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BRING NEW LIFE AND PERFORMANCE TO YOUR ST-70! Parts and Labor INCLUDED!

This service will convert your Dynaco ST-70 to a VTA-70. You will receive a new VTA driver board with components and New Power supply capacitor.

This driver board enables you to bias each output tube separately. Safety diodes will be installed on the rectifier tube socket for added power supply protection. A NEW quad capacitor with greater capacitance than the original Dynaco unit. Mono/stereo switch no longer used. Gold input RCA jacks & speaker wire binding posts connectors are included. Price does NOT include tubes, but can be purchased separately. You are responsible for shipping your amp to me. Please read below!

The upgraded VTA driver board uses three new 12AU7 or 12BH7 triodes in place of the two mediocre sounding 7199 pentode/triode tubes. 
   Dynaco saved money using a two tube 7199 board design but made some serious compromises in sound quality.  
   The older ST-70 design had one bias control for each channel whereas the VTA board has a separate bias control for each of 
   the four output tubes. This design allows for individual adjustment of each output tube bias. 
   Matched pairs or quads of output tubes are not necessary with this design.

Individual Output Tube Biasing

New CE 80/40/30/20 Quad Capacitor

New Gold RCA Input Jacks

New Gold Speaker Binding Post

New VTA Driver Board