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Old 9th July 2009, 10:16 AM   #41
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HI JH

you really need to try them in the more critical capacitor signal paths of amps and cd players to get their full flavour.
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Old 9th July 2009, 11:05 AM   #42
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Well now that you mention it.....,

I did a well matched B1 buffer to go between the Lightspeed and the F3 and it never did come good - I couldn't bakance the current to the caps (sounds a bit ridiculous, seeing that written like that, but that's how it seemed at the time!)

It needs about 10uf as o/p cap and with the 10 volts across it, one of the 10uF/63volt K73-16 might just do the job - will try it again and see how it goes.
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Old 9th July 2009, 11:35 AM   #43
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You need to intoduce another component just to listen to a cap?!

Can you not plug it in series with your existing chain? Like immeditely after the source?
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Old 9th July 2009, 12:41 PM   #44
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Yes, you can just add it in line with the source and have a listen and you'll get a rough idea about what sort of sound it has.

Unfortunately, this same device will probably sound rather different in a different situation like with high impedance and low bias voltages, for example, or perhaps, a series cap in a Sallen Key filter, or a feedback cap in an amp - you get the idea.

When people get different/poor result from an "unsuitable" application, an otherwise good device may be written off altogether.
For quite a few years, all poly/mylar caps have had a pretty average reputation - with me, too!

Now, we're seeing a general production device in a new light - it would be even more useful if we knew where they didn't function well, and why not.

From what's written on the thread above, most of the ccts that these caps have shown exceptional performance have been valve ccts with quite a bit of voltage across them - with the much lower voltages that I'm using them for, we're looking to confirm that we also get the same exceptional results. Hence the idea with a current common project, the B1 with 9 volts on it.

Pity they're so damn big tho! And perhaps a heatshrink sleeve/jacket on the metal case. The wires need rubbing clean, too.

Sorry for the mumbo jumbo and vague terminology - not intentional.
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Old 9th July 2009, 07:22 PM   #45
piero7 is offline piero7  Italy
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Quote:
Originally posted by audiojoy
HI JH

you really need to try them in the more critical capacitor signal paths of amps and cd players to get their full flavour.
Quote! Quote! Quote!

They are simply excellent capacitors everywhere you mount them!
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Old 9th August 2009, 10:41 PM   #46
Havoc08 is offline Havoc08  Denmark
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Forgive the ignorance, but what is a bypass cap and how do you use it/which applications?

Which uF value would be appropriate?
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Old 10th August 2009, 01:30 AM   #47
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Havoc,
This is a subject that's available on quite a few different threads here - with those that agree and those that think it's nonsense - as usual, it's somewhere in between.

Most big electro caps aren't as good at higher frequencies as smaller, "better quality" caps, so if you connect a smaller cap across the big cap terminals (as a "bipass capacitors"), this generally gives better sound.
There are sometimes problems - sometimes "ringing" occurs and resonance between the 2 caps, so it's not as simple as it first appears.

For example, if you add a 0.1uF Polypropylene bipass across a 220uF Elna Silmic, you generally get more top end and a "faster" sound (sorry for the vague) in some circuits like I use, but often it also introduces a ringing of the top freqs (eg: cymbols sound unnatural, that some people quite like). If you change the type of bipass to say a good quality polystyrene, you get a quite different top end sound altogether that you may not like at all - it get's a bit trickie (sometimes produces "fatigue").

And to add to the "fog of confusion", often when you use a 400volt bipass and only apply 10 volts across it, the caps doesn't function anywhere near it's potential. When you use these bipass caps in the signal path with low voltage but high impedance (like an amp's input cap) they will behave quite differently to when you put them into a high current use like the output caps in my set amp, power supply cap bipasses, etc.

What the guys here have found is that the humble, inexpensive PETP cap from Russia, seem to do it all!

There has been an enormous amount written about bipass caps over the years, so you'll just have to start reading. Perhaps someone can recommend a good starting point
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Old 10th August 2009, 06:30 AM   #48
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Quote:
Originally posted by jameshillj
Perhaps someone can recommend a good starting point

Get a soldering iron hot and at least one pair of ears
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Old 10th August 2009, 12:20 PM   #49
Havoc08 is offline Havoc08  Denmark
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Thank you james for the comprehensive explanation.

So you can actually use bypass caps both on signal level and on output?
You just parallel the bypass cap with the cap already there?

It sounds like it could be fun to try and at the price og the russian caps it's possible even for a student



@ analog_sa
lol.... I'm set to go then
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Old 10th August 2009, 01:16 PM   #50
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Yeah, you can have quite a bit of fun with this bipass thing.

Most people recon that the caps are the weak link in the signal chain and are the major source of the loss of fidelity - well, i disagree with this, as fidelity of the signal is dependent on everything starting from the power transformer type, the supply diodes, the connection wire, those caps, etc ,etc - everything makes a difference and you can use this in the final sound of your system.

A general rule of thumb to start this bipass thing is to choose the electro, lets say it's a 10,000uF/50 volter in the supply cap (the 2nd one in a C-R-C system) and let's say you're using basic Phillips caps and you want to make them "faster,brighter, etc" - I would begin with a 10uF/63v Propylene like a Wima, Solen, etc and listen to the effect. If that doesn't lift the sound enough, I'd try a good quality 220uF electro across that and see.
It's quite straight forward and teaches your ears "how to listen" to a sound difference.

Another example, in the power supply for say Rock/Roll and heavy classical, for a classA amp, you would look towards a "heavier sounding" supply, and it starts with a bigger transformer than required, slightly slower diodes like RURP860s rather than MUR820/ETH06/BYW29 and use caps like the Roe/Mundorf/F&T rather than brighter ones like Rifa, BHC, etc.
The choice of the components directly effects the sound, and this is just the power supply! Then comes the choice of rail regulation, if any, and so on.....

Mind you, there will be a lot of folks that think this is all a lot of rubbish and that adherance to the theoretical design will guarantee good results.
Well, I can't dissagree with that, but there is so much more to be had for a little bit of stuffing about and patient listening, and an open mind - the cost is generally minimal if your sensible and swap parts with others in your area.

I hold the view that the "amp + speakers + room" is an interdependent system and the source, preamp, crossover, etc are a seperate section and have their own particular compromises - this is the area that you can save an enormous amount of money with some smart shopping and get very good quality.

For now .....
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