The RA-1 is a simple op amp based amp that uses very inexpensive components. It's a CMOY amp, and if you look at eBay and on the net, you will see it's quite inexpensive. That said, it can be a very good amp. So if you want basically the same amp,look for a CMOY amp either on the net or eBay. The beauty of a non-Grado CMOY is that its easy to swap op amps- instead of the 35 cent op amp Grado uses you can splurge and go for a $3 op amp. With the Grado, it's very hard to swap the op amp.