I just built my first DIY AMP and played with it on my crappy garage speakers last night. It sounds good so this AM I hooked it up to my RTi12's in the living room.
Oddly, when I get my Rotel RSP-1068 to the 73-78db area the speaker protection circuit cuts in and turns the speakers off. The RSP-1068 goes to 95db and doesn't cutout with my RB-1091's (500 watt 8ohm, 1000 watt 4ohm ICE amps) at any level with these speakers.
I've read that these speakers are likely closer to a 4ohm load but why would the speaker protection circuit come on? This is an LJM designed speaker protection circuit.
Oddly, when I get my Rotel RSP-1068 to the 73-78db area the speaker protection circuit cuts in and turns the speakers off. The RSP-1068 goes to 95db and doesn't cutout with my RB-1091's (500 watt 8ohm, 1000 watt 4ohm ICE amps) at any level with these speakers.
I've read that these speakers are likely closer to a 4ohm load but why would the speaker protection circuit come on? This is an LJM designed speaker protection circuit.
I couldn't test with speakers tonight. The wife doesn't do loud music and I should listen to the pregnant woman. In the garage I messed around with it without the speakers attached. I checked the voltage with my other receiver as a source via my iphone. I cranked it up to +16.5db (max volume) and the amp modules cutout until I bring it back down to +15db.
Without load voltage wasn't dropping. I did crank the PSU up to +-62.5v vs the +-60v I had it set.
I also looked on the relay in the speaker protection relay. It is a 10A 250v AC/10A 28v DC relay.
These are L25D modules so I need to go look at the amperage they can produce. I'm not sure how the relay is designed either, is it 10AMP between the two channels or 10AMP/channel. If the latter the L25D has to be under that. Even at 4ohm.
Without load voltage wasn't dropping. I did crank the PSU up to +-62.5v vs the +-60v I had it set.
I also looked on the relay in the speaker protection relay. It is a 10A 250v AC/10A 28v DC relay.
These are L25D modules so I need to go look at the amperage they can produce. I'm not sure how the relay is designed either, is it 10AMP between the two channels or 10AMP/channel. If the latter the L25D has to be under that. Even at 4ohm.
It looks like the L25D might suck with 4ohm loads. These speakers are rated at 8ohm but people tend to believe they should be rated 4. Damn this sucks.
http://www.diyaudio.com/forums/class-d/259824-l25d-vs-hifimediy-6-channel-active-system.html
http://www.diyaudio.com/forums/class-d/259824-l25d-vs-hifimediy-6-channel-active-system.html
+1 for Nigel , looks like your PSU is out of puff and aux supply is below relay under Voltage . Which supply is it ? Measure aux supply when speaker protect is activated . Be careful with your supply voltage , your SMPS caps are rated 63 Volts !
I see a soft start PCB in the pictures , probably one already build in the SMPS .
Cheers ,
Rens
Rens,
Thanks for the comments. I ran a few tests this AM with the cover off and indeed the power supply is out of puff and itself is cutting out. I'll upload a video in a while. It's an connex electronics A1000SMPS. I'm not sure how I could be engaging protection circuitry with only two L25D's on a 1000watt RMS PSU. Voltage at the AMP modules is 62.5+- when it cuts out so it's not voltage droop there. 121 volts AC on the input.
I do have a soft start and plan to use a 12v trigger which is why I have the second soft start.
I'll link a video tonight after work.
With only 1 channel the SMPS provides the puff but the AMP module itself cuts out at 82db vs 95db max.
The module not connected to the speaker (but to the SMPS) does not cut out.
On my Yamaha receiver at other garage speakers no issues with cutouts until max volume.
Thanks for the comments. I ran a few tests this AM with the cover off and indeed the power supply is out of puff and itself is cutting out. I'll upload a video in a while. It's an connex electronics A1000SMPS. I'm not sure how I could be engaging protection circuitry with only two L25D's on a 1000watt RMS PSU. Voltage at the AMP modules is 62.5+- when it cuts out so it's not voltage droop there. 121 volts AC on the input.
I do have a soft start and plan to use a 12v trigger which is why I have the second soft start.
I'll link a video tonight after work.
With only 1 channel the SMPS provides the puff but the AMP module itself cuts out at 82db vs 95db max.
The module not connected to the speaker (but to the SMPS) does not cut out.
On my Yamaha receiver at other garage speakers no issues with cutouts until max volume.
Ok, looked at the gain level on the L25D modules vs the RB-1091 AMP's. Hmm, my RB-1091's have only a 27.15db gain where the L25D's have a 40db gain. That could make some since as to why I'm about 13db shy of "Max". I guess I need to read up about gain and level output. Any suggestions?
http://www.diyaudio.com/forums/anal...78-muses01-op-amp-mod-rotel-rsp-1098-18v.html
I believe the RSP-1098 uses the same internals as the RSP-1068 for the most part. Am I reading this right, Rotel has 18v line level outs on these units? What's typical?
http://www.diyaudio.com/forums/anal...78-muses01-op-amp-mod-rotel-rsp-1098-18v.html
I believe the RSP-1098 uses the same internals as the RSP-1068 for the most part. Am I reading this right, Rotel has 18v line level outs on these units? What's typical?
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