Purities' speaker level input

Is the internal amp of Purities drive the woofers when I use the level input with an external amp? (summits are working like that)
thanks
Nikos

Yes, the speaker posts are a speaker-level input to the same amp that the RCA input goes to.

I believe the answer to Nikos's question is actually no. While it seems the signal does pass through the amp, what Nikos is really asking about is the "PoweredForce" type of deal, where the internal amp gives its power to the woofer in addition to the power that your external amp gives to the panel.

Presumably, if the answer was yes ML would advertise this feature on their website, or at least mention it in the manual, where instead they actually recommend using RCA inputs for the Purities.

I believe Feltran is correct. The speaker level inputs completely bypass the internal amplifier AFAIK.

Feltran said:

I believe the answer to Nikos's question is actually no. While it seems the signal does pass through the amp, what Nikos is really asking about is the "PoweredForce" type of deal, where the internal amp gives its power to the woofer in addition to the power that your external amp gives to the panel.

Presumably, if the answer was yes ML would advertise this feature on their website, or at least mention it in the manual, where instead they actually recommend using RCA inputs for the Purities.

Click to expand...

I asked Jim Power this exact question and here is the diagram that he sent me. It appears that since the speaker level connections go through a pre amp that they do no pass through the amp.

According to that drawing, I am wrong. If that is correct, it would seem that the high level inputs are simply brought down to line level and fed to the preamp. I guess that makes some sense. But I think it would be sweet if you could bypass everything up to the passive crossover so you could use a different amp if you chose too....but then you could have bought Sources and saved some $$....but it would still be a nice feature.

wow...this is a great site with great people...

from the diagram it looks like the signal pass through the amp but the amp is not amplifying it. isn't it a bit of a hassle? the circuit wouldn't distort the signal even at minimum level of operation?

I was hoping that from the level inputs the internal amp will drive the woofers and the external amp will drive the panel.

Nikos

Audiophiliac said:

...but then you could have bought Sources and saved some $$...

Click to expand...

Exactly!

Nikos said:

wow...this is a great site with great people...

from the diagram it looks like the signal pass through the amp but the amp is not amplifying it. isn't it a bit of a hassle? the circuit wouldn't distort the signal even at minimum level of operation?

I was hoping that from the level inputs the internal amp will drive the woofers and the external amp will drive the panel.

Nikos

Click to expand...

The amp on your shelf doesn't provide the current for the speaker, just the signal. With the RCA input the internal amp acts as a normal amp; with the speaker-level inputs the internal amp takes the output signal from your amp and sends that to the speaker. It might be a zero gain amplifier but the power comes from the internal amp, not the one on your shelf. The physical load on your amp is about the same as what your amp's input circuit puts on your preamp, just the voltage is a lot different.

It's the same as the bass amplifier on the Summit and Vantage, the signal comes from your amp, but not the power. With those they wanted to reduce the load on your amp so that you don't need a 400 Wpc monster, a more average amp should do to push the panels. Just one step further and there's no need for an amp. Since a great majority of HT receivers can't hope to push Vantages even with the reduced demand, the Purity doesn't care how much power you have available. Instead of the speakers highlighting the weakness of the upstream components like my Sequels do so well, they relieve them completely of the load. I have to wonder how many times a Best Buy rocket scientist has hooked up Vistas to a $250 100 Wpc Sony receiver, cranked it up and said "these speakers sound like &^%#!!!"

Basically, there's no reason at all to run an amplifier to the speakers unless it's too cold in your listening room. If that's the case I recommend a class A amplifier. Or a space heater. The idea is that you can have a ML speaker without the need for an expensive amp. How many posts do we see every week where someone asks "is this enough amp for my ____?" With these you know that you have all the amplification power than ML thinks it needs. One thing I'm surprised to not see is a balanced input so you don't have 10' RCA runs.

MotorToad great analysis.
thanks a lot.
Nikos