Amp Problems - Please help

[nexrex]

Hey all, I am having some weird issues with my practice amp. It's an Orange Tiny Terror 15 watt amp/speaker combo.  :icon_scratch:

One of these:

It's hard to describe. I have had it about a year without any problems. I am having a lot of trouble getting a clean sound out of it. Even with the gain turned down, it seems everything I play through it sounds muddy. Kind of like an always on chorus effect. It also seems to be now more susceptible to feedback when I crank the gain. And it seems like it gets worse after about 10 minutes of use.

Any ideas?

Thanks

 

[Jusatele]

cut and paste from a tube page

Ugly sounding distortion can take several forms.

Harsh grainy sound

        * Output tubes biased 'way too cold
        * Rubbing or torn speaker cone
        * Rarely, the amp can be oscillating ultrasonically and still get some sound through, with a harsh, ugly sound.

Sound cuts out or squawks on loud notes

        * Failing coupling capacitor
        * Failing plate resistor, cathode bypass cap, cathode resistor or grid resistor
        * Intermittent ultrasonic oscillation

Muffled or constricted sound

        * Failing preamp tube; find the offending section by tube swapping and see if a good tube fixes the problem
        * Low signal tube bias is pushing it into saturation or cutoff. Measure operating voltages on the preamp tubes. The problem section will have tube pin voltages that are 'way off normal.
        * Failing coupling capacitors from the preceeding stage.
        * Failing plate resistor, cathode bypass capacitor, cathode resistor, or grid resistor
        * Power supply problem; a dropping resistor may have drifted far from it's nominal value, changing the power supply voltage enough to cause this.

Faint out of tune sound on every note
    Excessive power supply ripple, usually indicating that the power filter capacitors are going bad. This can also be caused by speaker cones and voice coils with problems so they just rub slightly, too.



 

[nexrex]

Thanks Justatele. Sounds like I need to find myself a good amp tech. I have changed tubes before in my other amps, but I am not really confident to do anything more than that.

 

[Jusatele]

if it only has 1 preamp tube, that would be worth changing out. I mean that is a less than 20 dollar gamble, if it does not work, then you have it worked on, and Tell the guy about the new tube put in to troubleshoot it. After all I bet his first move is a new preamp tube.

 

[nexrex]

Cool, I was thinking it might be pre-amp tube too. Like I said it seems to get worse as it warms up, and output just sounds very chorus like. Thanks