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December 2004
Audiolics Anonymous
Chapter 63
Blue Note Best Of 2004 Award
Article By Bill Gaw
Click here to e-mail reviewer
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.
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