[Jens]

Great job! I might try tantalums as suggested by Hugh. Any special ones that are preferred?

[andyr]

Hi,   

There has been a discussion of future upgrade or evolution of the GK-1.  Well I must admit the full potential of the GK-1R has not been reached which attest to the shear talent of Hugh's design.  I did the modification that Ginger suggested where C4 is switched with the LED.   There was also a change in a few resistors value.  I also did the Platinum mod.  Well the latest mod I just did with only three hours of burn in has improved the GK-1R the most, by conservatively 3 or 4 times better.  High, mids and bass are improved twice over.  Imaging is three-D.  Center image stage has been pushed back to the wall behind the speaker.  The mod is not expensive just ugly.  I replaced the super e-cap configuration of C4 with a film cap, Solen 47 uF 250V.  It is big measuring 1.5” x 2.1”.  I also replaced a BG at C7 with the same cap.  Just replacing the two caps with these two monsters did it.  You have to find space under and along side the board, but it is amazing how film caps will transform the GK-1R sound and sound stage compared to the BGs.  I first tried Jantzen Cross-caps but the Solens are better.  There are probably other film caps that sound just as good as or even better than the Solen but I am so satisfied.  My GK-1R is not enclosed so I can easy expand things.  Hope there is room to expand if yours is in a box.

Happy listening,
Philip

That's amazing, Philip!     What gave you the idea of using some film caps here?

Now Solens are not generally regarded as the be-all-and-end-all of caps for speaker crossovers ... so, although you heard they are better sounding than Jantzens, do you think there might be a better sounding film cap for here than Solens?

Regards,

Andy

[kyrill]

to be sure
the c4 and c7 are replaced where the original topology placed the c4 and c7 on the board?
i dont understand  the "switch" between C4 and LED. was it a switch in place?

[AKSA]

Hi Jens,

No special ones I can think of;  the market is not that diverse.  But tantalums should be almost as good as a film cap IN THIS APPLICATION where they are merely cancelling noise, rather than passing musical signal.

Hope this helps, and my sincere thanks to Philip for offering his valuable experience here,

Cheers,

Hugh

[rabbitz]

Now Solens are not generally regarded as the be-all-and-end-all of caps for speaker crossovers ... so, although you heard they are better sounding than Jantzens, do you think there might be a better sounding film cap for here than Solens?

Regards,

Andy

I've found the Jantzen better than the Solen in speaker xo's but both are outclassed by the standard white Mundorf M-Cap. I've tried the Supreme's, but not worth the coin IMO for xo's.

[andyr]

Hi Jens,

No special ones I can think of;  the market is not that diverse.  But tantalums should be almost as good as a film cap IN THIS APPLICATION where they are merely cancelling noise, rather than passing musical signal.

Hope this helps, and my sincere thanks to Philip for offering his valuable experience here,

Cheers,

Hugh

But, Hugh,

The question to me is:
* you specified C4 and C7 as Hitano electrolytics.  That's fair enough, given you can't be expected to try a million different caps in each position in the circuit.
* Ginger? then suggested the GK-1 sounded better if these were, respectively, a "Super-E" pair of BG 'Ns' and a BG 'N'.
* then Philip has decided to substitute Solen film caps ... and it sounds even better!  
* so why would "brand X" tants sound better?  Yes they are smaller and so will fit on the board but, unless you:
  a) try several brands of tants to compare their sound, and pick the best, and then
  b) compare the best tant against Philip's Solens (I happen to have some ... 'xept they're 47uF/400v)
  ... I don't see how you can say "some tants would be fine"?  

Regards,

Andy

[PT914]

Hi,

Hugh, if the tantalum works that means I have to change my board from ugly to colorful.  Aren't the tantalum usually colored in pastel?  I don't have any tantalum to compare to the Solens.  Can't wait to hear from others on how amazing this change is.

Cheers,
Philip

[gaetan8888]

Hello

A little note about tantalum capacitors.

Every time I used them they fail after only few years, I remember reading few comments about those cap failure from others guys in the Net.

Maby there is a question of quality but it may worth to do a check with Google about tantalum capacitors failure.

Bye

Gaetan

[AKSA]

Gaetan,

You could be right, and thanks for the post!  But the new ones from Kyocera, AVX and Kemet are getting very reliable, as they are widely used in the telecoms industry (cell phones) where long life and compactness is important.

Use them only at half rated voltage.  In the GK1, rate to 16VW.  And get the polarity correct!  Wrong way round and they physically blow up, incredible, like a little fire cracker!

Cheers,

Hugh

[LM]

To me the exciting thing is that from a combination of user enthusiasm/experimentation and newer more capable components appearing since Hugh’s (& Dahl’s) design, there are improvements to be had for all of us.  It took a while before the Platinum became the C1 cap of choice so as a non-engineer, I may have to sit back for a while till you experts experiment a bit.  So come on, times a wasting.

[AKSA]

Andy,

Stranger things have happened.....  I'd use a rabbits foot if it improved the sound, and mutter incantations at daybreak in Stonehenge.....  the fact is, the psycho-acoustic phenomenon is sufficiently subjective to justify trying everything, and this is one of the reasons I take Philip's suggestion very seriously.  My suggestion of a tantalum is based on experience as a feedback shunt cap, where it sounded very good indeed and as you will recall was specified in the GK1 from the outset.

