an innocent e-mail caused this review...
A while ago
I used to be subscribed to the now defunct "Lowther" E-Mail
list run by Bert Doppenberg of Lowther Holland. In the
context of a discussion about fairly inexpensive Amplifiers
for Lowther speakers someone then unknown to me, by the
name of Brian Cherry, mentioned he had a 300B Monoblock
Amplifier Kit which sold for much less than 1,000 Bucks,
direct out of Hong Kong from his Company - DIY Hi-fi Supply.
His website showed a nice looking pair of Amps, so I bounced
a quick e-mail back, saying half in jest along the lines
of - "If you really think your Amp's are as good as you
make them out to be, how about sending me a pair for review?".
As it turned out, the Amp is actually
a unassembled Kit version of the Consonance M500 Amplifier
manufactured by Opera Audio in Beijing. Now
I know, reviews in other mag's should not influence me,
but the one review I had read, from the German "Image
hi-fi" was by one the few people in the game I still take
serious (Roland Kraft) and very complementary. So I was
quite looking forward to the possibility to evaluate these
Well, Brian took the challenge and we soon had agreed
on a review. My first shock came on delivery of the kits.
No, it was NOT the fact that our receptionist at work
(where I had them delivered) promptly refused to touch
these heavy boxes and lug them around. My shock came from
the time scale. I had read the e-mail confirming dispatch
from Hong Kong only the previous day! Overall the Kit's
reached me in less than 48 Hours! I know plenty of fairly
large UK companies that cannot manage a similar delivery
time scale within the UK, never mind from a place on the
other side of the world, some 12,000 or so miles distant.
I figured that if kind of speed in filling orders was
anything to go by, these guys meant Business, seriously.
With most DIY Kit Vendors one is used to delays, long
delivery times and such and even happy to except them.
But boy is it refreshing if just for a change the reverse
happens. Shipping was via Fed-Ex Express, something that
for the UK and US adds around 220 Dollar.
So normally the shipped price for any private customer
would be $ 1,000 or less if you chose a slower shipping
Anyway, the English Manual seemed to have been fallen
out at the customs or something and her Majesties Customs
and Excise decided to hit with a nice Import Tax and Viciously
Added Tax Bill DESPITE the explicit statement on the papers
for the Kit's as "Product Samples for evaluation only,
no commercial value". But that happened on British
soil and cannot be held against DIY Hi-Fi Supply. Brian
send a replacement English assembly manual (25 Xeroxed
pages with plenty of photos) and also included the wire
upgrade which normally adds $ 20 to the cost of the Amp.
If you purchase the Kit's from Hong Kong import duties
and tax may be levied, please check with your local customs
and excise before ordering. One other possible snag in
ordering these kit's is that DIY Hi-fi Supply currently
accepts credit cards only via "PayPal". Other options
for payment include money orders and bank transfer. Our
local Hi-fi Club has recently purchased a substantial
number of valves from DIY Hi-fi Supply using Bank Transfer,
no problems and excellent service. Others who have recently
dealt with DIY Hi-fi Supply also reported excellent service,
so I think the excellent service I had was not an isolated
case or to impress a reviewer, but the normal mode of
business for DIY Hi-fi Supply.
Unpacking the "kit" revealed essentially two almost fully
assembled Amplifiers, very different in feel to the usual
large "mixed bag" or chassis and electronic tidbits. I'd
think to less experienced DIY'ers and those new to kit
building this simple fact together with the excellent
manual will likely generate a considerable degree of onfidence
that the completed Amplifiers will look nice and that
they will be able to build them.
The components supplied are of a wide variety, including
funky looking Chinese resistors (which nevertheless have
a reputation for good sound in the Chinese DIY community),
Black Gate and Solen capacitors. The overall passive component
quality is quite good, but nothing overly special, excluding
perhaps the Black Gate capacitors. The Valves supplied
are the quite respected Valve Art Nickel Anode 300B's
and generic Chinese 6SL7 equivalent Driver Vales and generic
Chinese 5U4 equivalent rectifiers. The wire from the wire
upgrade is continuous cast, oxygen free, enameled wire
with high temperature plastic sleeving. All in all a good
basic platform. I can appreciate the fact the DIY
Hi-fi Supply avoided to include much in terms of fancy
audiophile boutique omponents, as such are not only quite
expensive but also very much subject to taste. For example
I'm not greatly fond of Paper in Oil Capacitors while
others love them. Equally some people intensely
dislike my favorite foil & film capacitors. So, if
you do have any specific liking for certain parts or wire
buy the "Billie" kit plain and replace during building
what you don't like with your favorite bits, this is one
of the great benefits of kit building. If you are not
sure what you like, the complete upgrade kits offered
by DIY Hi-fi Supply will give a notable upgrade of sound
quality and are very much worth having.
