviewed in this rag, with a full review of how they work given by Dick Olsher (click here) and Max Westler reviewed the Slipstream Magic Bullets and Speaker Chargers (click here). Also there is excellent information supplied at Bybee's website, which you should read before continuing. No need to repeat what they've explained in full. Jack has two product lines:

1. Do It Yourself: Large Quantum Purifiers at $80 each for 4 to 15 Amp projects, the 0-4 Amp Small Slipstream Quantum Purifiers at $90 each and the 0-4 Amp Small Silver Slipstream Quantum Purifiers at $160 each.

2. Ready Made Products: Bybee Slipstream Magic Bullets for $400 per pair which have male and female RCA's with Small Quantum Purifiers in the middle for interconnects, and the XLR Magic Bullets for balanced interconnects for $880 per pair, and the Ultra Speaker Chargers for $880 per pair, The Angel Song speaker chargers for $1,200 per pair, or with 6 feet of his ribbon cable for $6,500 per pair, and various forms of Angel Song interconnects. Finally, for $550 the IEC Power Chargers.

Knowing my Scottish heritage and my tweaker's mind, you know I took the cheap way out and went with product line 1. Also, due to my cheapness I used the units where I thought they'd do the most good. While somewhat cheaper (maybe) than heroin, these units are just as addictive. Use one set and you'll be hooked. They do exactly as Dick and Max described. Every place I tried them, they removed noise from the system. More on that later.

The Power Charger's replacements were fairly easy to construct. You can order the large Purifiers with male and female IEC plugs from partsconnexion.com, a set of plugs and purifiers costing a total of $250 to $300 depending on the quality of the plugs. Add about 6 inches of 1-inch diameter shrink-wrap, and about $0.10 of silver solder, and about 20 minutes of work per unit. I built two of these for the inputs of my Walker Audio Velocitors, which then covered the six outlets of those units. Even cheaper and probably better, I soldered the Large Purifiers directly to the insides of my third Walker Velocitor. Remember to also use them on the grounds as significant noise can come through there also. If you have the bucks, and the skill, solder them between the AC inputs and transformers on each piece of equipment.

One can also use the small Purifiers between the AC inputs and transformer leads of low wattage pieces of equipment. Also each of my speakers had one soldered between their positive and negative inputs and my silver ribbon speaker cable. The final experiment consisted of soldering the Silver Purifiers to the inputs of my main speaker amplifiers, and replacing the small Purifiers on the speakers with them.

First, a word of caution. I did use the small purifiers in places not recommended by the manufacturer, who obviously doesn't want to get sued by somebody who uses a 4 Amp product on a 20 Amp amplifier. Also, Mr. Bybee recommends the small Purifiers in circuits and interconnects and the silver slipstreams primarily for use in the circuits of digital equipment. He recommends the Large Purifiers for AC and speaker wiring, especially woofers. The outcome was that every place I tried them, there was an improvement in the system.

With AC, the biggest change was a decrease in background hash, but not the same noise that line conditioners work on. I don't know what they are doing to the AC, and don't understand the scientific explanation, but there is a decrease in the noise floor above and beyond what the Sound Applications and Velocitor units accomplish. It removes a slight haze that hangs in front of the sound stage. I can't describe it further. In visual terms, its almost like clearing the air of a mild fog.

A similar effect occurs with use at the loudspeaker terminals, where further haze is lifted. Also, by clearing up the sound stage instruments are more defined. The Silver Purifiers worked even better than the small Purifiers on my low wattage speakers, but again, I use horns that rarely use more than 1 watt, so don't complain to me if your 80dB per watt speakers don't work with them. I'd experiment and start with the large Purifiers on woofers and the small Purifiers on the mids and tweeters and then maybe go with the silvers. The one place I didn't perceive any difference was using them at the amplifier and preamp inputs. I don't know whether this was system dependent or whether using them at the other places in my system negated any further improvement.

What was surprising was the marked effect heard with the small purifiers on the ac inputs and the Silver Purifiers on the outputs of digital equipment including my Denon 5900 Universal Player and my EAD 8800 Pre-Pro. Digital is much more susceptible to AC line noise than analog, and digital must also impart some noise to the analog output of D/A converters, because adding the purifiers at both places significantly improved the soundstage, making especially SACD's more analog-like and three dimensional. I only had enough of the silver units to do the left and right front channels, so did not experiment with 5.1 improvement, but even 5.1 recordings were improved with the Silver Purifiers in place on only 2 channels.

