amplifier keeps cutting sound to tinny sound

[greensusie51]

its only a cheap amp (too embarrased to name make) but only 3 years old. I 'd like to try and repair before forking out for another.

I checked all wiring to speakers and connections, all seem fine and when it cuts to this low tinny sound, it's both speakers, the same noise.

if i turn the volume up loud it goes back to the normal 'full' sound but as i turn it down again its cuts out again



Is it worth me opening it up to have a look inside for a dodgy connection or something blown? I know nothing about electronics...

 

[timtheenchanter]

sounds like a bad connection somewere, does it do it on all inputs?
if its a proper volume control try turning the volume control up and down vigorously, this should clean off any muck that has developed (do this with it turned off)

failing that, it needs opening up, its probably a dry solder joint on the inside somwhere, budget kit often has problems like this.

unlikely something completly blown if its an intermittent fault

 

[Hass]

hello
also if it's a cheap amp (no worries we all start somewhere or are skint), check the speaker cable through the wholelength to make sure there are no insulation breaks that could be shorting or other.

Also check if you have the spring fit cable clamp at the amp and speaker ends, it may be worth cutting of the last few centimeteres of the speaker cable and restripping new ends. Cheap kit normally has plugs and is fixed at the speaker end so may not work.

Also use a torch and if you have spring clips on the amp, hold them back and forth and see if the metal 'tongue' that grips the wire is still there and solid.
regards

PS. a new amp may not be so bad, as Richer Sound (good to somenot others) do pretty good deals on low end kit. How much did you pay for your current amp?

 

[greensusie51]

thanks for tips, but we think we have found the problem after looking on a speaker forum.

After assuming the cheap amp is to blame, my partner looked online about the speakers, mission 780's. Others have had the same problem with these speakers and think it is the bass drivers failing. hopefully we can fix this ourselves.

 

[alwest197]

You might want to try cleaning the volume control first..I had the same problem.

Try using some switch cleaner on the pots that control volume and balance. Quite often there is a build up of muck on the internal tracks that cause problems similar to what you are getting. Available from Maplins or good hifi shop. Usual reminder to disconnect from mains before using it. You may be able to dribble it down the posts after taking knobs off, or take the outer case off and spray direct on pots while rotating knobs.
I bought a areosol cost about £5.50 locally...done the trick.

Al

 

[Donkmeister]

If you use pot cleaner, don't listen to anyone who tells you that WD-40 is just as good!

I tried it with a guitar and it was days until enough had evaporated/worn off to get any sound out!

 

[alwest197]

good advice...wd40 leaves a residue...it is after all made from fish oil..great for the many things its made for...but not this job...

 

[greensusie51]

thanks we might try that too, as we are beginning to think its a combination of problems. We have been doing some renovations, but as careful as you are covering things up, especially with plastering, the dust gets everywhere.