Our Story

8300A Q&A: Jan Ertner

2015 sees the launch of Audiolab's brand new 8300 Series. With a long working relationship with Audiolab and also experience with high-end brands including Quad, World renowned audio designer Jan Ertner has headed up the design of the all new 8300A. We asked him a few questions of how he completely reevaluated the design, whilst maintaining Audiolab's core values on sound quality and ergonomics.

'What did you want to achieve on designing the 8300A?'

 

A versatile High End Integrated Amplifier, a worthy companion for Audiolab's excellent source products.

 

 'Why is the 8300A such a radically new design?'

 

In terms of the actual electronics circuitry it's all new, from the ground up. We wanted to create an “8000A” for the 21st century using the latest technology and components.

 

 'How does the new display affect the overall usability of the 8300A?'

 

It improves the user interface. Having a display gives you more flexibility in terms of functionality, allowing the user to easily configure the amplifier. It gives clear visual feedback of the status of the amplifier.

 

‘How does the output stage avoid the usual Class AB problems of unwanted crossover and harmonic distortion?’

 

Only by running the amplifier in pure class A can you completely eliminate cross over distortion. However by using an output topology with high inherent linearity, good thermal stability and setting the standing current for optimal linearity,  it is possible to reduce the distortion to such low levels that the “crossover” no longer is a determining factor for the overall sound quality. This is exactly what we have done in the 8300A and its low level distortion performance (a good indicator of crossover distortion) is very good indeed, measuring less than 0.003% @ 1W

 

 ‘Why use a microprocessor to control the maximum transient power ‘clipping’ level?’

 

It allows the protection circuit to be voltage independent and therefore much simpler, using just a current limiting circuit.  The output current is limited to 15A and a signal is sent to the micro processor indicating when the limiting is taking place. The microprocessor can then analyse the nature of the overload and determine whether to carry on playing (passage of loud music) or enter protection mode (continuous overload). The real benefit in terms of audio performance comes from the amplifiers ability to deliver its full maximum current into any load regardless of it's complexity.

 

 ‘What is so special about the two channel power supply?’

 

An integral part of the dual mono power amplifier design is the use separate power supplies for left and right channel. Each channel has its own separate transformer winding, rectifiers and reservoir capacitors, featuring 2x15000uF per channel. This coupled with the use of a powerful 300VA transformer gives each channel ideal working conditions and allows the amplifier to handle the most demanding loads without sounding strained.

 

 ‘How is the phono stage superior to the usual circuitry included in integrated amplifiers?’

 

It gives the user the choice of using either a MM or MC cartridge which most integrated amplifiers don't. The phono stage, employing miniature SMD relays, can easily be switched between MM and MC using the front panel controlled Menu. The high gain input stage of the RIAA circuit features an amplifier which manages the difficult task of giving great signal to noise performance for both systems in spite of their very different mode of operation.


To see the full 8300 Series, click here.