So, all in all, the Bybee Purifiers work as claimed, and are certainly worth their cost. I'm surprised that some manufacturers haven't picked up on adding these internally to their equipment, calling it an update and charging significantly more. Well, maybe some are? A reply from Mr. Bybee:

Dear Bill:

Thank you for giving me the opportunity to read and comment on your discussion of Bybee products. I would like to address a few points.

First, website addresses: The URL www.bybeeinside.com has been officially changed to www.bybeeconnection.com, although you can still reach it for another month or so with the original URL. The Bybee Connection website is in fact not my website, but an independently owned ecommerce retail business managed by my friend Eivind Sukkestad; it does carry all Bybee products, and as you pointed out, has a great deal of useful information.

My company, Bybee Technologies, has its own website, www.bybeetech.com. The information and layout of this site bears a very close resemblance in content and format to www.bybeeconnection.com, as the two sites were developed together. However, the purpose of www.bybeetech.com is informational, not retail commercial. I do not fill retail orders, but sell my products through the authorized resellers whose listings are found on the site. I hope this explanation will clear up any confusion concerning the two websites.

Large and small Bybee Quantum Purifiers: The large (15 A current-handling capacity) devices incorporate improved versions of the original rare earth metal oxide ceramics-based technology. The small (4.3 A) devices, both copper and silver, use new-generation signal purification elements based on carbon fiber and nanotechnology. I identify these models as Slipstream purifiers, and all of my manufactured plug- and-play products also bear the Slipstream name. Within their current-handling limitations, the small Slipstream Quantum Purifiers have generally been found to deliver even better sonic purification than the large ones.

Retail products and pricing: I simply suggest that readers visit one of the above-listed websites for complete and up-to-date listings, as several new, recently developed products are now available.

AC applications: Just a couple of things. First, the DIY AC power charger you describe will certainly provide improvements, but it will not be the equivalent of my Slipstream Power Charger, which incorporates a special configuration of large and Slipstream purifiers. Also, as easy and effective as treating primary AC (i.e., between IEC and power transformer) is, even more dramatic improvements can be achieved by adding purifiers to a component's secondary power supply (i.e., between the power transformer and rectification diode bridge). The secondary power modification should be attempted only by knowledgeable and qualified individuals; many Bybee resellers are experienced in these and other modifications.

Preamp and amp input modifications: I was somewhat surprised to find that you did not find these modifications especially effective. My own experience and that of many customers has been that these are among the most effective locations for placing the purifiers.

More modifications: There are actually numerous locations in different components where experienced technicians can place Bybee Quantum Purifiers. I am aware of instances in which as many as 30-40 purifiers have been added to a single component, with performance gains that have exceeded all expectations. Granted, that can become a very costly business. On either of the above-mentioned websites, the reader can click on the DIY RESOURCES header and bring up a MODIFICATION GUIDELINES document that describes the most commonly favored modifications for various types of components. Many of these should be reasonably easy for experienced DIY enthusiasts.

In closing, thank you for taking the time to work with my Quantum Purifiers. Although you may not have understood the theoretical explanation of how they eliminate various types of quantum-level noise, you have certainly characterized very well the benefits of this technology.

Jack Bybee 
Bybee Technologies

Tweak Of The Year
Walker Audio Extreme Super Silver Treatment
I'll bet any of you who've kept up with my columns over the past year knew this one was coming. This is by far, the best tweak at a reasonable price that I've used. There is no doubt in my mind that this stuff works to minimize resistance across any contact it is used on, and the lower voltage carried, the more effective it is. The two most helpful points are at phono contacts, both at the cartridge pins and the interconnects, where I've gained about 4dB of signal output, and on tube pins, where it removes significant amounts of what I thought was worn tube noise, but turns out to be probably corrosion of the tube pins. You'll be able to add significant life to those expensive NOS tubes. It works equally as well for output tubes and doesn't seem to degrade with their high temperatures.

