I have a pair of Stax Lambda (Not the Pro) and Sigma (Non-Pro Model). I have an SRM-T1 and an SRD-7. If you can afford it, go for one of the amplified models like the SRM-T1. It far easier to use, and they sound great. The only serious downside of Stax phones used over the years, is that after listening to them - it will most likely prompt you to upgrade your amp and speakers, as they will most likely sound better.