A few more ceramics

[jotarama]

I'm following this thread, and I think it's very interesting, so much so that I built this adapter to be able to listen to ceramic (or crystal) cartridges through a magnetic phono input. The adapter has two main circuits that can be switched between each other, one without any signal modification, to be able to use MM cartridges; the other is for ceramic cartridges adapted to MM inputs. In this second case there are two possibilities: you can select the "Velocitone" design from Sonotone or the one designed by Philips for its GP390 cartridge.

Since I had a Sonotone 9TA cartridge I tried it and the result has left me more than surprised, the sound is incredibly good. I think I'm going to get into this type of cartridges.

Some photos of the device:

[Toronado]

Oh nice. I like these little useful boxes.
My one is also switchable between bypass and Cermag. I have installed a stereo pot in addition. And a second switch for more different circuits.
Would be nice to collect the factory Cermag circuits in an extra thread. The schemes are provided in the cartridge boxes. But one isn't that lucky very often getting the cart with original Box.
I'm very interested in the Phillips circuit. What are the differences compared to the Velocitone?

Best regards

Roman

[analogadikt]

A BSR SC5M (including a 1/2" adapter) found its way to Ginestar today 



Have to wait with the trial until the new skirt for the QRK is installed.

Looks like this was copied in Japan.





Regards,

Anwesh

[LFC]

Very interesting thread. I always thought those were of no use, just historical. We can always learn  And while cleaning up I found a Rosette 107 with its clip in one of my drawers. Since I won´t use it, I would give it to someone who has the proper inputs and fun with it. Just for the shipping costs 

[wer]

Thank you Anwesh, interesting information 
Wonder if someone on LH has one, would be interesting to compare.

Have to find that Sonotone schematic, it seems simple enough so even I could still build it. Just paid for a 9TA ex Wurlitzer, and the circuit has the advantages of functioning without power supply.

[Toronado]

Argh. Werner, we completely forgot speaking about the Velocitone. I have all parts here and a few months ago I bought some very tiny ceramic condensers. So the Velocitone can fit in a SME headshell.

The Ronette in the picture is quite interesting. I know only the crystals as very good ones. Didn't know that Ronette also built ceramics (if this is one, but looks so).

Best regards

Roman

[wer]

Not sure I can fit the Velocitvone, since I could barely manage to squeeze the 9TA into a headshell. They are rather long by themselves, and the connector takes some more space.

[jotarama]

Oh nice. I like these little useful boxes.
My one is also switchable between bypass and Cermag. I have installed a stereo pot in addition. And a second switch for more different circuits.
Would be nice to collect the factory Cermag circuits in an extra thread. The schemes are provided in the cartridge boxes. But one isn't that lucky very often getting the cart with original Box.
I'm very interested in the Phillips circuit. What are the differences compared to the Velocitone?

Best regards

Roman

Hi, Roman, this is the Philips circuit. It is the one that the brand designed for the GP390 and was included in the cartridge. Obviously, for stereo, you have to do one per channel.





Differences? The Sonotone 9TA sounds louder using the Philips circuit, with more powerful highs but less defined bass. With the Velocitone circuit the sound is more balanced, the highs stand out less although they have enough presence, bass and mids are much better defined.
As I said, I really liked the sound. I have to get more capsules (Ronette, BSR...) to try them out. I think this can be highly addictive...


Wer, the Velocitone schem is this other (the right one)




This is my Sonotone 9TA

[wer]

Hmmm, that is just a voltage divider 

[Toronado]

Thank's Juan. This is really simple. But I wonder too. The Velocitone with its half-anti-RIAA is designed completely different. It pushes up the bass frequencies which are missing when you connect a ceramic to a low impedance input.

But you are right, this is very addictive.

Today I gave my last three untested Ronettes some time for playing. Two of the BF40 Fonofluid crystals are in good working condition. The third is showing a bit of its Fonofluid I think.



The other two may play one side Clinton Fearon each.





But... I don't like them really much. Very crystally. Deep wooly Bass, cutted highs. Quite nice with the Reggae in the Background but there is missing so much.

These has been the last ones to test from a 7-Ronettes-bulk. 4 are working. 3 Not. Thats ok for crystals.

But now back to ceramics.

Best regards.

Roman

[Toronado]

Here the circuits that Goldring requires for the CS-90 (left, simple voltage divider, too) and the CS-91E (right, more than the Velocitone).

Both are described as full anti-RIAA as one can see in the lower diagram. The broken line is the frequency response after circuit and pre MM (RIAA) stage. The full line is after RIAA equalization.



I would be very, really very happy finding a Goldring CS-91E in the Future. This manual came with the CS-90 I have.

Best regards.

Roman

[colin]

Hi Roman,

I agree about the BF40, mine is not impressive, even with a new diamond stylus.

Your mention of the Goldring CS90 gave me a nudge to try mine for the first time



Still using the Realistic amp ceramic input, I was pleasantly surprised with the clear treble response, and overall smooth playback. The CS91E would definitely be worth a listen.

[aboos]

Be aware of the fact that all these 'adaptor' circuits are not generally usabale for all types and brands of ceramic (or crystal) cartridges. They have been suggested by the companies taylor made for their own cartridge versions! Ceramic cartridges especially in the highs show quite different frequency responses as the mechanics of the cantilevers introduce resonances that alter the theoretical responses quite significantly. Furthermore, ceramic cartridges have a very high internal impedance which behaves like a capacitor: very high impedance for low frequencies and falling for higher frequencies. Furthermore, the values for the low frequencies very much depent on the ceramic element (they basically are a capacitor and their capacitance values range from a few hundred picofarad up to two nanofarad)
Bottom line: a circuit working well with one cartridge may completely fail when used with another one!

[Toronado]

Hi Colin,
yes, this is almost exactly my experience with the Goldring. Smooth and relaxed. Nothing is missing with everyday use. Maybe a little too calm...
I tried it with both the Velocitone and the CK input of my Telewatt. Both is nearly the same.

Hi Andreas,
yes, these differences become obvious when you look at the provided circuits of the cartridges.
But the Velocitone is very versatile with many carts.
I have to test more different circuits. Maybe there are better ones for some carts.

A more special case are the Dual CDS6xx. I find them very bass heavy with the Velocitone. Maybe this is the basic design from Dual to get the right bass with their relatively low impedance inputs (470K).
The CDS700 (Hifi, 2,5g VTF) is the most extreme concerning bass Response. With the Velocitone it is quite unhearable for me.

Best regards.

Roman

[jotarama]

I got a Ronette BF40 and mounted it on the headshell of my Lenco B20, being a stereo cartridge I wired it to mono. The turntable is connected to a Grundig 2070 tube radio, the tracking weight is 5g. For the first test I used a 10" record, very warped. As you can see, it plays without skips or any problem.

I like the sound, it's very authentic for these 50's records. I definitely need to get my hands on some mono cartridges of this type, I have a lot of fun experimenting with them.