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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


11/1/14

Acoustic Design For The Home Studio - Book Review

If you have ever browsed a technical book on acoustics it can be a bit intimidating. A ton of equations with a whole new language to learn. If you just want to "skip to the chase" you may want to read Acoustic Design For The Home Studio by Mitch Gallagher. It's available at Sweetwater.com for under $20.00.

Trenton-Blizzard-Acoustic-Design-Home-Studio-Blog

 

WHO IS THIS BOOK FOR?

This book is a great introduction to room treatment. It's written in a vary non-mathematical manner.
It's not for professionals. It's more like a "hands-on guide" for the home studio owner and musician. For some home owners, this may be the only book you need to immediately improve your home studio room acoustics.

HOW TECHNICAL IS IT?

There is only one equation in the entire book! Mr. Gallagher's approach is based more on explanations, illustrations, images and real world examples.

WHAT'S COVERED?

Here are some of the topics you may find helpful:
1. Golden Mean - "Golden proportions" are considered magical by some people in audio
2. Bass Traps - Bass Traps are like sex for your room. You just can't have enough
3. Diffusers - These bad boys help "smooth out" higher frequencies
4. Acoustic Software - Use it when you really want to "know" how your room sounds
5. Speaker Placement Rules - A quick guide to placing your speakers properly
6. Treatment Placement - Examples of "real world" room setups
7. Ceiling Clouds - These are interesting. I am definitely going to give these a try

CONCLUSION

For $20.00 Acoustic Design For The Home Studio is totally worth reading. It's also nice to have as a quick reference in your audio/recording library. 

Thanks for reading,
Trenton