F-30 head Issue REPLICATING and Issue from a Show

HI everyone Just an update, I was able to replicate this situation with the help of an attenuator.

SOrry for the double thread post...

Just to refresh, what I had before was that I played a small club and used my F-30, what happened was that I already had my master volumes on both channels set to maximum but I could barely hear myself, even the audience couldn't hear me. For all I know a 30watt tube amp should be loud enough to play small clubs must specially when hooked up to a 4x12 cab. There was one point during the show that when I put my clean channel's volume at 12oclock and the gain to 11oclock, I get a cracking distorted clean sound.

SO I tried to replicate this by getting an attenuator and new speaker cables.

So here's what I have set up:

Mesa F30 Head 8ohm(combo) speaker out =====> THD Hotplate 8ohm Amp input ====> Thd Hotplate 8ohm Output ===== Marshall 412b 8ohm cab


Here's the case without an Attenuator:

At bedroom levels, when my amp's master volume(both channels) is at 3, everything is good. Not great but good, it's just that the tone I was getting is not the one I'm expecting to get from a Mesa, but it was way better compared to my solid state. But whenever I raise the volume, I get this muddy tone with the lead channel and on the clean channel I get cracking and popping like the speaker just exploded.

Those are the problems I really wanted to get fixed and I believe that replacing the tubes would do the trick.


Here's the case with the Attenuator: (Take note that I have the eq set to flat just to get the right amount of tones on each channel to get a fair balanced sound)

I was trying to replicate the problem I had playing in a small club with my volume issues, I set the hotplate to -8db, I have my clean channel gain at 11 o'clock then the master volume at 11 o'clock. I get a sound that's like clipping sounding like the speaker exploded and could barely hear any good notes. It sounds muddy and cracking. It's like I have overdrive on the clean channel. Even when I roll my guitar's volume it generates this dirty clean sound.

With my lead channel I had the gain at 1 o'clock and my master at 11 o'clock then when I do palm muted power chords or major chord strumming I get this really dirty and muddy distortion like the speaker just exploded or something.

I think changing the tubes would help this out, I also noticed that whenever I switch from lead channel to the clean channel with a chord ringing, I hear this popping sound.

Please help me with this, I really don't know what to do now, it looks like I've done a lot already like tapping the tubes to check if theyre ok and others...

Tappinf the tubes doesn't prove they're OK, it just tells you if they're microphonic. You mentioned 2 or 3 times in your post that you thought you should replace the tubes. Why don't you go ahead and do that? It's a good bet, and if the problem turns out to be something else, you'll have a spare set. Either way, you need to start ruling out causes, and that one is the easiest.

Otherwise, give it to a tech to figure out.

elvis said:

Tappinf the tubes doesn't prove they're OK, it just tells you if they're microphonic. You mentioned 2 or 3 times in your post that you thought you should replace the tubes. Why don't you go ahead and do that? It's a good bet, and if the problem turns out to be something else, you'll have a spare set. Either way, you need to start ruling out causes, and that one is the easiest.

Otherwise, give it to a tech to figure out.

Click to expand...

Thank you so much for the reply. Ok then I think I need to be buying new tubes for it. Thank you I hope this takes care of the issue. Is this issue I'm having happen quite often for tube amps?

Tube amps are like Harley-Davidsons (I have had both). They both need a lot of TLC even in the best of times.