TSD-15 Optimum Loading

[Justcallmedad]

I acquired recently an EMT TSD-15 cartridge (MC) and I would like to know if someone on this forum has "play" with it, and could give me some advises on the best loading network for it (R and C).
The turntable is the EMT 938, but suited with the MM preamp, the RIAA preamp seems astonishly good even if there is a lot of 741 op amps !!! I am trying some fet input / non feedback designs to replace it, so one more question : is it best to use a step up transformer or a multiple fet input stage (low noise).

Before I get the TSD-15, the T.T. was suited with a Stanton cartridge (broadcast use).

I am newbie in Vinyl so a lot of advises are welcome.

Thanks.

[audiotux]

Hi Justcallmedad ,
try 200 Ohms , capacity is included in the Phonocable to Pre-Pre ,
and is normaly uncritical for MCs .

Greetings from Germany

Jürgen

[Justcallmedad]

Hi audiotux,

Originally posted by audiotux
... capacity is included in the Phonocable to Pre-Pre ,
and is normaly uncritical for MCs .

This turntable is not suited with a Pre-Pre, the original cartridge was a MM Stanton, so I don't think that the cap is included in the phonocable, but I have read in some web sites that the TSD-15 is suited with a 0.33uF tantal ???

Links to TSD-15 specifications:

fabtech

fabtech - pdf

EMT -> then "Tondose"

I tend to be agree with you about the cap, but why EMT equipped the TSD-15 with 0.33uF ?

[audiotux]

Hi Justcallmedad ,
the capacity is included by ( or trough ) the Phonocable ,
that means all the cable from cadrige to preamp and is not critical
for MC . Feel free to try it yourself , with variable settings .
200 Ohm is a good startingpoint with a Pre-Pre

Greetings from Germany

Jürgen

[Justcallmedad]

Hi audiotux,

Yes I know what you mean, but in the TSD-15 cartridge, as shown in the link (EMT then Tondose) in the last photography we can see two small caps that looks very much like tantalum capacitors as indicated on the (fabtech-pdf) datasheet.

Why a so high capacitor ???
I know that for an MC cartridge the loading cap is less critical than for an MM one, but why a so high value and moreover a tantalum one !!!

Do you have an EMT/TSD-15 turntable?

Greetings from France

[EC8010]

Moving coil cartridges are lower impedance than moving magnet, so if they need capacitance to fiddle their response, we should expect it to be a much higher value. Note that the specsheet you linked to notes that the capacitor is built-in, so this implies that if it's needed it's already there. In other words, don't worry about it.

Further, I looked at the diagram for the EMT938 moving coil pre-amplifier for the TSD 15 cartridge. It loads the cartridge with a 221 (220 would be fine) Ohm resistor, but no loading capacitor.

[Justcallmedad]

Hi EC8010,

Many thanks for the info

What surprises me is the so high value of the loading cap, together with the tantalum technology, according to the EMT website.

Could you post here, or e-mail me the moving coil preamplifier diagram ? Even if you have the entire RIAA amplifier I will be interested to have a look on it .

[EC8010]

Here's the diagram. I didn't notice it on my first look, but there's a 3.3n capacitor almost loading the input. It's there to prevent RF problems, and the cartidge loading is incidental.

[Justcallmedad]

Thanks EC8010,

It seems that in my TSD 15 sfl, there is no capacitor, so it's o.k. and like you said this is not the capacitor the most important, but the loading resistor.

Firsts tests seems to lead to a value around 100R.

If you have a complete schematic of the EMT preamp, I am interested in having a look at it, to see how they can get a quite good sound from a 5533 and lots of 741!!!

Now the continuation of this "adventures" will be in the thread called RIAA preamp.

[Werner]

I would be interested in the full EMT preamp schematic too!

Dad, the pre may be good, but don't forget the TSD-15, which is
a very fine cartridge indeed. In addition to which I am green with envy for your 938.

The capacitor is an integral part of the generator design. You can see it clearly in just about all EMT offshoots: