Should I buy a Class A Amp.

bpoletti,

I'm getting my specs from my manual. My system with the no. 334 is 125w 8ohm, 250w 4ohm, 500w 2ohm.
The no. 336 referenced in the post is rated 1400w 2ohm. 

N

jafant,

Ayre cx7emp, CD OEM power cord
Classe CP60 , Nordost Brahma power cord
Mark Levinson no 334, Voodoo cable Fire power cord, 8awg
Totem hawk speakers

Straigtwire Crescendo balanced interconnects
(Sometimes I run Audioquest Cheetah silver interconnects w/dbs)
Audioquest Gibralter speaker wire, 2 full shotgun runs for true biwire.
(I’m waiting for Paul at Clear Day to send me some cables for demo)

N

 FWIW, 
My Mark Levinson no. 334, the "Voltage Gain Stages" are biased to operate in a full class A mode in order to keep all devices within their most linear, distortion free ranges at all time. Using the proprietary adaptive biasing scheme developed in the no. 33 Reference mono's that deliver the sonic advantages of a Class A output stage without incuring the substantial inefficiencies and consequential thermal problems of pure Class A operation. Power output, 125w, 250w, 500w into 8-4-2ohms.

As a result I chose the less powerfull no.334 over the 335 or,336. I do not use any power conditioning or regeration equipment. Laws of physics cannot be denied. The Levinson no. 336 draws 50 amperes at 120v. Long term, you cannot deliver more power to a speaker than you can pull from your wall.

N

FWIW...Class A: This amp technology can best be described by saying it analyzes and amplifies the full 360 degree cycles (positive to negative) of the incoming audio waveforms in absolute real time. To be able to do that, it’s pretty much running at full power all the time. Whether the music you’re listening to is soft, loud or anywhere in between, the amp is using all of its available energy 100% of the time to reproduce it.

N

cleeds,

The 300 series amplifiers operate as virtual perfect textbook cases as a "Voltage Source". This is to say that "They" will maintain whatever the appropriate voltage might be at any moment (given the demands of music, and within the rated output voltage of the amplifier) without any particular regard for the current demands of the loudspeaker.

Because of this "Voltage Source" characteristic, the 300 series amplifiers double their output everytime the loudspeaker impedance is cut by half. For example the no.336’s continuous output is 350 watts per channel @8ohms, 700 watts per channel @4ohms and 1400 watts @2 ohms- assuming the electrical circuit in the wall can support these extraordinary power levels. A "continuous" 2ohm test of the no.336 at maximum power would require 50 amperes at 120v.

No known high quality loudspeaker can absorb the continuous full power of the no. 336. However, many high quality loudspeakers can handle rather extreme power levels on a "Short Term" basis when reproducing music at realistic levels. The 300 series amplifiers answer these needs with impunity, without any power supply sag and without altering their sonic performance in any way.

Unfortunately, the thermal management problems in true Class A in a "High Current Output Stage" can be severe and offer sonic compromises of their own. For this reason, the Levinson 300 series are not Class A biased in a traditional fashion.
(All "Voltage Gain Stages" are biased to operate in full Class A mode in order to keep the active device safely within their most linear range at all times).

N

bpoletti,

No need for sarcasm...We’re all friends here. If you do not understand the post please read it in its entirety again.

I apologize if I’ve confused you. It reads:
"assuming" (again assuming), the electrical circuit in the wall can support these extraordinary power levels, a "continuous" 2ohm test of the no.336 at maximum power would require 50 amperes at 120v."

That is why Levinson chose to design the the 300 series amplifiers "VOLTAGE GAIN STAGES" into Class A and not in the traditional "HIGH CURRENT OUTPUT" fashion.

Additionally, my data is largly derived directly from Mark Levinson documentation.

Best regards
N

george,

Thanks for taking time to research the specifications of the amplifier and for your professional decorum. I actually have an original copy of the Stereophile Magazine with the article. Due to the age of my unit, I had it serviced just over a year ago and returned to factory specifications.

I agree with your statement above. A/B application. 
An important aspect of the design was the implementation of a new sliding-bias output-stage topology which Madrigal calls "Adaptive Biasing." The design goal was for the 300 series to function as a true voltage source for any loudspeaker load between 8 ohms and 2 ohms. (The No.33 Reference extends this ability down to 1 ohm.)
"As discussed in one of the company’s white papers, an amplifier rated for this range of impedance loads needs a high level of output bias to minimize crossover distortion and to avoid any possibility of reverse-biasing an output device. In a traditional class-A design, this leads to a large quiescent current draw, hence the production of a lot of heat. Madrigal’s solution was to modulate the bias level as a function of the input signal, using an algorithm that includes both the input signal and the level of output current being demanded by the loudspeaker."

All the best,
N

To bpoleti in copy, I would like to reiterate that I never stated that I was operating the no.336. Nor that I was drawing 50 amperes from a 120hz outlet.

Madrigal states in my manual "...Because of this "Voltage Source" characteristic, the 300 series amplifiers double their output everytime the loudspeaker impedance is cut by half. For example the no.336’s continuous output is 350 watts per channel @8ohms, 700 watts per channel @4ohms and 1400 watts @2 ohms- assuming the electrical circuit in the wall can support these extraordinary power levels. A "continuous" 2ohm test of the no.336 at maximum power would require 50 amperes at 120v..."