Electro-Harmonix 6CA7EH Power Vacuum Tube (Matched)
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 tubesEL34 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 | Excellent tubes!
by Chris Robinson
These EH-6CA7s remind me of the older EI's that I would use on tour with my old Matchless in the 90's when they were easier to find. I use them instead of El34-s for a touch more boldness and headroom with my old Chieftain and it does the trick. Also using old GE 5751s in V1 and the PI positions.
Electro-Harmonix 6CA7EH | It’s like an EL34 and 6550 had a baby and that baby kicked all sorts of ass.
by Scott
Beefy, full tone. The EH-6CA7 brought my amp back to life.
Electro-Harmonix 6CA7EH | Classic Rock Tube
by Mike
Have a octet of these EH-6CA7 in my Primaluna Dialogue HP amp. Much more high and mid information with a tighter low end than the Electro-Harmonix EL34's. They took about 50 hours to really come around, but worth the wait. A bargain price with performance that shines, at least in my hi-fi amp. Been running them 10+ hours nearly daily for 8 months - no problems at all & sound great. A unique sounding tube, I listen to classic rock from cd-sacd's with PL Dialogue Premium tube pre-amp & Aurum Cantus M102SE's with ribbon tweeters and they just SING & POP! I've tried KT88's & 6550's and these IMO sound much more balanced & musically satisfying. I've been told these are mainly for guitar amps, but in my system they have found a home. Check 'em out in your hi-fi rig, I think you'll agree. by the way, the preferred series 5AR4 rectifier tubes are excellent in my pre-amp, best I've tried! Mike
Electro-Harmonix 6CA7EH | Mini Silver Jubilee? get these!
by Mike
These EH-6CA7 were recommended by others for use in a Marshall Mini Silver Jubilee. Excellent, just what I was looking for. Gives the amp more of a Big iron sound like the original Jubilee series.
Electro-Harmonix 6CA7EH | Excellent in Orange Rockerverb MKIII
by John
These EH-6CA7 have been fantastic tubes, and I absolutely love these in my Orange. I'll be sticking with these instead of the EL34's I was using before.