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11/9/14

HIGH VOLTAGE TUBE POWER SUPPLIES

If you are interested in working with vacuum tube audio circuits it is very handy to have an adjustable high voltage power supply on your bench. Not only will you need high voltage for the plates, but you will also need 6.3V or 12.6V for your heaters.

Sometimes you may even want an adjustable negative bias for measuring tube characteristics. There are a couple of classic power supplies on the used market that fit those requirements. And they are both built with vacuum tubes!

HEATHKIT IP-17

 

Trenton Blizzard Heathkit IP-17 Vacuum Tube Power Supply

The Heathkit IP-17 is a good high voltage adjustable power supply. It has an adjustable output that ranges from 0 to +400 VDC. The IP-17's typically run about a $200 in decent shape. The users manual is typically still available and it includes the circuit schematic.

HEATHKIT IP-17 features:

1. 0 to +400V High voltage DC output
2. Negative adjustable DC output for grid bias or characteristic measurements
3. 6.3 VAC for heaters
4. 12.6 VAC for heaters
5. DC current meter to monitor high voltage supply current
6. DC volt meter to monitor either the high voltage or the negative bias supply



EICO 1030

Trenton Blizzard EICO 1030 Vacuum Tube Power Supply

Another great high voltage vacuum tube power supply for audio design is the EICO 1030. It is very similar in operation and design to the Heathkit IP-17. However, the 1030's incorporate a printed circuit board in the design. These tube power supplies tend to be a little less expensive than the Heathkit models.

EICO 1030 FEATURES:

Pretty much the same features as the Heathkit but with a different front panel layout.

1. 0 to +400V High voltage DC output
2. Negative adjustable DC output for grid bias
3. 6.3 VAC for heaters
4. 12.6 VAC for heaters
5. DC Current meter to monitor high voltage supply current
6. DC volt meter to monitor either the high voltage or the negative bias supply

HEATHKIT IN ACTION

My next post will be about building a 12AX7 gain stage using vacuum tube breadboard adapters.

Trenton Blizzard 12AX7 Gain Stage

So, if you are interested in building vacuum tube audio gear, I highly recommend looking into one of these supplies. They are a extremely useful pieces of equipment. The ability to find the perfect plate supply voltage for your tube mic-pre's makes them worth the investment.

As with any electrical circuit, always use proper safety precautions and never let anyone touch the energized circuit!

Thanks for reading,
Trenton