I like the sound of my practise amp but it's not powerful enough can i connect it to a larger amp without getting feedback/distortion?

Sounds like the output capacitors are breaking down, or you have a faulty pickup causing feedback, this can also be caused by bad cables close to ac power causes hum and distortion.

sounds like an internal connection problem. open access panel and check the solder connection is not broken or loose. Be sure the metal mesh jacket is not touching the lead wire as that would cause a scratchy noise and feedback, or maybe near the internal cable causing feedback

Hi!
At this point, I would just take it to a tech rather than poke around in it. It sounds like the power section is the problem as you have guessed, but without the technical knowledge you'd be shooting in the dark. That particular amp is right on the line of being expensive enough that would be worth repairing, but you might do just as wel to check Ebay for another used one.
Good Luck!

Guitar amps have preamp sections (think unpowered audio mixer) and power amp sections (Crown rack-mount amp). An excellent way to isolate audio problems if amp is still producing audio is to check the preamp out (line out). Preamp output distorted = preamp failure. Connect MP3 player to "Power Amp In"...sound distorted = power amp failure. In your case the latter is the case as your "line out" is clean. Also test each speaker for clear sound as speaker cone damage from being overpowered is fairly common. At 300w. I'll assume the failure was not from cranking the volume to loud but a shorted speaker or speaker wiring could zap the power amp in an instant.

The bad news is it could be any of them. or it could be the lighting- CFL's and regular flourescent lighting are bad for audio, as are switching supplies used in TV's, microwave ovens and some musical gear. They are worse than lighting dimmers for noise.

The thing to do is start at the speaker itself and work through the chain of devices to find the one distorting. An old transistor radio is useful here. Most actually do have enough power to faintly drive a large speaker- listen for scraping and rattling- it would mean the voice coil windings may have come loose or the coil form is damaged from heat.

Move back to the amp input and try again- this time listen for a clipped sound if the speaker checked out okay. It would sound like the Charlie Brown adults in the cartoons. That would be a failure of an active component in the amp. If you now hear rattling or scraping- the speaker voice coil is bad and should be repaired or replaced.

If it sounds good, move back to each deck. apply your radio- volume turned down to an input it one is provided. Each should sound clean like the amp did. If no sound or distorted sound is found here- which is the most probable location, it is likely one of the IC chips is at fault. Likely a 4558 if an IC fault, otherwise suspect dirt or hair on the encoder connected to the spin platters.

Make sure the guitar CANNOT "HEAR" the amp you are using. Local regeneration (feedback below the level to sustain full feedback) will give a boom sound like in a cave. If you get near enough to the amp for feedback to build up, you can actually see the string vibrating and building up. The loudness has much to do with the amp you connect this too and the settings

More infornation is required to provide a real answer, but I can give you a few possibilities:

1) There is a problem within the feedback loop that is allowing some frequencies through. This will be more prevelant at higher volume levels.

2) If there is a tube pre-amp section, the tube can be "microphonic". This too is generally more likely at higher volume levels.

3) Defective components in the amp section. These may pass some DC voltages that will sound like distortion.

If you can, please experiment a little to try to find when the problem is most obvious. With more details about when the problem occurs may give us enough info to determine the cause. Otherwise a trip to a service shop that has access to test equipment will be required.

Dan

Proper level setting of the mixer is important. HOWEVER if the clipping is occuring at the speakers the only possible problem MIGHT be that you have a supersonic feedback that is saturating the speakers above your hearing range, Be sure you don't boost the highs too much with the EQ as this can cause the feedback that you can't hear. Also make sure that you power the speakers from the SAME receptacle as the mixer, even if it means running an extension cord to bring power to the mixer. This is to avoid a low frequency hum and common mode distortion/damage. A low frequency hum could cause the clipping.
It would be a good idea to get a sound meter to check the sound level. You should be able to reach 85 Db from this system without clipping. If you need more than that, you MAY need more speakers if the band instruments are too loud. Also if the band has amps that get into the vocal microphones that adds to the clipping level... make sure the mics don't "hear" the band instruments. Make sure your speakers are toward the audience from the mics to avoid the supersonic feedback problem. If the vocalists can't hear themselves with that configuration you need to set up seperate stage monitors.

There are some pretty good videos on YouTube about proper mixer level setup.

You haven't told us what "signal" you ran in... Make sure ALL interconnected equipment is powered from the same receptacle. All audio lines should use balanced interconnects where possible using XLR or TRS cables. Cross connect another amps preamp into the effect loop input to check the power amp portion.

There are many components in the system. Electrolytic capacitors are most suspect. C49, C50, C45, C51

There are many others but these are top suspects. You MAY be able to detect a change by cooling these components with circuit cooler spray.

ALSO check the +/- 16 volt power sources in the unit.