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Old 10th August 2010, 04:07 AM   #1581
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so should i change the set resistors ? what value whould you try ?
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Old 10th August 2010, 04:13 AM   #1582
Salas is offline Salas  Greece
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If your secret phono needs +100-100mA, parallel a third 33R to the existing 2 and you will have +/- 160mA. Your dummies should be 100+100R in that case. Use some little sink especially on the CCS Mosfets. Those ones near the setting resistors.
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Old 10th August 2010, 04:21 AM   #1583
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Ok, i will try that tomorrow. I need a rest. I have sinks handy. Parallel i have worked on the high speed buffer. I knew that the "double Szikley" whould cause we trouble. That damn thing is fast ! I got the DC points working and i have an idea but that has to wait for tomorrow too. Thanks for guiding me. You are great !
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Old 10th August 2010, 04:24 AM   #1584
Salas is offline Salas  Greece
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You are near success. Tomorrow.
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Old 10th August 2010, 04:31 AM   #1585
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We will make it work, no question. Good night or whatever you do.
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Old 10th August 2010, 02:16 PM   #1586
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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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Old 10th August 2010, 02:48 PM   #1587
Salas is offline Salas  Greece
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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.
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Old 10th August 2010, 02:48 PM   #1588
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You should find another level of improvement if you can use a shunt reg for each channel and very short (less than 2cm) and fairly thick wires between the shunts and the phono.
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Old 10th August 2010, 04:16 PM   #1589
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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.
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Old 10th August 2010, 04:29 PM   #1590
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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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