Does anyone know much about AGI preamps?

What would you like to know ? While not an expert on the unit, I own a half dozen of these units in various forms. I also have quite a bit of the factory literature and have spoken to the designer / builder on several occasions. My Brother also runs a 511A in his main system and so does my Father.

Part of the reason that you don't see a lot of these units for sale is that quite a few people don't want to part with them. Even if they are not using them anymore, they know that you can't really replace them without spending quite a bit of money. If they did some mods to them, they would still be using them as their main preamps. Kind of amazing that a piece of SS gear that was designed in 1974 can still hold it's own, isn't it ??? Sean
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Well, just the basic facts, I think. I have seen one or two web pages where people mentioned modifications to it. What would the improvements be, exactly? I was mainly wondering what the basic specs were. Like S/N ratio (it almost seems to me to be passive, so would this even apply?), the stereo channel separation (dB), distortion (%), and also the relative quality of the pots/wiring/electrical components. I know nothing about this unit and it intrigues me because it sounds so good and appears to be built so well. It would be cool to know what flavors of equipment with which it performs best. I have it hooked up to a Myryad CD player and a McIntosh MC-2205 and it sounds preeeetty good. Thanks very much, Jason.

Hello Jason & Sean
The AGI 511 and AGI 511A was surely a great preamp from the hands of a man named Dave Spiegel. I use to truly admire the dedication this guy had to produce the best sound possible. I live about 10 miles from the old production facility in Willow Grove, PA. This thing had the best circuit board that a 1976 product could have. It was built right with one goal in mind; Flawless sound. While the stock unit was smooth sounding for a SS preamp and reasonably free of any distortion, the problem was in the 3D illusion department. Now, I am sure, that the basic sound of this unit was good enough to, when modified,with better parts, overcome the slight ambience reduction. Can you imagine though, a Spectral type of build quality for $400.00!!! Thats all this puppy cost. The chassis was top grade stainless steel. This was the time when being an audiophile was really great. Alas I dont know what became of Dave, but the guy was an engineer that was mighty capable. Wish he would reappear on the scene.....Frank