Ceramic Cartridge Phono Pre-Amp

[williamsunique]

Some op-amp designs from the 1970s, including some for hobbyist construction, used a servo driven by the DC offset at the output to negate that offset.  These servo circuits could be more complex than the amplifier circuit itself!  One op-amp phono stage that I constructed used a nonservo circuit and a trimmer to adjust the DC offset.  It was an "always-on" design so once it warmed up the DC offset remained close enough to zero.  But it all could get dizzying enough to drive one back to tubes!

Yep, been there done that.  It was mainly unsuccessful and I went back to using a decent capacitor in the output. 

Paul.

[decanterlime]

Hello,
I have tried many different types of ceramic cartridges with the Sontone circuitry. My question is with a ceramic cartridge how do you get rid of the hum or feed-back sound when not playing them on a record?
During normal play back you do not hear this hum (this is also true if I play through aux on amp or line-in on a stereo mixer)But during the time when you are not playing the record and your amp is set on 8 volume you do hear the hum. Its not too annoying but is this property only relevant with ceramic cartridges?
I think the ceramic sound is definitely punchier debatably more detailed and somehow coarser or harder sound. With a MM elliptical the sound is more sweeter.
Mark 

[bluetomgold]

I finally got round to building the Sonotone circuit posted on page 2 by Gene. Put it in a nice little box with a bypass switch so you can toggle between magnetic and ceramic cartridges. I haven't had much of a chance to play with it but it seems to work well.





I bought quite a few of the components needed to get a bulk saving so if anyone's interested I'd be happy to build more to order. Drop me a PM to express interest.

[analogadikt]

I finally got round to building the Sonotone circuit posted on page 2 by Gene. Put it in a nice little box with a bypass switch so you can toggle between magnetic and ceramic cartridges.

That is looking pretty nice, Tom Please do share your detailed impressions

Regards,

Anwesh

[bluetomgold]

That is looking pretty nice, Tom Please do share your detailed impressions

Regards,

Anwesh

Thanks Anwesh!

I finally got round to fitting a ceramic cartridge in a headshell - one of these ridiculously cheap things, which I DIY adapted for 1/2" mount a couple of years back...

https://www.ebay.co.uk/itm/Phono-Ceramic-Turntable-Cartridge-with-Stylu-for-LP-Vinyl-Record-Player-C-/182722154200?mkcid=16&mkevt=1&_trksid=p2349624.m46890.l6249&mkrid=706-127636-26712-0

Listening to a blues compilation it sounds way better than it has any right to - very vivid and direct sounding with a surprising amount of clarity and detail at the frequency extremes. Not at all lo-fi, but as hoped, it's doing something that my MMs and MCs don't...

The box is also effectively "transparent" with an MM cartridge connected. Although when I just hooked up a Stanton 500 (with eliptical stylus) it sounded dull by comparison! I quickly switched back to the Chinese ceramic.

I'll definitely be digging through my stash and trying out some vintage ceramics.

[wer]

I wonder what material they use for the stylus tip? If it were diamond they would likely mention that in their blurb.

[stratokaster83]

I wonder what material they use for the stylus tip? If it were diamond they would likely mention that in their blurb.

Probably corundum - the stylus looks pinkish/purple in the photos, although this doesn't mean much...

[analogadikt]

Thanks Anwesh!

I finally got round to fitting a ceramic cartridge in a headshell - one of these ridiculously cheap things, which I DIY adapted for 1/2" mount a couple of years back...




I'll definitely be digging through my stash and trying out some vintage ceramics.

Thanks Tom for this feedback.

Enjoy the music 

Cheers,

Anwesh

[bluetomgold]

There are versions on eBay claiming to have diamond styli which still cost less than a pint of beer. I'm not sure how relevant the lifespan of the stylus is when replacements are so cheap - I'd be more concerned about the quality (i.e. polish) of the stylus tip. I think it's safe to say that this isn't a cartridge for prized audiophile pressings, but it's great fun with the right record.

A bit of further testing last night indicates that the output of the Chinese special is a bit too hot for the Sonotone circuit - with a "loud" 45 I heard clearly audible preamp distortion. Maybe I'll try another cartridge this evening.

