does my ac30 need new tubes?

[Jbrazz]

it is my first tube amp so im kinda new to this so bear with me.

 

some times when i play a note the amp will make this sound, much like the sound you get when you run the needle accross a vinyl record. and this will last quite a while.

 

ive tried giving the amp a 'tap' and it seems to affect it in some way.

 

im guessing i need new tubes....

 

 

halp?

[mrweems]

New tubes wouldn't hurt.

 

I'm about to retube mine just for the hell of it.

[Jbrazz]

about how much will it cost?

 

Is it possible or a good idea to do itmyself?

[mrweems]

about how much will it cost? Is it possible or a good idea to do itmyself?

 

 

Cathode bias, meaning you can retube it without biasing.

 

SO yes, you can. Just make sure you get the correct tubes. There are a few discussions on this in the ac30 thread.

 

But IMO.

 

Gz34 = Get a NOS Mullard one if you can. They outlast every GZ34 replica out there, i'm still saving up for one. They are only like $70, new ones are about $20.

 

EL84's = 4 = ac30. many different recomendations are said to this. I use JJ's b/c they are cheap and reliable. And ac30's eat them up like candy.

 

Now preamps.. Not to sure on what to get here. This will determine how your ac30 works though. Pending on what tubes you get will change your headroom to making somethings a bit warmer / brighter..

 

Ecc83 are also the same as 12ax7's.

 

But like i said, go through that thread and get some tips.

Also placement is a huge key to the way it becomes unique.

[echodeluxe]

do this:

 

open up the amp, slide the amp out, and turn it on. turn the volume up a little and turn standby ON.

 

tap all of the tubes lightly one by one. if any of them crackle, you could have dirty sockets but most likely, its a tube.

 

dig it, yo.

[TomCTC]

do this: open up the amp, slide the amp out, and turn it on. turn the volume up a little and turn standby ON. tap all of the tubes lightly one by one. if any of them crackle, you could have dirty sockets but most likely, its a tube. dig it, yo.

Duh-duh-duh-dangerous!

[echodeluxe]

Duh-duh-duh-dangerous!

its only dangerous if he licks something. hes fine.

[HeartfeltDawn]

Tap it with a pencil and you'll be fine.


If you do buy new valves and don't want to spring for a complete new et quite yet, get a GZ34 from Ebay. My Ceriatone dc30 had a similar problem. It was making horrible static-type sounds, a 'tearing' electronic sound, very nasty. I assumed it was the EF86 valve first as these are notoriously microphonic but it turned out to be the GZ34. As Mrweems said, the newer ones don't have the build quality of NOS GZ34s.

[echodeluxe]

exactly

 

the new tubes are {censored}. they cant handle the ac30's current, it runs really close to its max current rating.

 

get a weber copper cap. its from weber, its $22, it wont go out on you.

[Mistersuperfly]

Tap teh tubes... As far as EL84's go, I wholeheartedly suggest TAD tubes... they are built like rocks and sound really good, my Goldtone had JJ's in it and it's a whole new animal after putting these in.
http://thetubestore.com/tadel84.html

If it has the stock tubes, you would probably be best served giving it a whole retube anyway... JJ 12ax7s are good as are quite a few other brands, JJ or TAD powertubes, JJ also makes a good GZ34.

[echodeluxe]

hmm, those tads look promising.

 

reliable?

[mrweems]

Tap teh tubes... As far as EL84's go, I wholeheartedly suggest TAD tubes... they are built like rocks and sound really good, my Goldtone had JJ's in it and it's a whole new animal after putting these in. http://thetubestore.com/tadel84.html If it has the stock tubes, you would probably be best served giving it a whole retube anyway... JJ 12ax7s are good as are quite a few other brands, JJ or TAD powertubes, JJ also makes a good GZ34.

 

 

i've been curious to try those out. the tad's that is.

I'm not sure what tubes are in my ac30. but i was thinking about possibly putting some of those in it.

 

more headroom? better clarity? whats so much better about them besides reliabiliyt?

[echodeluxe]

i have two jj ela4's and two mesa ela4's in mine right now

 

my amp was losing volume and cracklling alot, and i figured out it was TEH TUBERS so i swapped a pair out and had to grab an emergency pair from gc.

 

they sound fine, the amp is back to working order, but i wanna get a nice quartet of some reliable el84's.

 

i also wanna find a smoother 12ax7 for V1.

