Hello All,
I have finished with the cap modifications to the GK-1, as new output caps arrived this week and were quickly installed. I have now christened my GK-1 as GK-1 Platinum, as the Sonic Platinum caps have brought the GK-1 to new heights of audio performance.
The C-1 input Platinum cap has been in the preamp now for just over a month. The sound as reported in my earlier post is much the same, although it does seem as if things have opened up a bit lately to a much broader and wider sound presentation. Every little musical detail seems to be easily heard, with tinkly little things twinkling quickly, whacks being soundly quickly whacked, and notes lingering into long decays.
The new output coupling caps are 1 uf Mundorf Silver/Oils. I had been thinking of 250V VH-OIMP’s as their size was easily accommodated on the board, but in the end I went with the Mundorf’s. They are nearly as large as the Platinum’s, but not as heavy. I was able to fit them on the board, barely.
These caps have made an immediate and noticeable difference in the sound, adding a nice refinement to the pre-existing sound that I heard with the Auricaps in this position.
In summation, the modifications are as follows:
C-1 input cap to SS gain stage – Sonic Cap Platinum 1 uf
C-19 input cap to tube grid - Sonic Cap Platinum .01uf
C-21 output coupling cap - Mundorf Silver/Oil 1 uf
The teflon caps are the single most definable improvement I have ever made to an audio system, more so than even a total unit replacement. This is not just a simple cap modification; it is a total unit sound upgrade of immense proportions. The playback sound of the audio system is taken to a totally new level with these caps.
There also is not cheap way to accomplish this. The 1uf Platinums are $100 ea. and the VH-Audio TFTF’s are 30% more. One may be tempted to just get a small bypass cap as a cheap option. I just don’t think bypassing a signal path cap works. I’ve tried this in the GK-1 and Aksa N+ output couplers and heard absolutely no difference in sound. You need to use the full value cap in the C-1 input cap position!
You have to think of this as a total audio system upgrade rather than a cap change. Thus, the cost of the caps is really a bargain with the sound that results.
Hugh has heard the sound of this modification in my system himself, just a few days ago. Unfortunately the new output caps had not yet arrived, but they are more like icing on the cake. He’s heard the improvement the Platinum teflons make to the sound. You can contact him direct for his personal opinions, impressions, and thoughts.
Finally, if you have a GK-1 and want to take it to the ultimate level of sound reproduction, the teflon cap modification is a MUST. You cannot do anything else to the unit, or your system really, with as much impact as this modification!
Steve
