Detail 01
6550 type
High-power output tube. Stays clean much longer than a 6V6 or EL34, with firmer bass and more headroom.
Product detailSKU #1274034486322
Tung-Sol6550 Tube Medium/Green Duet
Sale
1/4
Independent shopping perspective
The Korena take
Matched pair of 6550 power tubes, medium-graded. Replacement set for high-headroom amps built around 6550 or KT88-family output tubes.
Strong match
Who this is for
- Retubing a loud amp that needs to stay clean at volume
- Bass and large guitar heads with 6550 output stages
- Players who want tight low end over early breakup
Consider the trade-offs
When to look elsewhere
- Small combos running 6V6 or EL84 tubes
- Players chasing early, soft power-amp breakup
- Anyone replacing all four tubes in a quad amp with one duet
What matters in use
The specifications, translated
Catalog numbers tell only part of the story. These are the details most likely to change how this product feels, sounds, or fits into a setup.
Detail 02
Matched pair (duet)
Balanced current draw across the pair, which keeps hum down and the output transformer working evenly.
Detail 03
Medium grading
Middle of Tung-Sol's current-draw range. The general-purpose choice when you're not chasing a specific feel.
Detail 04
Green code
Tung-Sol's grading marker for this bin. Useful for reordering the same feel later or matching a second duet.
Detail 05
Higher price than smaller power tubes
6550s cost more per tube than 6V6 or EL84 types. Budget accordingly if your amp takes four.
Final check
Know before you order
- 01Plan on a bias adjustment after installing — most 6550 amps are fixed-bias
- 02Four-tube amps need two duets; order matched grading for both
- 03Confirm your amp actually specifies 6550 or KT88 before ordering
Product questions
Before you decide
Straight answers to the questions shoppers most often ask about this product.
01Are 6550 and KT88 interchangeable?
They're closely related and many amps accept either, but not universally. Check what your amp's manufacturer specifies before swapping types.
02What does the green code mean?
It identifies the current-draw bin — medium in this case. Note it down so a future replacement pair can be ordered with the same grading.
03Will these give me more overdrive?
The opposite. 6550s are high-headroom tubes, so the power amp stays clean longer. Overdrive has to come from the preamp or pedals.
04Do I need two sets for my amp?
If your amp has four output tube sockets, yes — order two duets and try to get them in the same grading so all four behave alike.
Reference
Full specifications
The complete catalog record, organized around the decisions musicians make when comparing gear.
1 detailsBody & build
- Color
- Green
