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
supersaiyanquest 