A few years ago, as a result of a studio clearance I acquired, FOC, some decent small speakers to use with our desktop PCs. I've got a pair of Mackie CR4 (this is the later and current version https://mackie.com/en/products/studio-mo...CR4_X.html ) while Ruth has a pair of M-Audio speakers that are about the same size https://m-audio.com/products/view/studiophile-av-40. Both amply good enough for what we do and much better than the odds and sods of Altec etc PC speakers I've had before.
The M-Audio ones needed new reservoir caps to stop the hum and that's all I did to them until recently.
The other day I noticed that Ruth's speakers were only working one channel. Get them on the bench and start to troubleshoot without a schematic. Then my scope probe slipped and dispatched the output amplifier chip. Available for about £7 from RS but a lot of faff to replace. I gave them away on Freecycle, describing them as faulty but not how they got that way
We'll order a pair of Mackies to replace Ruth's speakers.
So far so routine. This morning I had no sound on my PC. One out, all out! Not a peep, no clicks or hum when disturbing the connectors. Nothing. Get them on the bench and open up the active speaker. Download a schematic which was easily found. Check power rails OK. Insert some audio from a signal generator. Present part way through the amp. On a whim I probed the (disconnected) speaker output and there was signal. Reconnect the driver and it works. Put it all back together and it still works.
The only explanation I can think of is there was some sort of bad connection in the speaker.
The M-Audio ones needed new reservoir caps to stop the hum and that's all I did to them until recently.
The other day I noticed that Ruth's speakers were only working one channel. Get them on the bench and start to troubleshoot without a schematic. Then my scope probe slipped and dispatched the output amplifier chip. Available for about £7 from RS but a lot of faff to replace. I gave them away on Freecycle, describing them as faulty but not how they got that way
We'll order a pair of Mackies to replace Ruth's speakers.
So far so routine. This morning I had no sound on my PC. One out, all out! Not a peep, no clicks or hum when disturbing the connectors. Nothing. Get them on the bench and open up the active speaker. Download a schematic which was easily found. Check power rails OK. Insert some audio from a signal generator. Present part way through the amp. On a whim I probed the (disconnected) speaker output and there was signal. Reconnect the driver and it works. Put it all back together and it still works.
The only explanation I can think of is there was some sort of bad connection in the speaker.
www.borinsky.co.uk Jeffrey Borinsky www.becg.tv
