O.k. a quick sim, all BC-327/337(40)'s
Gain about 28dB
Noise about 24nv/Hz1/2
THD near -85dB
PSU-load 75mA
As one can see, the design has a 'not do good' PSSR and the 75mA (per 15V rail) is thus demanding, it (the PSU) needs to be firm and precise.
The output offset (with the ideal transistors) is 11mV (not to bad at all).
Found it Six-Transistor Ultra Low-Noise MC Phono Preamp
And now I see 🙂 this is a pre-pre to be placed before a MM system
This is all i have :
http://pia-hifi.de/wp-content/uploads/c-37_g.pdf
They even do a differential input that has a 6dB noise disadvantage over parallel symmetric.
This new input transistors must be very good because this phono stage is even 1dB more quiet then the last one and that was very quiet.
There are no DC blocking capacitors on MC input stages. Input bias current is probably very high. Commercial manufacturers do not care about current flowing inside the coils of MC cartridges.
Yes, I know , I have Paradise phono. Input current trimming is a good thing. But, C-37 phono is very expensive phono preamp with perhaps 2000na of input current.The Paradise stage that we have designed here has a bias current trim.
My version of Paradise, with Jung Super regulators. Noise and hum free.
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When looking closely at the Accuphase PDF, I can see "C6000" printed on the MC transistors. Toshiba 2SC6000 data sheet you can find on the net.
best regards, Hartmut
best regards, Hartmut
Toshiba 2SC6000....you can find
C6000 can be ordered from RS Australia for less than $0.90 each (USD, ex 10 percent Australian sales tax), less than $0.75/pc for orders over 100.
Would be nice if the MPP thread was visited by a friendly Aussie.
Single source for buyers from Europe is Odyssey Electronics in Massachusetts (small home business at 20 miles distance from Boston).
Much more expensive than RS and the shipping rate hurts the wallet.
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Any plans for a phono stage anything like the Paradise?
I heard one recently and I loved it. Only problem is they are unobtainable now and so I wondered if there was anything to follow it.
If anyone has a set of boards they could sell me that would be awesome.
👍
I heard one recently and I loved it. Only problem is they are unobtainable now and so I wondered if there was anything to follow it.
If anyone has a set of boards they could sell me that would be awesome.
👍
The Paradise is difficult to follow. This was a team efford over many years against all odds.
Bashing and trolling in no small measure.
We have a new design, the Zion.
It came about because there was a desire to make a fully balanced phono stage.
At the end it got so complex that it did not lend to a DIY version.
The circuit diagram is there though in the Zion thread.
Bashing and trolling in no small measure.
We have a new design, the Zion.
It came about because there was a desire to make a fully balanced phono stage.
At the end it got so complex that it did not lend to a DIY version.
The circuit diagram is there though in the Zion thread.
How about a new GB for the Paradise, with space for a couple of caps across the +/-/GND input and on the shunt for the PNP and NPN? Maybe HF decoupling on the lytics as well?
;-)
;-)
As I have published record-player-cabling-systems before I feel obliged to inform you that I did it again 🙂 if you are interested have a look at this thread:
https://www.diyaudio.com/forums/analogue-source/328015-grounding-tonearm.html#post5562425
https://www.diyaudio.com/forums/analogue-source/328015-grounding-tonearm.html#post5562425
If there's no interest in coordinating a group buy, why not release the build files so individuals can get them made.
I have not posted much here lately because a have very little time for DIY.
Just for fun I build the Renardson MC Pre-Pre, a design that is a bit similar to what QUAD did.
Unfortunately I could not make it work so far. I build several versions. All play music but it sound distorted and noisy.
I may be oscillation, on the scope the output shows spikes.
I tried to mail Mike Renardson but I can not find an email address on his site.
As far as I can tell he has not build the circuit himself so far.
Has anybody an idea what I could try to make it work ?
Just for fun I build the Renardson MC Pre-Pre, a design that is a bit similar to what QUAD did.
Unfortunately I could not make it work so far. I build several versions. All play music but it sound distorted and noisy.
I may be oscillation, on the scope the output shows spikes.
I tried to mail Mike Renardson but I can not find an email address on his site.
As far as I can tell he has not build the circuit himself so far.
Has anybody an idea what I could try to make it work ?
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Hi Joachim. It might be worth building the Quad as it is a crazy idea that works. Everything Quad made was a bit crazy, Yet Quad always seemed the quintessential English gentlemen. Quad claimed the phono stage was influences by current dumping. Douglas Self said 0.05% thd too high. If I had presented it at college I would have been told off. To define crazy the valve power amp was a longtail pair with a short tail using EF86 driving KT66. It couldn't possibly work, yet did. Quad 303 is bonkers, I love my one. Crimson being a version.
Rendardson have a very interesting single input stage for a power amplifier. He uses a NPN PNP complimentary input pair which avoids any compromise on linearity whilst allowing the simplicity of 1960s designs. He also uses feed-forward correction. As phono stages often need current, why not adapt his power amplifier?
If it were me I would use 9 V batteries at first. Yours circuit looks that it should work. You can try 47 uF on the LM317/337. It is slightly better and I never had a problem. Takes noise floor down about 2dB. After the regulator a simple resistor will do as the circuit defines a simple current source. I love LM317's. It's very hard to make them work badly except in cascade. LD1084 seems no worse!!
Rendardson have a very interesting single input stage for a power amplifier. He uses a NPN PNP complimentary input pair which avoids any compromise on linearity whilst allowing the simplicity of 1960s designs. He also uses feed-forward correction. As phono stages often need current, why not adapt his power amplifier?
If it were me I would use 9 V batteries at first. Yours circuit looks that it should work. You can try 47 uF on the LM317/337. It is slightly better and I never had a problem. Takes noise floor down about 2dB. After the regulator a simple resistor will do as the circuit defines a simple current source. I love LM317's. It's very hard to make them work badly except in cascade. LD1084 seems no worse!!