I'm new, What phono pre do you recommend?

[gtyler]

Hello,

I've been a member for a while, but I'm still new at this. I've been honing my skills and getting ready for my first real from scratch DIY project. Now that I'm ready, I need some advice. I would like to build a phono pre with extremely low noise and excellent sound reproduction, so I have been considering a battery powered design. My problem is I don't know what design to use, or what designers are well regarded, or how to tell that a design will very clean and accurate. Here are the designs that I have been considering in no particular order:

inDiscreet Phono Pre-amplifier [English]

DIYHiFi.org • View topic - "Duplex" 2SK369 MM phono preamp

Boozhound Laboratories JFET Phono Preamp Kit

I'v also been looking at this one but with an external power supply.

Hi-Fi RIAA Phono Preamp


I am leaning toward the indiscreet phono pre simply because the guy seems to know what he is talking about and he's not selling anything so he's not going to try to talk up his design, but of course that's not the best basis for a decision.

Has anyone here done any of these projects?
I would love to hear what anyone has to say about any of these projects.

Thanks

[Nico Ras]

The first two uses passive equalisation. Some audiophiles will swear that it is better. Hard to tell though.

The first circuit uses a off-set power supply which may be difficult to realize using batteries and the the discharge of the batteries may not be equal thus may affect the performance during longer listening periods.

Rod Elliot does not publish bad schematics and it may be a lot easier to build and get repeatable results.

I have not encountered any circuits from Boozehound, but judging from what he offers, it seems like he knows what he is doing.

Good luck,

Nico

[pinkmouse]

Thread moved to a more appropriate area.

[gtyler]

Originally Posted by Nico Ras

The first two uses passive equalisation. Some audiophiles will swear that it is better. Hard to tell though.

The first circuit uses a off-set power supply which may be difficult to realize using batteries and the the discharge of the batteries may not be equal thus may affect the performance during longer listening periods.

Rod Elliot does not publish bad schematics and it may be a lot easier to build and get repeatable results.

I have not encountered any circuits from Boozehound, but judging from what he offers, it seems like he knows what he is doing.

Good luck,

Nico

Thanks for the advice. After your response, and after hearing from Rod Elliott via email about the possibility of using batteries, I am now leaning more towards his design with a separated mains power supply. I guess i have never heard a phono pre that runs off mains power and is totally silent, but then again, I have never heard a phono pre with a separated power supply. Right now I am using the MM phono stage of my Yamaha C-4, and it is quite good, but when the volume is high I can still hear (very faintly) a hiss form the amp. I'm hoping this project will eliminate that. Do you think it will?

Any more advice regarding phono pres that you can give is welcomed.

[vinylkid58]

Originally Posted by gtyler

Right now I am using the MM phono stage of my Yamaha C-4, and it is quite good, but when the volume is high I can still hear (very faintly) a hiss form the amp.

If the hiss isn't any louder (relatively), than the noise floor when playing a record, then it really shouldn't be an issue.

jeff

[Calvin]

Hi,

if the Yamaha is a bit too noisy for You, all the other circuits won´t probabely any better.
A differential amplifier as frontend for example has higher intrinsic noise than a single ended or complementary stage. Additionally the differential stage of the inDiscreet lacks in symmetry, thereby giving rise to distortion.
The local feedback degeneration resistors R4/5 are of high value and increase noise considerably. Passive equalization asks for higher gains which has to be considered regarding noise and distortion figures.

The noise issue of large emitter-/source-resistors also applies to the Boozhound. A bit weird that both gain stages of the Boozhound are identical. It is rather common standard to have the most gain in the first stage.

The Duplex is imho superior in noise performance compared to the former two stages, as the resistor value niveau is generally lower.
Like the Boozhound it requires just one supply rail.

The two stage OPamp design uses Opamps of unsuffiecient performance.
As a rule of thumb the noise spec of the op amp should be lower than app 5nV/sqr(Hz) for MM-pickups which the outdated TLs clearly miss.

If I had to choose the Duplex would be the most interesting circuit of the four.

jauu
Calvin

[sreten]

Originally Posted by gtyler

Right now I am using the MM phono stage of my Yamaha C-4, and it is quite
good, but when the volume is high I can still hear (very faintly) a hiss form
the amp. I'm hoping this project will eliminate that. Do you think it will?

Any more advice regarding phono pres that you can give is welcomed.

Hi,

No it won't. Any RIAA stage will have treble hiss compared to the other line
inputs, it is inevitable, and in a decent design far lower than groove noise.
(With non-optimum grounding also more hum, but that can be fixed.)

I don't think you have a hope in hell as a first project of bettering the C4
phono stage, with its MC input, double MM inputs and loading options.

Spend you time and effort elsewhere, What's your turntable/arm/cartridge ?

rgds, sreten.

[vinylkid58]

Originally Posted by sreten

I don't think you have a hope in hell as a first project of bettering the C4
phono stage, with its MC input, double MM inputs and loading options.

I admit I've never heard the C4, but I'll wager my "first time project" Pass Pearl sounds at least as good (if not better) than the MM Yamaha stage. I'd love to do a comparison, but certainly not going out of my way to find a C4.

jeff

[sreten]

Originally Posted by vinylkid58

I admit I've never heard the C4, but I'll wager my "first time project" Pass Pearl
sounds at least as good (if not better) than the MM Yamaha stage. I'd love to
do a comparison, but certainly not going out of my way to find a C4.

jeff

Hi,

It might, but its a one input medium MC stage, its very inflexible compared
to the C4, and without knowing the source (MM), completely inappropriate.

There is no evidence at all the C4 phono stage is the most limiting factor.

rgds, sreten.

The C4 in todays money is a circa $2.5K preamp, with serious phono stages,
as its the right sort of vintage where they were the most important input.

[vinylkid58]

Originally Posted by sreten

It might, but its a one input medium MC stage, its very inflexible compared
to the C4, and without knowing the source (MM), completely inappropriate.

Actually, it's very flexible, and works quite well as a MM stage.

Originally Posted by sreten

There is no evidence at all the C4 phono stage is the most limiting factor.

True, but this IS a DIY forum, and the poster wants to build something.

jeff