The further advantage of the tantalum is that they are tiny, absolutely tiny, and exhibit extremely wideband characteristics, with very low ESR.  That's ideal for cancelling noise.  The downside of the larger caps like Solen, Mundorfs et al is their bulk;  flying leads must be arranged, and the very size of the cap makes it highly susceptible to RFI and spurious noise.  Make it too large, and the benefits are lost, so there are good reasons for going small as possible.  The new copolymer caps are worth a look, too, Rubycon make them, and I'm using them already in a new 200W amp called the Aztec which should be ready in about three months.

Kafe Friday at 10?

Philip,

The small size of the tantalums is highly attractive, and saves some awkwardness.  How they perform is the moot point.  I reckon they will be good, but care must be taken not to run 'em hard, so voltage rating should be 16VW.  AVX appear to be the most progressive manufacturer at this stage.

Thanks again,

Hugh

[jules]

Thanks Philip ... this sounds like a very interesting mod. An RTX relcap could be worth a try without breaking the bank.

Kyrill, the "ginger mod" consists of:

  * Use the LED from L1 in the C4 position.
  * In the spot where the LED was [L1], use a cap. [I presume this is where Philip has used the Solen since he's also using the "ginger LED mod".]
  * Change R13 to 470 ohm
  * Change R14 to 10 kohm.

jules

[markus46]

Hugh,

Is there any chance that this change (tantalum for C4 & C7) could make its way to the pre-built Swift?

Assuming of course that there is general agreement by those that have tried it that it actually does improve the sonics.

Regards
Mark

[AKSA]

Hi Mark,

Possibly, but I have to be damn sure it betters the original design.

That said, I ALWAYS check these things.  And I have a few ideas of my own, nuttin' stands still......

'We pursue a policy of continuous improvement, and make no apology for it, so there......  '

Hugh

[LM]

Mark,

Further to Hugh’s comment, there is another bonus from Aspen re improvements.  What I love is that later ‘production’ changes can mostly be incorporated at the owners cost on Aspen built (not kit) models as I have done on a couple of occasions to bring my Soraya to the latest spec.  As his modification costs appear reasonable and uninflated for this service, it’s a win, win situation for the owner that is way beyond what anyone else appears to offer.  What’s more, the warranty is preserved.  I only hope he can manage to keep this option going as I am always tempted by the latest and greatest.  The only problem I have with it is that he always seems to be able to improve on the unimprovable.   It’s a beautiful thing though. aa

[VYnuhl.Addict]

Lyn,

   I must agree, Hugh and his nature of always being determined to build a better mousetrap often manages to hit the target 100%, the mad logical scientist. Of course it all starts with a sound circuit, then over time the tweakers brigade takes hold and improves it further with sometimes boutique, and sometimes non boutique subbed parts , Im always thrown aback by how much "voicing" can further refine a product and having a set of a hundred different music loving ears cant be bad for this process...The Soraya is a beauty, most definately..


Colin

[AKSA]

Folks,

Let me reveal Aspen's secret weapon - it is VYnuhl-addict himself!!   

I'm proud to say that everything I've come up with in the last 18 months has been tested exhaustively and assessed sonically by Colin.  This collaboration has accelerated development by a factor of perhaps four times;  he is much younger than I am, and jumping out of his skin with energy.  I just sit in a cafe with a pen, and doodle - Colin builds it, assesses it, then I do the pcb and layout design, ship the boards to him, and we confirm our hunches.

Wait until you see the latest 200W amp, the Aztec, this is the range topper, and it will, I think, have profound impact in the high end world.  All three stages, input, VAS and output, are radically different to anything out there at present, and Colin's input has been huge, thanks Colin!!     At least, that is my hope.  More tricks than a monkey on a mile of vine, to quote CJ Baker, famed small block NASCAR builder of the eighties.

Cheers,

Hugh

[andyr]

OK Colin,

It's obviously up to you, then!  aa  You need to do the testing of GK-1 C4 & C7 with:
* Solen film cap as per Philip's findings.
* another film cap if in fact a physically smaller one can be found.
* tantalum cap, as per Hugh's "suspicion".

    Regards,

Andy

[AKSA]

Andy, my good friend,

Where are your manners, Squire?   

Colin does things only when and if he wants to do them!!

Besides, Philip, who is 1 smart man, has great credibility and if he says this works, then it does, I'm quite sure.......   

Ask me, I will give you an answer!!   

Broach the topic over coffee tomorrow!   aa

Cheers,

Hugh

[andyr]

Andy, my good friend,

Where are your manners, Squire?   

Colin does things only when and if he wants to do them!!

Besides, Philip, who is 1 smart man, has great credibility and if he says this works, then it does, I'm quite sure.......   

Ask me, I will give you an answer!!   

Broach the topic over coffee tomorrow!   aa

Cheers,

Hugh

Hugh, of course Colin does things only when and if he wants to do them.  I didn't mean to imply otherwise ... however, from your post about him, I suspect he's the sirta guy who is dead keen to extract the best sonics he can out of his gear and therefore would be interested in trying out what Philip did. 

And I certainly don't disbelieve Philip ... in fact I think he's a genius for actually trying it out!     Given that I also have the "Super-E" BG Ns in my GK-1 and Philip has heard that the Solens sound better, it is definitely something I need to get around to when next I attack my GK-1 (for the teflons!  aa ).

Yes, see you tomorrow for kafe ... when we can discuss things which shouldn't go into print! 

Regards,

Andy