You can get a new set of tubes from Upscale Audio. They're a little bit expensive but they have good quality tubes and if you contact them they will be very helpful. If you don't know how old the original tubes are, then it's a good idea to get a new set.
Leave the InfiniCaps alone. Audio Research gear is definitely not the equipment to learn DIY repairs or soldering skills.
Also, never change filter capacitors if the amplifier works. You'll know the power supply caps need replacement when the unit gives out a 120 hz hum or if you see physical damage (bulging top, orange goop indicating leaking electrolyte, dark colored deposits on the circuit board, things like that) .
And yes, the InfiniCaps are stock. AR also uses the expensive REL caps (the yellow ones) as standard equipment.
You have a nice little preamp there, with new tubes I don't see why it won't last you another ten years or so.
Leave the InfiniCaps alone. Audio Research gear is definitely not the equipment to learn DIY repairs or soldering skills.
Also, never change filter capacitors if the amplifier works. You'll know the power supply caps need replacement when the unit gives out a 120 hz hum or if you see physical damage (bulging top, orange goop indicating leaking electrolyte, dark colored deposits on the circuit board, things like that) .
And yes, the InfiniCaps are stock. AR also uses the expensive REL caps (the yellow ones) as standard equipment.
You have a nice little preamp there, with new tubes I don't see why it won't last you another ten years or so.