What?
You are kidding me!
Relays are the least invasive way to disconnect a speaker. Good relays in good condition do not affect sound quality as I have measured this (and listened to satisfy one hard to convince person). I replace relays all the time, problem solved.
Silicon is highly non-linear! It is called a ... what? Semiconductor! It is inherently high resistance. Output impedance depends on feedback and output configuration. Multiple output devices can lower impedance a little but is more useful in safely handling huge amounts of current (which you don't need by the way).
Stoic manufacturers? How about competent manufacturers using good designs? Cost and a good story seldom equals a good amplifier. I've worked on just about everything including stuff you can't carry. Amps that use two AC circuits to run. One thing is true, above about 250 to 300 watts, circuit requirements work against low distortion. Never mind the fact you don't need that much power. If you do, there is something very wrong with your speakers! Coil temperatures will be high, throwing out box tuning. Also killing efficiency by at least 2 dB (I measured some).
Sound reproduction is a science where trained engineers do a better job and always have. Engineering teams make the best products, and always have. There was a period where solid state was new for high end design. They had to figure out what worked. In the process, it was discovered some components were more linear than others. By the way, it was the test and measurement engineers that discovered that. It took audio guys a couple decades to catch on and some still haven't.
We use the best solution to a problem, pure and simple. I'm sorry that doesn't agree with your ideas. We test empirically by measuring plus listening. We make our livings doing this, so we are fully involved. Always looking for a better solution also. The only problem with relays are that they get damaged or wear out. Beyond that they seem to be the perfect solution, and they are replaceable (by design). Anyway, you seem to think we do not think or listen. Not true at all. It's easy for a few individuals to make a name for themselves or try to increase market share by going against normal good practices, and they make up stories that maybe could be true under specific circumstances that differ from normal circumstances. ever notice the same thing in alternative health, politics and anything else open to unsubstantiated opinion?
You are kidding me!
Relays are the least invasive way to disconnect a speaker. Good relays in good condition do not affect sound quality as I have measured this (and listened to satisfy one hard to convince person). I replace relays all the time, problem solved.
Silicon is highly non-linear! It is called a ... what? Semiconductor! It is inherently high resistance. Output impedance depends on feedback and output configuration. Multiple output devices can lower impedance a little but is more useful in safely handling huge amounts of current (which you don't need by the way).
Stoic manufacturers? How about competent manufacturers using good designs? Cost and a good story seldom equals a good amplifier. I've worked on just about everything including stuff you can't carry. Amps that use two AC circuits to run. One thing is true, above about 250 to 300 watts, circuit requirements work against low distortion. Never mind the fact you don't need that much power. If you do, there is something very wrong with your speakers! Coil temperatures will be high, throwing out box tuning. Also killing efficiency by at least 2 dB (I measured some).
Sound reproduction is a science where trained engineers do a better job and always have. Engineering teams make the best products, and always have. There was a period where solid state was new for high end design. They had to figure out what worked. In the process, it was discovered some components were more linear than others. By the way, it was the test and measurement engineers that discovered that. It took audio guys a couple decades to catch on and some still haven't.
We use the best solution to a problem, pure and simple. I'm sorry that doesn't agree with your ideas. We test empirically by measuring plus listening. We make our livings doing this, so we are fully involved. Always looking for a better solution also. The only problem with relays are that they get damaged or wear out. Beyond that they seem to be the perfect solution, and they are replaceable (by design). Anyway, you seem to think we do not think or listen. Not true at all. It's easy for a few individuals to make a name for themselves or try to increase market share by going against normal good practices, and they make up stories that maybe could be true under specific circumstances that differ from normal circumstances. ever notice the same thing in alternative health, politics and anything else open to unsubstantiated opinion?
Spade connector resistance in fact improves, the older they get. This was a very surprising result in a scientific test of different connector types. The extremely high surface pressure from the contact edge leads to a kind of cold welding.
They are considered cheap, because they were used in cars. They are the next best thing to soldering wires. Of course, the connection to the wire has to be perfect too.
They are considered cheap, because they were used in cars. They are the next best thing to soldering wires. Of course, the connection to the wire has to be perfect too.
If you guys ever really repaired equipment before, spade connections are always the culprit, and they only loosen and work harden and shrink because of oxidation, over time.
Soldering is best, Gold plated contacts next, but with relays, they cant do that because of sticking, so they use something less conductive and more oxidation prone.
