Golden Voice KT88+


Golden Voice KT88+




1. Improve the cathode emission materials and structure, so the electronic emission capability enhanced. At the same time , increase the area of anode metal plate to improve power of anode dissipation

2. Strictly control the size error of filament, anode and various key parts, and make sure that the product has good consistency.

3. Products burn-in under high voltage 600 v (burn-in time 2-3 times of ordinary products), long hour burn-in to allow less impurity and less intrinsic baseline noise, and more stable performance over long lapse of time.

4. Use gold-plated tube needle and upgrade to a stronger metal base, while improving the quality of the tube seat, the whole tube is more elegant and elegant.

5. The products are screened and tested with imported test system, and the Ia and Gm are used to match the products to ensure the stable and reliable product quality.

Golden Voice KT88, GV KT88

Golden Voice KT88, GV KT88
Golden Voice KT88, GV KT88
Golden Voice KT88, GV KT88
Golden Voice KT88, GV KT88

KT88

KT88 is a beam power tetreode, its anode limited dissipation power is 42W. In the audio amplifier, the power can be 100W when it is used as push-pull class AB1 with double tubes, it can also be used in electronic voltage regulator circuit. KT88 is similar with CV5220 and 6550,they can be replaced by each other.

Heater
UH………… 6.3 V
IH………… 1.6 A

Maximum Rating
————- –KT94 KT100 KT94 KT100
Ua……………… 800 800 800 800 V
Ug2………… 600 600 600 600 V
Ug1…………-200 -200 -200 -200 V
Pa………… 42 45 35 40 W
Pg2…… 8 8 6 6 W
Pa+g2… 46 49 40 45 W
Ik……………… 230 230 230 230 mA
Uh-k……… 200 200 250 250 V
Tbulb……………… 250 250 250 250 C

Rg1
with cathode bias
— —Pa + Pg2≤ 35W 0.47 MΩ
— —Pa +Pg2 > 35W 0.27 MΩ
with fixed bias
— —Pa +Pg2≤35W 0.22 MΩ
— —Pa +Pg2> 35W 0.10 MΩ

Direct Interelectrode Capacitances

— – – –triode connection and tetrode connection
input……… 16— -9.3 PF
output……… 12 — -17 PF
grid to plate……… 1.2 —-7.9 P

Static parameter

tetrode connection
Ua…………………250V
Ug2……………… 250V
a………………… 140mA
Ig2(approx)…… 3mA
-Ug1(approx)……15V
Gm………………… 12mA/V
ri …………………12KΩ
μg1-g2…………… 8

triode connection
Ua.g2……………250V
Ia+g2……………143mA
-Ug1(approx)… 15V
Gm…………………12mA/V
ri…………………670Ω
μ………………… 8

Series KT88 KT94 KT100

KT88-978

Recommended Operating Conditions(reference value)
Push-pull.classAB1.cathode bias.triode connection.

Ua.g2(b)………………400 485 V
Ua.g2(O)………………349 422 V
Ia+g2(0)………………2×76 2×94 mA
Ig+Ig2(max.sig)……2×80 2×101mA
RL(a-a)………………4 4 KΩ
-Ug(approx)………… 40 50 V
Pout………………… 17 31 W
Dtot ……………… 1.5 1.5 %
Pa.g2(0)…………… 2×26.5 2×40W
Pa.g2(max.sig)……2×19 2×27 W
Rk……………………2×525 2×525Ω
ū(g1-g1.pk)…… 78 114 V
Zout………………… 2 1.9 KΩ

Push-pull.classAB1.cathode bias.tetrode connection.

Ua(b)……………………560 V
Ua(0)……………………521 V
Ug2…………………… 300 V
Ia(o)……………………2×64 mA
Ia(max.sig)……………2×73 mA
Ig2(0)…………………2×1.7 mA
Ig2(max.sig)………… 2×9 mA
RL(a-a)……………… 9 kΩ
Rk……………………2×460 Ω
-Ug1(approx)…………30 V
Pout……………………50 W
Dtot……………………3 %
Pa(0) ………………2×33 W
Pa(max.sig) ………2×28 W
Pa2(0) ……………2×0.5 W
Pg2(max.sig) ……2×0.7 W
?(g1-g1.pk) ………60 V

KT100
Push-full.class AB1.fixed bias.ultra-linear connection.
(40%tapping points)
U a.g2(b)………………560 460 V
Ua.g2(0)………………553 453 V
Ia+g2(0)………………2ⅹ50 2ⅹ50mA
Ia+g2(max.sig)…… 2ⅹ157 2ⅹ140mA
RL(a-a)…………… 4.5 4 KΩ
-Ug1(approx)…… 75 59 V
Pout………………… 100 70 W
Dtot ………………………2 2 %
Pa+g2(0)………………2ⅹ27.5 2ⅹ27.5W
Pa+g2(max.sig)………2ⅹ33 2ⅹ27 W
ū(g1-g1.pk)…………140 114 V
Zout…………………… 7 6.5 KΩ

