©2001 Jeremy Epstein. No reproduction, retransmission or web distibution without prior written permission.

This page has information about the
"Darling" amplifiers.
diy audio
octal riaa preamp
"free lunch"
6C45P riaa preamps
teres turntable
tuned quarter-wave pipes

The "Darling" amplifier experiments

After hearing about Bob Danielak's experiments with cheap, fun triode amps using the 1626 output tube for a while, I wrote to him and we began a long process of experimentation, some done in tandem, some seperately. His original "Darling" design, published in the pages of Sound Practices magazine, used 8532 (a high mu single small-signal triode) to drive a single 1626 per channel.

1626 is an indirectly heated power triode which was developed for ship-to-shore radio transmitter service. Using a single 1626 per channel power outputs are on the order of 3/4W, or as Bob likes to put it "seven hundred and fifty milliwatts!"

Bob Danielak maintains a page with great information about the "Darling" series, including versions done by some other experimenters, and this page shows some of the things we came up with together.

I was using speakers of moderate efficiency at the time and I was skeptical about the results I would get using such a small power amp, so we started discussing the idea of using two 1626's per channel in a parallel/single ended arrangement. I built up several experiments including a transformer phase-splitter push-pull version, an IT coupled version, and a few more. I ended up with the version shown here.

Later on I learned how to make this amp in a direct-coupled version, which was pretty cool. This amp has recently been modified to use the "Free Lunch" topology, I will draw up a schematic for that one at some point.

I wrote an article (intended for Sound Practices magazine but never published) about our ongoing lovefest with this basic design, and you can see it here.

I just want to mention two things here:

Bob always ends like this:

have fun!