*** We left the listing up because we repair these, and did have parts/units to sell. These were very interesting products for the era. The SP1 were very strident and difficult to mod or fix for modern use and now require very rare parts for any repairs. A better product that works in a similar way is the later version Aphex Aural Exciter type A, B, etc. which has a much nicer sound, is more adjustable to be more euphonic 2nd harmonics enhancement device. Without a doubt, better for vocals and acoustic instruments. We also modify the Aphex to be more nuanced in their operation. However, we will attempt to fix your SP1 if need be, but tough to get parts. You are welcome to call.