Pre-amp tube replacement for Orange Micro Terror: JJ 5751 review

I recently purchased JJ’s iteration of the 5751 pre-amp tube. I have been using the stock JJ EC883 tube on my Micro Terror for the past year and thought a replacement, or at least a backup that I can experiment with, wouldn’t hurt.

I specifically chose the 5751 tube based on the description I found on Eurotubes.com.

The JJ 5751 has all of the qualities we have come to expect from JJ Electronic, a nice tight low end, a natural open mid, a great harmonic structure and a sweet high end that is not brittle. This is a great tube for V1 if you’re trying to drop the gain a little and improve headroom. You can also use a balanced version of this tube as a phase inverter to further increase headroom in amps that incorporate a long tail phase inverter circuit and usually use a 12AX7 or ECC83.

I liked how it was described and I would say that they are right on 100% with the description. Now, the main reason I selected this tube was to somewhat improve the amps’ gain tone. If you’ve played through a Micro Terror before, you’d know that coaxing any high gain setting with the volume cranked would sound really muddy and un-refined. JJ’s 5751 was the perfect cure. It instantly took away the unbearable mud you’d usually hear with gain knob past 3 o’clock and volume cranked. This tube is definitely a keeper. I have now shelved the stock EC833s.

Clean. My Lace Hemi humbuckers are described as having sparkly, bell-like tones. For a while, I’ve never really paid much attention to this as I am down tuned to C# standard 100% of the time. I really don’t expect to hear Fender-esque tones, nor have the desire to. The very first tune I played after plugging into the Terror with the replacement 5751 tube was APC’s The Stranger, one my favorites off their 2nd album. With the tone knob on my guitar rolled off to about 3-4, I was really amazed to hear an acoustic like tone with a really sweet high end yet still retaining that woody mid sound which I really like. Far from a Fender type clean, but a clean sound that I really like. Detuned, acoustic-like, with bell like top end that is strong and refined.

Distortion. I made a few adjustments on the rest of my rig to compensate for the change in the Micro Terror’s tone after changing into the 5751. The verdict is still in progress, but I do love my distortion sound on the stock EC833s. If plugged in direct, the 5751s gain is no question better than the ec833s as it retained clarity even with the amps gain knob past 3 o’clock and volume cranked. The predicament is with balancing and eq’ing the rest of my pedalboard in, which is something I still have to experiment with.

Settings: Amp volume cranked, tone at 1 o’clock, gain at 11 o’clock if using pedalboard distortion/OD. Gain at almost 3 o’clock when plugged in direct.

Verdict. Definitely a keeper. I would reckon that the JJ’s 5751 would sound good with any amp from Orange’s Terror series. I also think it would sound good in any V1 position of an all-tube amp. If you’re looking to tame the gain stage of your amp without losing volume, then this is for you. I play mostly classic riffigin’ and modern sludge, doom, stoner tunes and the tone I get from the 5751 suits me fine. Now, I need to secure funds to try out some JAN 5751s. 

Cleaning preamp tube pins of the Orange Micro Terror amp

HACK OF THE DAY

Cleaning the preamp tube pins of an Orange Micro Terror amp head

El Mikro El Terrible El Mickro Terorista

I was browsing thru the archives of Eurotubes.com with the intent of replacing the preamp tube of my Orange Micro Terror. The sound I am going for is really geared towards, dirt, grit, mud, more mud and then some fuzz. But recently, I’ve noticed that my sound muddied up by a few more notches moving towards unlike-ability, hence, my desire to experiment with other tubes. I was initially looking at a reissue of the Tung Sol 12AX7 because of rave reviews of it on forums, but I left my choice open for other JJ variants knowing how durable they are. Eurotubes peeps are known to be big JJ tube geeks, so they know their JJ tubes more than any other seller in the market, I reckon.

The JJ 5751 wound up to be the likely replacement candidate. I like what the description make it sound to be. It sounded to be just the right ticket for me to reduce gain and increase the amps head room. I am sold on JJ’s 5751 variant and actually bought one the same day when I saw that my trusted online supplier has it on stock. More on the JJ 5751 as I intent to publish a separate article about it in due time. 

Gut shot of PCB and the socket of the pre-amp tube

After I made the tube purchase (along with more goodies), I resumed browsing thru the Eurotubes article archives. One article that struck me is about the fact that the majority of tube related issues can be attributed to dirty preamp tube pins. Like most metal, the preamp pins oxidize over time. Rust on the pins has been found to be one of the main reasons why tubes may go bad and loose its tone. The article makes a point about how a simple tube pin cleanup will make the tubes spring back to life.

That sounded an easy enough hack for me.

This would be my first attempt at working with an amp tube. The brute in me second-guessed whether or not my flimsy fingers would break the seemingly fragile tube. I later found out though that the tube is sturdy enough to be wiggled-free from the PCB socket. Just make sure to rock it back and forth gently enough not to bend the pins past a few degrees. Also, don’t press it hard when putting it back or you migh crack the PCB board.

Stock pre-amp tube of the Micro Terror. A JJ 12AX7 EC883S

I used a q-tip, dipped in denatured alcohol, to clean the pins and socket of the PCB. I also used tissue napkin to clean dust and sludge. Being my first tube removal experience, I was overly cautious not to bend the pins of the tube. I made sure to use the same tissue to handle the tube as i’ve read that skin oil actually contributes to lessening the life of an amp tube. I re-assembled everything back. Plugged the Micro Terror to the speaker cab, and my LTD ec-50 to the amp, un oh! The amp sings again! A stark contrast to the lifeless sound it had before. I noticed that there’s a touch more clarity and the sound is now more refined. Definitely, mud and fizz drastically lessened. Cleans sounds more ‘sterile’, but in a good way. All in all, I highly recommend this simple mod, actually, more of a tube amp (okay, I know my amp is only a hybrid, but it has a tube so it counts!) maintenance thing more than anything else. For practically free, I suggest cleaning your own preamp tubes as frequent as a couple of months or even just once a year. This simple hack would definitely improve any guitarist tone.

Salamat!

– Jay