Ceramic Cartridge Phono Pre-Amp

[wer]

Thank you Andreas.
Unfortunately no room for multiple resistors. Have 5 Meg, but was afraid that might be a bit high. Matters not, the 3.9's are on the way.

[aboos]

... and the journey continues:

'Wer' was so kind to send me a Sonotone 9TA. It is NOS and all rubber parts, especially the yoke, seems to be as new - not brittle as was the case with my 9TAHC.
As the Sonotone 9TA has a lower capacitance as the DUAL CDS671, i increased the input resistor of the EQ amp from 3.9 Meg to 6.8 Meg to get the corner frequency to 50 Hz again.
And here is the FR measurement (made with a VTF of 3.5 gr):


The frequency response up to 4 kHz is very close between the DUAL CDS671, the SPU and the Sonotone. Both ceramic cartridges show a resonance between 8 kHz and 11 kHz. The DUAL shows small ripple and a significantly reduced output above 12 kHz while the Sonotone develops a 5 dB peak but output is only -3dB down above 11kHz up to 19 kHz!!

The sound characteristics of the Sonotone is very close to the DUAL in the bass and the mids (deep and punchy bass, excellent mids). The Sonotone is a little more detailed in the highs however has also some mild tendency for sibilance (5 dB peak at 9 kHz?).
Both ceramic cartridges sound extremely good and at least in the bass and midrange can easily keep up or even better the SPU  . The SPU has some advantages in the highs as it combines the details of the Sonotone with the smooth sound of the DUAL.

And all this for only a fraction of the price - the SPU entry level cart goes for €500-600 while the DUAL cartridge with preamp cost me less than €100 (don't know what 'Wer' had to pay for the Sonotone). These ceramic carts with the dedicated EQ preamp are definitely a keeper 
 

[wer]

I am waiting for an NOS 9ATHC from the UK (a gift from a friendly PFM member), and am curious to find out if it is any more civilized at the high end. Iirc i paid about EUR 20 for the 9AT, but that was at least 4 years ago.

[wer]

Finished the AB-pre a while ago after changing the rail-splitter, but it would no longer fit the box. The new box arrived last week, and the pre is ready gor testing. Decided to use a 8V battery instead of a wall wart to further reduce hum pick-up. From the 9V input i get +/- 12V, which should be fine.

Testing will start as soon as the Russco is ready, which should be middle of next week.

[decanterlime]

Are ceramic cartridges affected by turntable motors be it two pole or 4 pole or their fields?
I know MM carts are affected by 2 pole motors.

TIA
Mark

[pde2000]

Are ceramic cartridges affected by turntable motors be it two pole or 4 pole or their fields?
I know MM carts are affected by 2 pole motors.

TIA
Mark

Ceramics and strain gauges use the bending force from the cantilever to generate a signal, so no magnetic detection should be involved.  The cable between the elements and the amplifier could pick up electrical interference if there is a fault.  If a ceramic cartridge picks up a hum then it's probably mechanical.

[decanterlime]

Interesting Paul and thanks.

I will like to share     

I have tried this and it is utterly superb. Its similar to the Sonotone circuitry.But there is more fizz in the cue ball so to speak.

Incidentally I now use BSR SC7M  ST17 stylus which come in a complete headshell form black or in white and I just saw the end off near the 4 terminals bit and glue it to a SME universal headshell with care as to the parameters. They chuck out 50mV and to me this passive circuitry is utterly superb with no hum. I can turn my amp up full blast and all there is is a slight hiss.
I may never go back to MM or MC cartridge again. The detail in this set up is alluring and I like that harder sound. MM's sound sweet but muffled or stammered if you know what I mean no matter what super dooper amp I use.
I have used the Sonotone 9TA HC but its not as fizzy as the BSR.
Compliments
Mark

[stonetostone]

Hi Mark
Could you show me where you cut the cartridge and glue the body,as they say every picture tells a story.
steve

[decanterlime]

Hi Mark
Could you show me where you cut the cartridge and glue the body,as they say every picture tells a story.
steve

I still use Tom's (Bluetomgold) mm/ceramic preamp too. I cut down hum by wire in the brass stylus clamp of stylus to Red ground (green) of the SME headshell.
You can solder or friction fit with the wire tag. Fiddly but worth it. I found with the shared new circuitry hum became non existent for me 

compliments
Mark

[stonetostone]

Just been playing the acos gp-104,which i allways thought had a fault as the stylus bottomed out at any playing weight so yesterday i had a look at the stylus it pulled straight out of the rubber mount i don't know if these are supposed to do that so i fitted another stylus perfect tracking listening to it at the moment.I just fitted an earth wire from tom's ceramic box to the phono earth easy peasy.
steve

[bluetomgold]

Just been playing the acos gp-104,which i allways thought had a fault as the stylus bottomed out at any playing weight so yesterday i had a look at the stylus it pulled straight out of the rubber mount i don't know if these are supposed to do that so i fitted another stylus perfect tracking listening to it at the moment.I just fitted an earth wire from tom's ceramic box to the phono earth easy peasy.
steve

I wonder if it would be useful to add an earth binding post on future builds? I have typically run the earth wire direct to the phono stage but I can see that in some cases this might not be practical...

[stonetostone]

It could just be my setup tom,although straight to the phono stage i get no hum(mm cartridge)

[stonetostone]

Hi Mark
A very good recomendation on the bsr ceramic cartridge it's playing at the moment nice sound i'm liking it more than the acos 104 that i have,i've made some mod's to it though as you do i'm playing it through the realistic mixer the same one that toms selling very nice combination.

[decanterlime]

Yes I can see you have fixed a fixing plate to the top of the BSR which does give you adjusting ability and alignment.
In my case I just superglued the BSR to a adequate SME headshell knowing the stylus distance (in my case 54mm to 55m from the back of the headshell plate for Rega geometry...i only use effective length 237mm)
My next notion is to research an expert who can change/replace the stylus for an elliptical one to a certain size. That may be interesting and have better tracking ability?
Mark