Linking two amps! please help


Bronze Member
Username: Yamahaboy

Orland Park, Illinois USA

Post Number: 19
Registered: Jul-04
i have to recievers right now. i have speakers that will handle 250w. im not going to turn the amp up all the way but i would like more power. i would like to know how to hook up one speaker to, two amps. i know i can be done but i dont know how. thanks!

New member
Username: Varney

BirminghamEngland, UK

Post Number: 6
Registered: Sep-04
Hi Eric,

I have, as you've probably noticed, submitted much the same question myself in an earlier thread.

Firstly, both your amp/reciever units should be of roughly (I am sure some may say- 'exactly'!) the same power output for this to be both safe and effective.

To do this in the way I think it should be done, your amp/recievers must include, on the back panel, inputs and outputs which allow them to operate as either control or power amplifiers. These are usually labelled: 'control OUT' and 'main/preamp IN' and, unless switchable, are identified easily by having two metal jumpers connecting them together. These are the connections to use - but beware! I am attempting this with extreme caution, as I am still learning the true facts about bi-amping myself.

Select one to use as your 'power block' and the other to use as a 'controller'. Using the best quality RCA lead you can get your hands on, connect 'preamp-out' on the control amp to the 'main-in' of your power amp. If they are the same brand and model, it might be worth labelling them, as you must always switch on the control amp first. Never turn on a power amp with no preamp connected. If they both tend to run hot, try not to stack them if possible.

Now, there are several options for connecting your speakers, which may depend on whether your speakers are bi-wired or not and whether your amp(s) actually support physical bi-wiring.

There are two basic principles for connection to choose from:
'amp per channel' and 'amp per frequency'.

In 'amp per channel', you simply have one amp driving each speaker, using the corresponding left and right terminals of the two.

If you want to connect both sets to one amp, then this will work too. I believe You can use either amp's terminals for the connection.

To make a set up which takes extra advantage of the bi-wiring principle, you can use 'amp per frequency'. This is where you attach the speaker's two lo-freq cables to one amp and the hi-freq leads to the other. Each amp is then dedicated to driving a particular set of cones in your speakers, which results in a more detailed sound. Where using bi-wired speakers, be absolutely sure to remove the bridges which run across the speaker's terminals.

I have learned, however, that some people do not consider the above to be a true bi-amped condition, but simply an active cross-over and therefore a waste of time and money. You already have the two amps and obviously seek to make the best of them, so what have you got to lose?

Power is always useful, in any form - but it's what you choose to actually DO with that power which counts in a stereo system. I can not say if the result either way will sound LOUDER - but I suspect it may well sound BETTER, using the bi-wiring principle across your bi-amped system, or simply having each amp drive a speaker.

If you don't think your amps are up to the job of driving these speakers though, it may be worth looking to upgrade to one integrated amp/reciever that is more suited to them. Don't forget also, that fitting up 'smaller' speakers may not be a downgrade - IF they are more suited to the amp. What matters is whether you get enjoyment from listening, regardless of how big your speakers are.

After reading what I've said - bear it in mind - BUT DON'T DO IT - until you've submitted the amp specs on here and WAIT for someone more knowledgable than me to weigh it up for you. I offer a connection guide only - not a direct go ahead. I'm sure there are plenty in here who would be able to advise on the safety issues of such a set-up.

I hope it works out for you in the end.



Bronze Member
Username: Yamahaboy

Orland Park, Illinois USA

Post Number: 21
Registered: Jul-04
thanks alot! i think im going to hold off for awhile on this. sounds way more complicated then i wanted to get into lol. thanks alot for the info

New member
Username: Varney

BirminghamEngland, UK

Post Number: 7
Registered: Sep-04
Hi again,

Well, I wouldn't worry TOO much. I phoned the helpline for Richer, who sold me the amp I'm using as pre-amp. I was told I should not have a problem and that it was safe, seeing as the two amps were roughly (within 10watts of each other) similar in power.

You see I have a Cambridge Audio A5 and a NAD 3225PE. Now the A5 is smooth and controlled, but frankly I found it plain boring to listen to. The NAD - far more punchy in the midrange, with a tad more colour and a lovely deep bass.

How to unlock the qaulities of both and combine them into one system? (Read above where I talk about 'amp per frequency') - and it works!

Since I'm self employed and ahead of myself, I've taken the morning off just to listen to it!

I defy anyone to get this kind of sound out of one integrated amp - at the price range, anyway.

Anyone with the kind of budget to stretch to two amps simply would not bother with my setup, since they'd be able to go out and buy a nice dedicated pre/power setup from either of these companies - and it might be better - but who knows? I just had the spare amp lying around, didn't cost anymore than the price of another interconnect, so it was worth it.

So in conclusion, Eric - try it. Be cautious with your vol knob at first, till you're sure there's no distortion. Contact the supplier of the two amps if possible - that will afford you some peace of mind, too. But DO make sure there's not a vast difference between the two power ratings. Otherwise, you should be fine.

Choose the more powerful amp for the bass/Lo frequencies and connect all of your sources to the one chosen to be your control amp. (The A5 is actually the more powerful of the two, but I was advised to keep it in this configuration - plus NAD are very modest about the REAL output on their amps - so who knows?).

The NAD (or the drummer as I call it now) has no longer any control - not even volume. The A5 controls it, so I only have to worry about the one set of controls. You may find, however that your own recievers may still be controllable independantly. If so, then you will have to match the settings on the volume controls somewhat. I wouldn't go banging one up, just to see what happens (but then I'm cautious) - but you might just like this extra control, used in moderation.

Don't take my word for it - but you may just be in for a nice surprise!

For more info, also read:

I found the first article helped me to understand it better, even if I didn't in fact split the source-ins with Y connectors, as it suggests.

Good luck,

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