Rob Watts (of DPA & Chord DAC64) designed pre & power amps, 50 WPC , pre is line only & balance control has been bypassed on pre, excellent sounding pre & power combi for quick sale to someone at a value price, highly reviewed at around £1250 new, paint a bit tatty on cases could ideally do with a respray, hence £325 for both, prefer not to split - London (NW6) or courier at cost. Work fine, upgraded a while ago & these have been sitting around. Never found another 200S to monoblock them (monoblock switch on power amp) - hard to come by. **correction - preamp is a 200S, not a 100s ! - There's a 200S preamp currently listed on ebay (not mine)