So I'm thinking of getting this board here to replace the DS-300.
You can reverse polarity on the board with the switches to make it an inverting amp, and it seems like it checks off every spec on the list that Eva provided, except for the mute function. The board does have a standby option though. Now, I'm a bit confused as what MUTE does, is it speaker protection or does it actually mute the amp? Will this new board I've linked go on standby when there is no signal detected, or do I have to wire something up to make it do that? I've also seen speaker protection circuit boards on ebay, and will buy those if they perform the same function as MUTE. I'm totally a n00b on this stuff, so sorry if some things may be obvious to the vets on this forum. Think these are a good fit?? Thanks for any advice on this!!
You can reverse polarity on the board with the switches to make it an inverting amp, and it seems like it checks off every spec on the list that Eva provided, except for the mute function. The board does have a standby option though. Now, I'm a bit confused as what MUTE does, is it speaker protection or does it actually mute the amp? Will this new board I've linked go on standby when there is no signal detected, or do I have to wire something up to make it do that? I've also seen speaker protection circuit boards on ebay, and will buy those if they perform the same function as MUTE. I'm totally a n00b on this stuff, so sorry if some things may be obvious to the vets on this forum. Think these are a good fit?? Thanks for any advice on this!!
Attachments
Alright, so I tested the voltage going to the DS-300 and it's +/- 68v... so the boards I mentioned above won't work since they max out at 65 volts. Sure does make a board (AA-AB32291 2x250W IRS2092) that is much cheaper and has a typical voltage rating of +/-70 volts so this board will work. I ordered these boards and they came today... and the build quality seems superb! As far as if it is inverting or not, I will have to test to find out. This board has a switch on it to use it as "bridged" instead of stereo, but I will have to see if that means just for output or for both input and output by hooking up one of the RCA plugs and seeing if it works. I'll update once I rig this all together 
Amp is Working! Have a grounding question though...
So the AA-AB32291 2x250w IRS2092 board from Sure Electronics is rigged up and working! I'm definitely having some sort of grounding issue as I can hear a slight hum/hiss coming from the sub when there is no input signal. Maybe this has to do with not having anything hooked up to MUTE.. I'm not sure. It could also be a bad ground since AGND and DGND aren't linked up and I believe they should.
Here's how I hooked it up. T500 rectifier/crossover board labels on left.
IN to signal + (RCA) input on the new amp
AGND to signal - (RCA) input on new amp
DGND to GND on new amp
OUT to speaker + on new amp
AGND to speaker - on new amp (upon closer evaluation, this AGND goes nowhere on the rectifier/crossover t500 board)
I then tried to connect the two AGND together so I could use that for my speaker negative (that was a mistake, not realizing what AGND is for), and also link AGND and DGND via the two holes on the chassis, using the capacitor from the ds-300 that went from AGND to the chassis in between agnd and the chassis.. and I must have sent the DGND through AGND and now i'm getting no sound whatsoever. I included pictures showing what I tried to do. My guess is I fried the ICs and ordered those and I'll replace them.
I'm trying to figure out, how would I properly link AGND and DGND together? It seems like in the old ds-300 they were linked together at the heat sink, which is why I did what I did, but maybe hooking up speaker neg to AGND is what messed things up? Is it ok to make the "star point" for AGND and DGND at the chassis holes?
Thanks!
Have a grounding question though...So the AA-AB32291 2x250w IRS2092 board from Sure Electronics is rigged up and working! I'm definitely having some sort of grounding issue as I can hear a slight hum/hiss coming from the sub when there is no input signal. Maybe this has to do with not having anything hooked up to MUTE.. I'm not sure. It could also be a bad ground since AGND and DGND aren't linked up and I believe they should.
Here's how I hooked it up. T500 rectifier/crossover board labels on left.
