[Oz_Audio]

I have been on holidays for the passed couple of weeks.

Whilst in Melbourne doing the family thing, my wife, Helen and I dropped into Hugh and Sri (his lovely wife) house and enjoyed the hospitality of what seamed like old friends, even though it was the first time we had met.  I think we spent about 4 hours with Hugh and it was a very enjoyable afternoon.

Included in with the coversation was some listening to good music.

I had a chance to listen to a GK1 stage1, 55 and 100 Nirvana'ed AKSA's and the AKSonic.

I really wanted to listen to the AKSonics and they are the best box speaker I have heard.  Very open, transparent with no boxiness.  Midrange and bass are fast and accurate and the adjustability of the box really works.  They could be changed so suit any room or listening preference.  I did feel the high frequencies could be better, but for the price its a no contest.  Do not get me wrong, the highs are very good and I believe high frequencies are a very personnel thing.  If I did not have the speakers I have now, the AKSonic would be sitting in my house now!  They are that good.

I listened to these speakers with both the 55 and 100 and felt the 100 is a better match with the AkSonic, the music was more effortless in its presentation.

Hughs GK1 is made on the production board, mine is a beta and I will be upgrading some caps to the production version.  What can I say, simply a stunning pre with bass to die for.

After listening to Hugh's system, we had a splendid lunch and then Hugh and Sri took us down to the local Cafe for a coffee.  Nothing like a good European coffe in the middle of Melbourne!

Thank you Hugh and Sri for your hospitality and keep up the good work,  Helen and I will be back for more coffee!

Mark.

PS,  Hugh gave me a pre production phono preamp (beta has been done) and I will build and report back in a few weeks.  Finally I will be able to listen to the Linn again.

M

[U4EA]

Oz,

Thanks for the report.  Not much info around about the Aksonics.  

On a seperate note...I want a wood case like your but saw that you mentioned the heat from the tubes cracked the wood in between them.  So I figure I will leave my tubes inside the wood box.  If I build a down under version like you did any idea what I could use as a good heat reflecting metal.  I want a wood top but would put a piece of metal under a portion of it (right above the tubes) to relflect the heat.

[PSP]

Hi U4EA,
If I could make a suggestion, I'd think in terms of spreading the heat rather than reflecting it back towards the tube (BTW, if you did get substantial reflection, you might reduce the lifetime of the tube, the caps, etc)... Instead, could you line the top of your wooden box with a 3mm (1/8 inch) or thicker aluminum plate?  (Copper would be OK too, more mass, more heat capacity, better thermal conductivity too, but the thermal conductivity of aluminum is already good enough.)  This would prevent the temperature from getting high locally (the entire top would be warm vs. the spots just above the tubes hot, then dehydrated, then cracked).  You could also ground the metal plate and get some EMI shielding (whether you need it or not).

Reflection of heat by metals varies a great deal depending on surface cleanliness, degree of oxidation, the wavelength of the infrared radiation (determined primarily by the temperature of the tube, look up the "Planck curve" and "infrared" in a physics book).  IMO a "reflection" strategy is less likely to be effective than an "absorb and spread the heat around so it's uniform" strategy.

Peter

[Oz_Audio]

I would build another box of wood for the GK1, but I would go for a flat piece of stainless steel or aluminium for the top, still easy to buid and have the good looks of wood.

I will get some more photos done when the phono stage is installed.

Mark

[massappeal85]

Quick question: is the phono-pre tubed or SS?

[AKSA]

Hi Mass,

The phono pre is SS;  with tubes it is possible to have too much of a good thing - power amplification using tubes, for example (flame suit donned, visor in place...... )

Since the GK-1 has very carefully metered tube sonics, more tubes (which at low input levels are soooo  noisy!) were not favored.  So I moved to SS, and concentrated on getting outstanding sonics from the best opamp I could find (I ain't sayin' which one!).

Then, this pristine, detailed signal is passed through to a tube for a master performance!

Cheers,

Hugh

[Jonpike]

Hi U4EA,
If I could make a suggestion, I'd think in terms of spreading the heat rather than reflecting it back towards the tube (BTW, if you did get substantial reflection, you might reduce the lifetime of the tube, the caps, etc)... Instead, could you line the top of your wooden box with a 3mm (1/8 inch) or thicker aluminum plate?

Here's another suggestion..  you might try mounting the metal plate on short standoffs, so there's a thin air gap between the wood and plate.

Then, with slotted air gaps letting air circulate out from inbetween, and in from the cavity below, you could end up with even less heat getting to that fine woodwork..  

Idea being the plate soaks up most of the radiant heat,  the airspace keeps most of it off the wood, and airflow conducts it out of the case.

Good ventilation practice, however you do it,  will help a lot..

Jon

[U4EA]

Thanks Jon I love the idea.  Plus it will look high tech and I can BS my unsuspecting friends.  

Now I just have to figure out how to cut some neat slots in the metal.

[Jonpike]

Thanks Jon I love the idea.  Plus it will look high tech and I can BS my unsuspecting friends.  

Now I just have to figure out how to cut some neat slots in the metal.

Oh.. well, shows how it goes when you don't have audiovisuals handy..    

My idea was having slots in the wood (i.e. openings in the case) preferably in the back panel where you can't see them,  one slot UNDER the metal (so airflow goes thru the space between the wood and metal plate) and the other down low so cool air will be drawn in and flow thru the space inside, up and under the plate, and out the top.  Uh, this implies the plate on the inside top of the box.

I was envisioning long router cuts (1/4"?) the full width of the back or side panels, nicely out of view.  Or, well finished slots could be addition to your design.  

Hmmm..   two intake slots low on the sides, with the exhaust one across the rear panel back or top might look pretty cool..

[U4EA]

I will have to think on this one.  Maybe some aftermarket headers for more exhaust flow...  

[Jonpike]

Heh..  try a hobby shop,  you might find some appropriate sized ones off a dragster model..  and you could probably find flame decals there, too!!