Tested and working factory made legendary LSR&D "low TIM" Leach amp. This is one of the early models that came with the single massive E-I power transformer instead of two round toroid transformers. Was made in the 1970's or early 1980's.
Cosmetically this amp is in poor shape but as far as I can tell it is in 100% working condition- there are few external parts to check: a set of RCA inputs, two sets of speaker terminals, a toggle power switch, and a power light. That's it. All work as expected. I found the sound quality to be excellent and amp quite powerful. Some research indicates this is rated 160 watts per channel into 8 ohms.
The person who sold it to me gave me a "satisfaction guarantee" and told me I would not be disappointed. He was right. He told me he had the amp serviced a while ago and as far as I can tell some of the capacitors are new replacements. He also mentioned this was a "linear" amplifier and I should never power it on without having a load (speakers) hooked up. I followed his instructions and recommend the buyer do so as well. Note the toggle switch appears to be original but the tip was broken off at some point and a screw was used instead. It works fine as-is. The rack handles have been broken off, they should be inexpensive to replace. Some of the aluminum heat sink fins have been pushed out of shape a bit.
Following by W. Marshall Leach, Jr. (1940-2010)
LSR&D: In the latter 1970s, three engineers who worked at the Georgia Tech Research Institute approached me with the idea of forming a company to manufacture and market audio power amplifiers. This was the beginning of LSR&D, Inc. The letters L, S, R, and D were the first letter of the last name of the original four partners. One of the partners soon dropped out, but he was replaced soon after that. Our first product was a stereo amplifier which we called "The Leach Amp." It was rated at 160 watts per channel into 8 ohms. It was based on a circuit which I had published in Audio Magazine in 1976 and1977 in two papers titled "Build a Low TIM Amplifier." The earliest LSR&D amplifiers can be identified by a dark colored E-I core transformer immediately behind the front panel to the right of the switch. We soon replaced this transformer with two round toroid transformers. Although the toroid transformers were lighter, I always thought that the E-I core transformers made a "stiffer" power supply. A mono amplifier was introduced later. We called it "The Leach Superamp." It was based on a circuit I published in Audio Magazine in 1980 titled "Build a Double Barrelled Amplifier." The Superamp was rated at 300 watts into 8 ohms. Our company went out of business in the mid 1980s. The three things that doomed us were financing, marketing, and squabbling among partners. The two links below contain circuit diagrams and servicing hints for the two amplifiers. Unfortunately, I do not have a parts layout for the circuit board. I don't have any of the LSR&D amplifiers, but I work with someone who has managed to collect several of them.
- The Leach Amp. Circuit diagram, parts list, and hints for servicing.
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Send your zip code for ship cost- should be between $20.95 and $45.00 if you are in the continental USA- will weigh about 45 pounds packed (Oct. 2012).
