New In Box Gain Matched Pair JJ Electronics Tesla 12AX7 ECC83-S Vacuum Tubes

Im using the JJ's in my Pro-Ject Tube Box s. This is a Phono Pre...FYI. The Tubes instantly woke up my Vinyl Playback. Highs were more distinct with separation. I do hear an increase in low and mid range. I have Gold Lions in my Black Ice Audio Tube amp in my other setup. Im actually leaning towards trying the JJ's. in that setup as well. This is a fun sounding tube that gave my system a nice boost in performance. Id Buy again. Especially at that price.

These tubes really made a brilliant difference on my hybrid tube amplifier. After about 15 hours of use they settled in nice with clear high notes and lovely midtones and bass you can hear more than feel. Cannot speak on longevity yet because they only have been in use for around 50 hours. Good value so far.UPDATE: These tubes are performing flawlessly after one year of daily use. Very impressed! This is the only tube for my little amp!

My preamp uses two ECC83 tube's and two ECC82 tube's. I wrote a longer review of the 82's and everything I said about them applies to these. I am very satisfied with the sound of my system. The addition of the JJ tube's made everything better. Definitely worth buying.

They sound good and seem very good quality. I abused them bending the pins to fit my PCB boards. No problem at all. The China brand got the pins loose and broken glass with the same operation.

So I’d go for the short bottle ones on Fender amps. However I bought these for a Ampeg VT40 guitar amp. Had a microphonic one and just decided to get a pair just in case. Never can have too many preamp tube choices. For me they sound really great, and work on high gain amps well. Maybe a little different bottom than my Japan National 70s short tubes….those were more original to the amp, and sounded more rounded. However most would be hard pressed to tell. I use one of these in one channel for a more modern sound. Then I use another tube for an older sound.But they sound pretty modern to me. I still need to break in more than the 15hrs I’ve used them. But so far no complaints…just make sure you know there are longer than the non S version. So they do offer a bit more headroom before breaking up. And they tend to sound good in cranked amps to me. If I had a Fender Deluxe I go with the normal version. But a Marshall or Super Reverb you are cranking…these get the job done! Great for spares as well

Bought my first used tube amp! Of course it was making some weird ass noises. Replaced them with these JJ’s and it’s a whole new ballgame.

After install, my amp is rapidly popping, unaffected by volume or tone levels. Replaced my 30+ year old 12AX7 tubes with these, swapped them a few times to be sure I seated them right, and these are worse.

I used these to put in my Marshal DSL1HR amp head, and they work well.