I have compiled a separate little builders log web page
(click here) from pictures taken during the assembly,
so I spare you details. In general assembly was easy and
straightforward. I hit two major snags, one being a VA
300B which had obviously suffered a shift of the internal
structures due to rough handling during transit,
shorting out grid and cathode and thus making the valve
unusable. The other was that all voltages where much too
high. The high voltages (which would severely prejudice
valve life) where the result of the rather high mains
voltage in the UK. After discussions with DIY Hi-fi Supply
and the factory I fitted a dropper resistor to reduce
voltages, current kits should have gotten a new Mains
transformer allowing for a wider range of voltages to
I changed two things. First the kit fits the Inputs to
the side of the Amplifier. Good for a short signal path
but seriously unusable in most Hi-fi Systems. I fitted
the input to the back, giving up the option to have the
4 and 8 Ohm taps of the output transformer directly. If
I need to change it now requires the take the transformer
hood off and change the connection on the transformer.
Secondly I used my own cable for the input wiring, exactly
the same as what I'm using in my own interconnects.
I mention these issues here not to scare potential kit
builders, but make clear that even a well designed and
tested kit might under certain conditions cause problems.
I have perhaps one or two more issues with the "Billie" Kit in general. The monoblocks are not laid out mirror
The result is that if the Amplifiers stand next to each
other the visual appearance is not very pleasing. Also,
the small toggle switches mounted on the back of the Amp's
are not only fiddley and not very confidence
inspiring, but being located on the back of fairly large
amplifiers they are a major PITA (Pain In The A? to operate,
especially switching off when the amplifiers are hot.
Okay, so these gripes are only about appearance and ergonomics
and one should not forget that we are talking about a
major piece of kit which due to self assembly only costs
about $ 1,000, so perhaps I should go easy, but hey I'm
a "Hi-fi Critic", so criticizing is what I do? One more
note, the Gain of these Amplifiers is rather low, in almost
all systems an active line stage ideally with pretty high
gain will be required. Both the 5687 equipped line stage
of my Arthur Loesch Preamplifier and the ECC81 toting
line stage from the DIY copy of Shindo Laboratories "Claret" have high gain, so no problems here.
While assembling the Kit I was of course aching to replace
all these cheap components with my own favorite "boutique" parts, however I felt that this was a review that should
be done strictly according to Hoyle. No fancy footwork
and crooked backdoor tricks. As you will see, I did not
quite succeed, but much of the audition was done with
the amplifiers using the components as they came out of
As the pair of VA 300B's with the defective Valve where
replaced I up fired the Amplifier in my system first using
Svetlana 300B's, my long-standing 300B reference. Dropping
the brand-new amplifier into the system instead of my "Legacy" Amp while repeating whatever was just playing
(Eric Clapton Unplugged in this case). While I could immediately
notice that the "Billie" had a number of small deficiencies
(though remember the amp was in no way burned in), in
general I was positively surprised by the sound I heard.
Very natural, open and generally pleasant. I noticed that
the slaps against the body of the acoustic guitar lacked
a little impact, the general tone was slightly rough and
the final degree of "air" and treble detail was missing.
This general perception remained even after a considerable
burn-in. But hey, I am comparing an Amplifier kit costing
$ 1,000 to an Amplifier I designed and build as an exercise
in going "all out". This Amp has faced a lot of competition
over time, matching or exceeding the performance of such
excellent units as the Art Audio Jota and the Border Patrol
300B amplifier in my system. So given that the "Billie"
managed to keep me captivated with music and no "take
it away it's awful" impulse was triggered (I get this
quite often in my system) the "Billie" sung very well
indeed. Given especially the prosaic passive components
and the quite lowly Valves equipping the stock kit it
sounded much better than it had any right to. I
tried also the Sovtek 300B Output Valves I had at hand,
both the standard bakelite base and the new (Electro Hamonix)
ceramic base one. Once I received the replacement Valve
Arts I tried these also. While my extensive audition
results including almost all currently available 300B's
will have to wait till next month, I found the stock VA
300B to give a fairly bright tone, a very open sound with
rather more of an edge to it than I like. A friend commented
that the harmonic balance of brass instruments seemed
to be altered to a rather tilted up sound. I found this
Valve to work well with the Beauhorn B-2 Speakers I reviewed
in last month issue. These speakers have a very soft top
end, also found often as a matter of voicing on
modern smaller stand mounting speakers. The extra brightness
of the Valve Art Output Valve will work well here.