IN to signal + (RCA) input on the new amp
AGND to signal - (RCA) input on new amp
DGND to GND on new amp
OUT to speaker + on new amp
AGND to speaker - on new amp (upon closer evaluation, this AGND goes nowhere on the rectifier/crossover t500 board)
I then tried to connect the two AGND together so I could use that for my speaker negative (that was a mistake, not realizing what AGND is for), and also link AGND and DGND via the two holes on the chassis, using the capacitor from the ds-300 that went from AGND to the chassis in between agnd and the chassis.. and I must have sent the DGND through AGND and now i'm getting no sound whatsoever.
I included pictures showing what I tried to do. My guess is I fried the ICs and ordered those and I'll replace them. I'm trying to figure out, how would I properly link AGND and DGND together? It seems like in the old ds-300 they were linked together at the heat sink, which is why I did what I did, but maybe hooking up speaker neg to AGND is what messed things up? Is it ok to make the "star point" for AGND and DGND at the chassis holes?
Thanks!
Attachments
Not to just jump in but I have a set of these that I'm getting ready to restore. What about building a crossover that just uses speaker level power to drive the sub? Or a external amp for the sub?
Trying to go over a lot of options. The fix Greg posted shows a lot of promises as well. How difficult was it?
Trying to go over a lot of options. The fix Greg posted shows a lot of promises as well. How difficult was it?
Hi,
So after consideration, I ended up buying these:
LJM Finished Amplifier Board L20D IRS2092 Top Class D Amplifier Board 200 250W*2 8ohm-in Amplifier from Consumer Electronics on Aliexpress.com | Alibaba Group
They are much better since they aren't over powerful like the Sure amplifiers are. The L20D is 1 channel, and much smaller and will fit inside the speaker much easier. The L20D amps are also much cheaper than going anything external. I highly recommend these over the sure amps!
You could go with external amps, and drill holes and run speakerwire directly to the woofers, but I wanted to keep my t500s original.
The wiring process isn't too hard, I desoldered the old ds-300 amp modules, and soldered in pcb connectors (Amazon.com: WMYCONGCONG 440 PCS 2.54mm JST-XHP 2 3 4 5 Pin Housing and Female Pin Header Terminal Connector Kit (2 3 4 5 Pin): Home Audio & Theater) and then used 18awg wire to hook it all up. crimping the connectors to the wires was probably the most time consuming part.
The wiring for the LD20 is eaiser too since there's less grounds to worry about. The speaker + on the LD20 goes to OUT on the old amp, DGND goes to GND on the LD20, AGND (The one next to DGND on old amp board--one of the AGNs goes nowhere!) goes to signal - on LD20, and the respective VCC- and VCC+ go to V- and V+ on each board. You may have to reverse the wires going to the subwoofer itself, (I did) as I have read in this thread that the DS-300 is an inverting amplifier. Let me know if you need any help!
So after consideration, I ended up buying these:
LJM Finished Amplifier Board L20D IRS2092 Top Class D Amplifier Board 200 250W*2 8ohm-in Amplifier from Consumer Electronics on Aliexpress.com | Alibaba Group
They are much better since they aren't over powerful like the Sure amplifiers are. The L20D is 1 channel, and much smaller and will fit inside the speaker much easier. The L20D amps are also much cheaper than going anything external. I highly recommend these over the sure amps!
You could go with external amps, and drill holes and run speakerwire directly to the woofers, but I wanted to keep my t500s original.
The wiring process isn't too hard, I desoldered the old ds-300 amp modules, and soldered in pcb connectors (Amazon.com: WMYCONGCONG 440 PCS 2.54mm JST-XHP 2 3 4 5 Pin Housing and Female Pin Header Terminal Connector Kit (2 3 4 5 Pin): Home Audio & Theater) and then used 18awg wire to hook it all up. crimping the connectors to the wires was probably the most time consuming part.
The wiring for the LD20 is eaiser too since there's less grounds to worry about. The speaker + on the LD20 goes to OUT on the old amp, DGND goes to GND on the LD20, AGND (The one next to DGND on old amp board--one of the AGNs goes nowhere!) goes to signal - on LD20, and the respective VCC- and VCC+ go to V- and V+ on each board. You may have to reverse the wires going to the subwoofer itself, (I did) as I have read in this thread that the DS-300 is an inverting amplifier. Let me know if you need any help!
