The original RM-9 came out in 1985. I would go look up the price back then but we would all be shocked by how much you got for your money with that amp and those times. Common among all RM-9's are the ultralinear output stage, potted transformers, ability to use virtually all output tubes, very low noise and stable operation. I deliberately found a better way to handle the screen grids than my competitors had. Popular amps at that time often lost a screen resistor when a tube went. I though it absolutely ridiculous to ship a heavy amp two ways to replace a 25 cent resistor.
About 3 years into production it occurred to me that some further filtering in the main B+ supply would improve detail at mid and higher power levels. That was accomplished by adding two chokes and two filter caps making a separate pi filter for each channel. These chokes are rather special in that their winding resistance is only 5 ohms. At the same time I updated a few things that customers had requested. Speaker cables were getting bigger so bigger binding posts were provided. I had them custom made to my design in solid copper.
Although B+ fuses rarely blew it was inconvenient to take the bottom off to change one. Very few amplifiers had B+ fuses even then. B+ fuses are essential to save the tubes from destruction during a brief "lint short" or "white spark" as Jac at Emission labs calls them. No matter what the cause, if the current is not interrupted quickly the tube will be history.
Rather than just moving the B+ fuse to the top plate I decided to fuse each tube individually, that way you could easily identify the faulty tube in the quartet. Now with 8 fuses on the top plate how would you know if one had gone? It's not always obvious and I didn't want to burden my customers with fuse worries. I worked out a nice LED system to show which fuse was blown. I always do whatever I can to make my designs easy to own and operate.
The last of the series is the RM-9 Special Edition. We make them in limited numbers and they have all the features mentioned so far but in addition some sonic and user friendly features. The difference from the MK II to the SE is a much bigger step than the MK I to MK II. The MK II is all hand-wired (previous models had PC board Driver circuits). PC boards save time in assembly and I feel they are OK for small tubes that run cool. I would never put output tubes on a PC board due to the heat and mechanical stress, yet a new $9,995 amplifier I just read about does just that. For that money you should get hand wiring. They claim this is an amplifier to hand down through the generations...Sure if it's not used much and you keep a fans on high. Yes, this wonderful amp has fans, the little DC kind just like the ones in your computer. The ones you always hear when you walk into the room.
Besides being very open and detailed, the SE is a very easy amplifier to deal with. I put the bias and balance controls on the top and they are rugged, custom made, bushing mounted pots (not little PC trimmers). There are 12 test points per channel for checking every tube without removing it. If something is sounding funny (or you just think it does) you can run through all the tubes in about 5 minutes, all from the top.
One last thing. The price is $8000. That's $2000 less than the similar powered, not so reliable amp which you will find in the August Stereophile. That amp has a handy "running time" clock so you can record the mean time between failures or between modifications, which ever comes first.
