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In Reply to: V-Cap experience? posted by Srajan Ebaen on January 16, 2007 at 02:43:29:
I have a tube amp (push-pull) which uses 2 caps in the signal path on each channel (4 caps total) I've made acquaintance with the manufacturer and we've been trying several cap types in those positions. V-Caps were used in 2 steps, first we replaced one pair (one cap/channel) and weeks later the other pair, after the first was fully broken-in.IME the V-Caps brand new don't sound balanced, not harsh or bright either, but they're quite "regular" on the midrange and show a curious "extended echo" effect that some may take for "outstanding detail", which goes disappearing with time. After about 200 hours, they seem to be "right in", but that's an illusion, you start to experience "bass disbalance" which is something like mid-bass goes away and you start getting a very extended and solid bottom end. Then for the next 200 hours, things go steadily and quite slowly going into place and it's not after 500 or more hours that the caps are actually spot in with a balanced frequency response, correct detail level and the best by large mid-bass that I know of, in the proportion a cap in the signal path can influence it. Probably you need all that time to get the upper-midrange sounding smooth and pure.
The second pair of V-Caps was pre-burn-in into a machine that the manufacturer designed. This saved the "stormy" time that happens in between the 200-500 hours term and the initial "hyper-echoic" sound. The caps sounded more balanced right from installed, but it took well 200 hours to get again a pure midrange and a balanced bass from bottom to mid-range.
Of course I'm sure this can be completely different depending we speak of tube amps, SS amps, push-pull or SET designs, and the places of the circuit the caps work into. Maybe in other kind of gear results and break-in impressions are different.
Follow Ups:
I have noticed the same long breaking-in with Russian K72 and FT-2 caps. After 2 months of continuous burning (connected to transistor receiver in series with 8 ohm resistor, 6 W avg. music into the resistor), and additional burning in the actual circuit, they sound very balanced and produce extraordinary clean highs. This was the first time I heard loud orchestral strings reproduced properly.All the comparisons I've read about were dismissive of Russian caps. But from what I hear in my tests, I don't think I need anything better, esp. for 30-50 times the price.
For me the Russian Teflons sounded right at the start while the V-Caps sounded harsh. As I don't have the patience listening 500 hours to harsh sound for burning in I sold the V-caps immediately.You see so many reviews of V-Caps here on the Audio Asylum as Chris Venhaus invites you to write one after sale; complete with link.
Thank you very much!
I am interested in this burn-in machine. Is there any way to get one, or get a schematic diagram of it so I can burn in capacitors (hopefully multiple capacitors at once)?
I know one manufacturer who used various burn in machines and claims that music is best for proper burn in. I personally use a CD on repeat directly into an amp and put the device under test on the output of the amp(could be any old receiver)and after the device under test put a load to ground (resistor). You can use a high powered resistor and measure the AC voltage across it and say have 5 or 10 watts of continuous music going through the capacitor or cable. If you use a very small cap, you can parallel it with a super big one so there is plenty of current draw and all frequencies would go through the cap. Every day or so you can change the type of music, so you get all flavors of burn in. Works great. One week of continuous high powered music will make a major difference and with very little cash out lay....except for some minor electricity (assuming you have a spare old amp and old reliable player).
Soulds like a plan to me! So would a 10 watt 8 ohm resistor be a good value? I would also like to burn in multiple components all at once. Would pairs of large and small caps strung together in series be feasible?
I would run all the caps in parallel...that way even small values would benefit from all frequencies. You have to decide what voltage/current you want to burn them in at. If you put 10V RMS into an 8 ohm load you get 1.25 amps of current....times 10v you are getting 12.5 watts of power. I have not done enough experimenting to know what voltage and what current to run things in with. When I did interconnects I ran about 12VRMS into a 100 ohm resistor...this gives .12 amps and around 1.44 watts. Normally an interconnect would never see more than 2 volts RMS and into a 10K load minimun....this would be .0002 amps of current and .0004 watts....so you see, what I was doing is 6 times higher voltage than it would ever see and also 6250 times more current. It certainly worked. Could I have used higher voltage and current....sure....will it sound better...I don't know. Play and let us know.If you are using caps in high voltage places (coupling caps and bypasses in tube gear, for instance)....you might want to bias the caps with DC as you burn them in. You could have one big cap as your voltage blocker coming out of the amp...put a 125V or whatever supply after it and then hook up your caps to be burned in and then the load resistor....this way the AC will pass through all of this and your caps will also have the DC bias on it that it would see in circuit. Just a thought.
I can think of two commercial units. Audio Excellence in Arizona makes a cable cooker. Hagerman makes the Fry Cleaner cooker. Both could be configured to condition caps I believe.
....they could be run in series via the binding posts (high-level circuit), with no practical limit. Some amplifier manufacturers are doing this already. Thanks for thinking of me.
I'm thinking of switching out the caps in my ARC PH3 phono preamp, and will probably try out a few different brands. Ideally, I would hook up twenty or so in series and let them burn in for a week or so. However, I can see a problem with different values of caps. The smaller values would block lower frequency signals, so it might make sense to burn in caps of only the same value in a chain.From the long times that I've seen mentioned for burning in V-caps though, this could end up taking a few months. I think that I would be getting the Fry cleaner rather than the cable cooker because of its lower price. But am I right in guessing that it has less power, and therefore longer burn-in times?
However, I can see a problem with different values of caps. The smaller values would block lower frequency signals, so it might make sense to burn in caps of only the same value in a chain.That's the theory. However, the Cable Cooker is sending a very powerful, high-voltage/high-current multiplex signal that I believe makes that theory irrelevant in practical terms. Please note that the Cooker is not passing an audio signal (or sine wave). Some end users have conditioned complete crossovers (outside of the speakers) with great success. Those generally have a variety of caps, and values.
From the long times that I've seen mentioned for burning in V-caps though, this could end up taking a few months. I think that I would be getting the Fry cleaner rather than the cable cooker because of its lower price. But am I right in guessing that it has less power, and therefore longer burn-in times?
It's not something available for sale, the manufacturer built it under his own design and I have no schematics, but for what I saw at his facilities, it uses some sort of continuous music-like signal and has a built-in meter to check the current and voltage driving the caps. I don't think the V-caps really "need" it, they're quite listenable all the time the burn-in takes, but that lapse in between 200 and about 500 hours can be discouraging at some moments if you don't know where you're leading to.
To share comments I've gathered so far.Up to 150 hours of back/forth changes, at times better, at times not until the V-Caps stabilize and are all better. 50-60% success at this point. Then solid one-directional progress up to 400 hours for 90-95% of glory. Up to 1200 hours for the final subtle improvements. This from people who have used these caps professionally in modifications and end users who've done the cap comparison dance and were meticulous in taking notes.
The latter also have itemized differences in break-in speed based on circuit juncture, i.e. higher current flow accelerated things in higher-level circuits and slowed it down in low-level junctures.
Nearly everyone agrees that in the first 50 hours, things can be mediocre to absolutely unlistenable.
The Teflon/tin-foils are said to take longer than the oil-filled V-Caps which sound better sooner.
What did the elephant say to the naked man? Not too bad - but can you really breathe thru that thing?
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