Being an electral hobbiest, I love to learn, but unfortunately I'm well out my depth here and as such going to ask for some help!
A local charity has asked me to fix a amped speaker for them - free of course. A DB technologies Opera 402D.
They used it at fundraises and such like.
Normally I'd spend the time to get there myself but that's not really an option.
Whats happening with it is there is a high range and low range speaker. Upon input the low range made no sound and the high range would only make sounds really high and squeaky- paonfully so if the volume is turned up - and though the mid and low were no existent and the high was really garbled. Upon the back of the transformer there is a 4 bit connecter, two leads to each speaker. When there lead are swapped over the symptoms are also reversed. The high range is silent and the low range make the same sounds. Changing any settings, ranges, Mike, speaker inputs etc make no difference what so ever. Nor can I see and damage, blown caps, heating or wierd smells when studying the circuitry.
Would anybody help me with this?
Better still I live in the UK in Aylesbury, if there is anyone even remotely close by?
Appreciate this may be a little forward but If it was not for who it's for I would on not asked, except for advise here and there.
Quite happy to pass on my contact details If that's ok.
Thanks people!
A local charity has asked me to fix a amped speaker for them - free of course. A DB technologies Opera 402D.
They used it at fundraises and such like.
Normally I'd spend the time to get there myself but that's not really an option.
Whats happening with it is there is a high range and low range speaker. Upon input the low range made no sound and the high range would only make sounds really high and squeaky- paonfully so if the volume is turned up - and though the mid and low were no existent and the high was really garbled. Upon the back of the transformer there is a 4 bit connecter, two leads to each speaker. When there lead are swapped over the symptoms are also reversed. The high range is silent and the low range make the same sounds. Changing any settings, ranges, Mike, speaker inputs etc make no difference what so ever. Nor can I see and damage, blown caps, heating or wierd smells when studying the circuitry.
Would anybody help me with this?
Better still I live in the UK in Aylesbury, if there is anyone even remotely close by?
Appreciate this may be a little forward but If it was not for who it's for I would on not asked, except for advise here and there.
Quite happy to pass on my contact details If that's ok.
Thanks people!
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These powered speakers usually have Class D amps, which are not worth fixing in cheaper products. Definitely not for newbies, they contain DC storage of wall AC voltage and are lethal if not handled properly.
You can possibly buy a new "plate amp" of suitable wattage, and install on the existing heat sink. The aluminum fins on the back of the speaker. In the US I would try to buy a plate amp at parts-express.com . I have no idea who to purchase from in the UK. You will need new heat sink compound between the amp heat surface and the heat sink on the back.
I would check the driver suspensions to make sure the woofer not ripped and scraping the windings. Push in and feel for rubbing of wires on something solid. If so that is trash too.
A system replacement which could be much more reliable in future would be a warehouse PA amp and a full range speaker in a cardboard box. MMA-875t is a Peavey product I have puchased for as low as $20 plus freight+tax. Crown 180A and 280A are similar but a little more pricey. There are off-brand version warehouse amps for sale, look for a 4 ohm, 25 v and 70 v outputs. A RCA jack input is necessary on the Peavey, the screw terminal ones are for phone lines and wrong voltage for line level inputs. The crowns have screw terminals for alternately line level and telephone. The official full range driver is visation BG17-8 although I have salvaged the equivalent drivers from projection TV's sitting on the curb for the garbage man. The visiton is 40 watts, the salvage ones were 13 and 8 watts. The driver goes on the end of a 200 mm x 200 mm x 350 mm smiling box with a hole cut out of the end for the sound to get out. I use machine screws with elastic stop nuts & washers to make installation permanent. Another hole 25mmx25mm is cut in the back end of the box for some bass reflex action.
You can possibly buy a new "plate amp" of suitable wattage, and install on the existing heat sink. The aluminum fins on the back of the speaker. In the US I would try to buy a plate amp at parts-express.com . I have no idea who to purchase from in the UK. You will need new heat sink compound between the amp heat surface and the heat sink on the back.
I would check the driver suspensions to make sure the woofer not ripped and scraping the windings. Push in and feel for rubbing of wires on something solid. If so that is trash too.
A system replacement which could be much more reliable in future would be a warehouse PA amp and a full range speaker in a cardboard box. MMA-875t is a Peavey product I have puchased for as low as $20 plus freight+tax. Crown 180A and 280A are similar but a little more pricey. There are off-brand version warehouse amps for sale, look for a 4 ohm, 25 v and 70 v outputs. A RCA jack input is necessary on the Peavey, the screw terminal ones are for phone lines and wrong voltage for line level inputs. The crowns have screw terminals for alternately line level and telephone. The official full range driver is visation BG17-8 although I have salvaged the equivalent drivers from projection TV's sitting on the curb for the garbage man. The visiton is 40 watts, the salvage ones were 13 and 8 watts. The driver goes on the end of a 200 mm x 200 mm x 350 mm smiling box with a hole cut out of the end for the sound to get out. I use machine screws with elastic stop nuts & washers to make installation permanent. Another hole 25mmx25mm is cut in the back end of the box for some bass reflex action.
