Musician Gear & Tech Discussion

I have to replace the valves in my amp. Anyone care to voice what they like/would recommend?

I have a Marshall JCM 800 channel switching 100 watt amp if that makes a difference.

Thank you to anyone who responds.

I'm not too familiar with Marshalls, I run a Fender Super Reverb and a Peavey MX, both 6L6 power tubes, while I think the JCM 800 uses EL34's. They tend to have an edgier sound to begin with, and Marshalls are designed for higher gain, so you have entirely different characteristics.

The best tubes are NOS (New Old Stock) but hard to find and expensive. Sylvania, GE, RCA, and a couple others made tubes years ago, and a few are still out there waiting for someone with enough money to give them homes. I have a Sylvania 6L6 in my Fender Champ, it sounds noticably better than the Fender tube I took out of it. I got it at a resale shop (cost me a whole dollar) and it was probably made around the 1950's.

I've run Peaveys, Fenders, Ruby and Groove tubes in the Peavey MX over the past 15 years, the Ruby and Groove tubes were probably the best sounding ones.

The easier to find and more economical new tubes are sometimes not the same. Especially in some of the Chinese factories quality control is not great so individual tube quality varies. Sovtek has a good reputation, Groove Tubes and Ruby both tend to be pretty good. I've also used Peavey tubes in my super Reverb, they seemed to perform well, right now I'm running a pair of Chinese tubes that have done fine so far, about 3 years.

I think in general Sovtek and Groove Tubes probably have the best reputation.

You are correct. The fenders use the 6l6 and the Marshalls use the El34. I am leaning toward the Svetlana valves. I was wondering if anyone had a preference.

I found this place on line. They come highly recommended. Prices seem decent.

http://www.thetubestore.com/

I forgot about Svetlana, yeah they have a good reputation too. It's too bad tubes cost so much more than a set of strings, so it's not economically advisable to just try different ones out...but you're looking at around $60 for 4 tubes for a 100 watt amp, or more, while I get guitar strings for around $5 a set. Quite a difference...

I'll be replacing preamp tubes first, all my power tubes are fairly new, so I'll be replacing a half dozen 12AX7's but then I have to get at least 4 spare power tubes, preferably 6...2 in the Super, 4 in the MX, 2 in the Classic, but it needs repair so it's not an immediate issue, but if I ever happen to have to replace everything at once, I'm looking at a big bill...

I think one of my preamp tube replacements was a Svetlana, can't remember though, i've slept since then... Might have been Sovtek...

Don't forget when you replace power valves you have to get the amp bios'd. That's another $100 or so.

No need for bios-ing on the pre amp valves.

Yeah, I know that. Fortunately I haven't had to mess with the bias yet, when I swapped tubes it was still within tolerance. Guess I just got lucky...

Since my Super Reverb has a "hum balance" setup, I'm thinking about swapping it over to a fully adjustable bias, all it takes is a couple of resistors, just haven't decided whether I really want to go into my amp wiht a soldering iron...again...I've already replaced every capacitor in it, that's what it took to fix it when I got the amp. It would play great for about 15 minutes then the volume would drop as if someone had pulled a power tube. Afraid the whole time it was going to turn out to be a bad output transformer, I replaced the caps anyway. 30 years old and dried out, they needed it, and soon as I soldered in the last one it started working like a new amp. And sounds like one too.

Don't know much about the Peavey and it's on a PC board, not wired, so I might have to take it to a shop if it needs to be done later one. I'll have to look into it, but so far it's ok.

I got my Svetlanas today (a matched quad) and they kill. Love them. Man what a huge difference.

Coolness has been achieved!