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← KT88
Rolling Candidates to replace KT88
Beam Tetrode — Octal
⚠ Safety
Drop-In Replacements
✓
CV5220
✓
KT88S
✓
KT90
Top 10 Picks
6550
drop-in
6.3V
✓ Close
KT77
drop-in
6.3V
⚠ Close, low Pa
6CD6G
drop-in
6.3V
⚠ Close, low Pa
6L6GC
drop-in
6.3V
⚠ Low Pa
7581
drop-in
6.3V
⚠ Low Pa
350B
drop-in
6.3V
⚠ Low Pa
5881
drop-in
6.3V
⚠ Low Pa
6N3C
drop-in
6.3V
⚠ Low Pa
6V6
drop-in
6.3V
⚠ Low Pa
6Y6
drop-in
6.3V
⚠ Low Pa
Rolling Candidates (128)
i
Heater:
2.1V
0
4V
0
6.3V
9
●
8.4V
0
12.6V
0
13V
0
15V
0
16.5V
0
18.9V
0
19V
0
21V
0
22V
0
25V
0
26.5V
0
30V
0
33V
0
35V
0
45V
0
show all (18)
Fit:
Drop-in
1
Adapter
8
Status:
✓ Close
3
✓ Safe
6
⚠ Close, low Pa
2
⚠ Low Pa
117
9 shown (target 6.3V only)
▣ Compact
⚙ Thresholds filter
6.3V Heater
(9 candidates)
Tube
Status ↑
Pa
Ah
Fit
6550
✓ Close
42
W
1.6
drop-in
KT170
✓ Close
85
W
1.85
adapter
KT150
✓ Close
70
W
1.75
adapter
KT120
✓ Safe
60
W
1.8
adapter
EL156
✓ Safe
50
W
1.9
adapter
EL51
✓ Safe
45
W
1.9
adapter
12E1
✓ Safe
35
W
1.6
adapter
6HV5A
✓ Safe
35
W
1.8
adapter
7027A
✓ Safe
35
W
0.9
adapter
Generated 2026-04-09
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