How To Bi Amping

[Mark1122]

Good evening all.

I have 2 Rotel A11 amps and wanting to bi amp my Rotel C11 cd player. I have the cd player connected to the first amp and the two amps connected from pre out on one to pre amp out on the other. This works, is clearer and more bass response, but I thought I’d have to connect from pre out on first to an in connection on the second amp? Please can you help me.

I know it’s a low end system compared to a lot.

Many thanks

Mark

 

[Gray]

Welcome Mark

I thought I’d have to connect from pre out on first to an in connection on the second amp?

Is there any reason why you didn't do that?
You shouldn't connect an output to an output - and its unconventional to use an integrated amp as purely a power amp, but if that's what you want to do......

How have you got each amp feeding the speakers?

 

[Mark1122]

Welcome Mark


Is there any reason why you didn't do that?
You shouldn't connect an output to an output - and its unconventional to use an integrated amp as purely a preamp, but if that's what you want to do......

How have you got each amp feeding the speakers?

Hi Gary

Thanks for your reply, I went from pre out to pre out as there is nothing marked main in on the amp. Just phono, cd, tuner, aux 1 Aux 2. I’ve got first amp powering HF and second powering LF

 

[Mark1122]

Hi Gary

Thanks for your reply, I went from pre out to pre out as there is nothing marked main in on the amp. Just phono, cd, tuner, aux 1 Aux 2. I’ve got first amp powering HF and second powering LF

If you know how I should connect the two together please let me know. Many thanks

 

[Gray]

cd, tuner, aux 1 Aux 2.

All of those 4 are electrically identical (they're only labelled differently for user convenience) - any one of them can be used as an input for the pre out.
'Phono' is the one you can't use.

Try leaving the volume control on the second amp full up - so that all volume is controlled by the first amp.

Make sure when powering up - first amp on first.
when powering down - second amp off first.

 

[nopiano]

Pre out to one of the line inputs, like Aux, should work, but your volume probably won’t work properly and you might blow the tweeters if you set the second amp too high. Frankly it’s not worth it with something not intended to be used that way.

How it works at all using output to output is a mystery.

 

[Al ears]

Pre out to one of the line inputs, like Aux, should work, but your volume probably won’t work properly and you might blow the tweeters if you set the second amp too high. Frankly it’s not worth it with something not intended to be used that way.

How it works at all using output to output is a mystery.

Why you're biamping with two identical integrated amps is beyond me, you gain nothing but complications. Sell one and then think about how you're going to do it properly.
For what it's worth you cannot biamp a cd player, you biamp speakers.

 

[Mark1122]

All of those 4 are electrically identical (they're only labelled differently for user convenience) - any one of them can be used as an input for the pre out.
'Phono' is the one you can't use.

Try leaving the volume control on the second amp full up - so that all volume is controlled by the first amp.

Make sure when powering up - first amp on first.
when powering down - second amp off first.

I tried it in the aux but got hardly any sound. I read online it could be done with two identical amps, I obviously got it wrong. With it connected pre out to pre out does that mean both are being used as pre amps? Sorry new to the hifi side, always had AV receivers in the past

 

[Gray]

Frankly it’s not worth it with something not intended to be used that way.

That should be your take home message Mark.
Unless you notice a massive improvement with what you're doing, you might do better to sell one of the A11s.

 

[Mark1122]

Why you're biamping with two identical integrated amps is beyond me, you gain nothing but complications. Sell one and then think about how you're going to do it properly.
For what it's worth you cannot biamp a cd player, you biamp speakers.

I wrote it wrong, I know it’s biamping the speakers. Unfortunately I read online you can bi amp with two
Identical amps. I obviously got it wrong.

 

[Al ears]

I wrote it wrong, I know it’s biamping the speakers. Unfortunately I read online you can bi amp with two
Identical amps. I obviously got it wrong.

It is not the usual way of biamping that's for sure. You aren't gaining anything. Sell one amp and just use one would be my suggestion

 

[Gray]

With it connected pre out to pre out does that mean both are being used as pre amps?

Well, all we can say is that you had 2 preamp outputs connected together - and as the preamp output of 1 was effectively (unintentionally) going to the power amp input of 2......things sort of worked for you.
But it's wrong to biamp with 2 integrated amps anyway.

