Cant help taking the bait SJ sorry, I can resist everything except a tangent ... I'd say everything from the sound source to the sound receiver (the ear) is relevant in sound reproduction and is what I think of as the audio signal path. I usually try to concentrate my limited attention span on the physical tranducers (mics and speakers) and the environments in which they operate, as their contribution to distortion in the audio signal path is so significant. I try to search out wonderful recordings made by great engineers, with great transducers (tried MA recordings?) and most af all I try to listen to as much live music as possible!
Anyway that's enough off topic meandering ! you were quite right SJ.
First batch of Nichicon caps arrive tomorrow - time to start melting 🙂
That is completely understandable and I am right with you. The thing is, unless you replace parts with exactly the same as the originals you will risk the sound being slightly different. Not necessarily worse or better, but different. And it is just a risk.
Like C37 says, don't agonize over it. Try to relieve yourself of the burden of feeling like you have much control over the outcome!
Working out to good accuracy what change in psu capacitor spec/construction will result in what sonic difference and how much sonic difference is nigh impossible. It depends on many, many things about the rest of the circuit. Eg: Some circuits have higher power supply rejection ratio than others and it varies by frequency, some have specific impedance requirements, and so on; some circuits perform better if the two psu caps are closely matched in capacitance value. Low THD is usually desirable but it is often impossible to find published specs.
I'd be curious to see Kemet comparing one cap with split-foil and an otherwise identical one with normal foil, measuring the two and showing any differences. Then relate those differences, if any, to sonic quality in a particular amplifier circuit. I haven't seen this. Then you would have to decide somehow if any differences are significant for your own amplifier. 🙄
So you are left with doing your own listening experiment swapping different cap types in and out. Or you can hope that the reason Mission chose split-foil caps in the first place was because of some true sonic benefit that you can hear and not just for marketing. Or you have to find some plausible theory with some evidence that makes split-foil always give an audible improvement in any amp.
The debate has been had numerous times. Your point about listening to as much live music as possible is a good one as you learn what music should really sound like and this helps your brain interpret psychoacoustically the very compromised information it is being presented with in your room
Then there is the "buyers remorse" dilemma.
If faced with a choice of capacitors of uncertain benefit, if you choose the one with the most reassuring hyperbole then you may feel better in the end because you will assume the other choices that you rejected are worse (otherwise their hyperbole would have been better) and you made the right decision. If you don't you may feel like you missed out.
This can lead to a hyperbole arms race. 😀
If faced with a choice of capacitors of uncertain benefit, if you choose the one with the most reassuring hyperbole then you may feel better in the end because you will assume the other choices that you rejected are worse (otherwise their hyperbole would have been better) and you made the right decision. If you don't you may feel like you missed out.
This can lead to a hyperbole arms race. 😀
Under those circumstances, one could keep swapping them back and forth and enjoy the "different is better" illusion at minimum cost
😀 Yes. Maybe something like a valve amp but with the psu caps, rather than the valves, exposed and in sockets so you can plug them in and out.
Quick, patent it!
Correct. The current comes from the power station but your neighbours fridge is connected to the same wires as your amp. Any voltage spikes due to the fridge switching will be on the wires. And don't say that isn't
the case coz I have experienced it.
Anyway I'm not responding as it is hijacking the original topic.
ahhhhh the sweet balm of reassuring hyperbole ... (listening to Alice Coltrane at the moment)
Yes SJ, Really listening to live acoustic music, experiencing the reference, is the most important thing - 30 quid spent on that beats 30 on components any day.
Thanks for your input everyone - I have almost stopped researching - and agonising 🙂 - over split foil caps now. Just reading the specs of the last of the pesky little blue rolled up plastic KP1834 jobs.
Will post a pic of the replacements and completed refurb
Hopefully this thread will help others refurbish and recap their old cyrus 1 's
cheers to everyone for their input
No.
The current comes from the PSU capacitors and the decoupling capacitors.
The mains recharges those capacitors if and when they become depleted.
The recharging is usually over a duty cycle of around 10%. During the other ~90% the mains is effectively disconnected from the LV side by the rectifier.
Interference attenuation is a separate issue. We do not power our system using interference energy. We normally install devices to attenuate the interference, not turn it into useful power.
AT - Would you be kind enough to point me in a good direction to learn about decoupling ?
best laugh of the thread
Dear Board,
I have been offered two of these : TDK B41456B8688M 6300uF 63 V and spec says a ripple current rating of 17 amps.
Is there a reason for not using such things in my audio amp ?
cheers
I have been offered two of these : TDK B41456B8688M 6300uF 63 V and spec says a ripple current rating of 17 amps.
Is there a reason for not using such things in my audio amp ?
cheers
Those Epcos should be very good quality.
But they are expensive.
Will the screw fixing fit the board?
Epcos have a wide range of 35V and 50V capacitors that are much cheaper.
But they are expensive.
Will the screw fixing fit the board?
Epcos have a wide range of 35V and 50V capacitors that are much cheaper.
Hi Andrew, thanks for your reply, the ELNA's that are on there are solder tagged and the Nichicon KG I was going to order are not so I'll have to add some wire whatever. The epcos are from a friend so no worries on price 🙂 . I just noticed the huge difference in ripple current between the epcos and the Nichicon LKG1J682MESCBK (4.6amps versus 17 amps) and wondered what was going on?
The epcos are 36x56mm so will fit -and are not that much bigger physically than the Nichicons which are 35x50 . I thought their mut be a catch, and poss not suited to a hifi amp.. ? but if you say they are ok I will go ahead and fit em
They are better than OK.
But you might not hear, nor measure any differences.
My first non kit stereo amplifier used 12off 6800uF 63V from RS, with RS embossed labelling (don't know who manufactured them). They were the cheapest I could find at the time c1978 and I thought that was too dear. They still measure good.
But you might not hear, nor measure any differences.
My first non kit stereo amplifier used 12off 6800uF 63V from RS, with RS embossed labelling (don't know who manufactured them). They were the cheapest I could find at the time c1978 and I thought that was too dear. They still measure good.
More metal often leads to more ripple capacity.
For ClassAB you can virtually ignore this parameter.
It becomes more important when the continuous current draw from the PSU is high. The ripple voltage in the earliest smoothing capacitors can lead to overheating and/or shortened life. This usually only applies to ClassA, or very high bias ClassAB.
For ClassAB you can virtually ignore this parameter.
It becomes more important when the continuous current draw from the PSU is high. The ripple voltage in the earliest smoothing capacitors can lead to overheating and/or shortened life. This usually only applies to ClassA, or very high bias ClassAB.
The datasheet says the LKG are 30x50 so are the same width as the originals. If the TDKs will fit and they are not too old (within 10 years is ok, maybe longer) and you are getting them on the cheap then go for it.
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