chipco3434 said:
This is the Grayhill switch that caught my attention in DK catalog. Part# GH7104.
It offers 2 decks (2 poles per deck) and choice of 1-6 adjustable positions. So this one will allow switching both signal and ground for each channel. Similar, Grayhill switch (but PCB mounted) was used in an older ML preamp.
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Peter
Well, as someone who almost gave himself a heart attack the other day after I absent-mindedly soldered the output cap of a 5V reg in back to front, then powered up to a pretty bloody huge bang after only a few seconds, it wouldn’t be my preferred way of testing caps.
I’ve still not found the can of the ‘lytic, which is at least better than finding it in my eye!
Your advice is frankly dangerous, irresepective of your own experience.
Andy.
Well, as someone who almost gave himself a heart attack the other day after I absent-mindedly soldered the output cap of a 5V reg in back to front, then powered up to a pretty bloody huge bang after only a few seconds, it wouldn’t be my preferred way of testing caps.
I’ve still not found the can of the ‘lytic, which is at least better than finding it in my eye!
Your advice is frankly dangerous, irresepective of your own experience.
Andy.
I have my GC 5 weeks in use now. The sound is very clear and natural. I have used best parts and the BG NX and BG FK has become better the more hours I listened.
The amp is really very special. For this amount of money there is nothing equal.
When I listen to my JLH, the JLH is more open, the soundstage is wider and deeper, the dynamic is better and the heatsinks are much bigger.
Peter: Have you builded a JLH? I hope you find the time to compare these amps.
regards
Günter
The amp is really very special. For this amount of money there is nothing equal.
When I listen to my JLH, the JLH is more open, the soundstage is wider and deeper, the dynamic is better and the heatsinks are much bigger.
Peter: Have you builded a JLH? I hope you find the time to compare these amps.
regards
Günter
Reverse Biased Cap
Peter,
One of the favorite tricks of my collegues to impress newly acquired personel was to mount a reverse biased electrolytic cap in the amplifier under repair.
The loud bang scared the hell out of him. Of course this is extremely dangerous as parts and electrolyte can get into your eyes and damage you vision for ever. Also the panic reaction can have a dangerous effect.
Why have the caps to be nude? Is this some kind of obsession with nudity? Well then go to the naturist beach! I can hardly believe the sound is better.
Peter,
One of the favorite tricks of my collegues to impress newly acquired personel was to mount a reverse biased electrolytic cap in the amplifier under repair.
The loud bang scared the hell out of him. Of course this is extremely dangerous as parts and electrolyte can get into your eyes and damage you vision for ever. Also the panic reaction can have a dangerous effect.
Why have the caps to be nude? Is this some kind of obsession with nudity? Well then go to the naturist beach! I can hardly believe the sound is better.
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Not often, but here I strongly agree with Fred that Peter Daniel's advice is not the first I would recommend, to apply reverse polarity.S.C said:
This is not safe practice especially for novices I would suggest to Ohm-measure between can and the pins. Negative pole is always(?) more or less in contact with the can, totally safe and easy.
peranders said:
I take this as an even stronger warning to Peter
Personally I would never do this exercise.
Well, I got my warning already in first hand experience.
Back in 1982 a friend of mine brought a receiver for repair. At that time I didn't have much clue about troubleshooting (not to say that I have now), but I opened the unit, pluged it in and poked inside. I was checking the inside for few minutes, when suddenly a strange sound started to be perceived. Next thing I felt was a sudden impact into my left eye. I lost the vision right away and in pain was sent to hospital. I spent there almost two weeks, and eventually I got my vision back, but permanent damage was made. The muscles in the iris were dammaged, so at bright light my left pupil didn't get smaller, I was getting glare from street lights at night and what was worst, a cataract was formed on the lense (that is a small residue that is in direct field of vision).
I left it like that for many years and eventually decided for an implant. Although I was assured that it will be perfect exchange it didn't came out exactly like that and I had to wear correction glasses if I wanted to stay in focus (with that eye). Later I even took a laser surgery, but it still didn't fix the vision completely. It's more or less OK for far sight, but totally useless when working near field. I still don't need any glasses, but when working on circuits these days I'm only using one eye.
So be careful, boys snd girls, with warming up electrolytics
The suggestion of measuring resistance between case and pins is totaly useless with modern day electrolytics and what John suggest is probably much better approach, that is, if you really HAVE to know
ALW said:
Andy,
Of course there are caps and caps. I expressed my experience of the caps I've handled, and the supplies incorporated. I've also come across caps that have been in service for many years (at much less than their rated voltage) reverse connected, that gave "good service". Probably 5v is on the limit for getting away with it.
The fact that you were unlucky with your cap should indeed be a warning to us all.
I certainly shan't be using any "nude" caps
Hi,
As if nude caps are the problem?
If you don't know what you're doing find yourself a different hobby.
Anyone advising/suggesting potentially dangerous methods for testing components on a forum should have his/her head examined.
And some of you are even raising kids? Moderators and ex-moderators?
Shame on you all.
I'll leave you all to your kindergarten for that's what's this forum has become lately.
Cheers and good riddens,
As if nude caps are the problem?
If you don't know what you're doing find yourself a different hobby.
Anyone advising/suggesting potentially dangerous methods for testing components on a forum should have his/her head examined.
And some of you are even raising kids? Moderators and ex-moderators?
Shame on you all.
I'll leave you all to your kindergarten for that's what's this forum has become lately.
Cheers and good riddens,
Electrolytics do sound better without their sleeve and I did not believe that either when someone pointed it out to me. I even know guys that take off the alu case and make a wooden one (!) instead filled with bees wax 
This is really one of the weirdest and potentially dangerous practices I've seen since I am doing this audio-hobby.
Because of safety I don't do it though. Short circuits, possible reversing polarity are some of them.
This is really one of the weirdest and potentially dangerous practices I've seen since I am doing this audio-hobby.Because of safety I don't do it though. Short circuits, possible reversing polarity are some of them.
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