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If you were in LA, you could solve the amp problem with a Crown m180a for $25 local pickup. $75 freight to me, rediculous freight overseas. https://www.ebay.com/itm/266038112045?epid=1201418421&itmmeta=01HVHHWHDS888FDM0PQ5XX106Y&hash=item3df11b6f2d:g:f8oAAOSwURdlH17q&itmprp=enc:AQAJAAAA0GNW3EresCIPLawK91C0jqdRGaw9GrLKxOrcleHT9R/oUOmwgyoT/HRai6HcQ/ypUaMHQFbRP54f6N0fdRZ1U1hHL8igqo8czVkIccShIYqhup41VSuII+l6LAZlRyD6+LF6gpBdy4gqk/QMDq0luL0u5nR81/ttx934VgFvRV6sHazzV9NhR05Unl7cTqDc9yjJuG3ms49T6ggvcdI7Ww0/aX+xvmRsXx80Ale9Hh2/SGpB2TseFKRA+Ge1SrG0XuCMSNn6/PbbnMcraBGZcj4=|tkp:Bk9SR_yW8rHcYw
There are also crown 37 watt warehouse amps out there: https://www.ebay.com/itm/355306671220?itmmeta=01HVHNDYVSANQK5V54NN764DRT&hash=item52b9ed8c74:g:tB8AAOSwUhZiop2o:sc:ShippingMethodStandard!47130!US!-1&itmprp=enc:AQAJAAAA4Pvg87gKn0BJiSOOpt5uUCY4az/6828CBaqMpDAk6udeVxm2l016GxGnHc50gnIlzOAkWOpkTBdbDQG2C1tAXSGCLas9Hjhac8fYCPVm438TS/zh0vV2A86ZxwhWnjRCxx+noFlgnGbVPdkDUpGW5cxsCD0Rl5sfUfouzbUDkqjFFcBwIsmAqhceytlRtIxGtbfSDI7WSMdnDlFqfublu75QOVWdFks9MVhixEzAhTbEU/kTCOgoLmV2XbcSbmX+LVVS0ool9exefwBYx4CmDzF8J+aiKix4ylp3l1WS/cYw|tkp:BFBMgO63tdxj
That one is a rediculous price unless the vendor installs the 8 speaker in your ceiling for you. However, get on gumtree, UK ebay, facebook marketplace, see what you can find for not much money. If one of these warehouse amps is defective, they are repairable by amateurs with a DVM a pocket radio, a trashy speaker, and maybe an analog VOM. +soldering iron, solder, needlenose & slip joint pliers, 6 way screwdriver, diagonal cutters, safety glasses.
The crowns seem to have line level & phone inputs in all cases. The Peavey's, they have one line level input, plus various adapters plugged in the back, usually for telephone, although sometimes a 2 channel to monaural line level input card. I would trust one of these over some import cheapo plate amp any day. The $20 mma-875t worked out of the box, an MMA-8150 I paid $50 for only worked if the case was off, but ce la vie.
Happy repairing, or replacing.
There are also crown 37 watt warehouse amps out there: https://www.ebay.com/itm/355306671220?itmmeta=01HVHNDYVSANQK5V54NN764DRT&hash=item52b9ed8c74:g:tB8AAOSwUhZiop2o:sc:ShippingMethodStandard!47130!US!-1&itmprp=enc:AQAJAAAA4Pvg87gKn0BJiSOOpt5uUCY4az/6828CBaqMpDAk6udeVxm2l016GxGnHc50gnIlzOAkWOpkTBdbDQG2C1tAXSGCLas9Hjhac8fYCPVm438TS/zh0vV2A86ZxwhWnjRCxx+noFlgnGbVPdkDUpGW5cxsCD0Rl5sfUfouzbUDkqjFFcBwIsmAqhceytlRtIxGtbfSDI7WSMdnDlFqfublu75QOVWdFks9MVhixEzAhTbEU/kTCOgoLmV2XbcSbmX+LVVS0ool9exefwBYx4CmDzF8J+aiKix4ylp3l1WS/cYw|tkp:BFBMgO63tdxj
That one is a rediculous price unless the vendor installs the 8 speaker in your ceiling for you. However, get on gumtree, UK ebay, facebook marketplace, see what you can find for not much money. If one of these warehouse amps is defective, they are repairable by amateurs with a DVM a pocket radio, a trashy speaker, and maybe an analog VOM. +soldering iron, solder, needlenose & slip joint pliers, 6 way screwdriver, diagonal cutters, safety glasses.
The crowns seem to have line level & phone inputs in all cases. The Peavey's, they have one line level input, plus various adapters plugged in the back, usually for telephone, although sometimes a 2 channel to monaural line level input card. I would trust one of these over some import cheapo plate amp any day. The $20 mma-875t worked out of the box, an MMA-8150 I paid $50 for only worked if the case was off, but ce la vie.
Happy repairing, or replacing.