http://www.diyaudio.com/forums/soli...00watt-class-power-amplifier.html#post3029416
(Thorens TD550, JK Reference transport, Omega phono. Switched to 3x80mm silent fans instead of 2x120. Still thinking of rebuilding the output stages to get to 5A quiescent current, instead of the current 3.25 I live in a graveyard 9 of 12, soundproofing of my listening room did ~€7k)
(Thorens TD550, JK Reference transport, Omega phono. Switched to 3x80mm silent fans instead of 2x120. Still thinking of rebuilding the output stages to get to 5A quiescent current, instead of the current 3.25 I live in a graveyard 9 of 12, soundproofing of my listening room did ~€7k)
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I want to do a longer listening tests and comparisons before I write about it but so far it is very transparent.
Thanks
Do
at 40PSI, this product seems very similar to Kerafol but at a much higher premium price unfortunately...
http://www.tglobaltechnology.com/datasheets/TG-X.pdf
I guess I will have to import Kerafol 82/82 190mmx190mm sheet from Conrad in Europe... Will cost a pretty penny but still cheaper than the TGX from TGlobal. Unless someone in Canada or USA has part of a Kerafol 86/82 sheet to sell?
Thanks
Do
http://www.tglobaltechnology.com/datasheets/TG-X.pdf
I guess I will have to import Kerafol 82/82 190mmx190mm sheet from Conrad in Europe... Will cost a pretty penny but still cheaper than the TGX from TGlobal. Unless someone in Canada or USA has part of a Kerafol 86/82 sheet to sell?
Thanks
Do
Yes but they're not the proper format for the Sanken MT200 package. Would have been nice if they had the sheets as well.
Ciao!
Do
Anyone in Germany can help us buy a few sheets and post them out ? I'm in for two of the 100*100 ....
Just found the North American distributor
MH&W International Corp.
They should be able to get everything. If someone is willing to buy a lot and sell in sheets, I will buy some for sure.
an oscillation
Try using decoupling capacitors. Insert it between the + and - supply voltage. Put it directly on pins predriver or power transistors (on both channels). It helped me to get rid of the oscillation.
Best regards
Bohdan
Hi pinnocchio,
Try using decoupling capacitors. Insert it between the + and - supply voltage. Put it directly on pins predriver or power transistors (on both channels). It helped me to get rid of the oscillation.
Best regards
Bohdan
Hi Bohdan,
It seems like my issue was related to heat transfer from the lead of the Sanken BJTs and not an oscillation.
In any case, it is good information to take into account.
Thanks
Do
This is a picture of my extrema in experimental setup. I designed the pcb's myself looking at the schematics and pictures of the amps on the net. I like to build every part of any project myself for 100%. But big thanks to Mr. Sassen for the great design! You will notice an addition to the project. I have put a microcontroller PWM controlled buck converter in between the powersupply of the VPWR+ and VPWR-. This way the current stays constant at 4 Amps, but the wattage will drop when the voltage is lowered. Now the voltage is set at a fixed level, and the amp in stereo at the moment of writing this is taking 90 watts. But the next step is to build a balanced DAC with PCM1704's combined with a dsp that will adjust the voltage according to the music level. Result will be a sort of class A / class D combination. I will keep you updated on the project.
An externally hosted image should be here but it was not working when we last tested it.
Very nice work dijwim!!
I was thinking of modding the psu and add a R value of .22 ohms in between the large caps for each rails for extra filtering. My amplifier is now working very nicely and sounds really good but one last little intermittent issue on the regulated FE psu... Sometimes when I have a signal already connected and playing on the amplifier and I turn it on, the regulated FE psu refuses to start... I have to turn off the amplifier and stop the signal, then power up and we're fine... This is a strange behavior of the regulated PSU. Don't know if you've encountered this?
Do
I was thinking of modding the psu and add a R value of .22 ohms in between the large caps for each rails for extra filtering. My amplifier is now working very nicely and sounds really good but one last little intermittent issue on the regulated FE psu... Sometimes when I have a signal already connected and playing on the amplifier and I turn it on, the regulated FE psu refuses to start... I have to turn off the amplifier and stop the signal, then power up and we're fine... This is a strange behavior of the regulated PSU. Don't know if you've encountered this?
Do
Yes I had the same issue, i solved it by placing a 47K resistor over the Collector - Emitter of T5 and T10. This helps the startup process of the FE psu.
My DAC and DSP board for the extrema is finished 
. This weekend I will start writing the software that will modify the powersupplyvoltage according to the audiolevel.
. This weekend I will start writing the software that will modify the powersupplyvoltage according to the audiolevel.An externally hosted image should be here but it was not working when we last tested it.
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Today I finished my DAC and DSP board to control my extrema. This weekend I will start with developing the software for the DSP that will control the powersupplyvoltage according to the audiolevel. This way I hope to create a very power efficient extrema amplifier. Below a picture of the finished board:
An externally hosted image should be here but it was not working when we last tested it.
Yes I have some trouble getting the picture correct on this forum
.Did you try the powersupply fix by the way?
Last try for picture ;-)
An externally hosted image should be here but it was not working when we last tested it.
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