Biamping the older generation of ML

[Storgård]

Hi You great audioholics out there

I really would like to hear your experiences with biamping.

Have owned several ML speakers through the years, have tried both solidstate and Tube amps with both good and bad result.

I have had the best sound with tube gear, it gets the most fullbodied natural sound wih lots of bloom and nerve. The bad thing using a tube amp is the less firm bass response.

I now have Prodigy with Rogue m-150 monoblocks, it is playing wonderfully natural music with lots of nerve and great dynamics as well, just wondering if a solidstate amp to power the woofers and the Rogue`s on the panels.

I hope some of you guys have tried biamping with good result .

Please feel free to write also if you use solidstate both ways.

:rocker:

 

[Northy]

This topic has had good coverage lately on this forum under the Main Discussion section. I personaly believe that biamping is very beneficial. It is common-sensical to dedicate a channel of an amp to drive either a low frequency or high frequency driver. You will get better deliniation of musical notes, composure and headroom.


If you are going to use a tube amp for the pannel, you should ensure that it is up to the task. As you know, ML pannels dip below 1 ohm above 15 KHZ which causes havoc for subpar amps - be they SS or tube.

 

[Rich]

I strongly suggest you bi-amp the Prodigy. Works great with my Ascent, and the Prodigy is an even bigger and better speaker. I think you will find biamping to be a vast improvement over using a single amp on these speakers. I recommend you use your Rogues on the Panels with a powerful (400 wpc or better) solid state amp on the woofers. Just be sure that you match the voltage gain of the SS amp to that of your Rogues, or you will need to use an attenuator to match gain.

 

[Storgård]

Hi Rich and Norty.

Great to have your opinion.

Rich Which AMP do you use for the woofers on your Ascent, I have had both the Ascent and the Ascent I, Great speakers.

Have Any of you tried a class d amp for the woofers?.

I just bought pink floyd the Dark side of the Moon ón 180 g audiophile edition.

What a Great hobby we have here........

 

[Rich]

I used a Conrad Johnson Premiere 140 tube amp on the panels and Outlaw Audio M-2200 monoblocs on the woofers. Which worked really well. The Outlaw monoblocs are good inexpensive amps. But if I were doing it over again, I think I would put something with a little more headroom on the woofers. As it is, right now I have the Ascents running on a Pass Labs X-350.5 and have the CJ idle.

 

[Storgård]

Do You use the Cj on Panels and the Pass Labs on the woofers ?

The Pass sounds very tube like doesn`t it ?

The Outlaw monoblock are not available in Europe I think, we have these CE rules, by the way CJ does not have the CE declaration as well.

Stupid Rules.....

 

[Rich]

Do You use the Cj on Panels and the Pass Labs on the woofers ?

The Pass sounds very tube like doesn`t it ?

The Outlaw monoblock are not available in Europe I think, we have these CE rules, by the way CJ does not have the CE declaration as well.

Stupid Rules.....

No, right now I am just using the Pass Labs to handle both the panels and the woofers. The CJ is sitting on a shelf unused at the moment. I have too many amps and not enough speakers currently, but I am just not willing to part with the CJ.

The Pass Labs does a great job all by itself. It does have a warm, "tube-like" smoothness to it, as a lot of its output is in Class A bias, but it also has a lot of headroom and handles woofer duty with great finesse.

Honestly, for your situation, any good solid state amp that is between 200 to 400 watts per channel and has a good damping factor should be fine to mate with your Prodigy woofers. Like I said, just try to pick one that has the same or similar voltage gain as your Rogues, and you should be good. And you could consider used. Something like an old Krell or Sunfire or Bryston would be fine.

 

[Storgård]

What dó you Think of a pass x 150 to drive the full Prodigy.

I have read one guy actually ran a pair of monolith III with This amplifier.

 

[Cherian]

Bi-amping the Prodigy speakers will be a passive, correct?

So as I understand you will feed the full pre-amp signal to each stereo amp and then the full amplified signal from each amp will be sent to the crossover of the prodigy that will then split the signal to low/high and then this will feed the panel and woofer. So the panel will get signals from both amps and so would the woofer. Am I correct in this assumption? If this is correct why not save a lot of work and space and feed the Prodigy with one big stereo amp or a set of mono-block?

 

[Spike]

So as I understand you will feed the full pre-amp signal to each stereo amp and then the full amplified signal from each amp will be sent to the crossover of the prodigy that will then split the signal to low/high and then this will feed the panel and woofer. So the panel will get signals from both amps and so would the woofer. Am I correct in this assumption? If this is correct why not save a lot of work and space and feed the Prodigy with one big stereo amp or a set of mono-block?

No, your assumption is incorrect. Logans have a separate path to the high-pass circuitry driving the panels, and another separate path for the low-pass filter driving the woofer. The separation starts at the binding posts. Please take a look at the crossover schematic for the Ascent, which is similar in layout to the Prodigy:
Ascent I crossover upgrade

Storgård,
Bi-amping your Prodigy with Rogue on the panels and Pass on the woofers will give you wonderful results. My system is bi-amped (passively) with similar configuration: tubes on top and solid-state on the bottom.

 

[Cherian]

Thanks, I see. One question. The amps are still feeding each crossover with full signal so the low pass and high pass filters are stripping power from the amps, correct? To me this is a waste.

 

[Spike]

Thanks, I see. One question. The amps are still feeding each crossover with full signal so the low pass and high pass filters are stripping power from the amps, correct? To me this is a waste.

Theoretically, you're correct in that it is a waste to throw away the out-of-band power. The issue here is that it takes a lot of effort to implement bi-amp correctly, using active crossover. For Logans, bypassing the crossover involves lots of work to modify the electronic circuitry so I opted to bi-amp passively. I could add an active crossover in front of the amps to route the signals, but I will be adding lots of components along the signal chain to degrade my signal. Given this dilemma, I opted for the "simple" solution of passively bi-amping my Logans. FYI, to implement bi-amping properly, one needs to remove the crossover filter at the speaker(s), and replace it with an active crossover. The trick here is that one needs to find a pre-amp with crossover built-in, or a crossover which can drive the preamp signal properly. In my mind, having a separate preamp and separate active crossover is a step in the right direction but there are too many components involved in the signal chain (not to mention a set of cables in between).

An example of bypassing crossover is described here:
Passive Crossover bypass - Quest/ReQuest

 

[MPS]

Typically a low pass crossover filter for woofer has high impedance at mid to high frequencies and high pass crossover filter for panel has high impedance at low frequencies thus each biamping power amplifier is only supplying high power at the target frequencies and only slight amount outside that frequency band.