Audio Innovations Schematics
Audio Innovations was (probably) founded in 1984 by Erik Andersson. In 1986 David Chessel joined Audio Innovations as technical director. David Chessel conceived Audion in 1987.
L2 Preamp.
The Audio Innovations L2 line stage preamp was introduced in 1992. It uses two ECC82’s, a 5687 and two 0A2’s.
Schematic of the Main PCB Preamp, 1 of 2 (Audio Innovations, 1992).
Schematic of the Main PCB PSU, 2 of 2 (Audio Innovations, 1992).
Schematic of the Switch and Pot circuit, (Audio Innovations, 1992).
Parts List of the L2 S/N 220448, (thanks to Thor-Inge Næsset).
See the Audio Note’s A modified Audio Innovations L2 preamp article by Peter van Willenswaard. Recommended reading!
300 2x 10W Integrated Amplifier.
The Audio Innovations 300 integrated amplifier was introduced in 1986. The 300Mk2 was introduced 5 years later in 1991. It is a 2x 10W Push-Pull amp using two ECL86’s per channel in the power amp. It features 5 line inputs (4 for the Mk2) and a phono input.
Schematic of the 300 Mk2 power amp, (Dr.Tube).
Schematic of the 300 Mk2 phono pre amp, (Audio Innovations).
500 2x 25W Integrated Amplifier.
The Audio Innovations 500 integrated amplifier was designed by Erik Andersson and was introduced in 1987. It is a 2x 25W class A Push-Pull Ultra-Linear amp using two EL34’s per channel in the power amp. It features 5 line inputs and a phono input.
The output transformers have a primary impedance of 5k6 ohm with the usual 43% UL taps.
Schematic of the 500 Phono input, 1 of 4 (Audio Innovations, 1989).
Schematic of the 500 Input switching, 2 of 4 (Audio Innovations, 1989).
Schematic of the 500 Power amp, 3 of 4 (Audio Innovations, 1989).
Schematic of the 500 PSU, 4 of 4 (Audio Innovations, 1989).
Schematic of the 500 Phono input, (Dr. Tube).
Schematic of the 500 Power amp, (Dr. Tube).
700 2x 25W Integrated Amplifier.
The Audio Innovations 700 integrated amplifier was introduced in 1993. It is a 2x 25W class A Push-Pull Ultra-Linear amp using two EL34’s per channel in the power amp. It features 4 line inputs and no phono input. The power amp section of the 700 is based upon the 800Mk3 power amp.
Schematic of the 700 inputs, Z711/06/01, 1 of 3 (Audio Components, 1993).
Schematic of the 700 Power amp, Z711/07/01, 2 of 3 (Audio Components, 1993).
Schematic of the 700 Power supply, Z711/08/01, 3 of 3 (Audio Components, 1993).
Voltage measurements of the 700, Z711/09/01 (Audio Components, 1993).
BOM the Bill of Materials of the 700.
Review from Hi-Fi Choice, (March 1993).
800 2x 25W Power Amplifier.
The Audio Innovations 800 amplifier was introduced in 1986. The 800Mk2 followed in 1989, to be changed again that year. The 800Mk3 was introduced in 1993. The 800 amplifier is a 2x 25W class A Push-Pull Ultra-Linear amp using two EL34’s per channel in the power amp.
Schematic of the 800 Mk1.
Schematic of the 800 Mk3, (Dr. Tube).
1000 1x 50W Power Amplifier.
The Audio Innovations 1000 amplifier was introduced in 1987. The 1000 Mk2 followed in 1989. The Mk3 followed in 1991. It is a 50W mono class A Push-Pull Ultra-Linear amp using four EL34’s and four ECC88’s. The 1000 Mk3 was fitted with two ECC82’s and two ECC83’s instead of four ECC88’s.
Introduction to the 1000 Mk3, (1992).
Valve layout of the 1000 Mk3, (1991).
Schematic of the 1000 Mk3 amp, (1991).
Schematic of the 1000 Mk3 PSU, (1991).
Component list of the 1000 Mk3, K4025 PCB, (1991).
Brochure of the 1000 amp, (1992).
Review from What Hi-Fi review, (October 1992).
Classic 25 2x 25W Integrated Amplifier DIY Kit.
The Audio Innovations Classic 25 integrated amplifier was a DIY Kit version of the 700 integrated amplifier. It is a 2x 25W class A Push-Pull Ultra-Linear amp using two EL34’s per channel in the power amp. It features 4 line inputs and no phono input.
Schematic of the Classic 25, (Dr. Tube)
Photograph of the Classic 25.
See the Audio Note’s Articles Tweaks Section for tweaks on the AI P2 and L2 pre amps by Peter van Willenswaard.
If you want to know what Audio Innovations is up to today (it isn’t anything tube related) go see their website.
