Re: where to buy?
The BG's can be ordered in the Netherlands at http://www.acoustic-dimension.com/
Prices are fair too.
Jan
rmgvs said:
The BG's can be ordered in the Netherlands at http://www.acoustic-dimension.com/
Prices are fair too.
Jan
Regarding WIMA caps, for audio bypass/decoupling I wouldn't use anything besides the MKS series. In my experience, others (eg MKP) make the sound thin and without 'body' when used for rail bypass/decoupling.
http://www.wima.com/applicguide.htm
http://www.wima.com/applicguide.htm
If you are happy to order from the US, especially if you are buying large quantities, Percy Audio is cheaper for Black Gates. They also have Nichicon Muse.
www.percyaudio.com
www.percyaudio.com
Hi,
I see, as a coupling cap....
Well, I don't know what the Rifas sound like in particular but if you can't get a Black Gate cap that suits you, the best you could do is bypass the electrolytic cap with smaller values filmcaps.
Assuming you need to block a low DC voltage at the output of that preamp you could try bypassing the electrolytic cap with say 0.010µF upto 10µF 63VDC MKP. (metallized polypropylene)
Space permitting, of course.
That should clean up most of the higher midrange and highs.
If you could calculate the exact low frequency you want to pass, you may find that the 63VDC caps combined to say, 100µF aren't really all that big after all.
Hope this helps,
I see, as a coupling cap....
Well, I don't know what the Rifas sound like in particular but if you can't get a Black Gate cap that suits you, the best you could do is bypass the electrolytic cap with smaller values filmcaps.
Assuming you need to block a low DC voltage at the output of that preamp you could try bypassing the electrolytic cap with say 0.010µF upto 10µF 63VDC MKP. (metallized polypropylene)
Space permitting, of course.
That should clean up most of the higher midrange and highs.
If you could calculate the exact low frequency you want to pass, you may find that the 63VDC caps combined to say, 100µF aren't really all that big after all.
Hope this helps,
I've compared tantalums, silmics, solid aluminium, oscon, BG Ns, ansar supersound polyprop and PPS caps.
Tantalum are nice though not great on clarity or high frequency extension, nor 3D; musically involving though. solid aluminium are very musically involving though a tad bright. Oscons are very 'funky' and have good bouncy bass though a tad confused and a bit 2D. BG Ns are very smooth, clear and detailed with a lovely silky 3D sound though I find they have the yawn factor- not very involving somehow and mush instruments together musically. PPS are my favourite so far with very tight puchy bass, involving mid; musically involving though revealing in the treble. Your source better be up to scratch or they can be too much. Can sound a bit grey. Silmics are nice and organic, involving though not the last word in clarity but easy on the ear. Ansar polyprop I found relentless and overbright. No like. All IMO and in my system of course. Get the impression that electrolytics are easier on the ear though not so revealing or 3D.
There is nothing wrong with a bit of mixing to get the balance right for your system. At one point I was mixing pps and silmics/tantalums to good effect. Think of it as mixing spices for a curry. Really want to try RTX some time as they sound great from reports but costly if its a wrong choice.
cheers
Ced
Tantalum are nice though not great on clarity or high frequency extension, nor 3D; musically involving though. solid aluminium are very musically involving though a tad bright. Oscons are very 'funky' and have good bouncy bass though a tad confused and a bit 2D. BG Ns are very smooth, clear and detailed with a lovely silky 3D sound though I find they have the yawn factor- not very involving somehow and mush instruments together musically. PPS are my favourite so far with very tight puchy bass, involving mid; musically involving though revealing in the treble. Your source better be up to scratch or they can be too much. Can sound a bit grey. Silmics are nice and organic, involving though not the last word in clarity but easy on the ear. Ansar polyprop I found relentless and overbright. No like. All IMO and in my system of course. Get the impression that electrolytics are easier on the ear though not so revealing or 3D.
There is nothing wrong with a bit of mixing to get the balance right for your system. At one point I was mixing pps and silmics/tantalums to good effect. Think of it as mixing spices for a curry. Really want to try RTX some time as they sound great from reports but costly if its a wrong choice.
cheers
Ced
Hi,
Can this thread be cleaned up and made sticky, or sort of a mini faq? I would like to see less "plasticy sound" and "bouncing base" and alot more "high q" etc. To keep it simple say ..the best top 3 for each purpose, and a few scientific reasons why? Surely if it colors the sound so bad there has to be a reason behind it.
I agree with what someone stated about BG's, no good data available and all marketing "buy these...sound so good" and since they are the most expensive we gotta buy them? I need a better reason. Has anyone tested them with anything more than a listening test?
Since it's about caps, what's everyones favored reservoir cap?
Thanks,
Chris
Can this thread be cleaned up and made sticky, or sort of a mini faq? I would like to see less "plasticy sound" and "bouncing base" and alot more "high q" etc. To keep it simple say ..the best top 3 for each purpose, and a few scientific reasons why? Surely if it colors the sound so bad there has to be a reason behind it.
