MPP

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You don't need a monster, the Hammonds are pretty small n' cheap. Show them the datasheet asking for something like the 159ZA which is about 10x7x6cm. If they raise an eyebrow, just order 2pcs 159ZA online. In phono we need the RF out. Then the CCS won't need to be elaborate cascode and rather dry sonically. You will make perfboard reg prototypes, yes?
 
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i may do a version that needs some more like 100ma too has the value to be exact ?

I will see regs they run at 300mA so their gm stays warm.;) You will only need to prefilter with 10.000uF-159ZA-10.000uF Epcos best, no plastic bypasses, down to 25VDC reg in +/- . Double mono. 2 preferably R-Core 100W Tx and 2 soft recovery bridges. All that in a separate box. Shunts litterally on load. No wires, or just 2-3cm thick ones. Else you should use force/sense wiring. OK will send you a symmetric of proper reg CCT.
 
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I do them p2p, they do better that way. They are very simple ccts, and you can squeeze parts together avoiding nH thin copper pcb lines, also having air as dielectric. Superior subjectively. Will send soon. I want those for my bedroom in return. You can surely ask the fellow German speaker guys to wrap a little present to Athens, yes?:D
 
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I worked a bit on the ASAP-FET.
This version has lower noise and distortion plus adjustable offset. I call it ASAP-FET-LNLD. I like it.
Does anybody know where to get some low noise P channel-Fets ?
My friend is sales manager at Toshiba and even he could not help me. Toshiba stopped to make anything the do not make money with. He told me that in quantity the could only charge a few cents in the past per piece.
I would like to build it and listen to it. I tried N- channel fets from Linear Systems and they are very good. unfortunately they make no P channel. I see so many people searching for low noise P-channel that this could be a busyness opportunity.

Joachim, Linear Systems do make a P-channel now. At Burning Amp they had samples of the N-channel LSK170, the P-channel LSJ74 and the dual N-channel LSK389.

jd
 
tonight i had an idea for two varieties of the MPP that are even simpler.
The input is not a transimpedance stage any more but that has the advantage that other cartridges with higher impedance can be used. The bipolar version has around 250 to 500 ohm impedance depending on the idle current and a 6 dB noise advantage compared to the
un-bypassed MPP. it can be as low as 0.3VqHz. The fet version is slightly noisier and has a high input impedance. noise in the fet version can be reduced by paralleling. i hope this circuits are use full because they are ultra simple and should work well :
i call them ASAP-B and ASAP-F

Yes those are what I meant. I'm typical 3rd generation immigrant with little or no original language (family was actually from Noetsch, Aus.)
 
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I guess they know they need an air gap on the cores. Have sent you the CCTs with some notes BTW. Seen your interest about coils in Riaa on syn's thread it was I think. I had 2 highly regarded LCR tube phonos from Japan under scrutiny, they had nothing they did better, to the contrary. I believe your friend had done better. About electronics distortion minimals and their thresholds VS the much more in transducers level, both for speakers and cartridges, the logical order is different IMHO. Less distortion for comparable CCT complexity must not be considered as a merely smaller additive on a bigger problem, but as an indication of more linearity so not to further interact with the main problem. You are a renowned speaker designer. Could you recognise two different cdps or amps with adequately much lower self distortion than your speakers own, through them? If yes, its about how much info you save until reaching your speakers, for them and the room acoustics to truncate, not about that your speakers they can only pass some predetermined info quantity and that is all. IMHO of course. If on the other hand you could not, forget my non scientific hunches, have a pilsener, relax.:D
 
Distortion in speakers has another nature and origin then the distortion in amplifiers so curiously you CAN hear improvements to your amp over "distorted" speakers.
by the way, the pair i build for my self that is not so bad in distortion at all. at cruising level distortion is under 0.5% mostly 2nd and very little (under 0.1%) third from 70Hz to 10kHz.
on the other hand, yes, buy youself a good speaker and place it in an optimum position in a good sounding room and you have done your homework. i sometimes hear sytems of my employes. they of cause all have my speakers. one of them has an ALDI (famous german discount chain) 39,-€ dvd player and a cheap hometheatre amp and the sound he gets is 100 times better then what i regulary hear at shows and dealers. it`s not perfect at all but it has emotion and character so does the musical job of comunicating.
apropro coil: i think what mundorf will try to make it by simply winding the copper directy on an open bar so there is a HUGE airgap. we call coils made that way I-Punkt
. if that does not work they will try to wind it on a transformer or a ferite bobbin
P.S: as i already said, i had my lisening checked on Professor Klippels website and i can not diferenciate better 0.1% low order distortion . curiously i hear differences in cables, resistors, op amps etc. very easy and developed a particalar taste : big-focussed soundstage, dramatic dynamics, low colouration and good tonal balnce, wide bandwidth etc.
P.S: i also listened to some exotic japanese phonoamps and was surprised by the colouration. maybe asian people have other prorities although i have several asien friends that share my taste in sound. i sold a lot speakers to asia, especially taiwan, japan and korea so that fact remains a mystery
 
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They have other vowels, other living space, some atonic high pitched traditional instruments, they love delicate aesthetics, we simply can't know their priorities if we don't live with them enough. I have gathered they maybe give priority to etheral midhighs and cosy midbass. Maybe what FR speakers need, that they use a lot.
Distortion and noise numbers in electronics are not thresholds to listen to IMHO. Just indications to more information. If you get the MPP without any topological or bias changes to measure 6dB less THD and noise, just because some new bjt allows you so, the music is going to appear more informative and bolder. Same impact if you get it down to 0.05% from 0.1% or down to 0.025% from 0.05%.
To me its simply 6dB better, not just even less than less enough. If you manipulate it to measure better with more or different circuit, then you can't compare directly, its another pre. So we like 0.1% of that food and not 0.01% of another food. But we surely notice 0.05% better in the food we like. Then again don't take me any seriously, those are DIYer's non scientific hunches as I wrote before.
 
Hi Salas !
i have worked a little on the pre filtered supply. i would work with a double bridge.
only one channel is shown, i would go for double mono. the other option would be to use the pre filter for both channels and then use 4 shunt regulators, two for each channel (+- supply). what do you think is the best way ?
do you have a recommendation for the diodes in the bridge, for the transformer and what do you think about the filter caps across the bridge directly behind the secondary of the transformer ? sorry for the many questions but it will safe me a lot of time and i trust you.
 

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diyAudio Chief Moderator
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Check FFPF60SB60DS Fairchild diodes. I would avoid toroidals, good EI, or R-Core for best. 1u caps I use in my tube gear across the secondary, they work there. One good Transformer double bridge and prefilter with 2 +/- shunts, i.e 4 sides, one symmetrical reg per channel, is a good compromise that will allow resources for better quality parts where it counts. See if you like the thing as a whole with the phono first and then you can double your Tx, chokes, etc. seeking some little more isolation. The shunts when fed by CCS don't disturb much what is before them, and have very low output impedance for what is after them. If you apply carefuly and twist the force/sense wires directly to the second stage power & star ground nodes (even a coax for the sense if you see any nasties on the scope when probing the B+, B-) the impedance stays in spec and it is very difficult to have modulation from second stage to first. Then again you need to decouple towards the 1st stage with RC so to drop voltage, hence you get even more guarded. I prefer a good star earth node for each channel and one set of regs, than many applied, leading to more laborious grounding. At 300mA shunt's CCS setting each side, 4 total, make sure you got a thick metallic box floor to bolt the T0247s down or adequate sinks. 6.75W dissipation per side per reg you got to channel away.