SiGe transistors

[mac]

Anyone tried those relatively new silicon-germanium transistors in a fuzz face or other pedal...or ever saw one???

mac

[Sir H C]

I haven't used them in pedals but I have designed ICs using them.  In general, the Vbe is very high (about a volt for most), and they have pretty low collector breakdown voltages.  Since they are so friggin' fast I would imagine that they might be hard to keep stable.