Have you considered sometimes less is more ?
That is sometimes the "best" isn't necessarily so.
IMO the use of split supplies, DC servos and full
complementary topology is missing the point.
(In the Borbely design)
Fully balanced topology reduces even order
distortion leaving odd order distortion untouched.
In low level class A circuitry distortion is not really
a problem and IMO reducing even order is pointless.
IMO with the turntable and medium quality medium output
moving coil cartridge you appear to be considering I really
can't see any good reason the Borbely design would be
better than the Pearl design, and I can see several reasons
why its more "hifi" approach might not suit the application.
Another fundamental difference between the
two designs is active feedback for Bass EQ in
the Borbely against passive in the Pearl.
Not having heard or built either design, and personally
completely disagreeing with the garbage spouted about
FETs versus Bipolars, the Borbely design is too "hifi" for
me, I'd like something simpler and more elegant.
🙂 sreten.
That is sometimes the "best" isn't necessarily so.
IMO the use of split supplies, DC servos and full
complementary topology is missing the point.
(In the Borbely design)
Fully balanced topology reduces even order
distortion leaving odd order distortion untouched.
In low level class A circuitry distortion is not really
a problem and IMO reducing even order is pointless.
IMO with the turntable and medium quality medium output
moving coil cartridge you appear to be considering I really
can't see any good reason the Borbely design would be
better than the Pearl design, and I can see several reasons
why its more "hifi" approach might not suit the application.
Another fundamental difference between the
two designs is active feedback for Bass EQ in
the Borbely against passive in the Pearl.
Not having heard or built either design, and personally
completely disagreeing with the garbage spouted about
FETs versus Bipolars, the Borbely design is too "hifi" for
me, I'd like something simpler and more elegant.
🙂 sreten.
well just considering it's price - as a kit still extremely expensive - I really don't know.
I think I'll bulit both of them, the Pearl and the Borbely.
Better said: I'll begin with the Borbely one. We'll test it in high-end environment, which satisfied me quite well (a dream for my ears).. if it will produce about the same quality, like the factory-built one, or even better, I'll stick to it and forget the Pearl.
If not, I'll build the Pearl too.
I also have some another schematics of preamps from top level high-end manufacturers, perhaps I'll extract the phono amplifier circuit from one of them and try it. But I actually don't really think, it will be needed.
I think I'll bulit both of them, the Pearl and the Borbely.
Better said: I'll begin with the Borbely one. We'll test it in high-end environment, which satisfied me quite well (a dream for my ears).. if it will produce about the same quality, like the factory-built one, or even better, I'll stick to it and forget the Pearl.
If not, I'll build the Pearl too.
I also have some another schematics of preamps from top level high-end manufacturers, perhaps I'll extract the phono amplifier circuit from one of them and try it. But I actually don't really think, it will be needed.
You haven't heard of jitter? Of course, as Frank says mechanical vibration in the analogue parts may be also responsible.
Hi Vortex
A jFET input stage is a very good solution for MC systems IMHO
The integration of the RIAA preamp or at least a pre-pre seems to be a good and practicable idea. ThoughI did not do this myself so far, I remember that turntables with integrated MC preamps and accumulator based power supplies were presented at the High-End in Frankfurt last year and they sounded good. Sorry I forgot the brand I think they came from Scandinavia.
Definitely Yes. With a high gm jFETs such as the 2Sk369 you can easily achieve an amplification of 100.
I would strongly recommend a separate power supply.
I experimented with MC preamps for a while until I found my personal solution. I have it on my website.
www.klaus-boening.de
Cheers & good luck
KlausB
A jFET input stage is a very good solution for MC systems IMHO
The integration of the RIAA preamp or at least a pre-pre seems to be a good and practicable idea. ThoughI did not do this myself so far, I remember that turntables with integrated MC preamps and accumulator based power supplies were presented at the High-End in Frankfurt last year and they sounded good. Sorry I forgot the brand I think they came from Scandinavia.
Definitely Yes. With a high gm jFETs such as the 2Sk369 you can easily achieve an amplification of 100.
I would strongly recommend a separate power supply.
I experimented with MC preamps for a while until I found my personal solution. I have it on my website.
www.klaus-boening.de
Cheers & good luck
KlausB
If you like to stay on tubes take a look at Application notes from Svetlana EF 86 or a bit more exotic but inexpensive c3m (German post tube)
It doesn't matter, tubes, or not...
it should sound absolutely compromiseless 🙂
I'm thinking of two Borbely designs, one is the all-fet phono preamp but it needs to calculate the parts (not an easy job), the other is one which is a JFET-inputted tube preamp for MM/MC both usable, with numbers, everything, so we just have to buy the parts and solder them together as the circuit schematics say.
I'm still interested in the all-fet solution.
The fet-tube "combo" preamp of him was published by a magazine (I cannot remember it's name, perhaps somebody of you can give a link to it) ..
it should sound absolutely compromiseless 🙂
I'm thinking of two Borbely designs, one is the all-fet phono preamp but it needs to calculate the parts (not an easy job), the other is one which is a JFET-inputted tube preamp for MM/MC both usable, with numbers, everything, so we just have to buy the parts and solder them together as the circuit schematics say.
I'm still interested in the all-fet solution.
The fet-tube "combo" preamp of him was published by a magazine (I cannot remember it's name, perhaps somebody of you can give a link to it) ..
It was published by the now defunct Glass Audio.
Borbely has a copy of the article on his website:
http://www.borbelyaudio.com/phono.pdf
By the way, I agree that Borbely's equipment is top notch. I've built quite a bit of it including an early version of his fet phono stage and his all fet line stage. I'm still using the line stage but I've since retired the phono stage and moved on to tubes, with an FET/tube cascode as the front end.
I'm still experimenting with phono stages and recently finished a Pass Xono phono stage. It sounds quite promising but I still need to tweak it to sound the way I like. I haven't yet retired the tube stage, so maybe theres a message there.
---Gary
Could you please just eMail me the schematics with the exact parts list and values ?
I'd have a look at it. I'm building his preamp published in the former Glass Audio magazine - perhaps I can compare the two, which suits me better in sound.
If you won't, no problem.
Thanks 🙂
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