With my own Speakers (Tannoy 15" Monitor Red Dual Concentric's
in corner York enclosures and the "Magnificat" Speakers
based on antique Goodmans Drivers) I found the Sovtek
to give a much better overall balance with more detail
and refinement, making the VA sound positively rough edged
and a bit
aggressive. The considerably more expensive Svetlana 300B
turned in a much more evenhanded and refined performance
than either VA or Sovtek. However, leaving aside concerns
about reliability and availability of the Svetlana 300B,
I got even better sound from the "Billie" Kits using some
new Chinese made 300B's also supplied by DIY Hi-Fi Supply.
Made in a factory in the Tianjin Province near Beijing
these have been sold so far under a number of labels,
the ones supplied to me by DIY Hi-fi Supply are dubbed
TJ, short for TianJin. While my absolute champion is the
Globe Type one with a mesh Anode (pictured above), the
other TJ 300B Valves available have much of the magic
and sound of the Mesh Anode ones and are available from
only $150 the pair.
They are definitely worth having, in my tests I preferred
the basic Coke Bottle TJ to new production WE's.
I did some more Valve "rolling" with rectifiers and driver
valves. The fabled RCA "Red" 5691 sounded muddy and closed
in, pairing this with the Valve Art 300B gave a reasonable
balance to the sound, but lacked openness and detail.
Some Philips 6188 sounded nicely balanced, much better
than the Chinese 6N9. My favorites so far are fairly old
Sylvania and Ken-Rad 6SL7/VT-229. At any extend, I think
all of the old stock 6SL7 improved the sound of this amp,
so go out and get some. No need to go for the highly regarded money sinks, get some decent Philips or Tung
Sol, they'll hugely improve the sound of the Amp for only
a few bucks.
When I experimented with the rectifier valves I was in
for another shock. Replacing the Chinese 5Z3 with RCA
5R4GY gave a great improvement in tonality, giving a slightly
lightweight, but very evenly balanced and ethereal performance.
The music filled the room very well, also the behind the
wall! Some Mullard GZ34 (a.k.a. 5AR4) gave great power,
impact and pace, I got a similar sound from some Sovtek
and EI 5AR4/GZ34. The downside of the GZ34 was a slight
edginess to the sound. I recently got a second Mullard GZ32 to make up a pair and found this to lie deliciously
just in-between the GZ34 and 5R4GY. Lacking the slight
edge but with most of the pace and bass impact retained
this is my current preferred combination.
I compared the Amp over time repeatedly against my "Legacy"
and also against a pair of highly regarded monoblock amplifiers
from "Heart" Holland. As the "Heart" amplifiers cost a
similar amount as finished products as the fully assembled
units from Opera/Consonance I felt this to be
an especially worthwhile comparison. Previously the "Heart"
units had shown themselves very capable, neatly outperforming
both Cary and Canary Audio 300B monoblock amplifiers.
The units I had available where very recent production
and supposedly even better than the older units I tested
a while back. Well, using the TJ Mesh Anode 300B in either
amplifier (also using other 300B's) the "Billie" not only
showed off a much lower noise floor (the Hearts had notable
hum with my high sensitivity speakers) but offered with
the stock Chinese 5Z3 rectifiers a much better and lower
reaching bass, more detail in the midrange and a slightly
deeper and wider soundscape.
Okay, now perhaps some more listening observations from
my little black book. Some of my regular test records
for natural tonality and detail contain Baroque music,
played on original instruments, especially a range of
pieces by Haendel on the Hamonia Mundi label and on the
L'oiseau-Lyre Decca sub label. On Vivaldi's Gloria in
D Major I noticed for the stock Amplifier "Good soundscape,
voices a little too aggressive and edgy, strings have
a little edge". Switching the valve complement around
to TJ 300B's, Ken Rad Drivers and Mallard Rectifiers produced
the following rave: "Wow, never knew there was so much
space on this recording, the voices are just so real."
