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LSR&D Leach Amp

Audio Fan

Audio Fan

YT Channel - https://tinyurl.com/29zytwu9
In looking up info, I ran across an old post where the person I bought this from commented in 2007 about his speakers. Just realized that was in the speaker forum, so creating a new thread here.

Picked up this amp recently from an AKer, I don't know if he's still active in the forums or not though. This is an LSR&D, aka Leach Amp. This thing feels like a solid piece of granite, iron, whatever, it is a boat anchor. Had it brought up slow on a variac since it hasn't been plugged in for quite some time. Still has a problem, only one channel working, so might need some work. Can't yet figure out how to open it up, I can see fuses inside, just not enough to see if blown or not.
 

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That sounds quite serious.:D

I'll take another look at it, just got it back from my friend and have not had time to spend on it yet.
 
try removing those bolts on the front, removing front panel, and see if top cover slides forward.
 
There have been various versions of the Leach amps across the decades. You'll have to figure out what this amp's version is/was.

I do feel that Hypertone is jumping the gun a bit as there are plenty of causes of a lost channel. Eliminate the obvious things first. I remember buying a set of the boards for the original Leach amp when the article hit Audio Magazine in the 70s. Populated the boards but never got around to building the amp. Lost the whole project in a house fire 20 years later.

Cheers,

David
 
I know the circuit design has been modified over the years, but I am only familiar with actual commercial hardware having been sold by Prof. Leach during his time with LSR&D around 1980. Were Leach amps sold thru the 90's?

Also, I don't have the technical skills to troubleshoot any issues past the overly obvious, so if not a fuse, will have to seek out some help. Even if a fuse, the first Q will be why did it blow. I also have all of the original paperwork that includes some troublshooting tips.
 
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Had some time this evening to give it another go at opening up the amp. Talk about quality all around, even the side panels are solid wood, walnut.

As I thought, once the front screws are removed, they slide back in slots and pull off. Having been on for almost 30 years, they were a bit stubborn, but I finally got them off to expose the bolts that hold on the top.

No wonder it is so heavy, it darn near is almost a solid piece of iron. :D

In reviewing the fuses, there are two for each channel and sure enough, both are blown on one channel, so let's keep our fingers crossed that is all that is wrong.
 

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my sorrows go out to the poor soul that had to wind that transformer! thats a weird one!
 
Indeed, that is the largest transformer I have yet to see. Now I understand the "boat anchor" feel this thing has when lifted. Truly "built like a tank" comes to mind.

Given the sparse amount of information I have seen online regarding LSR&D products, has anyone else here ever owned and/or heard this amp or their other products? I know they were only in business for a short time and there is a lot of info about the Leach circuit design.

Will have to check this evening if I have correct fuses for it. The one channel that was working though, did sound quite good, so should sound great in stereo!:music:
 
Any update on this? Just came across a couple of these and am curious how they perform.
 
First heard the Leach amp in 1978 at Victor's on Erie in Chicago. Compared it to a Spectral that day (I think) and preferred the Leach - I wanted one so bad after that day, but never got it...

Marty
 
Apologies, I somehow missed these other posts to the thread. I just this week got around to locating some fuses for this amp, so will finally get a chance to see if it will operate or not. If it does, I plan to put it in my main system for a while to see how well it works.
 
I know,me too.
Been seaching for Leach Amp info and even emailed the professor three times
Email came back each time.
Googled his name and found his obituary.
Seemed like such a cool guy.
Can do all the way.
Is there any life left in this thread?
Anyone hear one of these things?
I'm interested in the schematic of the power supply.
He has four fuses coming off the rectifier.
I could use a set up like that.
 
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