SFAF Capacitor Listening Session
SANTA ARRIVES, by Ori Mizrahi
It’s the beginning of December, a month of jolly holidays and miracles, and sure enough we had some of that too. Along came our Santa on a long drive from Danville with his 10 years old son. Jeff brought many presents (no, he’s not Greek! – nothing against Greeks of course…) with him.
First and foremost, a few of the caps we tried in the afternoon session were from Jeff’s personal stash, and that by itself would have been a great contribution to the event. But then he lugged with him in the pouring rain a bulky custom tube amp with VHAudio silver/Teflon and copper/Teflon caps and a pair of Legacy Audio very heavy monitors. I would not want to move these so-called monitors too often!
We originally had Jim’s PASS DIY amplifier and a pair of KEF LS-50 Meta speakers hooked up for the listening session, but what Santa brought was irresistible. You got to love surprises like that!
And if you think that’s enough for a surprise, Jeff also brought a point-to-point custom-built EAR 834P phono stage, a two-chassis gem in deep purple no less, what a class. We used this phono stage at the end to listen to some vinyl and if you have to ask then yes, vinyl still rules…
Now you’d think that three times a charm, well there was a fourth as well. This time real gifts: a Shure M61 Germanium-transistor phono that needs a re-cap was the “door prize” and went home with Vince. There were custom cables that were used in a famous studio recording and those went home with Gregory, including four Cardas RCA connectors. Jeff brought some outstanding vinyl to play, what a great guy!!!
CREEPY NOISE IN FESTIVE TIMES
We all set up for the afternoon session, and started once again half an hour late. Perhaps it’s a local tradition, don’t you think?!
The system consisted of a Meitner server/DAC source driving a single-stage 12B4A tube preamp, which is also tube-rectified and tube-regulated. The amp and speakers were described earlier.
We used the preamp to test coupling caps. For each pair of caps, we turned off the system, disconnected the AC cord from the preamp (safety first!), verified that the supply caps are discharged and proceeded with the installation of another set of caps from our 7-pair list. Soldering was done by students from the morning soldering class. We are serious about putting newly-acquired skills to good use!
After the first cap swap, we had a noticeable buzz. Many theories came about but reality always wins. The temperature-controlled soldering iron was on the same AC outlet as the system, and the internal circuit emits noise. Tada, a great demonstration, isn’t it?
WHAT SAY YOU, OH MIGHTY CAP
Now that we exorcised the noise demons from the system, it was time to enjoy the music, or more precisely enjoy it seven times over… We used four short tracks for critical listening: Dave Holland “Hands” is a great recording for Flamenco lovers and we played the first 2 minutes of track 4. Next was John Nakamatsu playing Chopin “Fantasie Impromptu”, and once again we played track 4. We needed some vocals and Patti Smith’s acoustic rendition of “Helpless” was a perfect track, and you can tell where it’s going, it was track 4 on that CD… To complete the fun quota, the fourth track was a Django Reinhardt 1937 mono recording “Souvenirs” with Grappeli on a violin. Yes, track 4.
You know, sometimes you need days or weeks to tell what sounds better, sometimes it takes 10 seconds or even just the first note. When we switched caps from Sprague “Vitamin Q” to a lowly Panasonic metalized, there was an eerie feeling in the room, not good at all. We quickly cut down the pain and switched to the next experiment, which added Sprague “Orange Drop” to bypass the Panasonic. This sounded better, but it’s hard to tell if it’s the sound of the combo or just the Orange Drops…
We played another metalized cap which fared much better. It looked more serious too, and it wasn’t a Solen.
At the end we played three metal foil caps. The last two sounded phenomenal and they were pretty much in a class by themselves. REL-CAP RT-series is a tin foil and polystyrene capacitor, and has a great reputation, just ask John Curl. You know what, he’s right. It gave a balanced sound and an outstanding musical presentation. The “competition” was a V-CAP copper/Teflon cap. Teflon is rumored to need 1000 hours break-in, and thanks to Jeff we had two broken-in well-used samples of this species. The V-CAP excels in bass definition, absolutely great details and overall a great sound. Between these two overachievers, the win can be only on points… and it might be circuit or system dependent.
In the particular system, I thought that the sheer musicality of the REL-CAP cannot be denied. It’s my preamp, so I de-soldered the V-CAPs and put back the REL-CAP, where they forever live. Jeff owns both, but he saw my enthusiasm and gifted me a great present ahead the holidays. Bless you my friend!
CONCLUSION
So how do we summarize a great event like this?
I’ll start from the end and touch on the issue of quality of coupling capacitors in audio gear, especially in tube gear. Manufacturers produce beautiful engraved enclosures with high visual appeal, but balance the low budget by skimping on internal parts. Quality capacitors cost more. They are also bigger and take more board area, which increases the price even more. If you account for the cost of inventory and other factors, the final product price differential can be five or six times the cost differential of parts alone. This may not be a major issue for a $10K amplifier, but it’s a make-or-break for a $3000 piece of gear.
The afternoon session brought simple reality to the forefront. Physics of metalized capacitor structure will always limit its performance compared to a metal foil with a film dielectric. The latter costs more to manufacture, but the sonic results are well worth the price differential. If you upgrade the gear by yourself, then that extra cost is negligible. Check what’s under the hood of your mid-priced and vintage tube gear. If you find metalized or ancient caps, don’t think twice. A good metal foil cap that can be had for as low as $14 will bring that equipment to the next level, and you’ll never look back. Just do it!
That’s the practical conclusion of the event. It was an experiment that was not rehearsed up-front. I knew what I’m expecting to hear, but I left it to the experiment itself to work the magic, which it did. It takes some trust to do that, but this wasn’t my first rodeo… Enough said. Now leaving mundane everyday system issues aside, there are more important lessons that come to mind.
Despite nature working against us, despite the stamp of “Technical Material” on the class agenda and the listening session too, the good will of many worked out in mysterious ways to give us a precious gift – the realization that being an Audiophile is still a relevant and fun hobby!
Whether one enjoys the technical aspects or just likes to listen to good music, this is one great hobby to have at any age. Each one of us finds his/her way in the vast field of options and still feels part of the greater community. And in this time a year, you have to appreciate where we are and how lucky we are even when the world is just getting over a horrible pandemic and other less fortune nations and people are enduring hardship. There is always a bright side that we should be all thankful for.
Man, I’m starting to believe in the Christmas Bunny…
