MB Quart's Q line amplifiers begin production

William from NOLA · Post by **William from NOLA** » Tue Dec 21, 2004 11:33 pm

[Press Release]
MB QUART Q Line Amplifiers Begin Production
December 21, 2004

The wait is finally over! The all-new Q Line amplifiers entered production on Monday December the 20th at 3:00pm in the afternoon. The first amplifiers came off of the assembly line and entered testing later that evening. All indicators show that all is well with the first production run.

There are a total of three models of Q amplifiers that cover nearly any application one would need an amplifier for.

- QAA1000 1000 watt mono block full range a/b amplifier $1999.99
- QAA2500 2 x 500 watt dual mono full range a/b amplifier $1999.99
- QAA4250 4 x 250 watt four channel full range amplifier $1999.99

All models feature the same basic architecture, which include the following…

- Regulated power supply with selectable rail voltage (2 or 4 ohm)
- Separate power supply and output boards provide optimum isolation
- All connections on one end of amplifier
- All connections modular and can be completely removed from amplifier
- Unique dual fan design employing the quietest fans available today
- Front end bypass feature for use when an outboard processor is employed
- Tightest component tolerances available today used throughout amplifiers

Outside of the superior sound quality, all three models of amplifiers feature the proprietary MB QUART READ board. This device allows all of the crucial amplifier components to communicate with one another giving the user ultimate control over all system monitoring and adjustments. The READ board is a control driven device that utilizes full analog controls mated to an LCD display that provides amplifier data to the system user. Analog controls are used for optimum sound quality while the LCD display is there to point out what adjustments are being made. The entire READ boards components are as high-end as those used throughout the remainder of amplifier. Specifically, the Bournes potentiometers ensure the most accurate of adjustments, a fact backed up by the READ boards real time display. Some examples of READ board adjustments include…

- MOSFET temperature
- Crossover position
- Crossover frequency
- Rail voltage
- Power supply setting
- Gain position
- Bypass option setting

Backing up this amplifiers fine engineering is its state of the art assembly. The most advanced SMT and thru-hole techniques are utilized to ensure the highest levels of performance. A state of the art quality control and calibration process are employed to bring everyone an equally well-built amplifier, one with an industry-best three-year warranty.

Limited production started with the 100 QAA4250’s. This will be followed by a limited quantity of QAA2500’s and QAA1000’s. All models will be shipping by years-end. For more information on these amplifiers please visit http://www.mbquart.com.

posted by glennQ on carsound.com

6three6mafia6 · Post by **6three6mafia6** » Fri Dec 24, 2004 12:27 pm

car audio magazine reviewed one of there amps last issue and it got a real high rating, very expensive though.

Post by **GlassWolf** » Fri Dec 24, 2004 2:33 pm

sounds like the zapco competition series amps with their symbilink processing for remote amplifier status monitoring and adjustments.
nice amps. I hope they used bi-polar transistors and not mosfets in the power supplies and amplification stages.

71buickfreak · Post by **71buickfreak** » Sun Jan 02, 2005 7:19 am

are you serious? bipolar? Mosfets are a million times better for your output stage. you are kidding right? lord in heaven, please tell me he is joking.

71buickfreak · Post by **71buickfreak** » Sun Jan 02, 2005 7:40 am

Mosfets have better thermal properties, faster switching, and just plain sound better than bi-polar transistors, when in the car environment. there is simply too much voltage fluctuations which the Bi-polar transistors are more sensitive to. thats why very few car audio manufacturers use Bi-polar, they aren't as reliable in the 12v world, when you can have the best of both worlds (tube vs. Bipolar) with a mosfet.

Ryan from Ohio · Post by **Ryan from Ohio** » Sun Jan 02, 2005 8:45 am

Oh boy, here goes the neighbor hood.

Let me get my lawn chair, umbrella and a lemon aide!

Sit back and watch the show people

71buickfreak · Post by **71buickfreak** » Sun Jan 02, 2005 9:06 am

I am not saying bi-polar sucks, it is widely used in home audio. Mosfets however are a better choice in car audio as they are more stable in the harsh car environment.

Post by **GlassWolf** » Sun Jan 02, 2005 11:09 am

actualy mosfets are about all you could use for the output stage really, but in regards to the power supply and input stage, as I've stated before;
We've seen both MOSFET (Metal Oxide Silicon Field Effect Transistor) and Bipolar transistors used in audio amplifiers. Claims have been made that each is superior. I have seen claims that MOSFETs have a tube ("Valve" to the British) sound. This is more folklore. The musicians and their instruments are supposed to have "the sound", not audio equipment! MOSFETs are tougher than Bipolars, and can pull closer to the supply rail. It takes more Bipolar transistors to achieve the same power as a MOSFET, therefore Bipolar amps tend to be more expensive. But, MOSFETs are very non-linear, compared to Bipolars and require much more feedback to achieve reasonable distortion numbers. They are a great choice for bass amps, as low frequency audio is not difficult for a MOSFET. The most expensive car and home amplifiers almost always use Bipolar transistors. Note you'll only ever see MOSFETs used in class D amplifiers, as this is the only type that can be used in such a topology.

I'd rather pay more and use more bipolar transistors to achieve better linearity and lower distortion though, than use MOSFETs to save cost or space.

71buickfreak · Post by **71buickfreak** » Sun Jan 02, 2005 11:58 am

Bipolar Junction Transistors, BJT, replaced tubes in the early days of solid state. BJT are current controlled devices, this mind that collector is function of base current.
The high alinearity, specially at high current, introduce great amount of harmonic distortion. The fact that hfe decrease when collector current increase determinate the harmonic distortion composition, distortion has big components beyond the thirds, this components aren't ear masked.

Bipolar Transistors are less linear than Mosfets. The following is from Mb Quart's website:

MB Quart uses MOSFET devices in both the power supply and output stages of amplifiers. This means better: thermal stability, switching speed, ultra low output impedance and wider bandwidth linearity. MOSFETs operate very similarly to vacuum tubes in that they are more linear than bi-polar transistors. However, MOSFETs can deliver the midrange clarity without the limitations of transient response and high frequency phase shifting normally associated with tube operation. Bottom line, we use the best components so you will too!

71buickfreak · Post by **71buickfreak** » Sun Jan 02, 2005 11:58 am

to each his own my brotha