Circulation:

Since
3/23/99

25448

Tube
Amplifiers for

Electrostatic Headphones

-part 2-

This
Issue

Last month's OTL electrostatic headphone
amplifier receives a thorough rethink this month. Undoubtedly, many
of readers have preamps and amplifiers that will never be finished:
they may be fully functional and sound wonderful, but next month
they will be altered, modified, or rebuilt altogether, not because
they were wanting in any real way, but because a new idea or the
recent availability of some part or even boredom compels us to not
leave well enough alone. Our friends and spouses will shake their
heads and wonder if we wouldn't be better off buying some cheap
table radio instead. My power amplifiers have gone through at least
10 rebuilds, if not 20. It is said that you cannot hear my
amplifiers twice.
One reader asked if the ES OTL
outlined in last month's issue could be used to drive ES speakers.
The answer is that the circuits in this month's article are better
suited if scaled up.
This month's design idea
reveals how an expensive audio accessory can be inexpensively
incorporated into existing components.
Remember, if you
have a request or suggestion of your own for either an article topic
or circuit, please e-mail:

Editor

First
electrostatic headphone amplifier

(click image to
see enlargement)

Second
electrostatic headphone amplifier

(click image to
see enlargement)

In last month's issue, we ended with what
had been done to last month's final
circuit; in this month's issue we will continue with what
could
be done improve the design. Worthy goals for a better design might
be better balance, more gain, greater voltage swings, lower output
impedance, and less noise and distortion.
The
first stage can be used in two ways and consequently viewed in two
ways. If an unbalanced input signal is used, then the second
triode's grid goes to ground and the circuit is a Long Tail phase
splitter. On the other hand, if a balanced input signal is used,
then the second triode's grid finds its own input signal and the
circuit is a Differential amplifier.

In This
Issue

1

13
15

Electrostatic Headphone
Tube Amplifiers -part
2-
Design
Idea: Polarized Wires
E-mail
Publishing
Information
Glossary
of Audio Terms
Glass-Ware.com
Articles

www.tubecad.com   Copyright © 1999 GlassWare. All
Rights Reserved

NEXT >