Push-full.class AB1.cathode bias.ultra-linear connection.
(40% tapping points)
Ua.g2(b) …………………500 375 V
Ua.g2(0) …………………436 328 V
Ia+g2(0) …………………2×87 2×87 mA
Ia+g2(max.sig) …………2×99 2×96 mA
RL(a-a) ………………… 6 5 kΩ
Rk…………………………2×600 2×400 Ω
-Ug1(approx) …………… 52 35 V
Pout…………………………50 30 W
Dtot……………………… 1.5 1.0 %
Pa+g2(0) ………………2×38 2×28.5 W
Pa+g2(max.sig) ……… 2×17 2×16 W
?(g1-g1.pk) …………… 104 71 V
Zout……………………… 4.8 4.5 kΩ

Push-full.class AB1.fixed bias.tetrode connection.
Ua(b) ………………………560 V
Ua(0) ………………………552 V
Ug2 ……………………… 300 V
Ia(0) ………………………2×60 mA
Ia(max.sig) ………………2×145 mA
Ig2(0) …………………… 2×1.7 mA
RL(a-a) …………………… 4.5 kΩ
-Ug1(approx) ………………34 V
Pout…………………………100 W
Dtot………………………… 2.5 %
Pa(0) ………………………2×33 W
Pa(max.sig) ………………2×28 W
Pg2(0) ……………………2×0.5 W
Pg2(max.sig) ……………2×4.5 W
?(g1-g1.pk) ……………… 67 V

7 thoughts on “Golden Voice KT88+

  1. I received the tubes same day I enquired of the ship date.
    I thought you might like to know my opinion and put on your web site as a positive testimony.

    I recently installed a set of golden voice kt88+ tubes in my latest SET integrated tube amp build project. For the last 18 months I have experimented with different inter-stage coupling capacitors, input tubes, and power tubes trying to find some combination that would provide that last bit of improvement that I knew this build had. After many combinations tried, parts researched, purchased and returned to my parts bin, I purchased and installed a pair of the golden voice kt88+ tubes. The improvement was immediate, extreme, and oh so satisfying. Previously, this amp rolled off at the high and low end much sooner than I thought it should. With the kt88+ tubes, the high and low ends are extended producing a much more balanced audio range. The lows are also much better defined, sounding more like notes and not tones. The same is true for the upper registers. Kettle drums are real, producing the skin effect while symbols ring ever so clear. The mid range is cleaner and simply sparkles. Additionally, imaging and presentation are improved. There is much more space between instruments and the image is no longer limited to 2 dimensions. I now have the 3 dimensional bubble that I have been striving for.

    As an engineer and audio hobbyist, I highly recommend the kt88+. It has brought me much closer to my audio goal.

    Jim
    Angel Audio
    Engineer

  2. Hi,
    The valves have been used as part of an upgrade I am making to my Bewitch KT88 amplifier. This is a secondary system that I use principally as a digital music system.

    The system comprises:
    Bewitch KT88 amplifier
    SMSL M8 DAC
    Home made turntable with SME 3009 Series 2 Arm & Shure V15 III
    YAQIN 12B (modified) Phono preamp
    Gale Loudspeakers

    I normally play HD music files (FLAC, DSD64/128), primarily blues, 60’s/70’s rock, folk.

    The new KT88’s replace a set of 4 matched JJ’s which have been in the amp for many years. The new tubes are still burning in as I haven’t had too much time since getting them but I enjoy their sound more than the JJ’s – they seem to have more breadth and are certainly cleaner sounding. I’ll update you once they have a few more hours on them.

    I also noted that the heaters are much brighter.

    I hope that provides the feedback you are looking for.

    Cheers
    Ian

  3. The golden voice kt88 tubes arrived and I finally got there to pick them up. They are very well made and hold bias perfectly. They only have a few hours on them. Very good detail, but light in the bass. I never judge a tube until at least 50 hours so I am not worried, but they do have less bass than the KT88z or the Gold Lion reissue so far. Do you know how long they take to fully break in? Just curious. It is a very good tube for me, but right now it is light in the bottom end. I assume that will develop in the next 50-75 hours? They are biased at 75% of maximum dissipation, where I run all kt88 tubes in my amps.

    Thanks,
    Don

Leave a Reply

Your email address will not be published. Required fields are marked *