[pde2000]

Cheap diamond styli are always bonded, thus heavy tip mass.  The manufacture of sapphire tips is quite cheap and polish is easy to ensure because they are finished by agitating in a suspension of diamond dust, whereas diamonds need honing on a polish wheel.  Sapphire has additional benefits of not generating an electrostatic charge on the vinyl like diamond does.  Being cheap they can be replaced regularly, and for microgroove it is suprisingly short lived (you can see flats within a few hours).

https://www.pearl-hifi.com/06_Lit_Archive/02_PEARL_Arch/Vol_16/Sec_53/Philips_Tech_Review/PTechReview-19-1957_58-324.pdf

The suitcase style cheap players have these sapphire tipped ceramics, but also short arms and poor performance.  I have one which can run off a powerbank and be used to play singles on a picnic, like the portable gramophone.

[bluetomgold]

Cheap diamond styli are always bonded, thus heavy tip mass.  The manufacture of sapphire tips is quite cheap and polish is easy to ensure because they are finished by agitating in a suspension of diamond dust, whereas diamonds need honing on a polish wheel.  Sapphire has additional benefits of not generating an electrostatic charge on the vinyl like diamond does.  Being cheap they can be replaced regularly, and for microgroove it is suprisingly short lived (you can see flats within a few hours).

https://www.pearl-hifi.com/06_Lit_Archive/02_PEARL_Arch/Vol_16/Sec_53/Philips_Tech_Review/PTechReview-19-1957_58-324.pdf

The suitcase style cheap players have these sapphire tipped ceramics, but also short arms and poor performance.  I have one which can run off a powerbank and be used to play singles on a picnic, like the portable gramophone.

Good stuff Paul.

The poor performance of those cheap portable players is interesting given the good performance the cartridges are capable of. I'm aware that their design is compromised in just about every respect, but still it seems to me that the whole is less than the sum of the parts (perhaps the opposite of a classic Dansette type of player). I wonder whether there are any opportunities to hot-rod one. My guess is that the amplifier and speakers might be a weak point when it comes to "tone" and could be improved on without having to hack the unit apart too much.

Topic is relevant now as I am trying to get my 11 year old daughter interested in playing records and she has identified brightly coloured Crossley players as appealing - so I'm considering getting her one for Christmas. I've used one before so I know how awful hey are. I just hope the sound doesn't put her off for life...

[vs music]

Hello ! I read all 25 pages. This is an interesting topic . We should also try to make a SONOTONE adapter . I have one inexpensive ceramic cartridge ( Japanese , I think ) . In the early 70s, I listened to records on a radiola with a ceramic cartridge. And it sounded quite decent ( the radiola had large 3-way speakers). I 'll try listening to the ceramic cartridge again . Thank you all for interesting messages !

[wer]

Built the preamp posted by Paul in the OP, but it was unusable. It seems that the INA217 opamp is meant for low impedance input, which is not exactly how you would describe a ceramic cart. The hum was insufferable.
Got a suggestion for an FET based preamp on PFM, which i finally finished



Not at all neat, but rather compact 

Runnung on a 9V battery i get 3-4 mV noise at the output with an open input and no box around it. Have yet to figure out a good way of connecting the cartridge(s), a Sonotone 9TA and a 9TAHC within the headshell, but that is for next weekend.

[floppybootstomp]

Built the preamp posted by Paul in the OP, but it was unusable.

Well damn, I've gathered all the parts for that but haven't put it together yet, have a multitude of projects on the go atm.

I even put a case and PSU parts by but now I'm wondering whether it's even worth starting.

[wer]

Thank you Arkless Electronics on PFM:

A FET input op amp such as a TL071 (or 72 if needing stereo) should do it. Assuming TL071 then try 4k7 from pin 6 to pin 2, 470R from pin 2 to ground (or 100R in series with 1K trimmer for variable gain) and 2M2 from pin 3 to ground.
Input is between ground and pin 3 and output is between pin 6 and ground. Add an output capacitor if desired.
Power it with a split rail PSU and take +12V to pin 7 and -12V to pin 4 with PSU centre point/ground to the circuits ground. If even that is too complicated then you will need to buy a vintage amp with ceramic input... which will prob be so old it needs servicing anyhow!
Decent screening will be required as the very high impedance means it will be very sensitive to hum (opposite to what someone said up thread), although helped rather by the relatively high signal levels in use. Use well screened coax of low capacitance and keep it short as the lead capacitance is likely to effect the frequency response. If "tone correction" is needed then better to do it with known capacitance at input to preamp.
------------

I used a TL072 and a railsplitter in order to keep it small.
Toni, just hang on until i have a chance of testing it. If it is ok i have a spare TL072 and a TLE2426 which you can have. Output and power rail caps are the same as foir the INA217, all you need in addition are two adjustable resistors and a 250 uF cap for the rail splitter. Plan to use a 12 V or 18 V wall wart to drive it.
Do your carts also have a removable plug with 4 connectors for the headshell wires?