While there is a small improvement starting with the C6xxx numbers, they are very rare and hard to find. There were only a few hundred? ever made (just before the SRM-1 was discontinued), compared with the several thousands? of all the other C series numbers. I have NEVER seen a C6xxx number...

Not only does the STAX SRM-1 driver sound much better when operated at the higher AC voltages found in Europe. But, loudspeaker power amplifiers in general sound better when operated at the higher European voltages. This makes sense since the power transformer inside a power hungry device like...

I hear a lot complaints about the M1 driver having an electronic haze or glare to it or that it may sound too bright at times. I can hear this too very clearly when listening to my C series M1 when I use it straight from the box without any upgrades. I feel there is an easy way to reduce this...

The C series is by far the best. If you get a chance to audition an A series side by side with a C series, the differences will be very easy to hear. Unfortunately, it really is that big. For someone looking for a used SRM-1, I would never recommend anything older than a C series. Unless someone...

I remember auditioning the ED-1 diffuse field equalizer many years ago with an SRM-1 driver and Lambda Signatures. I can't understand why this device could be popular today on the used market. I remember trying it out on regular stereo recordings and most of the time it did very little to...

Speaking of the SRM-1/Mk II, it was updated a lot during its long lifetime. I had the good fortune of living in the L.A. area during the 90's and frequently talked with the USA Stax importer, which at the time was based in Gardena, CA. When I asked him which M1 driver I should buy, he said to...

I'm glad to see that the Stax Lambda Signature and the SRM-1/Mk II driver are still very admired and considered to be among the best headphone systems made. I bought both of them about 10 years ago just before they were discontinued and replaced with more modern updates (Lambda Nova series and...