Folks,
I note with astonishment that this thread has over 3000 views! WOW!! It seems Valhalla is rather popular!
Let me offer my thoughts on tweaking.
I say go for it.
It's important to you, and to Aspen, that we achieve the highest possible performance for the AKSA products, amps, preamps and speakers alike. The fact that you built your own means you have few inhibitions about tackling component upgrades - it's not as though it's a fully built, retail product. Along the way, you will discover that components all add their own sound, and that the final outcome is much like a recipe with ingredients of your choice. The fact that the choices are now yours confers intellectual ownership and redoubles your efforts. This is really interesting work, and shows how much of this craft is actually art, as you are effectively sculpturing the sound to suit your tastes.
However, different folks different strokes, and not everyone agrees on sound. Some like it sharp and accurate, while others like it smooth and mellow - and some like to mix these qualities. Needless to say, in some circles there is war between factions
(as Echidna sagely pointed out!) But do this long enough and you find that some combinations don't work, and sound terrible. This can be very disappointing, as you can easily throw away hundreds of dollars.
And there lies the rub. What is terrible? What is sublime? How is this imaging thang manipulated? Why did we just lose height in that recording? And so on.....
When you tweak you discover a few factors which the designer must live with uncomfortably. They are subjective (or 'perceived') quality, cost, and the spectrum of sonic taste in the listener, with the clear implication that you should aim for the middle ground to win over the most listeners.
I have chosen combinations of components in the AKSAs which deliver sonics adjudged by most to be superior at moderate cost. Many people's ears must go into this judgement, not just my own. For example, rather than use an expensive RTX 0.068uF 100V MultiCap for C19 in the GK-1, I use a quality axial foil polystyrene, which is almost as good but an order of magnitude cheaper because these are made as industrial products, not small-run audiophile components. I do this because I have to keep the cost of the kit affordable, yet still make sufficient from the sale to stay in business. I cannot do this if I supply RTX Multicaps right through the circuit, since you guys just would not buy. This is simple psychology, since price matters hugely in the initial impulse to buy. Nevertheless, I do include an Auricap at the output, because I found I just couldn't get the necessary sonics without it. I would also say that a dollar spent at kit purchase is probably equivalent to several dollars spent on tweak components, since after the initial listening experience your audiophile virus will reinfect and you will be itching to start tweaking, lowering your price resistance!
I guess this is the reason the Nirvana upgrades have been so very successful. These days almost every new AKSA power amp kitset sells with the upgrade. The 'Buy the software, pay for the upgrades' marketing ploy has been very successful because people are understandably wary, and like to test the water with their toe before diving in. When you think about this carefully, it's sensible because it means that the initial commitment is moderate, even if the upgrade components might individually be very expensive, like RTX caps. The fact that most sales now include the upgrade is testimony to increasing knowledge of the amplifier out there amongst DIYers, and trust is slowly rising.
Ultimately, when the dust settles and I actually have some time away from the GK-1 retail offering, I may offer a tweaker upgrade for the GK-1, also called the Nirvana. In the meantime, Larry, Mal, Chris, and all of you carefully tweaking your GK-1s, please share your experiences with us! It will make an even better product!
My thanks to all for their enthusiasm, participation, and continuing support.
Cheers,
Hugh
