Search old posts by serengetiplains, he experimented with injecting teflon caps (was it Fluorinert?) to reduce that effect. I suspect it's why I prefer silver mica in high voltage swings positions.
ESR and resistance and is not related to frequency.
ESR is directly related to physical device construction.
Impedance is frequency related and is a function of the capacitance of the capacitor and nothing else.
Two different things. Lowe ESR is more important in high current circuits like switching power supplies since it is in the sub 10 ohm range. ESR is constant.
Impedance on the other hand varies with frequency.
Steven
ESR is directly related to physical device construction.
Impedance is frequency related and is a function of the capacitance of the capacitor and nothing else.
Two different things. Lowe ESR is more important in high current circuits like switching power supplies since it is in the sub 10 ohm range. ESR is constant.
Impedance on the other hand varies with frequency.
Steven
It depends. For example if you have a turn table t can be a good source of very-low frequency rumble. Lower than the speakers can reproduce. THe larger caps pass this and it can eat up all the headroom in the amp.
If the amp uses grid stop resistors then worry about ESR is pointless. But with low ESR and no grid resistors you are setting up to oscillation in the radio frequency range.
What you want is for the coupling to pass the audio range and filter out the rest. "DC to Daylight" is not the best frequency response.
Okay, for the third? time, I'm not trying to increase the bandwidth of an amplifier, in my case, the coupling caps to the output stage which will not be altered, define a minimum frequency that can be passed to the ouptput trannies. No matter what I do to the cap between the input stage and the phase splitter, it will not make the output stage amplify LF rumble, warps or anything else.
I'm not trying to pass down to near DC in the intervening stages (although if to do so were problematic then people would/could never successfully direct couple amp stages).
It's merely a question to those who have ever tried subjective tests of does a smaller coupling cap sound better than a larger value coupling cap of the same type in the same position ?
If no-one has experimented with value rolling across the same type of cap in order to find out, that's fine. I was just curious.
Heck, enough real estate gets used in forums on Are Jensens better than Audio Note PIO's, how do they compare to Auricaps, Wimas, Jantzens, Dynamicaps, Mundorfs etc. Wasn't sure if anyone had done a test where thye took a cap they liked or at least knew the sound of well, found a non value critical position in the amp to do some playing and tested a range of sizes in order to come to a conclusion.
Evidently not.
I'm not trying to pass down to near DC in the intervening stages (although if to do so were problematic then people would/could never successfully direct couple amp stages).
It's merely a question to those who have ever tried subjective tests of does a smaller coupling cap sound better than a larger value coupling cap of the same type in the same position ?
If no-one has experimented with value rolling across the same type of cap in order to find out, that's fine. I was just curious.
Heck, enough real estate gets used in forums on Are Jensens better than Audio Note PIO's, how do they compare to Auricaps, Wimas, Jantzens, Dynamicaps, Mundorfs etc. Wasn't sure if anyone had done a test where thye took a cap they liked or at least knew the sound of well, found a non value critical position in the amp to do some playing and tested a range of sizes in order to come to a conclusion.
Evidently not.
By now it should be obvious you are asking at the wrong place.
I have never conducted proper tests but every time i use a smaller cap it sounds better. Large caps, even of top quality sound a bit slow. So, yes, i have to join those who recommend the smallest possible cap which will satisfy the bandwidth.
Polycarbs have been equalled and bettered by polyprops.
I believe clarity cap did some sonic research into this.
www.icwltd.co.uk/claritycap/news.html
richy
I believe clarity cap did some sonic research into this.
www.icwltd.co.uk/claritycap/news.html
richy
My answer wasn't clear? Yes, I think smaller is better, it's what I try to do in my designs, but neither I nor anyone else have any REAL data.
You may not be passing signal via the output stage coupling caps, but you DO have a power supply on the stages in question, right? You DON'T have an input high pass filter, right?
Those new Clarity caps (ESA/MR) are getting great reviews from people that I trust and usually agree with cap sounds. Would like to try the MR in the tweeter path and the ESA in the mid/woofer section.
No, I don't have an input filter, this is true, but as I said earlier, if people can be in favour of direct coupling the input gain stage with the phase splitter and therefore passing everything down to DC, please explain how the LF response of the coupling cap is going to bring about Armageddon? If direct coupling of a stage is potentially viable, then how on earth can RC coupling cause more problems due to the LF bandwidth of the coupling caps?
Cap related sonic issues? (maybe)
Low frequency related sonic issues? (can't see how)
I believe it has something to do with the shift in phase that occurs as a result of the capacitor.
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In the case of interstage cap; I agree with you but often up against the recommened datasheet value of the auto grid leak bias resistor i.e Hi cap value with low resistor value Or Low cap value with high resistor value for same response.
I tend to violate this and other rules when using tubes way below their max ratings. Apart from obvious DC leakage currents is there any other reason
not to go way over too high with this grid leak resistor value with small signal tubes ?
richy
Agree with SY and others that minimum cap size sounds better. Seems to pass more information (faster?), less coloration within a particular product line.
Oddly, I don't ascribe to the standard rolloff calculation of -3dB numbers in the 10Hz range as opposed to the use of closer to 1Hz, of course with staggered poles in a FB loop (and try to have only one coupling cap in a loop so this is irrelevant). For me, the bass gets noticeably better with a bigger cap in the -3dB @ 1-3Hz range.
Unfortunately, this goes against the desire for minimum cap size.
I found that, for me, V-Caps provide much better bass than any other cap I tried, with a smaller size (0.1uF) sounding like deeper, tighter bass than several PP caps in the 0.47uF range. Can't explain it, but other friends/builders experienced the same thing.
Go as small as good bass will allow.
Stuart
Oddly, I don't ascribe to the standard rolloff calculation of -3dB numbers in the 10Hz range as opposed to the use of closer to 1Hz, of course with staggered poles in a FB loop (and try to have only one coupling cap in a loop so this is irrelevant). For me, the bass gets noticeably better with a bigger cap in the -3dB @ 1-3Hz range.
Unfortunately, this goes against the desire for minimum cap size.
I found that, for me, V-Caps provide much better bass than any other cap I tried, with a smaller size (0.1uF) sounding like deeper, tighter bass than several PP caps in the 0.47uF range. Can't explain it, but other friends/builders experienced the same thing.
Go as small as good bass will allow.
Stuart
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