[Rocket]

hi larry,

i heard a pair of vaf dxc's a couple of years ago.  i thought they were good sounding especially compared with retail hifi store speakers here in oz.

i think though that diy is better value.  check out my speakers which i bought in perth from war audio which make completed and diy speakers:

http://www.audiocircle.com/index.php?action=gallery;area=browse;album=37

the speakers are mtm with raven 1 tweeters and 2 x focal 7 inch kevlar mid/bass drivers.

regards

rocket

[Larry]

Hi, Rocket,

Your speakers look great. I like the finish. If I were in Perth, I'd love to hear it. I was in Perth about 10 years ago.

The DC-X can be bought as a DIY kit too. I bought a kit and put them together. I wasn't disappointed with it. However, I like to hear other people's opinions to know more about it.

Cheers.

[Rocket]

hi larry,

woops i forgot that vaf have speakers available in kit form  

btw i was really lucky with the finish on my speakers.  i had it painted in piano black for $200au which i thought was a real bargain.

i was at a hifi shop today and i'd like to purchase or have built some some nice speaker stands and equipment racks to finish off.

regards

rocket

[DSK]

Hi Larry,
Sorry, I haven't heard any of the VAF range. I've seen them at the Melbourne Home & Entertainment Show over the years but they were always in an open downstairs room, making it impossible to audition them, and they seemed to concentrate on home theatre rather than hifi. Their published measurements are impressive, although this doesn't guarantee good sound.
When I bought the Ambiences I was looking for the best speaker I could find under A$10k. My room is big enough for the VAF I-93 flagship but it is a physically imposing speaker with low WAF ...and I couldn't audition them anyway. Interestingly, Nic Tatham has reviewed the I-93's but his personal reference remains the Ambience Ultra 1600. The mids & highs of the Ambiences (420hz up) are truly world class.
If you are looking for speakers at the DCX pricepoint, I would seriously consider Hugh's updated Aksonics. They use the same VIFA XT25 dual concentric ring radiator tweeter as the $37k Krell speaker, matched with an excellent VIFA woofer in a 2-way design. I am listening to Hugh's pair in my room at the moment and they are VERY impressive. They are physically small (very high WAF) but surprisingly, they are easily energising my large room and are excellent on all music genres. Awesome for under $1k.
Cheers,
Darren.

[Rocket]

hi larry,

the vaf dcx is a fine speaker.  i had a listen to them about 4 years ago when i was looking at purchasing speakers.

i can't remember the exact price but i think they were in the region of about $1500 au?  i eventually bought a pair of war audio speakers for $1400au which were better suited to my tastes ( i have since upgraded to another pair of war audio speakers).

darren,

hugh's aksonics have my interest as my wife wants to have a system she can listen to.  last year she blew one of my ribbons because she had the amp too high (i don't let her use it anymore).  my n.e.w. is still sitting there and i could utilise that as an amp.

regards

rocket

[Larry]

Thank you both, Rocket and Darren,

I had a chance to listen to Aksnonics.

I have asked Nic for his comments and expect some reply soon. I am particularly interested in what specifically I could have missed with a $1k'lish speaker with comparisons of a $10k'lish speaker.

[AKSA]

Larry, Rod, Nick,

This new version is the Mark II.  It improves in four areas over the Mark 1, being mid-bass body, dispersion, top end clarity and bass power.  Mid-range resolution is not much changed, build is identical (there are some internal changes relating to the port), and image is the same, though now the image follows you as you move around the room. (A bit like classy paintings in art galleries!)

Cost in increased to $AUD460, which is just under $US300.  The buyer must obtain drivers and timber;  all the rest, including built/tested crossovers on custom pcbs (my design), is supplied.  Those skilled in crossover design will know this is not trivial, and indeed a good crossover designer (in this case Ron Newbound) is largely responsible for the final sound of the speaker.

I was told by one knowledgeable speaker designer that the AKSonic pricing is not cheap.  That's true;  this is not your average kit speaker and the quality is a revelation, just like the power amps and the GK-1.  It is truly high end, and inexpensive by comparison.  I joke with my friends that if I doubled my prices I'd get more sales!

Those who purchased the Mark One can, with new drivers, update their AKSonics.  But they will need a complete new crossover since there are so many detail changes, and I cordially invite them to contact me if they are interested.  Be assured I will give you guys special consideration in light of your good faith buying the Mark I.

Hope this clears it up;  in the next day I will upgrade the website to reflect this new offering, which I think complements the amp/preamp range beautifully and embodies what Aspen is trying to achieve.  I'm very proud of this new AKSonic, and thank Darren for his kind and objective assessment.

Cheers,

Hugh

[Larry]

I have asked Nic for his comments and expect some reply soon.

