Bought this secondhand, mainly for the electronics. Consists of an average, standard 8inch woofer, mounted in a thin walled, 12inch cube enclousure. Relfex loading, with little internal dampening. However, I was surprised with the measurments I recorded (see attached).
Is this what one would expect to see from a cheapo small sub?
Is this what one would expect to see from a cheapo small sub?
Attachments
I have now changed the int. amp. TDA7375 but there is no change - the 'continuous rumble is still there. There are two pcb and two other chips but sourcing replacements of these chips is proving difficult. One is: 45580 / JRC / 40174 the other is: TLO84CN / GK5141J6 / STo3V6GKCHN - that is what is printed on the back of the chips. Anyone have any ideas as to where these chips can be bought?
I am now in the process of changing all the smaller caps. There is also a Zener Diode in there which I have changed but the on-going rumble is still there. It seems Maplins do not stock any caps with 82 in the value and I need an 823K 100v. cap (=0.082uf - or - 82,000pf) Any ideas out there. In fact has anyone read these posts of mine and are willing to input ideas?
We have a Eureka! moment! Having methodically changed all the radial caps, the Zener Diode and the Integrated amp. TDA7375, I started in on changing the smaller caps - the Mylar and disc type. Between each change of one or two caps I tested for 'rumble'. After changing three 2A104J 100v. Mylar types I tested the Subwoofer again and... that's when the Eureka moment occurred. So, apart from a low mains hum from the Subwoofer - which was always there - we are now back in business. You may congratulate me if you wish...
Hello Chris661 - thanks for the congrats! I was joking really about saying '...you may congratulate me if you wish...' as there didn't seem to be any response from 'out there'. You say "I'm in a hurry - I need to plug it ion and watch it burn, baby!" Well, that's just what my son's Violin/Guitar amp has just done. It's a KLA10 unit and smoke started pouring out from under the PCB. The Integrated Amp - a TDA2030 - gets mighty hot and started melting the contact paste. But the main problem was the huge hum.m.m which preceded the smoke. At this point we turned it off. After cooling we turned it on again and the hum.m. is still there so we turned it off again before the burning started. Michael
Sounds like you've a problem with that amp.
Might be an idea to post something in either the "chip amps" section, or the musical instruments section. Either way, you're likely to find people a little more specialised on the subject.
That particular chip, I've had problems with. Upon opening the little practice amp I'd bought faulty, fixed the problem and found the feedback resistors for the chip were on the main board, the chip being connected via a ribbon cable. This made the whole thing incredibly sensitive to everything. Waving your hand near it caused buzz.
Your problem sounds altogether more serious. I'd suggest first of all putting a fuse on the + and - supplies, so they'll cut the power before anything goes pop again.
Chris
Might be an idea to post something in either the "chip amps" section, or the musical instruments section. Either way, you're likely to find people a little more specialised on the subject.
That particular chip, I've had problems with. Upon opening the little practice amp I'd bought faulty, fixed the problem and found the feedback resistors for the chip were on the main board, the chip being connected via a ribbon cable. This made the whole thing incredibly sensitive to everything. Waving your hand near it caused buzz.
Your problem sounds altogether more serious. I'd suggest first of all putting a fuse on the + and - supplies, so they'll cut the power before anything goes pop again.
Chris
The problem has now been solved in my Storm 8 Subwoofer. It was nothing to do with the Woofer or its internal electronics... it was a faulty plug-in A/C PSU. I have now replaced this with the PSU from a redundant scanner. Such is life. Just thought everyone (anyone?) following this thread needs to hear of a satisfactory conclusion. (having said all that... will the rumble return?? watch this space...)
Michael
Michael
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