| TAD KT88 [message #98750] |
Thu, 03 July 2025 22:06  |
positron
Messages: 140
Registered: May 2020
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Master |
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Has anyone heard or have info concerning the TAD KT88? German manufactured or just tested for specs?
Cheers
pos
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| Re: TAD KT88 [message #98778 is a reply to message #98772] |
Thu, 17 July 2025 19:19  |
positron
Messages: 140
Registered: May 2020
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Master |
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Wayne Parham wrote on Wed, 16 July 2025 17:11
Oh wow, let me know what you think! I may have to buy a pair and check 'em out for myself!
I have a pair of original Tung Sol 6550 tubes. Not NOS 'cause I use 'em from time to time. But I treat them like they are precious family China. Not for use every day. Not even for every Christmas. Only for Christmas' when royalty visits. LOL!
And I have a bunch of Mullard 12AX7 tubes, which I have found that I like a lot. So I'd be happy to try Mullard KT88s. Not sure how I missed those before now. Somehow, I looked right passed 'em, I guess.
Will do Wayne. A friend had a used pair of 6 year old reissue Mullard KT88s
and they do spark my interest. Auditioned and the bass was less but tight,
maybe too tight, but then the M pair are somewhat used.
I can always tweak my monoblocks to increase bass (accuracy/naturalness)
if the new ones are a little light.
The 1,000 hour reissue Tung Sol 6550s had the same idle cathode current as
the other quad new TS in the boxes, was impressed, but then one of the used
TS started arcing with only ~440 p to k volts, 70 ma.
Besides that the TS side getters were pretty much used up, while the used
M had virtually no side getter deterioration.
Will be a little time to test, get some hours, but will report back Wayne.
cheers
pos
I just found a couple of selections from Anna Lapwood, Prince Albert Hall,
London. Had forgotten how majestic a pipe organ can sound. The first is a
cover of the Da Vinci Code.
https://www.youtube.com/watch?v=3HHtulwmk6U
https://www.youtube.com/watch?v=0WEY2A5MiWE&list=RD0WEY2A5MiWE&start_radio=1
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| Re: TAD KT88 [message #98792 is a reply to message #98780] |
Sun, 27 July 2025 19:48 |
positron
Messages: 140
Registered: May 2020
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Master |
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Wayne Parham wrote on Fri, 18 July 2025 07:59
Very cool, thanks!
Your welcome Wayne.
Well, I have received and some 17 hours on the quad, matched
by TubeDepot located in Memphis. I measured the idle current
and found that the 4 tubes were matched to within 1ma difference.
Actually 0,75ma. (I am not affiliated in any way with TubeDepot.)
Wayne, it is difficult to describe the sonic change due to
dealing with realism, live sound.
The new Mullard KT88s were clearly superior to the new TS 6550s
and other output tubes I have tried, in just about every respect.
I had a disappearing system for decades, then realism some couple
of decades, one could be satisfied with,, until,,
one auditioned more real, live. I think we all do that in our
systems. That presents a question.
When is one bumping against the recording
quality vs how much is lack of playback quality.
Poor quality parts, especially electrolytic capacitors cause masking
problems. Friends over verified what I was perceiving.
Don't mean to sound conceited, but friends and I perceive 1 part
in 4 million consistently. This is the result of using
accurate polypropylene decoupling capacitors from dac, phono stage srouces,
through to speaker crossover. Had no idea it would come to this
when starting back in 1980.
Friends and I can bypass a 47ufd Mundorf with a 12pf in the speaker
crossover and way too bright. I am currently using a series notch filter,
6.5khz across the full range driver. In series with the CL filter am using
a 3.3 megohm resistor, 3 meg sounds too full and 4 megs sounds too lean.
The Mullard produce Cleaner sounding, crisper/attacks, more natural bass,
venue is more realistic, spaciousness increased.
With the above said, typical systems with electrolytic capacitors may not
notice that much difference, between the reissue Tung Sol 6550s and
reissue Mullard KT88s. It will depend upon the system.
The new Mullard KT88s are now the standard for me.
If one gets a chance, a good read is a 2 part article
"Picking Capacitors" by Walter Jung and Richard Marsh.
I hope I have not come across as arrogant. The info is the
result of decades of lab work/research.
Cheers
pos
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| Re: TAD KT88, Mullard [message #98794 is a reply to message #98793] |
Mon, 28 July 2025 18:59 |
positron
Messages: 140
Registered: May 2020
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Master |
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Wayne Parham wrote on Mon, 28 July 2025 08:43
Thanks for the review on the Mullard KT88 tubes! I think I'll get a pair and give 'em a listen!
Before you do Wayne, I just compared the new Mullards to the
Winged C KT88s for a more complete review.
I like the Mullards better.
The WC KT88s are softer sounding, which is probably better for many.
The Mullard KT88s have a cleaner, sharper leading edge, midrange that is
not as soft sounding, and has taught bass compared to other tubes, so
conducive toward live sound,
but, if one does not use large enough coupling and decoupling capacitors
in their preamps and amps, the sound may, probably will, sound lean,
appearing to lack bottom end.
I use 2uf coupling caps in my 2 stage monoblocks and 6ufd output caps
set with 22k ohm impedance (including amp's input impedence (Z)
as my output capacitors in my preamplifier as an initial reference point
to see how I dealt with the lower frequencies.
Of course the decoupling capacitors affect the low frequency
response as well.
Cheers
pos
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