Bit off more than I could chew
I tried following the footsteps of gregdavid85 above and purchased a pair of the LD20 amplifier boards, but realized I am not capable of hooking them up properly. I actually purchased 4 LD20 amps by mistake. Not sending them back to China. Anyone interested in helping me out in exchange for two of these new amps? As of right now, one of my t500s is unassembled.
I tried following the footsteps of gregdavid85 above and purchased a pair of the LD20 amplifier boards, but realized I am not capable of hooking them up properly. I actually purchased 4 LD20 amps by mistake. Not sending them back to China. Anyone interested in helping me out in exchange for two of these new amps? As of right now, one of my t500s is unassembled.
Here is a message I sent to Markhenry, figured it might be of use on here as well:
So what you'll have to do is remove the ds-300 module from the bigger board. Take off the heat sink, and desoldering it off is kinda a pain but take your time. TAKE NOTE of what the pins say printed on the ds-300 module, you'll need to map that out cus the connections are not labeled on the bigger board. Once you do that, get some 18AWG wire, and get a kit of these https://www.amazon.com/gp/product/B0...?ie=UTF8&psc=1 pcb connectors.. I soldered these to the main board and used the wires to go to the LD20. Buy the crimping tool too--it'll make life much easier.
Note on pins on big board from t-500.. if you are holding the board vertically in your hand, with the big 100v capacitors on the bottom, the pin outs should read like this:
DGND -- This goes to PGND on LD20
OUT -- This goes to OUT+ on LD20
V+ -- This goes to VCC+ on LD20
MUTE (I ignored this)
AGND -- This goes to INPUT- on LD20
IN -- This goes to INPUT+ on LD20
AGND (don't use this one)
V- -- This goes to VEE- on LD20
Use different colored wire for v- and v+ from your other + and - signal wires. You definitely do not want to get anything mixed up.
Also, I'm not sure if the LD20 is not powerful enough, or if the power from the t-500 board is not powerful enough or if it's sending too many volts---when I play music loud, the sub cuts out, and It may be something like speaker protection on the t500 board. Everything works, and it's better than nothing. I discovered this once I put everything back together and sealed it up, so I suspect that something is drawing too much power when closed up.
Once you have everything hooked up and working, then it's time to mount the board. I mounted mine on the bottom inside the speaker case, which was a pain in the ***. You'll need to make a template from the outside and hold the board on the LD20 board outside and trace the mounting holes out. Take your time with this if you decide to go on the bottom. It would be much easier to go on the backside of the speaker, but I wanted the heat sink on the LD20 to be vertical, not horizontal.
Here's an album of pictures:
Amps - Google Photos
some of the pics are from when I tried the SURE Electronics amp, which I may give another shot all closed up as it's double the power. Please don't hesitate to ask any questions.. this isn't an easy job but if you can solder, make those pcb connectors, and pay attention to the wiring, it's not that bad. I'm definitely not an electronics guy just a tinkerer, took about a year for me to figure all this out! Researching which amps to buy probably took the longest, since there's not much info about the t500 amps and what power requirements they used.
So what you'll have to do is remove the ds-300 module from the bigger board. Take off the heat sink, and desoldering it off is kinda a pain but take your time. TAKE NOTE of what the pins say printed on the ds-300 module, you'll need to map that out cus the connections are not labeled on the bigger board. Once you do that, get some 18AWG wire, and get a kit of these https://www.amazon.com/gp/product/B0...?ie=UTF8&psc=1 pcb connectors.. I soldered these to the main board and used the wires to go to the LD20. Buy the crimping tool too--it'll make life much easier.
