Electro-Harmonix 6CA7EH Power Vacuum Tube (Matched)
Need matched power tubes? Don't worry! Price includes matching in any quantity you need for no extra charge. Need a matched pair? Just order "2" tubes. For a matched quad order "4" tubes. Matched sextets and octets are available as well.The Electro Harmonix 6CA7-EH power vacuum tube has been available for nearly 20 years. This power tube is a tribute to the legendary USA made Sylvania/Philips 6CA7 tube, with its fat-bottle and sturdy plate.
This 6CA7 vacuum tube can be used in nearly any EL34 tube amplifier, and is considered a drop-in replacement. However, it does have different bias voltage requirements than most EL34 vacuum tubes. We find often an increase of about 30-50% more bias voltage is needed to operate the 6CA7 appropriately. If you're not sure if your tube amplifier is compatible check with us or a technician you trust. If you're amp's stock bias range can't dial them in, usually a simple resistor change is all that's needed.
The history of the 6CA7 is quite interesting. Eric Barbour's article (Senior Editor, VTV Magazine 2001) has a good summary of how it began. In the very late 1960's, Sylvania "took a 6550 structure and changed the grids, so the tube biased like an EL34." Simply, Sylvania wanted something to compete with the popular British Mullard EL34 at that time. So in technical terms it is actually a tetrode and does have more of a 6550 tube sound characteristic because of it. Normal EL34 tube types are pentodes. Eric mentions the reason for why EL34 sound so different from 6550, 6L6, KT77, etc is because at the time they were considered a lower cost option with a softer vacuum than the 6CA7 and 6550 tubes. This leads to them being easier to drive, and having smoother overdrive, than 6L6 and 6550, especially when really pushing them in a tube guitar amp.
Other Electro-Harmonix tubes
EL34 Tube TypesAdditional Information and Downloads
Reviews:
EL34 Tube Review
Tube Matching Information:
Power Tube Matching FAQ
Perfect Pair System
Downloads:
Electro-Harmonix 6CA7EH Datasheet (PDF)
Download Adobe Acrobat PDF reader
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
16 reviews
Electro-Harmonix 6CA7EH | Good all rounder
by Steve -
I have a pair of these EH-6CA7 in a hot rodded JCM 800 slo mash up type amp I build and so far there hanging in there pretty decent. I run the gain around half and these clean up really nice with a tele or strat and get very nice full bodied cleans or nice overdrive with the volume up. With humbuckers they also clean up nice but add a boost or overdrive and they do thick percussive chug very well. They are fatter and more mid scooped than an EL34 but i really like them so far and are great for clean and dirt. They are different than a typical EL34 but very nice and worth a try if your looking for something different. I plan on keeping them in the amp and hopefully they last longer than modern EL34 tubes generally do with heavy use.
Electro-Harmonix 6CA7EH | The poor man's KT88
by Scott MC -
Was sad when a quad of EH KT88 being used in my Jolida started to fail, and recent pricing has made their replacements very dear. Has previously had a set of EH EL34, but found them simply unsuitable for the crunchy, bassy rock I listen to.
Hearing good things about these EH-6CA7 tubes, I ordered a quad and was very pleased. Although they were more recessed in the mids, with a slight bit less presence, their overall sound signature was a KT88 "light". Most of the good stuff was still there.
I rolled in a set of JJ 6CA7 to compare, and the differences were immediate and apparent. I could see the JJ sounding excellent in a guitar amp when crunch and dark tone is important. But not as well-suited for stereo listening.
Highly recommended for those on a budget.
Electro-Harmonix 6CA7EH | EH 6CA7
by Steven
Great tube that takes you from 6L6 to high gain EVH territory and very reliable!
Electro-Harmonix 6CA7EH | Too Hot to Handle
by Alan Johnston
I tried these EH-6CA7 in my old Heathkit 40 watt amplifier. They do sound very good, but these take more current so the power transformer runs hotter. To hot to touch after an hour, So I put the old Ei 6CA7s back in.
Note from thetubestore: The 6CA7EH tubes are similar to EL34 tubes and have a wide range of natural current draw. Many will run hotter if the amp is not rebiased. Assuming they are biased the same as other tubes, they will not run hotter.
Electro-Harmonix 6CA7EH | Great choice
by Patrick -
First Of all… excellent customer service and shipping speed was outstanding!
These EH-6CA7 really woke up my 91 JCM900 50 watt. Tone is great. Attack is more pronounced. Very satisfied!!