Tweet
Still having issues with my Peavey Classic 50 212. A random static noise. Talked to Peavey and they advised to change the power tubes. Did that and it has not changed. I want to change the other set of four tubes but want to make sure I understand what rebias is. Ive heard you all talk about it on here but I cant find where anyone explains how to do that. Thanks
-
-
If you change the power tubes, you should rebias your amp. Changing the preamp tubes does NOT require you to rebias your system. I'd recommend that if you are going to purchase new preamp tubes, put the old ones back in so you DON'T need to rebias you amp. If the problem goes away with your new preamp tubes, then we can help you with your rebias or just return the new power tubes.
joe... -
I did replace the preamp tubes. It did not fix the issue. You advised to put the old ones back in. Thats done. Now I have not bought new power tubes. I know you buy them in pairs and thats about all I know.Comment
-
-
I can't answer that. I'd say if you look around inside the amp and don't see some type of bias knob, then, yeah, it's probably a fixed bias. I know my Boogie was fixed bias and I had to purchase the tubes that had a cold/med/hot rating on them.Originally posted by lefty View Post
joe...Comment
-
Yea it is a fixed bias. Thanks for the help.Comment
-
If you have changed all the tubes and that didn't help, maybe you just have a noisy amp. You might try something like a Rocktron Hush in the effects loop. It will eliminate alot of unwanted noise and won't suck tone if adjusted right. Just a suggestion.Comment
-
Many tube-amps dont have a bias knob. But you can get a bias knob installed for anywhere from $50 - $150. Usually, from factory, the power amp tubes are biased "cold" so they last longer. You can get them biased "hotter" and the amp will sound warmer and much better at lower volumes. I think my 5150 is fixed bias too but an amp tech told me that he can install a bias pot in it so I can change the bias based on my tone preference. Yes, you have to buy "matched" pairs for power amp tubes.Originally posted by GodWentPUNK View PostSamComment
-
does it have a rocker switch for the ground? Try a different position. My 5150 has one and by default its at 0. You have + and - as the other two options.Originally posted by dk1ben View PostSamComment
-
I will try that. Thank you. It is hard to nail down what is doing it because it happens at random. I am yet to figure out how to make it do it. I hear it typically after i've been playing for awhile and say turn the volume knob down on my guitar to switch tab sheets or rest. However it has done it right after I turn it on. I can typically make it stop by turning the standby on and then back on after a minute or two. It never happens of coarse while the amp is in standby. Sorry if you already figured that out. As you can tell I am very new to tube amps. However I like the tube sound MUCH better than my old solid state amps. Thanks for all the help. I will post with the results with the rocker switch. I know it has one but I have yet to try it. It will have to wait until morning. Neighbors wont like it this late.
Comment
-
If it is random pops and static, chances are it's tube oriented... I have some pretty high end equipment and still have heard it and just sorta ignore it (if it's just occassional).
I realize you have changed tubes tho... sorta baffling... Many cheaper tubes (and some not so cheap) are known to make noises here and there tho... Little pops and static etc...
If it is a particularly unruly tube, you may dial in which tube it is by turning it to a higher volume and tapping the preamp and power tubes lightly and listen for it through the speaker (watch out where youre sticking your fingers tho).
If you hear a fair noise through the speakers when tapping, that tubes is microphonic. Some light noise is gonna be there in high gain situations, but if it's a lot, change that tube out (power tubes, change in set as you you know).Comment
Comment