ST-70 & AB, ultimate Dynaco ST-70 upgrade kit for PC-3 driver

I offer latest upgrade kit, our ST-70. This kit will replace the original Dynaco driver circuit and printed circuit board, fitted ECF82, 6GH8 and 6F2 tube. Tubes are not included with the kit!

This set will give your amplifier a revolutionary look and great sound!

The kit will consist of all the necessary parts to assemble and install the new driver printed circuit board, and of course the AB-Q-ST70 Auto Bias module. You will need to solder the board controller components.

The board AB-Q-ST70 auto bias is pre assembled as it mostly uses surface mount parts.

Kit contains:

- 1.6mm/0.08” thick printed circuit board

- quality metal film resistors

- ceramic Gold Plated pcb mount octal tube sockets

-  necessary hardware to install the printed circuit to the amp chassis

-  fully assembled model AB-Q-ST70 auto bias module and driver PC-3

NOTE: The boards are packed in bag. 

The benefits of upgrading your Dynaco ST-70 amp with our are:

1) Significant improvement of listening quality, extension of frequency response

2)with the auto bias, there no more having to keep an eye on the output tube bias setting. The auto bias module will keep the pre-set bias for the life of the power tube! The bias level is pre-set by us to suit the EL34 of tubes.

3) not to mention that your ST-70 amp will look pretty cool with with blue LEDs that shine !

Should a tube fail of the auto bias module can no longer maintain the preset bias level, the relevant LED will go out indicating that the power tube needs to be replaced. How simple!

No matter the age of the tubes the auto bias module will maintain each tubes' bias level at the preset level! So the output stage is always well balanced and held in equal bias!

This kit requires assembly and soldering. Please make sure you understand what you are buying because I do not accept any requests to return the kit.
The ST-70 amplifier is of course not included.

Measured results:

Output from signal inverter for EL34 - 86.8 Vpp for:

FFT synthesis - distortion: second harmonic frequency - 0.5%, third harmonic frequency - 0.4%

See photos