SET Asylum

Posted by tube wrangler (M) on September 15, 2023 at 17:32:51

In Reply to: RE: Ultralinear patent posted by Tre' on September 14, 2023 at 14:32:20

Pentode types: There will always be a time-delay
between plate and G2-- unless this
anomaly is corrected for-- a pentode
will never become a "good" triode no
matter how triode-connected or UL connected it is.

However-- there is a correction that
can be applied by designing the output
trans for the brand tube you are going to use--
(UL connection), OR by
designing a separate G2 supply that
applies the correction there-- or BOTH as I
am currently doing..

I am pursuing this KT88 thing
lately and over the last 2 years
I have made a few changes, as needed,
decided by direct comparison against
my own and other pure DHT triode amps.

Incidentally this pentode thing started
originally by using the KT-150.

I soon found SOME KT88 types that are
better built (don't rattle like a tin can from
crappy construction), and sound really good,
so the KT-150 quickly became an also-ran.

When a KT88 is run correctly, and
at the right plate current, and corrected
as stated (above), it can and does
sound just like the DHT triode amp with
some delightful additions:

(1) It has more bottom-end "crunch" and
layering of music, it has a deeper soundstage,
it has less hum (if both tube types have balanced A.C.
operated filament).

(2) The top-end extends further. In daily use, on
all kinds of music and sources such as Blu-Ray
movies, etc., this isn't needed, as the pure
triode DHT has enough of that anyhow, when used
with excellent parts.

(3) Once perfected, the two topologies sound
very much alike-- in practical usage terms--
but they won't measure alike....

All in all-- I love them both, and so do the
guys I know who are building both. All are SE
amps.

-Dennis-