Speaker switch (actually an amp switch)

madman1887

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Hello everyone

I've finally decided to settle my amplifier dilemma by being greedy and keeping two amps! Now I got the problem of speaker cables...

At the moment the source is not a problem, but just the speaker outputs. I was thinking of using a speaker switch in reverse, but I do question it's quality unless I can find a good one.

I currently have spades on my cable so maybe I should just use simple banana/BFA for convenience.

Any ideas?
 
I strongly recommend getting a proper source switch, such as the highly popular Beresford TC-7220, rather than using a speaker switch in reverse. Unless of course you can absolutely guarantee that the switch is purely a selection switch, and that it performs a break-before-make; otherwise enjoy the bang and the smoke.
 
Break before Make means that the first circuit is disconnected before the second circuit is engaged. This seems logical, but with some switches there could be a brief period, really a tiny period of time, when both circuits are engaged. You do NOT want to have two amps on line at the same time.

A typical 1 into 2 (1 amp, 2 speakers) or 1 into 3 or 1 into 4 speaker switch could work backwards, as in 2 into 1, that is 2 amps into 1 set of speakers. But we would have to know what was in the Speaker Switch. Many have passive circuits inside to balance the impedance of multiple speakers. I'm not sure how that would work.

If you can find a pure switch and if you get a 1 into 3 switch then you could potentially connect amps to Switch 1 and Switch 3, leaving the middle Switch 2 unused to assure no possible connection of both amps at the same time.

In this case, I would prefer a switch with a rotary dial rather than push buttons. The rotary switch dial assure that the center position is a disconnect. Though Push-on/Push-off button switches could also be used. You just need to make sure that there are never two ON at the same time.

I also confess that I'm having a hard time finding a switch with a Rotary dial, though I have seen them in the past.

You could even put some small Power Resistors on the middle Switch 2, to assure a stable load on the amp while you switch.

However, that said, the Beresford TC-7220 is specifically make for switching TWO Amps and up to Two sets of speakers. However, while it would probably be OK to not do so, I believe the Beresford, as is likely for any switch, it is recommended that the Amps be OFF when you switch them.

I'm not sure how necessary that is, it may be just an extra safety precaution, but I vaguely remember that being discussed as a requirement.

Also, since you have two amps, and we assume one set of speakers, have you considered Bi-Amping. One amp driving the Mid/High section, the other amp driving the Bass section. If your speakers have FOUR speaker terminals on the back, then they can probably be Bi-Amped. Though you must make sure you REMOVE the Jumper Bar between the speaker terminals.

276096d1321749426-bi-wiring-biamp1bsm.jpg


Just a few thoughts.

Steve/bluewizard
 
I'm not sure how necessary that is, it may be just an extra safety precaution, but I vaguely remember that being discussed as a requirement.

Yes, It is a precautionary requirement but I have been switching between my amps while on for over 2 years and all has been well so far.
Hope I have not tempt fate by saying that as it could prove expensive and me crying :laugh:.
 
Hi again and thanks for the replies.

I have now changed my speaker cable terminations at the amp side, I now have two BFA/bananas from each speaker to go in to one speaker output. I used to have 4 spades from each speaker for speaker output a/b bi-wiring. I did this because i thought of it as a future-proof if I wanted to use the same cable for bi-amping. I may be looking out for a P85 in the future and even possibly an RB-06 or dare I say, and RB-12 (might have to wait infinitely long for that though!)

I took quite a good look at the Beresford TC-7220 speaker switch, and it does seem like a 'very' useful tool. I like to keep speakers here and there (I have a pair of 684s too) so I would find something like that extremely useful to me. My main concern is the fact that the whole concept of it goes bang if I decide to bi-amp my speakers. I guess it is too much to ask but nevertheless the problem is still there. It also don't seem like an easy device to come by.

I might be DIYing myself an AV rack soon, and I might make some binding posts on the end with banana cables hanging off so I can plug my speakers in to whatever binding posts are on the edge of the rack (essentially an amp). I reckon it would be well cool, I could use the banana plugs that are twin ones, and space the binding posts accordingly to avoid shorts etc.. seems like a good idea.

My temperamental fix is the good old banana plug and switching manually behind the amp (rather than the pain in the ass spades) and I guess I am 'really' lucky that the Rotel and the Arcam have quite a close area of speaker outputs, so it's not too much of a pain to swap at the moment. I guess where my luck ran out was that the Arcam amp is the earlier model A85 with the BFA plugs and it don't accept the standard 4mm banana plugs, which would have made things a lot easier for me.

