Folks, please get real: When you know as much as I do about these sort of things, then you can tease me. 
Actually, this is my experience:
Levinson JC-2, Rotary Switches
JC-80, gold on silver hermetically sealed relays
Vendetta preamp, relays
Lineage preamp, Solid state fet switches
Parasound preamps, Toshiba solid state switches
Parasound PLD-2000, relays
CTC, silver on silver switches
Parasound JC-2, relays
I've tried them all, and I think that the scraping action of the silver on silver high tension switches are the best. Your results may vary.
It is amusing, because just 3 weeks ago, at CES, Dave Wilson was going on and on about a silver on silver rotary switch and how good it sounded. I wonder why?
Actually, this is my experience:
Levinson JC-2, Rotary Switches
JC-80, gold on silver hermetically sealed relays
Vendetta preamp, relays
Lineage preamp, Solid state fet switches
Parasound preamps, Toshiba solid state switches
Parasound PLD-2000, relays
CTC, silver on silver switches
Parasound JC-2, relays
I've tried them all, and I think that the scraping action of the silver on silver high tension switches are the best. Your results may vary.
It is amusing, because just 3 weeks ago, at CES, Dave Wilson was going on and on about a silver on silver rotary switch and how good it sounded. I wonder why?
Gold contacts (switched at near zero current/voltage) and mercury-wetted remain the choice for switching "dry" circuits.
I don't care to address the "sound" of contacts/relays... ridiculum ad infinitum. Silver is popular among relays for higher currents because the arc bi-products are conductive and the contacts are considered "self-renewing".
Silver contacts would never be recommended for a "dry" circuit.
I don't care to address the "sound" of contacts/relays... ridiculum ad infinitum. Silver is popular among relays for higher currents because the arc bi-products are conductive and the contacts are considered "self-renewing".
Silver contacts would never be recommended for a "dry" circuit.
poobah said:
Hi Poobah, excuse my limited knowledge here but what is a 'dry' circuit?
Edit: sorry about that I should have done a google before posting:
Dry Circuit Switching - Switching below specified levels of voltage and current to minimize any physical and electrical changes in the contact junction.
Got it.
Stan
pinkmouse said:
http://www.fujitsu.com/us/services/edevices/components/relays/signal/tmpl_series_ftr-b3.html
from my experince,something like this is pretty useful - if you want relays
Hi Stan,
The standard definition for a "dry circuit" is one with less than 50 uA on contact closure. Most relay contacts (not gold or mercury-wetted) expect a certain amount of current flow/arcing to ensure a good connection. This is because the arc establishes new contact "points".
Remember, ALL coffee grows in the mountains.
The standard definition for a "dry circuit" is one with less than 50 uA on contact closure. Most relay contacts (not gold or mercury-wetted) expect a certain amount of current flow/arcing to ensure a good connection. This is because the arc establishes new contact "points".
Remember, ALL coffee grows in the mountains.
Switches- the details count
Lucked into some nice 50 year old Centralab PS-105and PS-110 rotaries recently. These are 1/8" shaft mini style and use steatite wafers. Cannot tell if silver plated or real silver contacts.
After cleaning, these are so nice looking it hurts. They make the Elma look like the stuff at Radio Shack. Audio jewelery if there ever was any.
I have to agree about the importance of the switches. They were a major improvement over my previous English plastic bodied type. Wire them up like Croft where every other position grounds the input. Reduces crosstalk and makes mono volume controls a little easier to deal with.
BTW, great job with these Blowtorch! I am sure they are worth every penny. And thank you for sharing info on the design decisions.
George
Lucked into some nice 50 year old Centralab PS-105and PS-110 rotaries recently. These are 1/8" shaft mini style and use steatite wafers. Cannot tell if silver plated or real silver contacts.
After cleaning, these are so nice looking it hurts. They make the Elma look like the stuff at Radio Shack. Audio jewelery if there ever was any.
I have to agree about the importance of the switches. They were a major improvement over my previous English plastic bodied type. Wire them up like Croft where every other position grounds the input. Reduces crosstalk and makes mono volume controls a little easier to deal with.
BTW, great job with these Blowtorch! I am sure they are worth every penny. And thank you for sharing info on the design decisions.
George
silver contact switches
Hi Jacco, the solid silver contact switch like the Shallco is self cleaning. Try that with an Elma or clones. The Electroswitches I am using are closed.
jacco vermeulen said:
Thats why they are called professional !
The intrigueing thing of audio is that so often there is a reason for going back to basic. (though i wonder how well silver switches work in smog environments)
The CES is the place to be to snitch stuff from fellow collegues ?
Hi Jacco, the solid silver contact switch like the Shallco is self cleaning. Try that with an Elma or clones. The Electroswitches I am using are closed.
The Shallco switches are self cleaning. That is the point of it all. Relays don't self clean, so you have to use more passive materials, such as gold, directly for the dry contacts. However, the scraping action of the Shallco switches literally creates a fresh surface each time they are switched. Perhaps, once in a while, one should 'exercise' the switches to remove any sulfides that might be taken out of the outside air. Now, our virtually sealed interior in our preamp makes more sense, doesn't it?
Wipers
Well said, John, there is a world of difference in operation and long-term reliability between 'wiping' contacts (like Shallcos & the very similar UK made Bloore Edwards switches) and those which 'mate' by merely coming together 'in line', or in the same plane, like most relays.
There is no need to worry if one is switching milli-volts/milli-amps, or even hundreds of volts at several amps with these.
Unfortunately, there is a world of difference in the cost of these truly excellent-sounding solid silver contact switches, and *any* relay I have ever encountered, too!
Perhaps, the continual doubters will eventually begin to appreciate just why you make some of the design/component decisions which you do, which unfortunately and inevitably add huge sums to the final costs of excellent-sounding equipment.
Well said, John, there is a world of difference in operation and long-term reliability between 'wiping' contacts (like Shallcos & the very similar UK made Bloore Edwards switches) and those which 'mate' by merely coming together 'in line', or in the same plane, like most relays.
There is no need to worry if one is switching milli-volts/milli-amps, or even hundreds of volts at several amps with these.
Unfortunately, there is a world of difference in the cost of these truly excellent-sounding solid silver contact switches, and *any* relay I have ever encountered, too!
Perhaps, the continual doubters will eventually begin to appreciate just why you make some of the design/component decisions which you do, which unfortunately and inevitably add huge sums to the final costs of excellent-sounding equipment.
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