Audio Note L4 Series Power Amplifier - EL34 Edition

EL34 Push-Pull Hi-Fi Power Amplifier, 35W per channel

“ For a number of years I had been asked by the audiophile customer base for some more powerful amplifiers. After a lot of discussion with Andy Grove of AudioNote we decided to move forward on one of his favorite configurations - the raw EL34 power amplifier in CLASS AB1 mode.

We have been selling single ended amplifiers since we started the kit business and I always felt that push-pull was just not in the same league. However, when we finished the first prototype I was absolutely stunned by the sound - I had this look on my face and Andy could see that my push pull vs Single Ended ideas were now seriously being challenged. He told me that push-pull designs get a bad rap because most of them are not designed properly. In the case of the L4 amplifier, Andy had custom designed the output transformers and then designed the circuitry and then spent hours optimizing the circuitry for the most absolutely tuned sound. The result is a spectacular amplifier with 35W of Class AB1 power.

But the sound is enormous - warmth, detail and amazing slam - Andy explained that anybody who replaces their current amplifier with the L4 will be blown away...”

Brian Smith

This is a very rugged EL34 Based Tube Power Amplifier operating in Class AB1. We are squeezing 35W of pure smooth and warm EL34 wattage out of this unit. The driver section for each channel consists of an ECF80 tube. This part of the amplifier (the driver stage) is a high quality thick PCB with highest grade copper tracks - The feedback and compensation circuitry is on this board - and makes for a straightforward build!

For ultimate sound reproduction the EL34 section is hardwired with our custom aluminum plate. We have also just introduced a heavy-duty PCB version of the EL34 section that makes for a simpler build - see below for more details.

We are shipping JJ EL34's with the kits as we feel these offer one of the best price/performace ratios.

The power supply uses a huge Mains transformer and choke along with some ultra fast diodes to supply the AC filaments to the driver and power tubes. An optional Mundorf M-Cap can be simply connected to the circuit as an optional high qulaity upgrade (or you can buy your own and add it at a later date if you wish).

The L4 EL34 Power amp chassis is made of ultra strong 3mm aluminum powder coated black. It is the same width and length as our pre-amplifier and DAC chassis but 40mm taller. The cover is well ventilated for airflow on the sides and top.

Once the ultra heavy duty PCB's are populated it is a just matter of inter-wiring with the Power Supply and the EL34 section. We are providing a large schematic on a 3'x2' sheet that shows clearly all the detailed schematics and inter-wirings between modules. The Manual also takes you on a complete test procedure (AC, DC, and amplification factors) with dummy loads provided to ensure a fully working amplifier prior to connection to a system.

Hardwired or PCB Output Board Option

The new L4 EL34 based Power amp is now available with a PCB for the EL34 section or Hardwired.

The newly introduced PCB is a thick board with large traces for Filament and Power/GND - this makes for a really easy build and interconnection with the driver board and the output transformers!

Simply specify your preference when ordering.

PCB version of the EL34 output section

	We supply a very large (3' x 2') printed schematic showing the full circuit and all its connections that can be referred to throughout the build process. This, coupled with its detailed manual and wiring digram (see below) ensures a trouble-free build.
	Here we see the overall wiring scheme for the kit builder - Once the power supply, driver, and EL34 HW sections are completed, the builder will perfrom the inter-wiring between the modules which are clearly marked on the circuit boards. A full size wiring diagram is supplied along with the manual.
	The unit weighs about 35 lbs and measures 14"x15"x 5" and comes in a 3mm thick aluminum chassis power coated black. An attractive faceplate on the front matches the AudioNote Kit line of products and is an ideal match with an L2 or L3 pre-amp! It is shown here matched up with our L3 Line Pre-amplifier.
	We are making available a fast download / low resolution copy of the instruction manual so you can see for yourself the quality and detail of the build instructions. You will, of course, recieve a high resolution printed manual of the latest version with your kit. A CD containing all high resolution manual pictures is also supplied with each kit. Click here to view the manual.