If it were one serious relay, like a mechanical knife switch where spring pressure is applied in a more robust manner, then we would be talking.
But I opened up one of those small realys, its like a whif of a metal hair pressing 2 dots of silver to a piece of copper. It is not enough to get the job done properly.
Not great for signal integrity.
If it were an oversized cachunk 50a relay, it would sound better, and I would then be more open to the idea of having one in circuit, if it must be in there for another layer of safety.
Soldering is best, Gold plated contacts next, but with relays, they cant do that because of sticking, so they use something less conductive and more oxidation prone.
If it were one serious relay, like a mechanical knife switch where spring pressure is applied in a more robust manner, then we would be talking.
But I opened up one of those small realys, its like a whif of a metal hair pressing 2 dots of silver to a piece of copper. It is not enough to get the job done properly.
Not great for signal integrity.
If it were an oversized cachunk 50a relay, it would sound better, and I would then be more open to the idea of having one in circuit, if it must be in there for another layer of safety.
Well rschmitt100,
My connections are made with ring terminals, copper under 30 A brass 5-way binding posts. I did test copper (from lab voltmeters, a dead 3456A) and there was zero difference. The connection resistance is the lowest you can obtain, lower than solder. As Turbowatch2 pointed out, contact resistance decreases with time, however not enough to change anything.
Knife switches have poor contact. You should look at the switches used in RTD boxes made by Genrad or others. You really do not have any clue as to what you are talking about man! lol!
The contacts in relays are normally crimped connections. Those are gas tight. Do you know what that means? It is very difficult to get a better connection, and the material used for the contact base is not suitable for the actual electrical mating surface. Relays have been carefully engineered and evolved over a century. Do you really think you know better?
Now, a 50 A relay contact has poor contact pressure per unit area compared to a signal relay. Same for some connectors. Remember, each relay type has evolved over a century to deliver the best performance and longevity. Relay contacts also incorporate a wiping action (most anyway). The 50 A contact also is designed to withstand arcing, which smaller relays aren't so much, and signal relays not at all or minimal. You would be very unhappy with the performance of a 50 A relay used for signal purposes. I guess by "it would sound better" means you like your preamp switching to sound like car doors closing! lol!
Lab connections are made using Tellurium copper binding posts, and some form of spade or ring terminal of the same material. Sometimes we use banana jacks. The mating surfaces are cleaned with IPA before every use. Audiophiles would like them because they cost more, oblivious as to how to use them. The important point here is that calibration labs absolutely must have the most accurate and repeatable connections and measurements possible. The equipment used is directly tracible to national standards labs using artifacts or the actual physical standard. Thank goodness they stopped using Weston cells ages ago! If you had any understanding of the precision required, the repeatability and predictably we wouldn't be having this conversation. Lab work is all about connections and stable ambient temperatures. That and controlled humidity within a reasonable range. This is all recorded and equipment drift (the error budget) is calculated if factors vary from the initial calibration temperature by very much. That can cause a recall as well as an internal review. And you think you can hear better than the tolerances we're talking about here? Ahh, nope.
-Chris
My connections are made with ring terminals, copper under 30 A brass 5-way binding posts. I did test copper (from lab voltmeters, a dead 3456A) and there was zero difference. The connection resistance is the lowest you can obtain, lower than solder. As Turbowatch2 pointed out, contact resistance decreases with time, however not enough to change anything.
Knife switches have poor contact. You should look at the switches used in RTD boxes made by Genrad or others. You really do not have any clue as to what you are talking about man! lol!
The contacts in relays are normally crimped connections. Those are gas tight. Do you know what that means? It is very difficult to get a better connection, and the material used for the contact base is not suitable for the actual electrical mating surface. Relays have been carefully engineered and evolved over a century. Do you really think you know better?
Now, a 50 A relay contact has poor contact pressure per unit area compared to a signal relay. Same for some connectors. Remember, each relay type has evolved over a century to deliver the best performance and longevity. Relay contacts also incorporate a wiping action (most anyway). The 50 A contact also is designed to withstand arcing, which smaller relays aren't so much, and signal relays not at all or minimal. You would be very unhappy with the performance of a 50 A relay used for signal purposes. I guess by "it would sound better" means you like your preamp switching to sound like car doors closing! lol!
