Electro-Harmonix 6CA7 No Cryo Reviews

4.9 Rating 23 Reviews

Visit Product Page

Phone:

909.931.9686

Email:

joel.m@upscaleaudio.com

Location:

2058 Wright Avenue,
2058 Wright Avenue
California
91750

Visit Product Page

“Well, Upscale clearly knows their stuff and also has competitive pricing. These particular 6CA7 tubes sound great, and you can tell they are heavy duty quality for current manufacture. Here's to the beginnings of the return of decent current production tubes again!!”

Helpful Report

Posted 4 years ago

Joseph Recknor

Unverified Reviewer

“I love the beautiful detailed sound this superbly matched 6CA7EH quad makes in my Dynaco ST-70. This time I got them from Upscale and I am glad I did. The shipping box had room for generous padding and Upscale used energy absorbent foam cylinders thus preserving the precisely matching clearances in these tubes during transit. The tubes had matching date codes too, often a lead in to very tight matching. Stickers on the tube boxes showed Transconductance to match within 6% and when I measured them they were even a bit better than that! Current matching was within 1% !!!! when I tested them. So, best packed and best matched power tubes I have ever received. The sound detail is very fine. These replaced a quad of poorly matched 6CA7EH I got from another supplier whose packing just may not have protected them or maybe they just were not well matched to start with. Those had about 20% Transconductance variation and about the same on plate current, yikes! It is power tubes from Upscale from now on!”

Helpful Report

Posted 4 years ago

Thierry Gross

Verified Reviewer

“Terrific balanced valves,with bass authority is replacing Tungsol EL34b and 7591a. Really nice in my MP 301 mk3.”

1 Helpful Report

Posted 4 years ago

“Using these in a Decware Torii Jr. Very transparent, with nice bass extension. Clear highs. I’ve tried a few EL34 and substitutes. I prefer these and perhaps the JJ 6CA7s over EL34s or KT77 and KT66s—though I haven’t tried the Tung-Sol EL34s, which are also supposed to have a deeper bass extension than other EL34s. That said, I don’t think the Tung-Sols can achieve what I’ve found with the 6CA7s due to the 6CA7’s tube construction. As with the JJ 6CA7, the beam-forming plates are NOT internally connected to the cathode in the EHX 6CA7 (despite what you may have read elsewhere on the internet). This permits the use of the so-called Hazen mod, or CCE mod, found in many Decware amps. Though this mod is available when using the EL34, I think the beam-forming plates of these 6CA7s increases the effect of the Hazen mod over and above what the suppressor grid (G3) found in the EL34 can provide, and this *really* reduces secondary emission—and improves clarity, at least to my tin ears. Neither the beam tetrode Gold Lion KT77s or KT66s achieved as much transparency (my wife agreed), and I believe it is because neither has the ability to use the Hazen mod due to the internal connection of the beam-forming plates to the cathode in those tubes. If you are using a Decware amp or other amp wired to effectuate the Hazen mod, you owe it to yourself to try a modern production 6CA7. I think the EHX has better ”resolution” and highs than the JJ, while the JJ may have a touch more instrument separation and warmth.”

Helpful Report

Posted 4 years ago

K RYAN SHULTZ

Verified Reviewer

“I love these tubes. I’ve been using them in an unmodified Dynaco Stereo 70 for years now replacing them every year or so and keeping the spares for back up. Very rugged modern production 6ca7. They sound great in my circuit and thanks Upscale for the great service and fast shipping!”

Helpful Report

Posted 5 years ago

“As always, Kevin and Upscale provided an incredible customer experience. My amplifier is very sensitive to tube matching and my quad is dead quiet. Not sure, that these are the ultimate 6AC7/EL34/KT77 in my system, but a great back up set of tubes.”

Helpful Report

Posted 8 years ago

“A nearly dead-on copy of the Sylvania/Phillips version of the only truly American EL34, the big bottle 6CA7(no other EL34 variant of the golden era was ever made in the US!).Like the originals, these bias a little "hotter" than a regular EL34 tube and provide a very warm, powerful signal, with noticeably more volume at lower power levels.And yes they do look cool with a 6550-esque vibe.”

Helpful Report

Posted 13 years ago