The supposed critical listening session quickly degraded
in pure indulgence. Well, I guess the upshot is that stock
kit is pretty good with natural classical music,
with better valves it is amazing. While auditioning the
"Billie's" with Mussorski's Pictures at an Exhibition
(Reference Recordings CD, Eji Ojie directing) I noticed
that in stock condition the "Billie's" had notable lack
of impact in the nether regions and that strings sounded
slightly rough and edgy. That aside the sound was very
open and natural. Overall I found the result very listenable
and had I not gotten used to a much higher performance
level over the years I might be now raving how this is
the "best amplifier I ever heard".
Well, even with the best available valves fitted the "Billie's"
fall slightly, very slightly short. Yet listening to the
"Billie's" with my preferred set of Valves and playing
again Eric Clapton's Unplugged set I find now the impact
on the guitar body rendered with the right kind of impact
and within the limitations of the recording vocals are
intimate, detailed and smooth. The detail rendered on
such items like percussion is breathtaking.
If any sonic complaints remain it is perhaps an ever so
slightly overly warm midrange. Saxophones sound just a
tiny tic too creamy, vocals perhaps a little warmer than
in reality. At any extend, here is an Amplifier that can,
if fitted with suitably high quality valves offer way
more than a glimpse of the true High End. Indeed, among
the commercially available 300B SE Amplifiers I had the
chance to hear, the "Billie", a.k.a. Consonance
M500 Kit (and obviously also the Consonance
unit) rates easily in the top 5. The Border Patrol
Amplifier, relying here on my sonic memory betters it
in pure bass impact and pace a little, the Art Audio Jota
has more power, but both loose out in terms of transparency
The Audio Note Japan Baransu is I think better through
the bank (while not often in my system as I can't afford
it and must beg for having it over for an hour, it remains
my 100 points reference but only if fitted with NOS pre
1988 WE 300B's or STC 4300B's). Clearly Heart, Cary and
Canary audio slot in below the Billie/M500.
In fact, I'd say even if equipped with the stock Chinese
valves (and using identical 300B's on the others) the
make sure work out of the competition.
Given the price of the Kit and the performance both stock
and the potential for performance if fitted with the best
valves available I can only call it a huge bargain. Value
for money if I ever saw it. Even the assembled units at
around $2,500 to $3,000 the pair (depending on valve complement
and who you ask - prices from Germany, UK and US) are
excellent value for money.
The Kit's are pretty simple to assemble and hence suited
as a project for 1st time DIY'ers (but please observe
electrical safety). The assembled units solid and high
performance, if a lot more money. So for anyone who wants
a pair of good quality, affordable 300B monoblocks the
Billie Kits or assembled M500
should be high on the list. If you already have say a
Cary or Canary or similar Amp, I think some internal upgrades
and TJ Output Valves will give better value for money
than buying a finished pair of M500's,
but if you can build a kit have a go at the Billie's.
Actually, did I make quite clear that this Amplifier/Kit
comes from mainland china? Yup, from the same place that
supposedly only turns out low grade, unreliable, poor
sounding gear! Well, I had my bad experiences with products
"Made in PRC". So it is very encouraging and a nice break
from the usual prejudices and perceptions about
Chinese products to see that these Amp's are as well designed
and made as any I came across.
Okay, perhaps the litmus test is to ask me what is playing
in my system at the moment. Well, the Billie's of course,
fully loaded with the best valves I can get my hands on,
some passive parts replaced (especially the coupling cap
- at the moment Jensen PIO and the 300B Cathode Cap -
Black Gate). I am just playing through all my ABBA records
(okay - I have now ousted myself as individual without
taste). Playing now is "Lay all your love on me" from
the "Super Trouper" Album. I'm swaying in front of the
keyboard, sing along with the chorus and can barely keep
typing (but Steve will kill me if miss the deadline again).
Any Stereo that can do that to me is great. And the Billie's
are a major part of it. So go and listen for yourself.
I need to get up and dance, see you later.
And remember - Enjoy the Music Dudettes and Dudes!
Note: I considered it necessary to include two sets of
scores, one covering the stock Amplifiers made from the
contents of the Kit and one set allowing for the use of
the Valves I found to give best sound. This way both the
actual performance of the kit and the potential performance
of the amplifier is fairly assessed.