Mpp

[Salas]

Wishing success and relax. See ya!

[Joachim Gerhard]

Ok, will be back tomorrow with hopefully more compact measurement files. Just opened a beer. AHH, thats good.

[Joachim Gerhard]

Today a good friend came and we listened to the Hiraga Optime plus Telepath RIAA stage.
I have now outfitted the Hiraga and the Telepath with 25mH coils in the power supply. The sound was extremely dynamic and clean. The coils in the power supply had a very similar
effect to the coils in the inductive RIAA. More clarity, this time spread over the whole spectrum. I wonder why i had not tried coils in power
supplies before. They have a very positive effect and it is an easy modification. My friend is a CD guy, quite outspoken : "I never go back to vinyl". After a session of Jazz,Classical and Pop he got quite attracted and after i went to 45 (Holy Cole, Reference Recordings Berlioz) there was no way back. He ordered a phono stage and preamp from me and will buy a turntable. His words "Dynamics of Vinyl is better then CD". This is really a major change for him because he plays his Audio Aero player directly into his Audionet Max 2 Mono blocks. He needs furniture, a preamp, a phono amp and cables now. So i could say, the Hiraga Optime sounds better then CD. Well that is not fair because my turntable costs more the 30.000,- € in the shop and phonostages in the quality i am making them are hard to get and very expensive too. Anyway, i am extremely pleased about that move.
Today i will send the Measurement of the Hiraga Optime and Telepath combination. Distortion comes only from the Hirage because the Telepath has distortion under the noise floor. Overload is limited by the power supply. I run the Hiraga on +-9V and the Telepath on +- 13.6V. The Hiraga has only 2nd harmonic monotonic, independent of frequency and it does not sound like distortion to the ear. A Pre-Pre with a more complex spectrum should better have much lower numbers then that to compete subjectively i think.

[Joachim Gerhard]

Here is the RIAA curve. The RIAA is slightly falling, the way i designed it for best sound from the Telepath. The channels differ 0.2dB in Volume because the Hiraga has no feedback. Subjectively that was no problem. Voices where centered well and the soundstage was big and precise. Considering that my speakers are +-2dB this is really no big deal. Fanatics could reduce the 750 Ohm resistor in one channel slightly for exact match. I plan to design a matching RIAA stage for the Hiraga Optime ones i have it ready with transimpedance solution for the 75usec. That should be easy.

[Joachim Gerhard]

Here is my suggestion for a Hiraga Optime Transimpedance RIAA Phonostage.
This is one of the simplest designs i would call High End and success is guarantied.
I will build it and listen to it.

[Salas]

Originally Posted by Joachim Gerhard

I have now outfitted the Hiraga and the Telepath with 25mH coils in the power supply. The sound was extremely dynamic and clean. The coils in the power supply had a very similar
effect to the coils in the inductive RIAA. More clarity, this time spread over the whole spectrum. I wonder why i had not tried coils in power
supplies before.

0.6H frame chokes sometime in the PSU. Some inductance now still cool.
If the forthcoming shunts will work as intended, brace yourself.

[Joachim Gerhard]

I can send you some of my coils. They are ferite so do not suffer from Barkhausen effect and do not distort at lower levels. 600mH is extrem and i do not like to see the stray field. Anyway, you brought me into that coil thing and when your shunts make the speed of my system even faster (it is super fast right now) you have to visit me in hospital.

[Salas]

In constant current and separate psu box, well current rated high inductance air gapped frame chokes are a good deal. No AC considerations. If big enough, lower/better caps can be used as a side benefit. Could be wound on double C also. On the other hand your 4-6 Ohm chokes do a good enough job of pre filtering without significant R being nearer to a perfect inductor without resistance. We want the rectification gremlins and any RF out of the picture where the CCS of the reg is gonna stop acting as one, that is the purpose. As for the shunts, if they gonna work well, clean, and marry tonally with your circuits, ''speed'' is just one little parameter of the many they will strongly affect. You will determine for yourself after having your own experience soon.

P.S. Have you reviewed the circuits I sent you before you went to USA on your simulator yet, for possible draw errors, familiarization, etc?

[Joachim Gerhard]

I am shure that the powersupply is extremely important for sound and your design is totally over the top although very inefficient. Commercially it will be hard to packake and sell. No problem here and i like the discreet nature and tremendoes tweeking ability. I already learned that chokes are very beneficial and mine are small so could help a lot of circuits where there is not much space. For example in the Hiraga that draws only 2 mA a combination of 10mF+ 25mH +10mF is already 24dB down at 100Hz and around -120dB at 20kHz. i see no chance for even a long wave transmitter to go though that.

[Joachim Gerhard]

actually i draws around 4mA, i forgot the current mirror