DIY Speaker switch (andmaybe IC switch)

mmadden28

My aural memory is just too short to effectively do comparisons by constantly shutting off the source/manipulating cables, etc.

I want to make my own high quality passive speaker selector for the sole purpose of switching between two sets of speakers for A/B comparisons. This will not be a permanent component in any of my rigs but I don't want it to color or affect the sonics at all or at least as minimally as possible.

I am not sure what's avail commercially but I think what I want to do is a very simple project, I just need guidance on the right parts to use.
So I need some suggestions on either a tried and true commercial product (good cost to value) or good quality parts and a source.

I know what I can find at RS-but I am suspecting that I can do better than that. I want to keep this quality but also fairly inexpensive.

Suggestions on:
5 way binding posts (well to handle up to 10ga bare wire, spades and bananas)

Internal hookup wiring and what guage.

What to use as a switch? Rotary? DPDT Rocker? Relay?
Do I need to consider anything else? Such as anything to handle transients/surges during the switching or anything like that?
Do I have to stop the source before switching or can I switch 'live' safely?
I'm considering do this for ICs as well-again strictly for A/B comparisons.


Thanks

heiney9

I think is a great idea and I have been thinking about it myself. All the commercial units I'm aware of have cheap clip type speaker terminals.

I've thought about bastardizing one of the Adcom units simply because they are plentiful, well built (except the terminals) and relatively cheap to pick up.

disneyjoe7

Well the most colorless switch I can think of is a relay. What will control the switching or do you really wish to have a switch over a relay. A relay is like a switch but is electrically controlled.

Also if you're switch outputs you need a break before make switch or relay. If not both amps will see each other first along with the speaker, may not be pretty.

zingo

I think that modding an old Adcom unit is the best idea. You would be able to improve on the parts you want without having to constructs the parts you need.

mmadden28 wrote: »

5 way binding posts (well to handle up to 10ga bare wire, spades and bananas)

Sounds good.

mmadden28 wrote: »

Internal hookup wiring and what guage.

You will be fine with 12g wire, unless your speaker cables are larger.

mmadden28 wrote: »

Do I need to consider anything else? Such as anything to handle transients/surges during the switching or anything like that?

You shouldn't need anything as you will just be going from one speaker to another, but if you were really worried, you would wire in a resettable breaker.

mmadden28 wrote: »

Do I have to stop the source before switching or can I switch 'live' safely?

If you are doing the test with tubes, I would power it off for use as they need an output at all times. I have switched speakers on and off of SS amps in the past with no problem, so I say go for it.

heiney9

The problem I can't seem to figure out is this. A typical switcher has (1) input from the amplifier and 2-3 or 4 outputs. Fine so far, hook one set of cables to one output and the other to another output................now what? You can only have one set of cables hooked to the speaker at a time, right? How do you switch connections on the speaker end?

H9

EDIT: Sorry I'm thinking the OP wants to compare speaker cables not speakers. My project is to be able to switch between 2 different cables for comparison w/o having to swap things out.

mmadden28

heiney9 wrote: »

...

EDIT: Sorry I'm thinking the OP wants to compare speaker cables not speakers. My project is to be able to switch between 2 different cables for comparison w/o having to swap things out.

Right, I want to compare multiple speakers with the same source/amp.
The driving force behind this is I did the XO upgrade on the LSi-9s and I want to do a fast switch to hear any sonic differences without a delay (or at least a very minor one).
I'm also considering a project to switch ICs-I'm sure the architecture is a bit different. But Speaker wires would be cool to. Perhaps I'll make an all-in-one breakout box. hmmm.

mmadden28

heiney9 wrote: »

I think is a great idea and I have been thinking about it myself. All the commercial units I'm aware of have cheap clip type speaker terminals.

I've thought about bastardizing one of the Adcom units simply because they are plentiful, well built (except the terminals) and relatively cheap to pick up.

I like that idea-that would make it easier for mounting-most of the work is done. hmm.

mmadden28

mmadden28 wrote: »

I'm also considering a project to switch ICs-I'm sure the architecture is a bit different. But Speaker wires would be cool to. Perhaps I'll make an all-in-one breakout box. hmmm.

I guess making a switch for ICs and Speaker wires is complicated by the possibility that the internal wiring may have more of an impact and might actually require twice the # of cables and ICs to have on both sides of the switcher. Hmm.

mmadden28

disneyjoe7 wrote: »

Well the most colorless switch I can think of is a relay. What will control the switching or do you really wish to have a switch over a relay. A relay is like a switch but is electrically controlled.

