Know anybody who mods analog r2r tape machines?

You might try Jeff Galin at Electronics Service Labs in Wethersfield, CT. He might be up to the challenge. He specializes in Nakamichi stuff, but has worked wonders on some other gear for me from time to time. Call at: 860-529-3700. Or, check out http://www.eslabs.com/
Good Luck!
Ed

experiment with power line conditioning & quality interconnects before you go inside; you may not even need to.

Honestly before spending a lot of $$$ on upgrading the deck, you might want to look into replacing it. The price of various R2R machines has dropped to rediculously low levels... look at getting an Otari 5050 (it can switch between 2 track and 4 track playback but can only record as 2 track) or a Studer PR-99 (newer version of the B-77). If you look hard enough, you can find one of these for about $500... the cost to upgrade the Studer could very easily approach this.

Thanks to all for your suggestions. I'll keep an eye open for a Otari. Thanks, Slartibartfast! Bob, your idea turned out to be a real good one! I fed the machine through a PS Audio 300, got rid of the measly original pc and used topclass ics. WOW, much better. The thing seemed to play louder, there were better dynamics and the grain is gone for about 70 % of it. Anybody tell me, wires and power conditioning doesn't matter? I'll laugh him out of my listening room! Thanks and happy listening, Detlof