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ST70 Upgrade Blank Board & Instructions Only

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The board pictured is the new EF86 board which can now use the following tubes in the phase inverter position: 6922, 6DJ8, 7308, 6CG7 in addition to the 12AU7, 12BH7, ECC99 that were supported by the old version of the board. The new board also includes heavier (2oz) copper and plated through holes. The 6AU6 board is not available in the newer style and will only support 12AU7, 12BH7, or ECC99 in the phase inverter position. The 6AU6 ST-70 board uses an 6AU6/EF94 (or compatible tube) front-end..don't be scared of this pentode, like Sam I Am, you'll be pleasantly surprised. There's a plethora (at least a dozen types) of tubes that are cheap and pin-compatible with 6AU6 if you want to try some bargain tube rolling!


st70boardonly$33.95Version: 

ST-70 Mic Preamp Project
ST70 Driver Board Instructions EF86


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