Electro-Harmonix 7591A
The once extinct 7591 tube is now available again. The Electro Harmonix 7591A tube is smooth, yet punchy, with a sweet harmonix finish. Ampeg owners, rejoice! Their height can still be an issue, though, as they measure 3 3/8" (about 9 cm) from the bottom of the base to the top of the glass.
Other Electro-Harmonix tubes 
7591 Tube TypesAdditional Information and Downloads
Tube Matching Information:
Power Tube Matching FAQ
Perfect Pair System
Downloads:
Electro-Harmonix 7591A Datasheet (PDF)
Warranty Information and Return Policy
Warranty Period: 3 monthsAll our tubes are guaranteed for 3 months from the date of purchase. (Any exceptions will be noted on that tube's Warranty tab)
If you receive a tube that does not perform to the manufacturer's specifications, please do the following:
- contact us to get a return authorization
- return it via regular mail within 90 days from when we shipped it, and we will provide an exchange or refund of the full purchase price of the tube.
Returns not related to warranty or defect will be considered at our discretion, and are subject to a 15% restocking fee.
We can not accept returns that don't have an authorization, are past 3 month, or are returned improperly.
These guidelines may be updated without notice.
Ratings & Reviews
2 reviews
7591A in old Ampeg Gemini
by Mike T.
I have nothing but good things to say about the Electro Harmonix 7591A power tube. Strong, tight and responsive with vivid presence and clarity.
That's while playing a guitar with humbuckers or with single coils...... No effects..... Just a cord.
hope quality has improved
by arni
Bought 2 sets of these a few years ago (8) They are used in a fisher 500c and 800 series stereos. One set is still going strong, but the other 4 , the silvery coating went brownish, I think they may have been not properly evacuated. I tube analyzed them , and gassy.
I like the mechanical build, and i will try another set. But I hope the quality has improved since the takeover.