Lab connections are made using Tellurium copper binding posts, and some form of spade or ring terminal of the same material. Sometimes we use banana jacks. The mating surfaces are cleaned with IPA before every use. Audiophiles would like them because they cost more, oblivious as to how to use them. The important point here is that calibration labs absolutely must have the most accurate and repeatable connections and measurements possible. The equipment used is directly tracible to national standards labs using artifacts or the actual physical standard. Thank goodness they stopped using Weston cells ages ago! If you had any understanding of the precision required, the repeatability and predictably we wouldn't be having this conversation. Lab work is all about connections and stable ambient temperatures. That and controlled humidity within a reasonable range. This is all recorded and equipment drift (the error budget) is calculated if factors vary from the initial calibration temperature by very much. That can cause a recall as well as an internal review. And you think you can hear better than the tolerances we're talking about here? Ahh, nope.
-Chris
OMG!
WD-40 isn't really a contact cleaner, and it affects some materials badly over time. Rubber especially.
For switch and relay contacts, you should use a zero-residue cleaner. Any film left will oxidize over time, and attract all manner of deposits. I get mine from industrial aerospace suppliers. You know, when contact performance is critical?
Enjoy your spear. Personally I think your best weapon would be some good books (many, not one) and application notes (not white papers!!!). You really do need to learn this stuff from reliable sources.
WD-40 isn't really a contact cleaner, and it affects some materials badly over time. Rubber especially.
For switch and relay contacts, you should use a zero-residue cleaner. Any film left will oxidize over time, and attract all manner of deposits. I get mine from industrial aerospace suppliers. You know, when contact performance is critical?
Enjoy your spear. Personally I think your best weapon would be some good books (many, not one) and application notes (not white papers!!!). You really do need to learn this stuff from reliable sources.
You cannot make people hear stuff they don't want to hear. No matter how audible it is. Waste of time and effort.
What kinds of relays are you using that you can access the contacts in such a manner?
If they were actually being cold-welded, would they not then have some sort of mechanical bond even after loosening the screw/nut? I have only ever heard that the compressive forces allowing a gas-tight connection, but not that the metals are actually being cold-welded together.
Actually, a MOSFET transmission gate is better. Relays have a nasty way of arcing over when they have to break high currents, in particular on inductive loads, so they may not protect the speaker in case of amplifier failure. You can see some pretty spectacular examples here: https://www.halfgaar.net/dc-protection-with-relays
Exactly. WD = Water Displacement. I'm sure it can loosen up some gunk, but I'd be concerned about residues and - as you point out - its effects on parts you care about. Deoxit Gold is much better for cleaning contacts. Ya know... An actual contact cleaner.
Tom
For sealed relays and hard to get at ones too. All of the cases seem to be made of a nylon/fiberglass blend. But a sharp needle does still easily pierce it and usually the middle side is best, but make sure with your relays because you dont want to hit the coil.
I would use deoxit but I'm out.
Both Tom lol.
I would use deoxit but I'm out.
Both Tom lol.
Hi 454,
Yes, I missed the cold weld part. I have had metal cold weld but not in connections like this.
Hi Tom,
That is highly debatable (Mosfets). My tests disagree, but a mosfet doesn't degrade much so over an old relay they are better. I have seen relay contacts arc and melt together, however the relay was too light in those instances. It comes back to proper application. I have also seen high distortion with Mosfet relay replacements. Keeping it real and balanced.
If you use any cleaner that leaves any deposits of any kind, you must then wash the contacts clean with a zero residue cleaner. Deposits will burn if the contacts arc, that is a fact of life. Once that happens you have much greater problems. For switches and contacts, you are best off with a zero residue cleaner. there are very good reasons they use this in aerospace and military applications. You simply cannot afford premature failures for any reason.
Yes, I missed the cold weld part. I have had metal cold weld but not in connections like this.
Hi Tom,
That is highly debatable (Mosfets). My tests disagree, but a mosfet doesn't degrade much so over an old relay they are better. I have seen relay contacts arc and melt together, however the relay was too light in those instances. It comes back to proper application. I have also seen high distortion with Mosfet relay replacements. Keeping it real and balanced.
If you use any cleaner that leaves any deposits of any kind, you must then wash the contacts clean with a zero residue cleaner. Deposits will burn if the contacts arc, that is a fact of life. Once that happens you have much greater problems. For switches and contacts, you are best off with a zero residue cleaner. there are very good reasons they use this in aerospace and military applications. You simply cannot afford premature failures for any reason.
