I have just built my first stereo preamp and need to install an input selector switch. It seems there are two basic choices:
1: A simple rotary 2 pole switch such as by Grayhill.
2: A powered board containing relays such as by Twisted Pear Audio.
I have never installed either before and wondered which is better.
Which of these is better, sonically?
Advice appreciated.
1: A simple rotary 2 pole switch such as by Grayhill.
2: A powered board containing relays such as by Twisted Pear Audio.
I have never installed either before and wondered which is better.
Which of these is better, sonically?
Advice appreciated.
If the contacts are made of the same material, it wouldn't matter which. A relay is nothing more than a switch that is actuated by a coil.
Sealed telecoms relays with silver contacts are best - they won't get noisy as they are sealed. Switches get noisy over time. Agree on shorter signal path if you mount the switch on the front panel. Relays can be mounted at input sockets. I have been using relays in the same preamp for >10 years with flawless service - previously used switches and these became noisy after 5-6 years
Just my 20 cents worth
Just my 20 cents worth
I stand with relays.
I know one switch is the price of a reasonable relay, but if the budget is short, use a 2x6 Switch.
In this case, use a L shape aluminium piece and put the switch as near as possible of inputs and use an extender shaft to connect the switch with front panel knob.
I have been using these selays for long time.
I gave up of rotary switches because they always fail (mechanicaly and electronicaly).
I know one switch is the price of a reasonable relay, but if the budget is short, use a 2x6 Switch.
In this case, use a L shape aluminium piece and put the switch as near as possible of inputs and use an extender shaft to connect the switch with front panel knob.
I have been using these selays for long time.
I gave up of rotary switches because they always fail (mechanicaly and electronicaly).
smithy666 said:
relays are indeed more reliable..
switches get wore off easily than relays.
i also use relays as a load impedance selector on my amps.
I'm eyeing some 5 x 10mm telcoms relays for use to switch a cap into and out of the feedback path... a low budget tone control of sorts... a switch on leads would be a horrendous choise for this function, I would wager.
chalkandtalk said:
Meaningless question without getting into specific parts. IME comparing cheap relays (Nais) to expensive switches (Seiden, Elma, Daven) the switches win hands down. Which is rather sad as the relays look so cute and make wiring so much easier.
Never tried latching relays though.
Thanks for your advice guys. You have made me realise that relays can be very good.
I was keen to use relays for more in/out options, but was uncertain whether I would degrade sound quality. I have never used them before.
I have decided upon one of these:
http://www.twistedpearaudio.com/darwin/darwin.aspx
I's now on order. 😀
thanks again
Aidan
I was keen to use relays for more in/out options, but was uncertain whether I would degrade sound quality. I have never used them before.
I have decided upon one of these:
http://www.twistedpearaudio.com/darwin/darwin.aspx
I's now on order. 😀
thanks again
Aidan
Relays vs. Switches
The signals that are switched in a preamp are what are called "dry switched", meaning that there is essentially zero current. This is an important factor in selecting relays or switches, since some contact material will build up an oxide layer that only gets broken through when sufficient current is switched. This is one reason that high current relays are not recommended for very low signal applications. High and low current relays/switches also utilize different contact materials. If you have ever referred to switch or relay contact materials you will have noticed that high current contacts are typically made of silver or silver oxide, while dry switched contacts use gold or ruthenium. Silver is resistant to arc damage, while gold is resistant to oxide buildup.
Some relays have another advantage over switches, in that the contacts can be hermetically sealed, such as in the case of reed relays. Sealing allows contact operation is a non-corroding atmosphere and gives the relay an extraordinarily long contact life (hundreds of millions or operations is typical). I am in the process of designing a preamp, and I intend to use sealed reed relays for all switching operations.
The signals that are switched in a preamp are what are called "dry switched", meaning that there is essentially zero current. This is an important factor in selecting relays or switches, since some contact material will build up an oxide layer that only gets broken through when sufficient current is switched. This is one reason that high current relays are not recommended for very low signal applications. High and low current relays/switches also utilize different contact materials. If you have ever referred to switch or relay contact materials you will have noticed that high current contacts are typically made of silver or silver oxide, while dry switched contacts use gold or ruthenium. Silver is resistant to arc damage, while gold is resistant to oxide buildup.