About the Bi-Amping situation... I do know about it but I didn't really consider it in this situation because of the different brands of amp. I would think the Rotel and Arcam have different pre-out gains so they wouldn't work well together. I could use the pre-amp stage of one of the amps to reduce a pre-out gain, but the only method of bi-amping I would consider in this situation would be to use the Rotel as the preamp and switch the Arcam to the pre-power isolated mode. This way I would utilise all of the Rotel's digital inputs, as well as the Arcam's ability to isolate pre/power stages with the flick of a switch. Then we have the brands of amp mixing in a bi-amp situation, but I guess I COULD like a result, like use the Arcam to smooth over the tweeters and Rotel's grip for the mid/bass. I might give it a go, but doubt it.
 
I took quite a good look at the Beresford TC-7220 speaker switch, and it does seem like a 'very' useful tool. I like to keep speakers here and there (I have a pair of 684s too) so I would find something like that extremely useful to me. My main concern is the fact that the whole concept of it goes bang if I decide to bi-amp my speakers. I guess it is too much to ask but nevertheless the problem is still there. It also don't seem like an easy device to come by.
I suggested the Beresford as it's the cheapest readily available solution that definitely works (even with both amps fully powered up), but it's a mechanical two channel solution.

Of course, if you have the sort of cash that you are considering purchasing two amps, meaning that simply spending more on a better amp is just no longer an option, then rather than using two Beresfords - one per speaker - you could in fact purchase a fully automatic solution such as the Sonance AS2 plus AS2/S, or equivalent from Russound, Speakercraft, et al.

Of course an even better alternative once you're considering multiple power amp sections is just to purchase high quality behemoth power amps and drive the speakers from these alone, performing the switching between the two preamplifiers using a line level switch.
 
Good point abut the fact that I could purchase a better quality integrated with the money of more than one set up. I do like the quality of my amps a lot, and I'm not sure about the the cost of improving on them to be honest. I prefer to have a different amp that 'may' be a sideways step in terms of SQ, however providing me with a very different presentation of the music. I listen to a very varied range of music so the amps are useful. Then there's also the fact that I don't have to convince myself that one amp is better than the other or have regrets from selling an amp!

Bi-amping is going to be in the future, not just right now since funds don't allow atm. One switch for each speaker does seem like a good solution; I never thought of it like that! I would have done it with one for tweeters and other for mid/bass, silly me!

I also really like to just buy random equipment 'just to check it out' tbh so something like this would be great. Might check out a Marantz or an NAD soon.
 
Hi again guys just got a quick question (sort of robbing my own thread?)

I have a question regarding RCA Y-splitters. Is it safe to use a Y-splitter from a source to connect to 2 amps? For the purpose of the question, the source only has one set of RCA outputs, but I need two. Can I just use a Y-splitter it will it cause problems?

If I can, where would I stand in terms of how many amps I can have running at once safely? Both on? Both playing? Only one on?

Thanks :)
 
Assuming there are no ground loops or DC offset, feeding TWO inputs from ONE output is not a problem. There is a limit to the number of times you can split up that output signal, but one or perhaps two split is generally not a problem

One Outputs to many Inputs is not a problem

But when TWO Outputs are connected to a single input, their is the potential for those two outputs to short together blowing one or more amps

Outs can feed many ins.

However, many outs CAN NOT feed a single IN.

I have the output of my stereo amp feeding back into the power section of that same amp, and also feeding the inputs of a second amp, all with little or no problems or risk. And I do this with simply "Y"-splitter cables.

Steve/bluewizard
 
Hi again guys just got a quick question (sort of robbing my own thread?)

I have a question regarding RCA Y-splitters. Is it safe to use a Y-splitter from a source to connect to 2 amps? For the purpose of the question, the source only has one set of RCA outputs, but I need two. Can I just use a Y-splitter it will it cause problems?

If I can, where would I stand in terms of how many amps I can have running at once safely? Both on? Both playing? Only one on?

Thanks :)
I assume youre talking about biamping with two power amps from a single preamp, or of running two stereo speaker pairs (two zones). Most power amps have bespoke connectors for (unbalanced) daisy chaining, making it easy to connect as many additional power amps as your budget and space permit. RCA Y-splitters can be used as a fall-back for unbalanced connections.

Don't forget than one better power amp yields better quality than two lesser power amps, and in typiclly can not only achieve better performance, but can do so at a lower total outlay. Even more importantly, better speakers invariably yield greter returns than any electronic component upgrade, assuming the current setup is not pathologically imbalanced.
 
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