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Ok, so I'm pretty certain that at least one of my preamp tubes is out on my VoxAC15CC1(2007-2008 model). However, I don't know shit about tubes, so I'm going to be a big baby and ask ILF to help with every single step of this process.

I've noticed a low volume hum and a hiss separate from normal feedback. Now, that hiss is even more pronounced when I turn the reverb on. On occasion my amp will also let out a high pitched, low-volume squeal that lasts for roughly 30 seconds. I'm pretty certain these are all tube related issues. I just don't know how to go about fixing it.

Help me ILF, you're my only hope.

try this.

without anything plugged into the input, turn everything up on your amp and gently tap each preamp tube. if you hear anything loud/out of the ordinary it means that perhaps the tube has gone microphonic and you should replace that tube with a new one. remember to turn off the amp first! with preamp tubes, as long as you have the right type, you can just pop one in - no need to get the amp re-biased or anything like that. if you don't hear anything odd, just try replacing each one anyways and see if it helps.

Awesome, that is the kind of advice I never would've found on my own. Thanks a bunches.

All the info a google search has turned up is far more technical than practical. I don't want to build an amp from scratch, I just want mine to sound decent.

Hm, so I tried this. I wasn't able to get the covers off the preamp tubes, but that's something I just didn't want to mess with and will deal with later(with little effort I'm sure). Even giving a good tab on those, I could hear the noise you were talking about, stronger for one than the other.

So I guess I'm going to go ahead and change the preamp tubes. They're 12ax7(which seems to be the standard). Like I said I'm pretty much a newb to this, so what is the best place to get tubes? What would you recommend if I want to keep that bright Vox tone, but want to spend a minimal amount?

All I've been able to figure out is that the general consensus disapproves of Tung-Sols for keeping the Vox qualities that I want to retain. I'll keep reading up on this stuff until I actually have money to buy new tubes, but any and all tips, no matter how basic and obvious they may be, are welcome.

Get JJ ECC83/12AX7s they have a nice British flavor to them, sound great in Voxes and marahals. Not expensive either.

Check MOJO Music supply and Antique electronics.

MM

http://thetubestore.com/12ax70ectyp.html
Here they have some description for each tube brand they have.

I found the descriptions from that tube store website quite helpful, but in the end my amp tech gave me the same advice and sold me great tubes for cheap (12 bucks each I think for sovtek 12a7s - he also said to play around with them until I was happy as they sound different in different positions.......

most covers come off by pushing up and turning to the left.
if only one sounded microphonic, then you'll most likely only need to replace that one. the tubestore is good - i always buy my tubes from them... for the preamp tube just go with something relatively cheap. if jj or groove tubes make a 12ax7 i'd get theirs; i've tried fancy preamp tubes, etc and couldn't hear an appreciable difference, though i'm sure others will say otherwise...

V1 to V2: TAD 12AX7-C (the dealer put this one in due to microphonic I had with the Sovtek 12AX7LPS)
V3 to V5: Sovtek 12AX7LPS
That sound great for me.. I have a Bogner Duende combo.

ah yeah TAD are nice too. forgot about them

smallsnd/bigsnd wrote:ah yeah TAD are nice too. forgot about them

Less microphonic then Sovtek LPS.

for new 12AX7s i like the so-called "reissue" Mullards; i say "so-called" because they really don't resemble NOS Mullards at all, but look rather like long-plate Telefunkens. but i'm an old-stock tube nerd when it comes to preamp tubes. you can still get NOS or used/test-as-new tubes for decent prices that will KILL anything currently being built. i like GE the best; RCA are good for crunch; Amperex/Philips are nice and balanced overall; Telefunkens are supposed to be the shit and cost elephant dollars, but i find them rather bland. seriously, get yourself a nice old tube for V1; it makes a world of difference, especially right at the front of the circuit.

Love it... So, I have two old Kalamazoo's '65/'66 they're loud and fine and have stock Mullards... I'm gonna leave my finger grease off and assume since I rock them every day they're fine and can stay... What I was unsure of is I have really good luck with equipment I guess and probably wouldn't know if they go bad unless they stop working... Is there an in-between stage with tubes? I thought good=work bad=no work... Should I just play till they slopde?

dubkitty wrote:for new 12AX7s i like the so-called "reissue" Mullards; i say "so-called" because they really don't resemble NOS Mullards at all, but look rather like long-plate Telefunkens. but i'm an old-stock tube nerd when it comes to preamp tubes. you can still get NOS or used/test-as-new tubes for decent prices that will KILL anything currently being built.

+1
exactly

Telefunkens are dark sounding. If you don't like this, they sound for you like shit

What's the ILF consensus on Ruby tubes? Once again, I'm playing a 15w Vox combo and I want to retain most of that classic sound.

The reason I ask is that I really can't be arsed to order a $10 part with $10 shipping or the same part for $15 with no shipping or some such nonsense. The only store in the area that mentions selling tubes on their website says they carry Sovtek and Ruby tubes, and I'm pretty certain Sovtek isn't what I want. I'm going to keep doing my research and actually get on the phone with a couple stores to get some deets later today.