Some relays have another advantage over switches, in that the contacts can be hermetically sealed, such as in the case of reed relays. Sealing allows contact operation is a non-corroding atmosphere and gives the relay an extraordinarily long contact life (hundreds of millions or operations is typical). I am in the process of designing a preamp, and I intend to use sealed reed relays for all switching operations.
Re: Relays vs. Switches
That's hwy I use Fujitsu relays I've mentioned before. They have Gold-overlay silver-palladium contacts.
Also, they are sealed. All oxigen is 'burned' very fast... a couple of a few mA switching. Just turning on and of a LED. I do this in every sealed relay.
I don't know if this really works 100%, but for what I have studied at school...
analog_guy said:
That's hwy I use Fujitsu relays I've mentioned before. They have Gold-overlay silver-palladium contacts.
Also, they are sealed. All oxigen is 'burned' very fast... a couple of a few mA switching. Just turning on and of a LED. I do this in every sealed relay.
I don't know if this really works 100%, but for what I have studied at school...
The twisted Pear Audio kit comes with Omron G6K (not sure which version) relays. I believe these have silver contacts with gold overlay, so they should be perfect for the job - great value for $56.
I would agree. Good sealed relays are better than cheap switches, but slightly worse than silver on silver mil grade Shallco switches that cost a fortune, and are hard to turn.
audioDIYer said:
Some would choose a sealed and gasfilled relay, such as an SDS-NAIS or the Omron G6K.
Hi,
I'm in late, but gas filled (nitrogen) relays are my vote. They can fail, but are easily replaced. Try that with one bad contact on a switch.
On the other side of the coin, I have some HP equipment where the rotary switches require the very odd cleaning. Also not too bad. Rotary switches also retain their last position during a power fail.
-Chris
I'm in late, but gas filled (nitrogen) relays are my vote. They can fail, but are easily replaced. Try that with one bad contact on a switch.
On the other side of the coin, I have some HP equipment where the rotary switches require the very odd cleaning. Also not too bad. Rotary switches also retain their last position during a power fail.
-Chris
If you're worried about the relay failing, then just parallel two - the chances of both failing in your lifetime would be very very small. Problem solved.
I’m reopening this old thread because it is most related to my question.
I have a Transformer for voltage control with 24 outputs.
Currently they are connected to a blore Edwards PZ switch but I’m thinking of using relays for switching.
The thing is; I’d have to use 10 relays (Panasonic txs with contact material for low voltage) and the signal would go through 4 relays (each having 100mOhm resistance).
I already designed a pcb and wrote down a code for Arduino to control them, which gives me the opportunity to remote control.
The is a company that sells a stepper motor for their 24 pole switch but even more expensive than relays. I looked up some steppers but I’m not sure if they would step the 15 degree accurately.
Can anyone tell if going through 4 relays is worse than one switch? Or any other solutions !
I have a Transformer for voltage control with 24 outputs.
Currently they are connected to a blore Edwards PZ switch but I’m thinking of using relays for switching.
The thing is; I’d have to use 10 relays (Panasonic txs with contact material for low voltage) and the signal would go through 4 relays (each having 100mOhm resistance).
I already designed a pcb and wrote down a code for Arduino to control them, which gives me the opportunity to remote control.
The is a company that sells a stepper motor for their 24 pole switch but even more expensive than relays. I looked up some steppers but I’m not sure if they would step the 15 degree accurately.
Can anyone tell if going through 4 relays is worse than one switch? Or any other solutions !
And one more thing.
Panasonic has special contact material for low level switching of their tx relays. But they claim a maximum load of 10vDC / 10mA. Is the 10mA also for an AC load or even less?
Panasonic has special contact material for low level switching of their tx relays. But they claim a maximum load of 10vDC / 10mA. Is the 10mA also for an AC load or even less?
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