Note on pins on big board from t-500.. if you are holding the board vertically in your hand, with the big 100v capacitors on the bottom, the pin outs should read like this:
DGND -- This goes to PGND on LD20
OUT -- This goes to OUT+ on LD20
V+ -- This goes to VCC+ on LD20
MUTE (I ignored this)
AGND -- This goes to INPUT- on LD20
IN -- This goes to INPUT+ on LD20
AGND (don't use this one)
V- -- This goes to VEE- on LD20
Use different colored wire for v- and v+ from your other + and - signal wires. You definitely do not want to get anything mixed up.
Also, I'm not sure if the LD20 is not powerful enough, or if the power from the t-500 board is not powerful enough or if it's sending too many volts---when I play music loud, the sub cuts out, and It may be something like speaker protection on the t500 board. Everything works, and it's better than nothing. I discovered this once I put everything back together and sealed it up, so I suspect that something is drawing too much power when closed up.
Once you have everything hooked up and working, then it's time to mount the board. I mounted mine on the bottom inside the speaker case, which was a pain in the ***. You'll need to make a template from the outside and hold the board on the LD20 board outside and trace the mounting holes out. Take your time with this if you decide to go on the bottom. It would be much easier to go on the backside of the speaker, but I wanted the heat sink on the LD20 to be vertical, not horizontal.
Here's an album of pictures:
Amps - Google Photos
some of the pics are from when I tried the SURE Electronics amp, which I may give another shot all closed up as it's double the power. Please don't hesitate to ask any questions.. this isn't an easy job but if you can solder, make those pcb connectors, and pay attention to the wiring, it's not that bad. I'm definitely not an electronics guy just a tinkerer, took about a year for me to figure all this out! Researching which amps to buy probably took the longest, since there's not much info about the t500 amps and what power requirements they used.
gregdavid85, you said "Also, I'm not sure if the LD20 is not powerful enough, or if the power from the t-500 board is not powerful enough or if it's sending too many volts---when I play music loud, the sub cuts out, and It may be something like speaker protection on the t500 board." Did you ever resolve this issue of the sub cutting out?
I haven't figured that part out yet. I'm guessing it has something to do with either speaker protection on the t-500 board but who knows it could be speaker protection on the LD20 boards, since they have it as well. If someone who knows how to check the signal output on the t500 board that would be super helpful because too large of an input signal might have something to do with it and a resistor on the input signal might fix this.
Would you happen to know what would get messed up if I accidentally sent negative speaker signal through both AGND and DGND?? So on my first go on these, I had everything working.. but I had a loud hum coming from the sub. I figured the ground wasn't hooked up correctly. I bridged AGND and DGND and I had the Negative Output from my SURE amp (when I was using those) hooked up to AGND. (I basically sent negative speaker signal through the grounds, correct??) Now, everything turns on, but I'm getting no sound. Would it be the 4 chips on the t500 motherboard that got fried? Or do I have to replace all the transistors as well? Any help would be much appreciated! Thanks!!
I've gotten boards repaired by EdwardsElectronics only to fail after exactly two years. It's not the repairman's fault, it's just bad design of the DS-300 amps.
Hi there,
Contemplating repairing mine, the boards are working however I hear higher frequency noise when playing loud, almost as if the signal clips but I feel it's not loud enough to be a clipping issue. Initially thought this must be a driver bottoming out or scraping coil problem and changed to new subs but the problem persists. The noise is higher than a bass note almost like scraping but only happens on some notes and also not necessarily the lowest notes.. goes away when the volume is very low but pointless using it that way as this things supposed to boom.. any ideas or experiences to this typical problem?
Contemplating repairing mine, the boards are working however I hear higher frequency noise when playing loud, almost as if the signal clips but I feel it's not loud enough to be a clipping issue. Initially thought this must be a driver bottoming out or scraping coil problem and changed to new subs but the problem persists. The noise is higher than a bass note almost like scraping but only happens on some notes and also not necessarily the lowest notes.. goes away when the volume is very low but pointless using it that way as this things supposed to boom.. any ideas or experiences to this typical problem?