[mrweems]

i have two jj ela4's and two mesa ela4's in mine right now my amp was losing volume and cracklling alot, and i figured out it was TEH TUBERS so i swapped a pair out and had to grab an emergency pair from gc. they sound fine, the amp is back to working order, but i wanna get a nice quartet of some reliable el84's. i also wanna find a smoother 12ax7 for V1.

ei gold pin?
ehx?

What do you have in there right now?

Oh yeah, you want a matched QUAD for an ac30. not two different sets.

[echodeluxe]

oh believe me, I KNOW. it was an emergency situation.

 

i have, uh, oh man i forgot. i dunno whats in my preamp. probably groove tubes.

 

im gonna grab something better this next week (when i get paiddddd)

[echodeluxe]

i emailed bob at eurotubes about the JJ GZ34.

 

does anyone have any experience with the jj rectifier in their ac30? do they hold up?

[mrweems]

oh believe me, I KNOW. it was an emergency situation. i have, uh, oh man i forgot. i dunno whats in my preamp. probably groove tubes. im gonna grab something better this next week (when i get paiddddd)

 

 

Yeah. Next month i'm hoping to get some new tubes of some kind.

[HeartfeltDawn]

My Ceriatone dc30 had a JJ rectifier. It sounded OK but went microphonic over time. I've just got a new one and sold the amp. In my old Vox AC15TBX, I can't remember what valve I had for the rectifier. I'm sure it began with 'E'.

In the UK, I think the Harma valves are the best valves going. I retubed the AC15 with a full set of Harmas when I bought it and the difference in sound once I'd junked the Sovteks was huge. I used the Harma cryo EL84s and the regular 12AX7s and loved them. You can get regular and cryo versions of their GZ34 rectifier too:

http://www.watfordvalves.com/product_detail.asp?id=1036

http://www.watfordvalves.com/product_detail.asp?id=1426

It might be expensive for you guys in the US but the valves are really worth it. I tried Mullards in the AC15 and didn't like them. The sound felt too warm and a bit lacking in definition, even with the treble maxxed out. I loves teh Harmas

[echodeluxe]

yeah i was looking at those cryo harmas a while back. they seem cool, but pricey. and at the rate ac30s eat up tubes, its not really worth it.

[mrweems]

i emailed bob at eurotubes about the JJ GZ34. does anyone have any experience with the jj rectifier in their ac30? do they hold up?

 

 

i have one in my maz jr. it works great.

[echodeluxe]

well, the reason i asked is because ac30's run REALLY close to their max rated current, and that destroys rectifiers (well, newer ones anyhow) and thats why i built a solid state rectifier for mine. heres the video:

 

[YOUTUBE]OmGhAGnexfo[/YOUTUBE]

[Teahead]

Check out the slightly used old stock Sylvania EL84s at Tejas Tubes. At $110 for a matched quad they are excellent value, I've had a quad in my AC30 for almost a year now and a pair in my 18w Plexi too.

[Jbrazz]

before I take out the amp (which I dont even know how to do so a tutorial would be nice)

 

I tubes are uncharted land to me. I felling love with the stock sound so id like some that give me the most clean headroom. I guess I trust you guy to pick those out for me, since I had nothing to go off from.

 

I'm doing a total re tube so give me all ya got.

 

 

Thanks

[amp_surgeon]

CAUTION: Don't do this with an amp that does NOT have a standby switch. Always power up the amp in standby, and give it some time to warm up before flipping the standby switch to "ON".

The reason is that the solid state rectifier does not have the same warm-up time as a tube rectifier. If you apply B+ to the power tubes before they have a chance to warm up then you could permanently damage the coating on the cathodes.

You can use a homebrew rectifier with an AC-30, provided you always give it time to warm up before flipping the standby switch. Echo knew what he was doing before building and using this SS rectifier - make sure that YOU do too!

In addition, don't try to build one of these without using the power resistor. It's designed to drop the same amount of voltage under max load as a tube rectifier. If you leave out the resistor, or use the wrong value, then your B+ is going to be WAY too high, and you could fry your amp!

Also, if you happen to be one of those people who enjoys the aroma of a vintage cork, you should note that the the SS rectifier will sag under load, but not in the same non-linear fashion as a tube rectifier. If you think this will affect your tone then consider a NOS tube rectifier. You might also consider sacrificing a chicken and doing a voodoo dance in front of the tube before installing it!

[echodeluxe]

thanks jimbo, i should have put a disclaimer. i figured no one was really gonna try to build one unless they knew what the hell they were doing.

 

in all fairness, i have not noticed any change in tone, but i will be trying out that jj rectifier and doing an a/b comparison, as well as a comparison with the weber copper cap.

 

yay!