For those interested, Nic's response can be found at

http://www.avlmagazine.com.au/forum/showthread.php?s=&threadid=497.

My impression from the answer is that Ambience SuperSlim Ultra 1600 has been good at openness and transparency, among other ribbon speakers. (Did not mention whether it's better than conventional speakers like VAF. Let's guess so.)

Other than that, I cannot attribute other general words to any specific areas of sonics.

His preference is for Ambience, from the tone of his speaking.

I understand that ribbon is designed in consideration of SS. Did any of you try Ambience with a valve amp?

[DSK]

I understand that ribbon is designed in consideration of SS. Did any of you try Ambience with a valve amp? ...

Hi Larry.
For years Tony has been demonstrating them with tube amps. I have heard them demo'd with Audio Aero gear (Capitole valve CDP, Prestige 40w valve monoblocks) and Consonance Reference pre-amp as well as with SS gear (Elektra 250w amp) and the Ambiences are excellent with both. Although the SS gear produced tighter bass control and more dynamics, the tube amps provided a little more of that midrange magic they are famous for.

Nic's reply reflects my earlier comments about the Ambience openness and transparency and just getting better and better with better gear. They are more refined sounding than even excellent dynamic speakers. Properly setup they will cast a taller and deeper soundstage than almost anything, with more air. The perspective is from mid hall as opposed to the front row seat of many dynamic speakers. After living with them for several years the only thing I can think of that some listeners may not like, is that the ribbon does not push the same amount of air as a dynamic midrange driver. Thus the Ambience midrange is more detailed and transparent but does not quite have the vitality of a cone midrange that you "feel" rather than "hear". In my view, the Ambiences easily outperform most dynamic speakers on large scale works but, although they can rock too, listeners who crave that up-close in-your-face hit-you-in-the-chest type performance may prefer a dynamic speaker.

The newly released Reference 1800 uses far stronger magnets and achieves a sensitivity rating of 95db. To balance this, Tony has installed two of the bass cones in this design. As a result, they sound a little more dynamic than the earlier models and are a far easier load for small valve amps. However, they are about twice the price.

So, as always, horses for courses.

Cheers,
Darren.

[fred]

I'm finally, almost ready to start building my GK-1R.  Since so much time has elapsed since I ordered the kit, I have unfortunately accumulated a bit of excess money.  It seem logical to address this problem by buying some of the esoteric components you guys are talking about, to use in the initial build of my GK-1R.  

Looking through this discussion, I see a recommendation to use Riken Ohm at R11, R22, R9, R5, R26A, and R26B.  Also, to use a Black Gate at C4.

Any other suggestions?  I am desperately in need of assistance, my money having already burned through the pockets of several pairs of pants ("trousers," in Ozspeak).  Note: although problematic to me at the moment, my current excess money is not infinite, so I request advice a bit more targetted than "replace all electrolytics with Black Gates."

thanks

[AKSA]

Fred,

I believe you have all the pressure points here.

However, I'll throw it open to others who might have found more....  (grin!)

Malcolm?  You there, Bwana?

Bear in mind, however, that sound quality is subjective, and with new components in strategic circuit positions, the sound will not be same as originally I 'voiced' it.  Whether this is to your liking or not is something only you will know, but it will have different sonics to my own prototype GK-1s.

It's not convenient, since building is best done only once to avoid pcb damage, but it's not so silly to build it as is at first, then move progressively, one component at a time, towards a new configuration of components. This way you get to make choices which suit your taste.

Generally, however, I certainly approve of the Rikens, and the BGs are good, though pricey.

Cheers,

Hugh

[Malcolm Fear]

Im here.
I also used Auricaps at C1, C19 asa well as C21.
I put my Black Gate at C4. Phillip put 2 at C6 and C7.
If I was starting again, I'd put Black Gates everywhere everywhere.
To really save your trousers, someone has put a motor onto a DACT stepped attenuator. Now that would be cool!

[AKSA]

Thanks Mal,

I have to say I tested the Auricaps thoroughly about a year ago and found the following:

1.  With 20V or more of DC across them, they perform superbly, giving excellent bass and lovely, luscious midrange and a clear top end.  For this reason, they are my choice for output coupler on the GK-1, which has 48V of DC across it.

2.  With less than 20V, and particularly sub one volt, their performance became muddy.

At low DC bias, my favorite is the RTX from RelCap, which delivers excellent performance across the musical spectrum with only millivolts across it.  However, it was only slightly better than the Evox-Rifa which I normally fit to all kits, and which therefore gets the nod for the stocker.

