Are Hamsters considered tasty?? Seriously though...how does it all work out...I mean if I wanted to change a source I would have to switch 2 switches right?? Maybe we could come up with something better and only flip one swicth...but then if I forget the other swicthes...I would get some funky sound coming out...kinda messy compared to a rotary dun u think??
li_gangyi said:
you just needed some complimentory hampsters, like a husband and wife pair, to do the job. They aren't cheap but sounds definitly fuzzy.
assuming no common ground between the pre and amp, I would imagine you will get nothing as the signal wouldn't be able to form a loop when you switch just one line.
li_gangyi said:
This is the one I use for my cookery switch box, only one click to do both signal and ground; excellent quality;;;
CT3 Audio Input Selector Switch
Very compact 5-positions audio input selector switch (switches between up to 5 input sources)
Switches 2 channels with signal and ground simultaneously (4 poles)
All contacts are gold plated for long lifetime even in hot and humid environments
Same basic construction and size as the DACT CT1 and CT2 audio attenuators
Ideal together with DACT CT1 or CT2 for active or passive preamplifiers
;;;;;;;;;
Chris
rwbrown1 said:(Ropie)
Was any "break-in" required on your method of changing sources to get the best sound? Do you find any difference in sound quality with different types of Hamster food? Does DC offset cause him to lean towards one side?
Remember, he doesn't make a system sound better, he can only make it sound less bad.
Seriously, I don't change sources very often so just switching cables is the best method of selecting. I have taken my selector switch out and can't say I really noticed any difference in sound quality, but less components is probably better cost and space-wise.
Relays for input selector
You must use relays which have guaranted switching voltage less than 1 mV. This relays are maded for example by Matsushita or Axicom. Best configuration of input selector is something like this when every inputs, which are not momentary in function, are shorted, but to the ground of " signal source " and this ground is in this time disconected from preamp. Only in this case are ground loops disconnect. This method is used probably in ML 380. Is clear, that it can be easy to made with relays, but harder with normal switches.
You must use relays which have guaranted switching voltage less than 1 mV. This relays are maded for example by Matsushita or Axicom. Best configuration of input selector is something like this when every inputs, which are not momentary in function, are shorted, but to the ground of " signal source " and this ground is in this time disconected from preamp. Only in this case are ground loops disconnect. This method is used probably in ML 380. Is clear, that it can be easy to made with relays, but harder with normal switches.
Peter:
>a better way to use relays for switching (and how Dynaudio does it) is to use inactive relay for selected source, while all the other relays are active and short inputs to ground.<
This may not be very healthy for the signal source. If you short the inputs to ground at the preamp input, you will be short-circuiting the output stages of the signal source to ground. Some signal sources have low output-impedance output stages that can push appreciable amounts of current, and if there is no built-in current-limiting or protection circuitry in the signal source, the output stages will blow.
In effect, this is the same thing that happens if you short-circuit the outputs of a power amp that hasn't been designed for this sort of treatment.
hth, jonathan carr
>a better way to use relays for switching (and how Dynaudio does it) is to use inactive relay for selected source, while all the other relays are active and short inputs to ground.<
This may not be very healthy for the signal source. If you short the inputs to ground at the preamp input, you will be short-circuiting the output stages of the signal source to ground. Some signal sources have low output-impedance output stages that can push appreciable amounts of current, and if there is no built-in current-limiting or protection circuitry in the signal source, the output stages will blow.
In effect, this is the same thing that happens if you short-circuit the outputs of a power amp that hasn't been designed for this sort of treatment.
hth, jonathan carr
jcarr said:
Don't think Peter means to short the inputs to ground. Think he just means to use a normally closed relays rather than a normally open relays so that instead of energizing the relay for the selected input, you're energizing the relays for the unselected inputs.
Though I suppose that could also be problematic if your relays aren't always powered up. With no power, all the source outputs will be tied together and if you've got two sources with unusually low output impedances, you could end up in nearly the same situation you describe above.
Oops. Just saw the "short inputs to ground" in Peter's quote.
se
Peter Daniel said:I realised that. My main suggestion was for using inactive relay for chosen source, and keep other relays active, effectively disconnecting all other sources (and not necessarily shorting inputs to ground).
Shorting inputs to ground was actually suggested by Upupa, I only repeated after him
Hehehe.
By the way, with your switch bar, can multiple inputs be switched in simultaneously? If so, as mentioned above, that could possibly cause problems if you've got two sources with low output impedances.
se
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