It comes in a little jar with about enough to fill a teaspoon, but that amount will do every connection, from AC to speakers. While he makes the original Super Silver treatment still for $70, don't cheap out: get the $150 Extreme for two reasons. First, it is that much better. Second, this stuff is a pain in the butt to clean off every contact. Do it right the first time.

Product Of The Year
Vacuum State DPA 300B Power Amplifiers
This is getting monotonous! This is the third year in a row I've given product of the year to an amplifier, and the second year in a row that title has gone to Alan Wright's DPA Fully Differential Amplifier. There's a good reason. If you review my previous article, AA Chapter 52, I had the original set built for Vaic VV-32 tubes, because I had multiple sets hanging around from my first adventure with SET amps. The amps were so good, I decided to have a set built for 300B's. Alan's circuit innovation is to design a magic box (his words, not mine) to turn the push-pull circuit into a full differential output stage. While other amps and preamps use a differential circuit for the input or driver stages, he claims that this is the first design to be able to do this with the output stage, except for a tube power amp used in German atomic power plants for accurate positioning control of the power rods. In Alan's own words:

What this Magic Box does is ensure that the total current flowing through the two tubes (and hence in the output transformer) is absolutely constant -- so if one tube's current goes up just one microamp from (say) 60.000 milliamps (mA) to 60.001mA, then the other one will come down by exactly the same amount, from 60.000 to 59.999mA. This completely solves the microdynamic losses in a conventional P-P amp where these currents are not in any way precisely controlled, and hence allow/cause the cancellation of subtle but vital musical information within the output transformer.

When used at every stage of a power amplifier, this differential topology allows optimum microdynamics/resolution as well as surprising natural macrodynamics -- and no inherent weaknesses. Listening tests prove that this principle has at least the same midrange naturalness and microdynamics of the worlds very best SE amps without any added constant colorations -- as well as wonderfully accurate bass tonality and overall musical naturalness!

The circuit works in spades. The units have the clarity and deep bass extension of solid state, the microdynamics and midrange of single ended tubes. Missing though for the single ended guys is that luscious second order harmonic distortion that the SET crowd loves. In its place is a crystal clear soundstage.

TheVV-32 amps worked superbly for driving the mid-tweeters, but they didn't quite have that 300B or 2A3 luscious midrange when used with Plinius stereo 50 amps in balanced mode driving the woofers. I borrowed a set of 300 B amps from a friend just to see how the VV-32 DPA amps would sound in the bass range. Wonder of wonders, the bass obtained was the tightest I'd heard yet in my system, far surpassing what the Plinius solid state amps would do for control of the woofers. In addition, the bass was more defined, giving that feeling of low frequency energy which completely permeates a concert hall that is felt more than heard.

This amazed me considering I was using one 18 watt monoblock tube amp driving 2 12" horn drivers instead of dual 50 watt solid state amps in Class A mode. I was so enamored of the results that I decided to have him build a new set so that I could bi-amplify using 300 B tubes. I placed my order late last fall and finally was able to bring them home when I went over to the Munich High End Audio Show in May. This way I brought them with me on the airplane, thus skipping shipping charges and customs duty, and possible shipping damage.

The night I picked them up at Alan's apartment-workshop, I had trouble prying them out of his hands as these were the first of the 300B type produced, and he loved the sound compared to the KT-88 units he had been listening to. He was using them on a set of full range electrostats he had modified and the sound was superb. During that time, Alan had finalized his circuit and made several improvements: 

First, hum control pots were now placed on the top of the chassis directly behind their respective tubes. No more need to tip the amps on their sides for this adjustment. On the other hand I needed to do it only once with the VV-32 units and there has been no change in over a year.

Second, balancing the magic box is much more accurate than with the original units. The meter that came with the first units gave a relative value for the balance of 0, but there was no way of knowing the absolute variance, and Alan felt this was not accurate enough. It has been replaced with two banana plug sockets directly in front of the tubes. One only has to plug in a voltmeter, set it to millivolts and adjust a pot on the back of the unit to perfectly balance the output current of the tubes. Once the tubes warm up and are balanced, good ones will hold to less than +/- 1 millivolt once warmed up and broken in, the latter taking about 1 hour and the former about two to three weeks.