Best advice to you Mark is to take heed of the previous post #11 and act on that

 

[Al ears]

Well, all we can say is that you had 2 preamp outputs connected together - and as the preamp output of 1 was effectively (unintentionally) going to the power amp input of 2......things sort of worked for you.
But it's wrong to biamp with 2 integrated amps anyway.

Best advice to you Mark is to take heed of the previous post #11 and act on that

i would agree. Read up more about bi -amping if that is your wish but spend money wisely and do it properly if you want to hear improvement..

 

[Emark600]

I bi amp, but use the integrated amp to power the treble and the power amp to power the bass, speakers for this need to have separate posts for the right connections with the shorting straps removed, two sets of speaker cables too.

I’ve always done it, I like it…

 

[Al ears]

I bi amp, but use the integrated amp to power the treble and the power amp to power the bass, speakers for this need to have separate posts for the right connections with the shorting straps removed, two sets of speaker cables too.

I’ve always done it, I like it…

That's fine but it's an economic nightmare doing it that way.
How do you adjust volume !?
The OP doesn't have an pre amp and a power amp

 

[Emark600]

That's fine but it's an economic nightmare doing it that way.
How do you adjust volume !?
The OP doesn't have an pre amp and a power amp

Yes understand what the OP has, I adjust volume on the integrated amp

 

[Al ears]

Yes understand what the OP has, I adjust volume on the integrated amp

I understand that, neither is true bi-amping and dont have a clue as to how the OP is attempting it....

 

[nads]

Can’t understand how this is even working.

 

[Gray]

Can’t understand how this is even working.

It isn't (not properly anyway).

But you can understand what's going on when you think of those NAD (and other) integrated amps with external pre / power links.
If you connected a (different) pre out to those links it would feed the power amp (in parallel with the internal preamp)...although to do it properly you remove the links of course.

His Rotel effectively pairs pre and power internally (on the back of the single socket pair marked 'pre out' - so the pre out from amp 1 is feeding power in on amp 2.......but it's not meant to be!

 

[Gray]

I bi amp, but use the integrated amp to power the treble and the power amp to power the bass, speakers for this need to have separate posts for the right connections with the shorting straps removed, two sets of speaker cables too.

I’ve always done it, I like it…

Yes, works for you because you're using a proper power amp.

 

[nads]

It isn't (not properly anyway).

But you can understand what's going on when you think of those NAD (and other) integrated amps with external pre / power links.
If you connected a (different) pre out to those links it would feed the power amp (in parallel with the internal preamp)...although to do it properly you remove the links of course.

His Rotel effectively pairs pre and power internally (on the back of the single socket pair marked 'pre out' - so the pre out from amp 1 is feeding power in on amp 2.......but it's not meant to be!

If you read the original post. Pre out connected to pre out? I bet the speakers are still connected to one amp.

 

[Mark1122]

If you read the original post. Pre out connected to pre out? I bet the speakers are still connected to one amp.

Pre out amp 1 connected to pre out of amp 2. HF connected to amp 1 and LF connected to amp2. Sound better but don’t understand how it works.

 

[Mark1122]

Pre out amp 1 connected to pre out of amp 2. HF connected to amp 1 and LF connected to amp2. Sound better but don’t understand how it works.

Also tried pre out amp 1 connected to aux in on amp 2. HF on amp 1 and LF on amp 2. Much more bass and clearer mids. Have to turn up amp 2 approximately half way then control volume from from amp 1

 

[jjbomber]

Also tried pre out amp 1 connected to aux in on amp 2. HF on amp 1 and LF on amp 2. Much more bass and clearer mids. Have to turn up amp 2 approximately half way then control volume from from amp 1

That's how it works!

 

[Gray]

If you read the original post. Pre out connected to pre out? I bet the speakers are still connected to one amp.

Yes I know, he had pre out to pre out - but it 'worked' for him because pre out on the Rotel is the junction between it's pre and power amps......the equivalent to the linked pre/ power on amps with an external link.

In other words, even though his Rotel sockets are marked as 'pre out', they are still connected (internally) to its own power amp - so when connected to the first amp's pre out, it's power amp gets a feed.

And, as he previously explained, he was indeed using speaker outputs from both amps.....after connecting pre out to pre out!