Re: What's the best way of applying amp protection for power and speaker's 4 Project

unfortunately i was wrong about the Onkyo transformer it appears to have 3 secondary winding's providing 3 different voltages to the amplifier stage all split rail out, +/-24Vac Gray Wires, +/-33Vac Yellow wires and finally +/-48Vac and a common black wire centre tapped rail coming from the transformer and the +/-24Vac is hard wired straight to it's own rectifier then to the B+/B- of the amplifier,s reservoir capacitors, then the +/-33Vac is controlled by 2 relay's again going through it's own rectifier...

Re: What's the best way of applying amp protection for power and speaker's 4 Project

the modification is working under test (still to dig my old scope out and test with a sign wave for possible crossover distortion) and showing no constant DC values on the speaker output's apart from 37mV
My aim with this project is to create a monster power amp for my home theatre modifying 2 (already done) or possibly 3 (yet to try) of the 7 channel's to create a single channel capable of driving a single subwoofer @4 ohm's powered from a separate toroidal transformer providing independent...

Re: What's the best way of applying amp protection for power and speaker's 4 Project

Think i'm just going to settle for fuses in the power supply and standard DC speaker protection board's you get cheap from china in order to use it safely,

Would anyone with experience paralleling output transistors just check this out for me please,

here's a link to the pic of the driver board circuit and i'm interested in knowing if the 6 pin connector to the right of the pic that connect's to the circuit with the main output transistors and is shown on the link below...

Re: What's the best way of applying amp protection for power and speaker's 4 Project

Here's some pictures of the service manual covering the main part's im using, hopefully it will help....

here's the circuit layout from 1 of the 7 identical driver board's, please note i'm wanting to know if/how i can possibly use the IPRO & VPRO and VOLH sense lines for building my own protection circuit

[url]https://www.dropbox.com/s/ngkt81vhy2gphu1/Onkyo%20TX-875%20Amp%20Driver%20Board.png?dl=0[/url]

Here's the circuit layout of the X2 2sa1962 and X2...

Re: Infinity PS-10 Subwoofer Disassembly

I've recently attempted a similar repair with a monitor audio silver subwoofer however couldn't repair the switch mode power supply and didn't know if it had taken out the class D amp with it nor was it documented any where to what B+/B- voltage it required so played with the idea of replacing both with a diy solution using some of the class D boards available after getting the input doard working with a separate +/-12vdc but didn't feel comfortable putting it the back of a sealed wooden subwoofer to build up heat again and using it in my...

Hi, I'm interested in learning how to apply both speaker protection (DC on the output) and power supply protection to an amplifier to protect against short circuit and any other issues, would be nice to also monitor bias values

what's the best practice to apply this please ?


I've got the power supply and main 7 channel power amplifier module successfully working removed from a non working Onkyo TX-875 however now it has no protection what so ever, all i have left is 12v relay's to trigger for controlling power and 7 more to connect the speaker output's...

Re: New Members - please post your introductions here

Hi to everyone, I'm Paul, a self taught DIY electronics enthusiast interested in repairing and modifications stuff specially with audio/studio gear and joined hear to learn more and get help, support and guidance from the great community here

Re: New Members - please post your introductions here

Hi to everyone on badcaps.com, my name is Paul and i started in electronic's as a child both with taking broken electrical item's apart, well not all broken and my parent's got sick of finding me taking house hold item's to bit's so got me the old 50 in 1 kit's where you built everything by connecting wires between spring's ect

I actually now spend time repairing/modifying audio gear and other DIY projects