This method also has a second advantage. One can tell whether the tubes are matched when one puts them into the amplifier, as with the pot at its mid position, they should balance pretty closely. I had one set from a Chinese company of 300B's that were supposedly well matched, but the unit couldn't bring them into balance. A second set from the same company needed to be adjusted daily, and after three weeks were so far off that they couldn't be brought into alignment. Guess that company's quality control was not quite up to snuff. Just think, with all other push-pull amps made, if either one of these sets of tubes had been used, the amps would never have worked up to par, and you would not have been able to prove why they sounded less than optimal. With Alan's circuit, the output should be perfectly balanced at all times.

Third, he has removed the meter and balancing dial on the front of the amp. While I preferred its retro look, others didn't.

Fourth, the circuit has been designed such that it will take any tube with the same filament voltage, with a simple resistor change for the self biasing circuit. Thus he has a line for 300B, VV30, 32, 50 etc., and a second for KT-88 type tubes. My 300B amps are biased for 15 watts output and the 32's conservatively for 18 watts, while the KT 88 can put out 25 watts triode or 50 watts ultralinear with one set of tubes or four per amp in push-pull parallel for double the wattage. He also can use transmitter tubes such as 845's and 211's.

On to the build. The chassis is made of anodized aluminum, to stop eddy currents, in a sort of retro-modern look. All wiring is point to point using his superb silver foil. Transformers are top of the line Lundahl, and caps and resistors are high quality. In other words, like his other products, Allen builds these to highest professional equipment standards.

Driver tubes are the 6H30pi "Super Tubes" from Russia. One can use any output tube one wishes in the 300B series just by changing a resistor to adjust for operating current balance. Bias is fully automatic thanks to the "magic box". There are inputs for single ended RCA's, but balanced input is preferred using either the XLR or Redel plugs. Output is either by two sets of gold plated banana plugs or Centronics computer plugs if you use his loudspeaker foil.

An IEC plug allows use of any high end AC cord. Setup is easy. Turn the amps on, and after about two minutes of warm-up a solenoid clicks on the B+. If there is any 60Hz. hum, one adjusts the two pots on the top of the amp until the amps are dead silent. And I mean dead silent. Until I turned on the preamps, even with my head near my 108 dB per watt efficient speakers I could hear almost no tube hiss.

One then plays some music to warm the units up, then attaches a voltmeter to the two banana plugs on the top of the unit behind the driver tubes, sets the meter to millivolts, and adjusts the pot on the back of the amp to as close to 0 millivolts as possible. The two tube outputs should be as close to perfectly balanced as possible. This will need to be done at least daily until the tubes break in. Mine stabilized after about two weeks. Interestingly as I stated above, I could not bring one set of tubes into alignment right out of the package although the box stated that they had been matched, and a second set's balance began degenerating after about two weeks to the point where they could not be brought into alignment. One could hear the change as a coarsening of the sound and a decrease in both the microdynamics and width and depth of the soundfield.

A little hint. Parts Connection from Canada are having a super sale right now on some superb 300B's from Electroharmonix in Russia for $109 to 129 each for a matched set. I have tried several of them over the past few months and they have both functioned and sounded superb, mating extremely well with these amps. I have my stash already so feel free to get some yourself. The gold plated tubes sounded very similar to a set of new Western Electrics, at least in this amp, with a beautiful midrange and crystal clear highs. I couldn't say how the bass is as I have no way of using them with my bass amps. Interestingly, Alan notified me that he is also evaluating these tubes as his primary.

To me, these amps have all of the strengths of both solid state and tubes, single ended and push-pull, without any of the weaknesses. The VV-32 amps put a stranglehold on the woofers, giving tight, deep chest compression type bass, while the highs on the 300B amps extend out to beyond where my flat to 16kHz. tested ears can hear. The midrange is lush and full but without the bloating of second harmonic distortion single ended amps produce. The microdynamics give life to voices and instruments allowing one to hear inflections previously buried, while their quietness and lack of crossover distortion open up the soundstage to the low volume information that allows one to feel as if one is in the presence of live musicians with the right recordings. And don't be afraid of their relatively low wattage compared to the mega-amps. Remember, they beat my 50 watt "Class A" amps and were able to drive a difficult electrostatic load.

