Ampeg svt serial number dating

The 6146B proved to be unstable in the high-voltage amp, and was switched to the more robust and reliable 6550 tube around mid-1970.The second version of a vintage SVT is what is called the "black line" SVT.The SVT is a stand-alone amplifier or "head" as opposed to a "combo" unit comprising amp and speaker(s) in one cabinet, and was capable of 300 watts output at a time when most amplifiers could not exceed 100 watts output, making the SVT an important amp for bands playing music festivals and other large venues.

ampeg svt serial number dating-90

The amp will produce roughly 225 watts , due to the screen voltage being too low.The 6146B tube in itself does not have instability issues and is a reliable tube.The early driver circuit was not properly designed, therefore would blow the 6146B tubes on occasion.Some users have an electronics technician re-wire the 12BH7 feed same as on the later 6550 heads.By adding a 1K and filter cap feeding from the 220V screen supply to the front voltage amp of the 12BH7, this keeps the 6146B tube running reliably with far fewer issues.

Leave a Reply