The primary technical specs for good coupling caps appear to be dielectric absorption, which should be lower than 0.05 and is best with polystyrene, closely followed by polypropylene;  and slew rate, which relates to transient attack, and should be around 100V/uS minimum.  In this connection film caps (particularly the film and foil caps) are superior to electros, , but every year now electros, particularly the dry types like BGs, are improving. and Cyril Brenneman of EW believes that the non-polar caps are VERY good, almost as good as quality film caps.  It is my belief that most capacitor differences reflect variations in DA and SR, but I suspect also that Q enter into it, being a measure of characteristic impedance.  This last quality clearly makes caps topology-sensitive, that is, diff'rent strokes for diff'rent folks....

Having said this, YMMV, and Malcolm takes a slightly different, but entirely credible view.  This happens in audio a lot, and accounts for the 'house' sound of companies like Cary.  The only definitive course is to build it progressively, noting the 'sound' as you go, but it's awkward and potentially harmful to the pcbs.  I'm afraid it's your call, Fred, and watch those pants closely!  

Cheers,

Hugh

[stvnharr]

Fred,
You could always invest in pants - er, trousers, with heavy duty pockets.
Terrible problem having too much spare change.......

[fred]

You could always invest in pants - er, trousers, with heavy duty pockets.

You sound like my wife with such clothing advice!  My current wardrobe allows me to blend in with the homeless people I pass as I walk to the office. Don't want to be too conspicuous.  Plus, if they ask for loose change, I simply show them the holey pockets, avoiding a confrontation.

Regarding your advice, Hugh, I'm not quite sure that I'm ready to pull out the soldering iron quite as frequently as some here, which is why I thought I'd make any recommended changes up front.  As long as you have no grave misgivings, I plan to give some of these things a shot.

[fred]

I looked at Parts Connection for the BGs you suggested (Pk, 25V) - and they appear to cost a mere $1.10.  Are these the right ones?  Given the chatter about how expensive they were, I expected something 10 times this price.

[Malcolm Fear]

Hi Fred
Yes the Black Gates at these voltages are quite cheap.

[cmscott6]

I just finished the same changes as Malcolm, i.e. Black Gate PK at C4, three Auricaps, and the Riken resistors.  I had installed the Auricaps earlier, so my experience with the BG/Riken proved to be similar to Malcolm's: "who turned on the sub-woofer".  Bass is much more prominent, though not over-balanced, and lower bass extension is much deeper and clearer.  Acoustic bass, both bowed and plucked seems to have a much clearer image in space (on good recordings   ).  I'll be curious to see how this changes as the BG breaks in.  (I only have about 10 hours on it now.)

I've had a suggestion from a friend to try paralleling a polystyrene cap (ideally an RTX) with the Auricaps to try to get the best of both worlds.  He recommended paralleling with a value of 1/10 the value of the Auricap.  Hugh or Malcolm (or anyone!), do you have any thoughts on this?

[Malcolm Fear]

I hadn't thought of paralleling the Auricaps. Let me know if it works.

[ginger]

The paralleling of capacitors is a "Standard" Technique used widely thru' Electronics Industry.

As frequency goes up the Capacitive reactance comes down BUT the "SELF" Inductance of the Capacitor becomes more critical because the Inductive reactance is going up with frequency. At some frequency the capacitive and inductive reactances will be equal and this frequency is known as the "Self Resonant Frequency". Above the self resonant frequency it doesn't look like a capacitor any more, it looks like an inductor.

In general, the larger the capacitor, the lower the self resonant frequency.

To stop this happening you parallel the larger capacitor with a smaller one such that at high frequencies it will dominate and the parallel pair still behaves like a capacitor.

The "Rule of Thumb" is to use 1/100 th the value of the larger cap for the parallel cap. I've seen this taken to extremes in Radio Frequency Amplifiers where a 10uF Tantalum was paralleled with a 100nF Ceramic and a 1nF Ceramic.

Electrolytic Capacitors ALWAYS benefit from being paralleled with a film capacitor of about 1/100 th the value - for big value electrolytic caps you may have to use 1/500th etc. but its still worth doing. You can see that Hugh did this in a few places on the GK-1.

From my own experience with my valve amp I can confirm that paralleling the Polyproplylene 0.33uF Coupling Caps with 1500pF (1.5nF) Polystyrene Caps improved the top end significantly (ie X200 smaller in this case) AND paralleling the 68uF/20V OSCON Output Valve Cathode Bypass Capacitors with 0.33uF Polypropylene also helped.

Having said that, there are some situations which respond well to caps of particular type. Every Power Supply Electrolytic in everything I build will have a 100nF XR7 Ceramic across it for RF Suppression. (I use the AVX Skycap Series for up to 50V and muRata High Voltage Disc Ceramics for Higher Voltages).

Cheers,
Ginger