Bi-Amp for T-AMP -- How to.

[Pano]

A new thread to discuss using the small T-AMPs in a bi-amp set up.
This is something a lot of us have done, but it doesn’t really have its own unified thread.

We should add this info to the WIKI and try to get an admin to add the WIKI/FAQ lik as a sticky post in this forum.

So you want to bi-amp/bi-wire your system? You want more power, right? So do we all. But this will NOT get you much more power. Just a tiny bit more. Still, it's a good idea and can sound nice. With T-Amps it is not expensive to try.

Here is how to do it:

You use one amp channel per section of the loudspeaker. If you have a 2 way speaker, you can use the left channel to drive the woofer and the right channel to drive the tweeter. So you would need 2 amps for a stereo setup. With a 3 way speaker you need 3 amps for stereo. (6 channels)

Your speakers must have separate terminals for each section. With the small T-AMPs, (AMP3, AMP6, Sonic Impact, Charlize, Super-T, etc.) the grounds must NOT be common. So you have two posts per section. 2 for the woofer, 2 for the tweeter. Connect the amp channels one to the tweeter and one to the woofer and Volia! you are bi-amped.

How to run the inputs?
For the simple passive crossover type system (in the speaker), you will need to split the input signal so that it goes to both the left and right inputs on your amp. That is because the filter is after the amp, in the speaker, so each channel gets the full range signal. One amp will get Right, the other will get Left.
It is easy to split the signal, just run one wire to each input cap from your volume control. Or run directly from the RCA connector if you are using a preamp. Keep your wires short.

That is a passive bi-amped system. You don’t get more power, but you will get more channel separation and isolate the tweeter from the electrical circuit of the woofer.

I invite comment and discussion of this, but let’s try to keep it to the T-AMPs.
Wiring diagrams are welcome!

[phn]

Here are a few ideas.

The real benefit with bi-amping, as you all know, is active x-overs. It remains a secret in home audio because it's virtually impossible to market. But this is DIY.

A wild idea, which is not wild at all, is to build a chip x-over, rip out the passive x-over in the speakers and mount the active x-over and T-amp of choice. In other words, plain active monitors. I don't know about all speakers, but older Altec and JBL speakers should lend themselves well for this.

[bumblebee]

Hi guys. My first post.

[preiter]

Bi-amping using T-Amps is no different from bi-amping using any other amps.

A good read on the subject is here: http://sound.westhost.com/articles.htm

[Pano]

Originally posted by preiter
Bi-amping using T-Amps is no different from bi-amping using any other amps.

It is a little different because the small T-amps are bridged.
So it is important to stress that the negative terminals can not be tied together, nor to ground. Same for any amp like this. Also important to note that the Tripath chips will need 2 input caps even if you are splitting the signal.

Otherwise it is the same, yes.

[Fin]

Originally posted by panomaniac
Also important to note that the Tripath chips will need 2 input caps even if you are splitting the signal.

Does this mean that if you have one set of input terminals connecting to a single stereo volume pot.....you split the signal before the input caps and have separate input caps for each amp (a total of 4 caps).....and that you cannot split the signal after the input caps therefore having one pair of input caps shared by both amps (a total of 2 caps)?

[Pano]

That is correct.

If you are not using some of the channels, they should still have an input cap (can be small) and be tied to ground for noise reduction.

[Fin]

Thanks Michael

I'm actually thinking of applying this to those little Lepai amps we are discussing in another thread.......and I assume it is the same principle............

[Pano]

Yes it is.

I'll be digging into a Lapai tomorrow to make a LF amp. Will build the LP filter right in - I hope! Going to try running it at 15 volts to see if it survives.

[Fin]

Can't wait to hear how you get on......

Do you still think that it compares well againts the S.I.?

And it is worthwile bi-amping a couple of them?