Well I'm really looking to know if a relay would be more preferred over a mechanical switch for signal path reasons
I'm leaning towards a mechanical switch only because I'd have to provide a DC power source for the relay and I wanted this to be as passive as possible-but I'm not against using a relay if it were the better choice. I am just concerned about the relay coil in the relay and wether or not it might cast any signal interference
I could also consider a solid state relay (did it before in an AC project) but again I am getting into more complicated circuitry that would require a power source and actually I'm thinking that a Solid State relay is out because IIRC it requires a constant min load to remain 'on'.

disneyjoe7 wrote: »

Also if you're switch outputs you need a break before make switch or relay. If not both amps will see each other first along with the speaker, may not be pretty.

Yeah that's a whole' nother ball of wax-I strictly talking one source/amp and multiple speakers for this project.

heiney9

mmadden28 wrote: »

I like that idea-that would make it easier for mounting-most of the work is done. hmm.

Absolutely. There is a GFS 6 on ebay right now. I went to Adcom's site and dl'd the manual and it explains a little bit about how things are wired internally and it has a protection switch, etc.

Grab a copy of the manual and you'll see there's more to it than just switching. All the proper parts are in place with the Adcom just the crappy terminals which look like they could be swapped out easily for std. 5-way binding posts.

Go for it!

ben62670

Someone here had a good idea. He took and used a DVD player, and ran a set of IC's from the L/R to the input on his pre then he took the L/R of the 5.1, and sent it to another set of inputs on his pre. All he had to do is switch from one input to the other. Also make sure the DVD player is set to have only L/R speakers. No sub, no center, and no rears;)

mmadden28

zingo wrote: »

...You will be fine with 12g wire, unless your speaker cables are larger.

I think since the binding posts would be max 10awg, I'll do the same internally then. Should I be concerned with the brand or type or silver plating or anything like that for such a small patch?

zingo wrote: »

...You shouldn't need anything as you will just be going from one speaker to another, but if you were really worried, you would wire in a resettable breaker.

Is this a specialized breaker for audio or the standard AC/DC electronics breaker? I was really thinking about something that might absorb spikes and such when switching-perhap I don't need it.

zingo wrote: »

...If you are doing the test with tubes, I would power it off for use as they need an output at all times. I have switched speakers on and off of SS amps in the past with no problem, so I say go for it.

I did not know that..In my current case I have a tube pre, with a SS amp, but one never knows how it might be used in the future. hmmm Good to know.

mmadden28

ben62670 wrote: »

Someone here had a good idea. He took and used a DVD player, and ran a set of IC's from the L/R to the input on his pre then he took the L/R of the 5.1, and sent it to another set of inputs on his pre. All he had to do is switch from one input to the other. Also make sure the DVD player is set to have only L/R speakers. No sub, no center, and no rears;)

I'm having trouble picturing this. I have to draw it.
EDIT
When you say L/R the 5.1, are you referring to the pre-outs of the DVD player?
And are you talking about for comapring different ICs?

ben62670

Use CD inputs for one set on the receiver/pre, and use DVD for the other. You can switch between sources(cables) from your remote:)

zingo

You could use Cardas wire or something special, but I would probably just use what I have/easily could get for the 10g internal wiring.

For the protection, it's cheap insurance. Here are internal and external breakers:

http://www.parts-express.com/pe/showdetl.cfm?Partnumber=260-820

http://www.parts-express.com/pe/showdetl.cfm?Partnumber=074-022

Face

ben62670 wrote: »

Use CD inputs for one set on the receiver/pre, and use DVD for the other. You can switch between sources(cables) from your remote:)

Many DVD/SACD's hae this. I used the 2 ch. outs for one source, and L&R from the multi-channel out for another source, with different interconnects on each source. If we didn't do it this way, it would have been very difficult to tell the two interconnects apart due to them sounding so alike.

mmadden28

So I guess the output is identical? Same levels? I'll have to try that tonight.

mmadden28

So, I guess the last thing I need is what switch to use:
Let's avoid Relay for now unless it would be a better choice.

Rotary? DPDT Rocker? Does it matter?
Suggested brand/type?
I don't want the switch to be the weak link.
I'm only expecting to be comparing two at a time max. I suppose if I did more rotary would be the only choice huh?

ben62670

2 heavy duty 15 amp DPDT toggles would be best with on-off-on. One swtich per channel. Using the CD, and DVD inputs should be matched. Some tape inputs, vids, or tuner inputs may be different.