Got new DC-3, please help with tubes...

[lacto11]

I got my new DC-3, new to me anyway, last Friday. It is a beautiful thing, like new just taken out of the box. When I fired it up, it wasn't sounding so good, very hissy and microphonic even on low levels. I don't pretend
to know alot about vacuum tubes, never had an all tube amp, or a fixed bias amp, but I do read and I am learning. I played with switching the pre amp tubes around and sprayed the pins of all the tubes, power and preamp with some DeoxIt and that did reduce the noise quite a bit. I think these may be the original Mesa Boogie tubes from the late 90's, and from what I hear not good when new, so I'm going to retube the whole thing. Besides, just when I thought I had gotten the knack of changing the little buggers, I broke one last night.

I think I am pretty sold on trying JJ El84's for the power section, but not sure about the 12AX7's, if I should do it all with JJ or something else. I got some El34's for another amp from Eurotubes and liked doing business with him. Please any input is appreciated. If gp is reading this, tell me why you prefer RCAS. Also, I know I should get a balanced triode for the Phase Inverter tube, but should I pay extra to have the other five tubes balanced? Someone on this forum said that thetubestore.com "burns the tube to match the bias for boogies". What does that mean? I know that not all tubes of the same type will work in these amps, but are Eurotubes and thetubestore the only ones I can trust to send me compatible tubes if I tell them it is for a DC-3?

Sorry this is so long, but there is alot of knowledge on this board that I would like to tap into.

 

[fdesalvo]

Hey there and congratualtions on your lucky score! Do you have the combo or head format?

Preamp tubes that are on their way out are more obvious in combos due to the vibrations they are subjected to within the cab. A simple test would be to lightly pluck the preamp tube while the amp is in operating mode and listen for an mechanical noises such as pinging. Microphonic tubes will usually begin resonating once they are plucked. I would bet that a tube change is in order.

Alot of people rave about the "JJ" Tesla tubes, but I never liked them in any amps I tried them in- Peavey C30, Mesa DC, some of my homebrews...I find their ecc83s roll off the treble and sparkle in the preamp. Maybe that was just my experience, because people really love them!

It's also important to remember that most amp designers tune their amps to run with a particular brand of tube in mind. Mesa and Fender are just 2 examples of such companies who have made use of rugged, "lower quality" tubes. They make these tubes sound great! While the NOS stuff may carry alot of mystique and hype, I think they lose their charm in amps utilizing more than 2 or 3 gain stages in the preamp, where the details are lost in the saturation. They also lose their charm when they can't hold up to high gain at volume. I've seen 12AX7s go for upwards of $96, which is just rediculous.

Anyway, I'm ranting and I need my second cup of coffee EL84s are my personal favorite tube! No other power tube in common usage today has the same characteristics as the 6BQ5. I love how they sizzle when driven and get that greasy tone when you crank em! The JJs, again, sound too rounded for my tastes and I actually ended up liking the Russian stuff in my Boogie.

The best thing you can do is experiment--and you may be suprised with what you end up with! Take everything you read with a grain of salt becasue everyone is biased (hehe) and most folks choose tubes to make their Boogies sound like Marshalls and vice versa!

Rock on!

~F

Edit: It may seem that I am biased against NOS tubes, but I'm not. These tubes can sometimes improve the tone of any given amp and can help in remvoing a boxy, nasally, harsh, or brittle tone. I'm just tired of watching people get caught up in these substitution cycles and ripped off. People eventually spend less time playing and more time tweaking.

 

[lacto11]

Thanks for responding. I forgot to mention that it is a DC-3 combo.

 

[gp]

Hi, Do you have the manual? If not you can download it from Mesa,it tells you a lot about tubes.With the amp on tap the tubes lightly and see if they make noises,if so change them.I am partial to RCA 12AX7A's because they last forever and are very smooth and warm.For the el84's I went back to the Mesa's because everything else ran too HOT.But I had a real hard time with Mesa,it took 3 shipments of EL84's before I got 4 tubes that were usable and 1 died after a week.

 

[lacto11]

Hi, thanks for responding. I've got a manual so I know which tubes control what. I am hoping to get feedback on tonal differences of different brands, which I know is a subjective thing.