Looking for a schematic for phono stage.

[Bassadventures]

I currently have a nice DIY tube preamp but it does not have a phono stage. Are there any schematics for a M/M stage to add to an existing preamp?

 

[Stefanoo]

If you are looking for simplicity but good sound I would recommend the simplicidtic phono stage by salas.
You can also go for something more complex but very likely much better sounding then go for Paradise.

Hope this helps!

 

[kevinkr]

Here's a popular tube based design by Salas:
http://www.diyaudio.com/forums/analogue-source/140635-valve-itch-phono.html

And another by koifarm: http://www.diyaudio.com/forums/analogue-source/242855-mini-me-phono-preamp.html

My latest: http://www.diyaudio.com/forums/analogue-source/213769-muscovite-6s3p-tube-phonostage.html

 

[Koifarm]

Bassadventures, do look fore tube or solid state phono pre?

When you already have a tube pre may be a phono pre with tubes becomes to much harmonics.

 

[Bassadventures]

Im actually looking to add a M/M phono input to add to the circuitry of my tube preamp. Right now it is just line in. Id like to add inputs for phono to the case.

 

[sachu888]

Im actually looking to add a M/M phono input to add to the circuitry of my tube preamp. Right now it is just line in. Id like to add inputs for phono to the case.

What about this CNC MM Phonostage based on National Semiconductors design,one of the best.I am using one since two years.

Regards,
Sachin

 

[atupi]

Are tube phono preamps have a special sound compared to solid state ones ?
So far i've built Salas simplistic, Eliott P06, CNC MM Phonostage based on National Semiconductors design.
How it sounda tube based one compared to the my solid sate builds ?

I was planning to go for something more advanced like a Pearl 1 or Mini Me tube preamp.

Some experienced opinions would be apreciated.

Thanks!

 

[sachu888]

Are tube phono preamps have a special sound compared to solid state ones ?
So far i've built Salas simplistic, Eliott P06, CNC MM Phonostage based on National Semiconductors design.
How it sounda tube based one compared to the my solid sate builds ?

I was planning to go for something more advanced like a Pearl 1 or Mini Me tube preamp.

Some experienced opinions would be apreciated.

Thanks!

Hi Atupi,
I remember you CNC now has an improved layout with double sided PCB,uncut ground plane on top,and different pads to accommodate different size of caps.I am now using it with LME49990 with +/-10V and it sounds far better than earlier.My DIY Power supply voltage can be adjusted by 5k trimmers,so its good.Here is the latest pic:

An externally hosted image should be here but it was not working when we last tested it.

An externally hosted image should be here but it was not working when we last tested it.

Regards,
Sachin

 

[x-pro]

Im actually looking to add a M/M phono input to add to the circuitry of my tube preamp. Right now it is just line in. Id like to add inputs for phono to the case.

If you can find a 20-28V DC supply inside your preamp (less than 20mA needed), than you can use the simple circuit below.

Cheers

Alex

 

[Stefanoo]

Just a quick look at it...isn't this just a MC head amp?

 

[kevinkr]

Nope, look again..

 

[Stefanoo]

yes you are right I see the passive equalization. Pretty simple slick solution.
How much gain does this thing boost? I mean it seems there shouldn't be any issue providing 40dB or a little more out of it.

 

[x-pro]

yes you are right I see the passive equalization. Pretty simple slick solution.
How much gain does this thing boost? I mean it seems there shouldn't be any issue providing 40dB or a little more out of it.

In the MM configuration, as shown, about 39dB at 1khz, in the MC version (replacing the input JFET J1 with 2SK170BL and R2 with 47 ohm) - about 56dB at 1khz, if you bypass R2 with 1000uF - 62dB at 1khz. For the MC version you need to change the input load and remove R15 as well.

Cheers

Alex

 

[Stefanoo]

In the MM configuration, as shown, about 39dB at 1khz, in the MC version (replacing the input JFET J1 with 2SK170BL and R2 with 47 ohm) - about 56dB at 1khz, if you bypass R2 with 1000uF - 62dB at 1khz. For the MC version you need to change the input load and remove R15 as well.

Cheers

Alex

wow that is pretty slick for a simple circuit like that! I am pretty impressed!

 

[x-pro]

wow that is pretty slick for a simple circuit like that! I am pretty impressed!

It also can produce very good sound - IMHO better than the majority of op-amp based circuits, if you use quality capacitors in it and a good power supply (could be a battery supply as the current consumption is low). This particular version was created specially for DIY and is a variant of my circuit from 1994, produced for many years as the Creek Audio OBH-8(SE) and first published in 1999. Versions of this circuit also were used in many Creek Audio and some Cambridge Audio integrated amps for internal phono stages.

Cheers

Alex

 

[Stefanoo]

It also can produce very good sound - IMHO better than the majority of op-amp based circuits, if you use quality capacitors in it and a good power supply (could be a battery supply as the current consumption is low). This circuit was created specially for DIY and is a variant of my circuit from 1994, produced for many years as the Creek Audio OBH-8(SE) and first published in 1999. Versions of this circuit also were used in many Creek Audio and some Cambridge Audio integrated amps for internal phono stages.

Cheers

Alex

Yes I think you got the point! A simple circuit like this can be equipped with quality caps and power supply and it sounds accordingly good! Very simple circuit to make for the majority and very simple signal path. Classic circuit with mostly second harmonic's distortion...which is pleasant!
With my little experience I can say opamp based circuit are not match for this in the majority of the opamp based circuits.
Nice circuit!