I agree with what someone stated about BG's, no good data available and all marketing "buy these...sound so good" and since they are the most expensive we gotta buy them? I need a better reason. Has anyone tested them with anything more than a listening test?
Since it's about caps, what's everyones favored reservoir cap?
Thanks,
Chris
classd4sure said:
Does anyone have a specific methodology in mind? I did not believe in the fact that different coupling/decoupling caps have different sonic signature (standard measurements like THD or IMD show only MINOR differences) but unfortunately upon listening on a good system these turn out to be HUGE...
Agreed, this thread needs cleaning, but first how to test the caps? - maybe blind A/B listening tests but indeed something more meaty would be needed...
ced said:
Very good observations. I've been experimenting with RTXs, but I'm not a big fan of them. They sound a bit clinical and dry. Can't say they are involving either.
I found Siemens MKV to be most satisfying in coupling aplications. I tried combining caps for desired effect, but in a long run, I think the sound seems to be disjointed and artificial. Whenevr I can, I prefer to stick with a single cap.
Some more reflections here:
http://www.diyaudio.com/forums/showthread.php?s=&postid=267956&highlight=#post267956
For coupling caps in my JFET preamp (under development), I'm using TRW-35 high current polypropylene and Rifa high current polypropylene (PHE 420, I think...). I'll post when I get a handle on the listening characteristics. I also use Siemens or Wima polycarbonate caps for interstage coupling in some places or for the top-to bottom coupling cap for a "FETWhite" output buffer. I tend to use what i can find from local surplus sources or Ebay, being a parsimonious kind of fellow... The preamp is a simple open loop topology with a common source amplifier followed by a current-source loaded source follower as the basic gain cell. I'm using 2SK170 and PN4393. Distortion is ~0.4%, flat from 20-20k, all 2nd harmonic, or so the Audio Precision tells me. Sound? I'll find out when I drop the thing in a chassis and integrate it with the rest of my system.
For decoupling caps on the rails, I started out using some fairly substantial Panasonic FCs (560/50V), with 0.47uF Panasonic poyester stacked films for bypass. The big, low ESR electrolytics rolled off my supply regulator like crazy and left the regulators without much phase margin. I replaced the big caps with a pair of 22uF/63V HFQs. The have a couple of ohms of ESR, so they should provide some damping and leave my regulators with some bandwidth and phase margin . I'll post when I get a chance to measure and/or listen. The way I figure is that unstable supply regulators can't be too good for the overall sound. If you don't depend on regulatorsto supply the transient current demands, then you need to pad the rails with high capacitance to keep the voltage excursion down for a sudden current demand. With a closed loop regulator sitting on the rails, you need to compromise between current delivery and regulator speed and stability. I'll find out if my listening results bear out this blather...
For decoupling caps on the rails, I started out using some fairly substantial Panasonic FCs (560/50V), with 0.47uF Panasonic poyester stacked films for bypass. The big, low ESR electrolytics rolled off my supply regulator like crazy and left the regulators without much phase margin. I replaced the big caps with a pair of 22uF/63V HFQs. The have a couple of ohms of ESR, so they should provide some damping and leave my regulators with some bandwidth and phase margin . I'll post when I get a chance to measure and/or listen. The way I figure is that unstable supply regulators can't be too good for the overall sound. If you don't depend on regulatorsto supply the transient current demands, then you need to pad the rails with high capacitance to keep the voltage excursion down for a sudden current demand. With a closed loop regulator sitting on the rails, you need to compromise between current delivery and regulator speed and stability. I'll find out if my listening results bear out this blather...
decoupling topology
Hi All!
I am wondering that nobody seems to care about the
DC biasing of the e-caps.
In most circuits I see non biased or randomly biased electrolytics.
But if the bias has the wrong direction, then the behaviour of that caps can deviate dramatically from the spec. and high leakage can be expected. Depending on the real bias such effects occur very slow. This may correlate to the observation that some caps in this thread here did show very instable properties.
If I must use electrolytics in the signal path, I am checking for
the natural DC-voltage bias (best solution if a natural and more or less defined DC voltage is existing in the signal path).
Or I am using forced biasing.
Typically I am using some biased anti seriell topology like attached.
Disadvantages are that we now have two of that undesired components in the signal path and an additional
10meg against the rail .
Nevertheless I got amazing good results by this even with low cost
caps.
...looking forward to your comments
Markus
Hi All!
I am wondering that nobody seems to care about the
DC biasing of the e-caps.
In most circuits I see non biased or randomly biased electrolytics.
But if the bias has the wrong direction, then the behaviour of that caps can deviate dramatically from the spec. and high leakage can be expected. Depending on the real bias such effects occur very slow. This may correlate to the observation that some caps in this thread here did show very instable properties.
If I must use electrolytics in the signal path, I am checking for
the natural DC-voltage bias (best solution if a natural and more or less defined DC voltage is existing in the signal path).
Or I am using forced biasing.
Typically I am using some biased anti seriell topology like attached.
Disadvantages are that we now have two of that undesired components in the signal path and an additional
10meg against the rail .
Nevertheless I got amazing good results by this even with low cost
caps.
...looking forward to your comments
Markus
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