I feel these units are the closest I have heard to the proverbial "straight wire with gain." They could be put up against any amps at two to three times their price, which is rarefied atmosphere indeed. They have made my job of testing other products over the past six months far easier as they let all of the information through, warts and all. That's enough hyperbole. I think you get that I'm enamored and will live happily ever after with them.

Unlike most of my colleagues, I won't go into what they do for various recordings for two reasons. First, most of you probably have never heard the recordings used so you can't understand what was listened for. Second, no two people hear the same or listen for the same characteristics of sound, so what I hear may be completely different from your perceptions. On the other hand I will state that with the two sets of his amps in place, on recordings I've played several hundred times I've been able to hear things previously hidden that have added to the feeling that I'm at the original performance.

Up till now, the major problem with Alan's equipment has been a building bottleneck, as he was the only one that he felt could build them to his exacting standards, and Germany isn't exactly the most business and audio parts friendly place to work. Also, Alan's modification of Sony SACD players has been selling like hotcakes. Luckily he's seen the light, has been training two associates to his standards, and is moving from Germany to Switzerland just down the street from the Benz cartridge factory. Unhappily I couldn't talk him into moving to the USA as his significant other wanted to stay in Europe, but he now has a distributor here. His factory should be up and running by January.

Price for the amps per pair in kit form will be €4,950 and finished and tested by Alan for 9950, both with tubes but plus shipping. There may be a price increase once he gets his dealer network in place. At that price, these amps are a steal. And at the present winter rates for trans-Atlantic flights, you could go over there, pick up the amps directly from Alan, spend several days touring Switzerland, and hand carry the amps home with you for less than it would cost for transport and duty if they were shipped. Such A Deal! Now, a few words from Alan:  

Bill,

Thanks for the wonderful review (again), and I'm not just happy with what you have written, but also that you're so happy with my handiwork! There are a few things that need correcting as I have not kept you up to date, and you (understandably) expected the info on my website to be up to date - which some is not...

 Balancing the magic box is much more accurate than with the original units.

This has been changed quite a bit:

1. The balance pot has been relocated to the top plate, near the front panel for easier access. It is recessed a little into the panel, and requires screwdriver adjustment - no knob - so children or whoever can't easily fiddle)

2. Just behind this pot is a built in small digital meter, allowing digital accuracy without the need to play technician)

The batch we are currently shipping has a small analog meter set into the top plate, above the adjustment control - but it doesn't have the precision of the digital meter you are using. From the next batch on - Jan 05 - they will have the digital meter as described above.


Third, he has removed the meter.

No longer -- the KT88 amps you saw at my place are the only ones that will be built. They would have to cost exactly the same as the dpa300B amps but don't sound near as good -- and who wants an expensive KT88 amp? And the expected higher power is not readily obtained in practice . Hence until we come out with a quite different design with 100 watts or more -- using a rather special tube not normally used in audio -- the dpa300B when equipped with KR300BXL's or KR842 tubes will be the most powerful at 25watts

While the KT 88 can put out 25 watts triode or 50 watts ultralinear with one set of tubes or four per amp in push-pull parallel for double the wattage. He also can use transmitter tubes such as 845ís and 211's.

Incorrect as above. I know I wrote this in that "white paper" on my site but that needs serious revision - apologies) On to the build.

The chassis is made of anodized aluminum, to stop eddy currents.

Not so much eddy currents, but to be as non-magnetic as possible - without going to the very expensive and structurally difficult alternative of wood etc- to eliminate any magnetic interactions between signal currents and a magnetic chassis), in a sort of retro-modern look.

There are inputs for single ended RCA is, but balanced input is preferred.

Actually it works exactly as well with a non-balanced input via the RCA's -- this is because of it's differential topology being able to accept an unbalanced input signal and convert it perfectly into balanced for internal usage. The amps are shipped with a plug that is inserts into the balanced input socket to make it 100 percent unbalanced compatible. I believe you have a pair. Removing this plug returns it to it's default state. 

One further trick -- all dpa300B monoblock amps are now built mirror image, which complicates the building a little, but:

1. allows the speaker connectors to be positioned closest to the speakers on both channels, and not have the input cable cross over the speaker cable and/or the power cord on at least one channel!

2. They are optically mirror image, with a clear left & right channel "dual mono" appearance -- matching the RTP3C preamp's dual mono layout.