20 Most Recent
Alesis RA-150 Amplifier Questions & Answers
Amp cuts out after a while
My Alesis SA-300 started the cutting out when at moderate levels some months ago... Well, Radio Shack has instant gratificaion for those who have one in the neighborhood. Part number 275-249 will do the trick!
http://www.radioshack.com/product/index.jsp?productId=2062483
I replaced the Dong Woo part with the Radio Shack item and the amp is back to its old self... maybe even a little better. Loud, clean and steady.
Thanks to all you who have contributed to this thread.
Steve
Got an Alesis RA-150 off eBay to replace my
it may be an open input side coupling capacitor in the feedback circuit around the power amp. if the amp has a limiter in it it may be stuck. here is the service manual, in any case.
http://forum.vegalab.ru/attachment.php?attachmentid=75690&d=1265371278
My amp got hit by lightning and is not turning on
Start with the basics. Fuses, check transformer, look for burnt or damaged parts. With this kind of thing more than one part could have failed. Indeed you could have more faulty parts than working ones! Or it could be just one thing that's gone!!!
Help
Your first clue to going wrong with the repair is that the relay with two extra pins was the wrong type! So you need to look at the old one and read the ratings on it and search the net for one that does match it with the correct number of pins. As for the resistors you need to read the colour code of them and again search for something the same size. The colour code will tell you the type you need. If you don't know how to read the colour code search on the net for a resistor colour code calculator. As they look bad I would replace them, even if they did work, they could go dead later.
Not powering up at all
OK one thing at time first take cover off unit then check fuse if its blown there is a short do not replace fuse yet then locate bridge rectifiercheck it for short if it is unsold-er and replace it then locate output transistors and check all of them for short. if one of the devices that i told you to check is bad then when you replace it then replace fuse and try powering up unit. be sure to replace all shorted parts before replacing fuse and powering it up. DE
Samson power amp capacitor?-HELP!!!!
Its samwha brand with a 100volt working voltage 6800 microfarad capacitance value its next symbols seems to me the chemical compositions or stock code, and its maximum working temperature. Could be a low ESR type capacitor.
Hello. RA300 used only in
The first things to check are the devices on the heatsink. They do all the work so tend to go when pushed! Remember stereo amps are just two amps put together, so at least you have a good channel (which is the same as the bad one) to do tests with say an ohmeter.
Hi there, I have an
Hi Cristina,
You may download the service manual of your unit at this LINK.
I have an alesis ra
Check for a stereo/ mono switch in the front or back, and make sure it wasn't accidentally switched in the wrong position. Also check and make sure the wires are not crossing each other causing a short.
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