What are the reasons for ...
- andrew Ivimey
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#1 What are the reasons for ...
a click/surge/nasty spike in the loudspeakers when I switch off the amplifier
and what are the cures, please?
and what are the cures, please?
Philosophers have only interpreted the world - the point, however, is to change it. No it isn't ... maybe we should leave it alone for a while.
- pre65
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#2
What amp ?
Have you tried switching the preamp off first ?
Have you tried switching the preamp off first ?
The only thing necessary for the triumph of evil is for good men to do nothing.
Edmund Burke
G-Popz THE easy listening connoisseur. (Philip)
Edmund Burke
G-Popz THE easy listening connoisseur. (Philip)
- andrew Ivimey
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#3
amps not amp ... (earthing issues?)
Yes, that can give an amplified spike through the amplifier so can be even worse.
Yes, that can give an amplified spike through the amplifier so can be even worse.
Philosophers have only interpreted the world - the point, however, is to change it. No it isn't ... maybe we should leave it alone for a while.
#5
may or may not be relevent.....
I had a kt88 pp amp which was triode/ul switchable. When the amp was switched off there was always an audible click. I investigated and found that the UL/triode switch was on a solenoid so it was switching modes whenever it was turned off.......Among other things I removed this and hard wired it in triode mode, and all was well.....
I was almost certain it was the reason for frying one of my electrostatic transformers.....trixy little chaps these clicks and pops....
I had a kt88 pp amp which was triode/ul switchable. When the amp was switched off there was always an audible click. I investigated and found that the UL/triode switch was on a solenoid so it was switching modes whenever it was turned off.......Among other things I removed this and hard wired it in triode mode, and all was well.....
I was almost certain it was the reason for frying one of my electrostatic transformers.....trixy little chaps these clicks and pops....
There's nowhere you can be that isn't where you're meant to be
- andrew Ivimey
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#6
It's a good example of this Ed, thanks. My vague understanding is that some sort of DC 'spike' is getting through to the secondary windings of the output transformer, but how!? Clever stuff this electricity.
With a solid state amp a DC 'spike' is getting through the circuitry also able to present itself at the speaker connection in a very unsatisfactory and very damaging manner; its the tweeters that take the brunt of this.
But why oh why oh why etc etc.
With a solid state amp a DC 'spike' is getting through the circuitry also able to present itself at the speaker connection in a very unsatisfactory and very damaging manner; its the tweeters that take the brunt of this.
But why oh why oh why etc etc.
Philosophers have only interpreted the world - the point, however, is to change it. No it isn't ... maybe we should leave it alone for a while.
- Mike H
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#7
Ed's is a very special case example, sounds like; I'd go with Neal, switching off makes an arc across the switch contacts which is then amplified by the amplifier. The amplifier is not going into any special 'mode', it is just amplifying the electro-magnetically induced pulse while it's still got some juice left.
My germanioum amp did this mucho huge-io, cure was an 220nF X2 cap effectively across the mains transformer primary (2 pole mains switch). In parallel with a mains transient suppressor (VDR). The big pulse spike is generated by the transformer primary when the current is cut, i.e. by back EMF. It's very basic stuff. Kill the spike, no more switch-off pops.
HTH
My germanioum amp did this mucho huge-io, cure was an 220nF X2 cap effectively across the mains transformer primary (2 pole mains switch). In parallel with a mains transient suppressor (VDR). The big pulse spike is generated by the transformer primary when the current is cut, i.e. by back EMF. It's very basic stuff. Kill the spike, no more switch-off pops.
HTH
"No matter how fast light travels it finds that the darkness has always got there first, and is waiting for it."
- andrew Ivimey
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#8
aha! I hadn't seen Neal's comment - that makes sense and Mike, your addition is the icing on the cake, surely. I have seen this sort of setup. I need X2 caps and suppressors, bring them on!
Maplin's ???
Because it isn't just one amp that does this and it isn't just one valve amp.
Could it have something to do with the crap mains supply (I think) I have?
Maplin's ???
Because it isn't just one amp that does this and it isn't just one valve amp.
Could it have something to do with the crap mains supply (I think) I have?
Philosophers have only interpreted the world - the point, however, is to change it. No it isn't ... maybe we should leave it alone for a while.
- pre65
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#9
Perhaps you use the same "crap" mains switch on each amp ?
I use a Lorlin rotary type 4A DPST switch on all my amps and don't suffer the problems you describe.
Second line from bottom on this HFC link.
http://www.hificollective.co.uk/compone ... eters.html
I use a Lorlin rotary type 4A DPST switch on all my amps and don't suffer the problems you describe.
Second line from bottom on this HFC link.
http://www.hificollective.co.uk/compone ... eters.html
The only thing necessary for the triumph of evil is for good men to do nothing.
Edmund Burke
G-Popz THE easy listening connoisseur. (Philip)
Edmund Burke
G-Popz THE easy listening connoisseur. (Philip)
- andrew Ivimey
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#11
Been there, done it Ali, it changed the sound of the system but I don't think for the better. It wasn't my usual slapdash style either. It was a very interesting experiment and it may be a way of getting a purer mains supply.
I am thoughtful about this.
I am thoughtful about this.
Philosophers have only interpreted the world - the point, however, is to change it. No it isn't ... maybe we should leave it alone for a while.
#12
Yep, I recall Noel Keywood writing an article on this very subject several years ago and after trying it, he also concluded he didn't enjoy the sound compared with standard supply.andrew Ivimey wrote:Been there, done it Ali, it changed the sound of the system but I don't think for the better. It wasn't my usual slapdash style either. It was a very interesting experiment and it may be a way of getting a purer mains supply.
#13
Well, for the transformer, given that the voltage out is proportional to the rate of change of the voltage in, if the switch (as most do) just stops the voltage dead, then you would expect near infinite voltage out. Thats why you need the caps across the switch.
Whenever an honest man discovers that he's mistaken, he will either cease to be mistaken or he will cease to be honest.
#14
Interesting Mr I, I've found it well worthwhile. Be good to try it on different gear at Owston.andrew Ivimey wrote:Been there, done it Ali, it changed the sound of the system but I don't think for the better. It wasn't my usual slapdash style either. It was a very interesting experiment and it may be a way of getting a purer mains supply.
I am thoughtful about this.
- andrew Ivimey
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#15
indeed it would!
Philosophers have only interpreted the world - the point, however, is to change it. No it isn't ... maybe we should leave it alone for a while.