Tip of the Month - #26 (April 2001)
By Dick Olsher

1. Caps, etc.

It's ironic that so many words have been spilt in the audiophile press for the glorification of various cable products, whereas relatively little has been said about the sound of capacitors. If you're building or upgrading tube and solid-state gear take note: coupling capacitors can profoundly influence sound  quality far beyond the impact of fancy wire or connectors. Recently, I had this to say about cable: As an audiophile, the absolutely first question that should come to mind when considering a prospective cable purchase is: what grade is the conductor material? It's easy to forget that a similar consideration applies to capacitors. Most metallized capacitors are nothing more than aluminized Mylar. Even film-and-foil types rarely venture beyond copper or aluminum. The purpose of this sonic alert is to hoist silver conductor to the top of the flag pole.

Let me tell you a tale about a poor man's Ongaku. The Ongakucox  is a copy, build by compadre Ron Cox, based on Kondo's article in issue #2 of Sound Practices Magazine. It uses copper, wherever Kondo used silver. My samples are currently outfitted with Sowter output transformers. Other changes include monoblock configuration and elimination of the volume control. There is one 0.1 microF coupling cap in the signal path. The real Ongaku used a silver-foil cap in this position. For years we have experimented with various paper-in-oil and other fancy cap types, so that we had a darn good notion of what to expect. That is until the recent arrival of the Vacuum tube Valley (VTV) Ultra-Tone Silver Foil in Oil Pro-Caps.

These are of a proprietary design made for VTV in England using high-quality laser etched silvered alloy foil, precision wound with premium-grade Kraft paper. The paper is impregnated with a non-toxic oil as a dielectric (no PCBs are used). The leads are 0.9 mm solid or stranded silver plated OFC, depending on the value chosen.

After the caps were installed, Ron called to report the results. Punctuated by a liberal dose of  "wow" interjections, he reported a total sonic transformation of the Ongakucox. I've never heard him more excited, at least when it comes to audio things. In a nutshell: amazingly clear and vivid sound were his findings. When my amps returned from Colorado with the VTV caps installed, I had a chance to confirm Ron's impressions. I'm now ready to declare the VTV ultra-Tone silver foil caps as the most amazing coupling caps I have ever auditioned. These caps are incredibly pure harmonically as well as dynamically alive  and totally engaging.

At their asking price (US$22 for the 0.1 microF value), these caps cannot be beat. How about this tidbit of comparison shopping: an Audio Note 0.1 microF 600 V cap will set you back US$128. For more details check out the VTV web site: http://www.vacuumtube.com/Products.htm

Remember that all capacitors require several days of break-in to fully mellow out their sound.

  2. The Hammer Dynamics S-12 Loudspeaker Kit

I'm sure that many of you have heard by now about the passing of John Wyckoff, Hammer  Dynamics' designer.  The good news is that John's legacy to the DIYourselfer on a budget is alive and well. The business is now being run by Colleen Wyckoff (his widow) , and I have been assured that the S-12 is in production and shipping to customers worldwide.  Check it out at: http://www.hammerdynamics.com/