MPP

Now we are talking, as my friend Brian Dayly used to say. I put the CCS´s on finns and added 33 Ohm resistors to the set resistors for a total of ca. 11 Ohm. Now the Leds light up and i got 9.4V on the positive side and 9.5V on the negative. Offset in one channel is 7mA and in the other 4mA. Same as before and this is an open loop stage with a lot of gain without conventional servo or coupling cap. The CCS´s get warm but not hot so everything is in butter as we say here. The first i tryed is to cranc up the volume. No hiss, no humm, only a faint rush. Very good. The first record i listened to was Hellen Merill in Tokyo. What was immediate obvious was the quietness in the backround and how clean it sonded. I whould not describe that as black as many reviewers do. It is more a very bright but still nice white like the one you have in south Norway in late spring. Sounds on that canvas sound extemely undistorted and open. I can hear more ambient detail then i could hear with the LC Audio Low Noise supply and that was double mono plus coils and RC filtering. Seperation and immage focus did not suffer ether,
although i use only one Hypnotize for both channels. I checked that with "Return to Forever". On the track "Cristal Silence" there is a soprano sax playing 50cm on the left and 2m back from the right channel and this was as i know it. Percussion was nicely spread out from left to right up and well focussed. The bells and wistless came from about 2m high, a litlle less high then i am used too but with much better depth perspective. That sounds most natural to me. Before i had a sound that was sometimes a bit "hyper real" if you uderstand what i mean. On classic material i got a real shock.
Super clear with a lot of natural ambient detail. Extention in both direction of the spectrum is excellent without boom in the bass and without sizle in the treble. The music is just there and artifacts from the tracking are better surpressed then i am used too. Noise from the groove plus tick and pops are surpressed superbly well. Dynamic expression is huge and the bass is dry like the Sahara but solid as a block of granite controled by an iron fist. I can not hear that this supply has any priority for a certain range of frequencies. Where the LC Audio sounds lifely with very good timing in the fundamental tone aerea this Hypnotize is much more even handed without any loss of fun factor. If you now think i am happy with the performance you are right. This is the best PSU i had so far on my phonos and it is not even expensive or complicated. The only other experience i had with shunt PSU is the Twisted Pear Placid. It sounds excellent too but the Hypnotize is more freely floating whereas the Placid sounds extemely fast and rythmic but also a bit on the analytical side of neutral. A matter of taste and system matching. I like the Hynotize a little bit more but please do not see that as help to make a bying decission. It is purely subjective and i will use the Hynotize from now on as my new benchmark. I will do the meaner shunts this week and i am confident now that i can make them work.
Thinking about improvements i could make to the setup now i will replace the unbespoke 3300uF elcaps with Nichcon Fine Gold. I will shorten the wire to the PSU as much as i can and i will tyr to put in the 1uF Wima and the 1nF NPO again to compenstae for the short wire left but this can wait. I will listen some more days until i contemplate any changes. By the way i am listening now to the MINI MPP BWBA as described on my MPL thread that have an in room sensitivty of ca. 90dB ( 86 - 87 dB freefield and the noise will come up more on my 100dB efficient MPL but that needs also less volume to play load.
 

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diyAudio Chief Moderator
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Congrats!

Take out the 100uF caps bypassing the 5 leds rows on Hypno and use 0.1uF 1837 up and down the 5mm pcb pads so you can fit 0.2uF in total. Fit some chunkier sinks on all Mos and crank it up for CCS mA as much as comfortable for heat and for your now filter caps don't ripple hard. Use 1.6V/Rset ballpark formula with yours so to estimate target current. You got only 145mA (45mA over) per rail now. Try to go over 200mA per rail in total. Will massage the Mos better. Both those little easy tweaks are rewarding.
Your cabling is relatively long and thin for no Kelvin bridge arrangement. You can improve that too for now as you said. True, you may appreciate bigger and better filtering cap units as well.

Hypno is just a taste, a specialized board that people pressed to use as reg too. Double mono V1.2 remote sensed point to point is in another league, worth a try.

If you feel any sharpness when you put your Wima local decouplers back on phono, means they interact compressing the closed loop phase margin. If the cable inductance works in harmony and comes across better as a system, then leave them in by all means. Happy listening.

P.S. It will give you a new kick after 48hours play.
 
Thanks for all this sugestions. This is not a fixed installment so i need at least some length of wire to be able to experimant with other PSUs etc. Whould it make sense to install a common mode choke ( 100mH, 1.5 Ohm ) BEFORE the shunts ?
I have pretty big cooling finns installed and the Fets are not very hot so i have some feedom to raise the current. I am now preparing the meaner shunts. By the way i use Hyperfast ( 16nsec) 15A diodes from IRF. This is totally overkill but they fitted with some lead bending. I had no other at the moment.
 
diyAudio Chief Moderator
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I had in mind to suggest you use those coils before but its a small board with integrated rectification and you should hack it a with a hobby knife, its a bit inconvenient. Then you would need Cin for Pi filtering not to lose Vin-Vout, you will extend the loop area and ESR with flying cables to fit all those extras, so maybe back to near square one. The result will be more smooth space (not night and day) if done well. Have used Rin, Lin, CRC, CLC. I would firstly jack it up for current, use best filter caps, listen with MKP1837s over Vref LEDS instead of lytics, shorten/thicken lead out cabling. More productive IMHO. Use the nice coils to pi prefilter the V1.2s in a good intimate layout. There will be the real hard liquor party. Now with the hypno its just soft drinks, and its not even tweaked & broken yet.
 
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I see that your regulator is only 1mOhm @ 10kHz so i will shorten the cables and double the earth line. I will then put 0.2uF over the Leds, take the elcap out and reinstall the 1nF leaving out the Wimas. I think that should work at the moment. I wil look what set resistors i need for 200mA.

Those moves will give it some valuable extra. Will also further drop Zo with current. Caution, the output 100uF caps remain. Else you will only can play ''Oscillate Wildly'' by the Smiths. See if you like MKP only over the 5 LEDS exchanging those 2 elcaps towards ACin side. Most people liked the MKPs surely better, one didn't but its different ears and systems. Keep the elcaps aside for retrofit in case you will miss them.
 
diyAudio Chief Moderator
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See example. Those two to the right near the AC Trafo connector you can exchange for MKP as in the picture and listen. 99% of people in other stuff prefer them. In your phono, you tell us. Those to the left in the picture you leave them as they are.
 

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