It happens when i turn it on and there's an instrument plugged into the 1/4 input. It doesn't seem to happen when it's only a microphone. Sometimes it works for a little while with my instrument plugged in but then it starts making the loud noise again. This has only started to happen very recently when I switched out the dead batteries for new ones, so i'm pretty sure its not the battery, I even switched out the batteries for my guitar's pickup thinking that was the problem.
Hi, Quick Check. Very often the input socket which is soldered directly to the circuit board, will have a broken solder joint. This is common on a very large amount of equipment. Try waggling the plug about and seeing if the noise comes and goes.
Easy fix, re-solder joint. Permanent fix, connect socket to board with flying leads, or fix socket to board with hot glue or epoxy resin.
All the best, Chris the Fader.
SOURCE: Roland AC-60 Amp input impedances ?
I will solve the mystery...
The impedance varies depending on how you connect. It would be too complicated to explain the impedance to the average person.
From the schematic we have the TRS 1/4 inch jack having basically 100K and parallel 220 pf cap to ground EACH signal line and 10K resistance between. (The TRS jack if used disconnects the XLR and its components)
If one uses the XLR jack, one has an ADDITIONAL 100K each side in parrallel to ground PLUS an ADDITIONAL 2.2K resistor shunting between.
In ADDITION to the above, there is effectively 160K ohms to ground each side that is the input resistance to the input OP-AMP.
The effective impedance will depend on how and where you measure it.
Not sure what peizo you are using... For one on wife's violin we go into a X2 wireless which has about 1.6 Megohm. The receiver of course is fairly low impedance drive to the amp.
For the violin (Autolycus) pickup and others, severe distortion of the waveform existed when run directely into most amps and of course long cables worsened it at the high frequencies.
SOURCE: Brand new chromatic tuner tu-3
Change the battery first. It could be dying and just barely have enough power to come on at first, but not to do anything else. If that doesn't solve it, you've got a defective one and you can go exchange it.
SOURCE: Hello, My Boss CS-3 Compression Sustainer
Make sure you use Alkaline battery and NOT rechargeable type... the rechargeable battery will NOT work in the pedals (their voltage is lower even though they are labeled as 9 volt replacement).
Other internal problems can be due to cracked circuit board or broken solder joints. These are very common as people step on the cables when plugged in. This breaks the connection inside. A fuzzy sound often occurs when one of the contacts is marginal due to bad solder at the jack terminals.
Testimonial: "Thanks"
SOURCE: I have a very loud
If this ties to a keyboard, make sure the keyboard and this are BOTH plugged into the same receptacle. You should send a higher level from the keyboard (turn volume up to around 70% or so) and use less volume at the input gain of this amp. Use more at master volume if the amp has one if needed. If the hiss is there with NO input cables plugged in and input gains at 50%, that is objectionable, the amp probably needs servicing. Unused channel gains should be clear down.
SOURCE: My Roland Cube 20x Amp
If you take your speaker out you can see if it has blown the internal fuse if not it could be the exernal fuse the power adaptor
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Same thing happened to my Roland cube. I have a pair - one works fine and other one makes a loud line buzz and volume is only 60% of normal.
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