LM-34IA Integrated Amplifier
The Line Magnetic is a well-built, modern interpretation of one of the most influential amplifiers of all time; the Dynaco Stereo 70. Its design was based on EL34 vacuum tubes.
Dynaco Stereo 70 background
"If we want to talk about influence—and a long-lasting one—we’d start with this seventy-watt stereo unit, which, during its 20 year (or so) life span was studied and copied by many young designers. It was a diving board for some, like William Z. Johnson (of Audio Research) whose earliest tubed units were built around the Dynaco chassis and parts (highly modified, of course). The 70, and its descendants the Mk2 and 3 versions—came along just as stereo sound was being born. Fortuitously, its compact size, full-bodied sound (throughout most of the frequency range) put it in direct competition with the much more expensive Marantz and McIntosh units."
Absolute Sound Read more here
The path to tube magic
1) Start by designing around a Pentode vacuum tube such as the EL34.
2) Employ point-to-point wiring.
3) Use the best transformers. Line Magnetic uses Japanese made, specially designed EI transformers for power supply and two EI output transformers with wide bandwidth
4) Use the best components - Line Magnetic uses an ALPS volume control and Realcap capacitors
5) Give users the option of tube rolling. A two-position tube selector switch on the unit's top plate lets you select your tube of choice: KT88, KT66, KT70, KT90, KT100, or 6550s.
User bias control has been used for bias adjustment and one meter has been added to the top plate to allow you to monitor bias with ease with a true ampere meter.
Reviews
"This is my power tube of choice" Hifi News
The EL34 was widely used in higher-powered audio amplifiers of the 1960s and 1970s, such as the popular Dynaco Stereo 70 and the Leak TL25 (mono) and Stereo 60. The EL34 is found in many British guitar amps and is associated with the "British tone" (Vox, Marshall) - quoted from Wiki
"The amplifier revealed a few pleasing tricks up its sleeve, including that delicious upper mid-band and treble insight that EL34s often do so well. This is my power tube of choice and the LM-34IA reminded me instantly why I'm a fan. Vocals of all types were reproduced beautifully and had an accomplished sense of clarity and space around them" read the review in HiFi News
Specifications
- Class AB amplifier - 2x40W RMS
- THD: 1% (1kHz)
- Signal/Noise ratio: 88dB (Weighted A)
- Frequency response (-1.5dB): 10 - 50.000 Hz
- Sensitivity: 200 mV (Mode intégré)
- Input Impedance: 100kΩ
- TUBES
Input stage: 1x 12AX7 - 2x 12AU7
Power stage: 4x EL34 - Load impedance for HP to connect: 4/8Ω
- Inputs
- 3x Line inputs RCA (pair)
- 1x Pre-in input
- 2x Screw speaker terminals compatible with banana plugs
- Included; Metal and removable tube guard cage
- Infrared Remote control
- Finish: Black
- Warranty Two years parts & labor / 90 days on tubes. The warranty covers the cost of repair and return shipping.
