MY DESIGN L20D IRS2092+IRFI4020H 200W8R

[doctordata]

Originally Posted by NissanSR20Man

I am really impressed with your work, I am an emotiva fan myself and you really pulled off the look just fine.

Good job! Nice build, great detail. The real question... Have you driven all channels to see if the 1000 is enough? I am planning a similar build and keep coming up short on power in my head with a single 1000. I keep thinking linear is the way to go, but SMPS is so much cheaper and smaller. I keep hearing about horible buss pumping on multi channel class d setups, have you checked into it to see how bad yours is?

Thanks ,

For me the SMPS1000 is quite enough . I had this one specially build by Christy because our high mains voltage between 250 and 255 Volts with the whole neighboorhood (including myself) with solar feed-in to the grid .
The transformer has stranded wire , so the continues power is 1100 watts .
I use 50 volt rail voltage for the Amps and because my whole system uses high sensitive Tannoys ( 93dB ) I can reach very high sound pressure without any issues . I never had any bus pumping ( see post #379 )
When I drive the system in unrealistic very high volumes , the current limiter of the smps1000 kicks in ,but that never happens during a movie or listening to very loud stereo music .

Cheers ,
Rens

[ionutzxpo]

Hi guys,yesterday I received my L25D im very pleased by the sound it's very clear and natural.I made only one chanel for testing

[NissanSR20Man]

Doctordata - The comments about your speaker protection peaked my interest too. During the test after the mods, you did find the turn off time to be proper? I am not sure how fast the time really is, 1S or shorter? I have been pondering the protection scheme for some time. The bus pumping phase shifter of your is quite nice too! I planned on using cristy's BIPS module to offer the nice finished look of the jacks, and offer some line driver capabilities too.

Overall it sounds like you put your system through the ringer regarding testing. Its nice to know the ebay speaker protection circuit actually do work.

My multichannel setup would be for home theatre, driving a total of 8 full range speakers. The sub would probably be qty2 L25 bridged. Just cause I'm anal about commonality of looks and parts, I would probably use all L25 modules. My main speakers are 93db too and cannot wait to really push them hard. I have an antique onkyo reciever only "claiming" 60Wx2 in stereo mode. In multichannel it is pretty poor for my setup. My whole system is made up of athena audition series, not great but a really good speaker for little money.
Linky here
My Man Cave - Home Theater Forum and Systems - HomeTheaterShack.com

[ionutzxpo]

STEREO ...IT'S JUST WOW I CAN'T GET ENOUGH LISTENING TO THIS AMP FANTASTIC SOUND STAGE (IM USING A WM8740 DAC AND FOOBAR+ASIO DRIVERS)

[doctordata]

Originally Posted by NissanSR20Man

Doctordata - The comments about your speaker protection peaked my interest too. During the test after the mods, you did find the turn off time to be proper? I am not sure how fast the time really is, 1S or shorter? I have been pondering the protection scheme for some time. The bus pumping phase shifter of your is quite nice too! I planned on using cristy's BIPS module to offer the nice finished look of the jacks, and offer some line driver capabilities too.

I didn't document the timing when I tested the protectionboards , but remember the scopesettings were somewhere around 100msec per division and the relay did open within one divison , so for sure less then 100 mseconds at 50Volts DC

My Man Cave - Home Theater Forum and Systems - HomeTheaterShack.com

WOW that is some hometheater !!!!

I received some PVI1050 couplers today and did some interesting measurements on the speaker relay on this link A DC Fault Protection Circuit for Audio Amplifiers . I put 30 volts over the Fets (IRVP44Z just for testing) in to 8 ohm dummy load . The switch times are very good 50usec offtime (Leds in series 30 ma,Fotocells in series ).The coupler is a bit slower , 200useconds .This Fets have only 3000 pF input capacitance and the ones I ordered (IRFB3077PBF) almost 10nF, so I put 20 nF parallel to the PVI1050 output . The switch time went up , about 100useconds but the big surprise for me was that the fet keeps switching off in 50 usec ! So very safe within SOA .
When I have my bigger Fet's I'll make some drop in PCB's for the WLX-7 boards and keep you posted . Before I switch the mechanical relays to the Mosfets I will document some measurements on the old one and compare them to the new ones .

Cheers ,

Rens

Yellow is Leds Blue is dummyload

[NissanSR20Man]

Typical americans, we do everything big. If some is good, alot is even better, then massive would be a awesome.... I spent very little money on it, I did all the work my self. Some people on the theatre forums spend more on their speakers and amplifiers than I did on my whole house. I saw a guy on there with 15 amps at something like $40K USD each. Just stupid. This is why i love the diy and LJM modules. I can spend $500 or so and have an awesome amplifier that could sound just as good as commercial amps.

I would have never believed that the mechancial relays were that fast opening the circuit. With the addtional fet protection, the speaker protection circuit would almost totally invisible, meaning the protection wuold kick in prior to hearing any such problems prior. It is a shame the LJM modules remove all of the AMP7 protection features. External is more robust than using the power mosfets anyway. Good testing information

[doctordata]

Originally Posted by NissanSR20Man

It is a shame the LJM modules remove all of the AMP7 protection features. External is more robust than using the power mosfets anyway. Good testing information

I think he did the right thing .
External is the only way to go to be sure !
I'm using a small 12 Vac extra transformer to feed my protection circuits .
Not that I'm not trusting Christi's SMPS aux or the IRF reference design , but a little transformer is far less complicated than a SMPS or the Iraudamp reference design and has a lot less components to fail .

Cheers ,

Rens

[doctordata]

Just read this thread about AC line filtering .AC Line Filter
Does it make any sense to filter the line when using SMPS's and class D amps .
I see or hear no influence of the smps or the carrier of my class D amps in the rest of my gear ( I did see some video distortion , but that was gone after I used the proper interconnects )

Cheers ,

Rens

[alkasar]

Originally Posted by doctordata

Just read this thread about AC line filtering .AC Line Filter
Does it make any sense to filter the line when using SMPS's and class D amps .
I see or hear no influence of the smps or the carrier of my class D amps in the rest of my gear ( I did see some video distortion , but that was gone after I used the proper interconnects )

Cheers ,

Rens

Connexelectronic SMPS have mains filters embedded. Actually any serious smps should have. AFAIK, add a mains filter is redundant with SMPS. If you do add one, you better consider the interactions between the two filters.

[ZachAttack420]

When putting on the heat sink compound which side of the silicone pad does it go or does it go on both sides?

Silver compound okay?