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Input capacitance!?!?

A

Adam3004

pfm Member
Hi, I've just been reading about capacitance in relation to my Pre amp and cartridge etc. I didn't know anything about this so it's all pretty new to me. Can anyone tell me how important it is.

The reason I ask is I am using an Ortofon 2m bronze which recommends load of 150-300 capacitance. My pre amp is a Tisbury Domino which has a load of 200, I've been reading that my RCA will add more and the internal wiring of the cartridge even more. I'm now wondering if I'm going over the 300 limit. Am I paying to much attention to this or is it important to consider the loads etc.

Thanks in advance.
 
It does make a difference, however, whether said difference is perceived as better or worse can be down to a number of factors, even extending to the frequency response balance of the loudspeakers, and how they perform in a given position within a given room. Regardless, getting capacitance in the recommended zone is generally a good thing with MM cartridges, especially so, from the perspective of two (or more) bads not making a good.

What tonearm are you using and is it stock wrt wiring?
 
Thanks for replying. The TT is a project Classic, I'm using the tone arm that it came with, I'm guessing it's the stock wiring.

I'm now thinking about replacing the Tisbury Dimino, what's a good buy in the £300 price range, 2nd hand isn't a problem.
 
Too many manufacturers do not specify input capacitance,ideally you should get a phono stage with as low a capacitance as possible as it is always possible to add but much more difficult to remove-especially with many modern cartridges needing less than 200pf. (AT)
 
Wow. I’m going through the same thing but with a MC Rega Ania. This needs an input capacitance of 1000pF. The Project S2 Ultra phono-box that I’m using has a default setting of 100pF. The instructions say that for low output MC input capacitance is irrelevant. However, this doesn’t appear to be true. I set my phono box to its max 420pF and the hiss from the phono-box dropped considerably. I have in the last two days used various made up phono RCAs with different capacitance loadings. I have found getting closer to the 1000pF produces a more vibrant 3D effect which then becomes very wide and big sounding as it goes over the 1000pF which doesn’t sound good to my ears.
 
The Connect it E interconnect cables that come with Pro-Ject Classic are spec'd at 130pF. Pro-Ject don't appear to list the tonearm internal wire spec but these usually test up to 20pF at most.

As such, I'd guesstimate the total load capacitance that your 2M Bronze would 'see' with your pre at 350pF. This isn't necessarily a bad thing, however, should you wish to experiment, one way to get this down, would be to replace the Connect it E cable with an aftermarket alternative (including or adding a ground lead).

Many popular pro cables are rated 65pF/m, Klotz AC110 (Formerly 'La Grange' GY107) with Rean RCAs either end, for example, are not expensive and have no sound of their own.
 
Vinny said:
Unless the Ania is an odd-ball, MC are all but unaffected by cap'.
Click to expand...
this is exactly what the instruction manual said so I didn’t bother checking the input capacitance settings. However going from the default 100pF to the max 420pF reduced the audible level of hiss and adding further capacitance altered the sound as described above.

On Rega’s website the default setting on their phono stages is 1000pF to match their MC. In fact their PHONO STAGE capacitance loadings start at 1000pF for MC giving upto 4300pF.

http://www.rega.co.uk/fono-mc.html
 
I believe the bronze shares the same generator as the black and therefore may benefit from an alternative loading of around 32K and no capacitance other than the arm cable. This comes from the Steve Hoffman site where someone carried out pretty thorough testing on 2M Black loading. I've supplied several phono stages to users of these carts with no capacitance fitted and loading plugs to bring R down to 32K to quite a few satisfied customers and I believe @Tony L had his Black loaded this way IIRC with good results.
 
Thanks for all the replies. It seems I'm running at approx 50 above the recommended limit. I might try a new cable as suggested to bring this down, I'm loathe to go down the route of swapping cables so I'm undecided. I might buy myself a new preamp for Xmas instead. At the end of the day, I'm not unhappy with my current sound.
 
I have a Project S2 Phonobox and it’s the first time I have used load settings which are dip switches on the bottom. Previously used Graham Slee and Cambridge which didn’t use these. I use a Goldring G1042 MM cartridge. Could anybody recommend the best settings for this cartridge?j I currently have it on 40db gain and 200pf with 47 kr setting though it appears a little bright perhaps with reduced bass.The cartridge is weighted at 1.8 g.
 
Del monaco said:
Thanks. the settings are fine then.Ill play a little bit more with weight, VTA and will try alternative cable.
Click to expand...

If you have the stage set with 200pF, it is too high - like I said - THIS MUST INCLUDE CABLE CAPACITANCE. There is no reason not to try towards 150pF total also. What is the cap' of the cable? Subtract that from 200pF and set that or slightly lower in the stage.

Using a suggestion above, you could well have something like 50pF in the cables!!
 
There’s a load calculator here: http://www.hagtech.com/loading.html

the bronze has 630mH of inductance feed that in plus your loading capacitance then scroll down to find the calculated load resistance after the graphs

if you can get to 280~300pf then 47k is just about spot on
 
Del monaco said:
I have a Project S2 Phonobox and it’s the first time I have used load settings which are dip switches on the bottom. Previously used Graham Slee and Cambridge which didn’t use these. I use a Goldring G1042 MM cartridge. Could anybody recommend the best settings for this cartridge?j I currently have it on 40db gain and 200pf with 47 kr setting though it appears a little bright perhaps with reduced bass.The cartridge is weighted at 1.8 g.
Click to expand...

I recently had a modified Goldring 1042 with the S2 Ultra. I had it on 100pF ( switches 1 & 2 off) which sounded great.
 
cobbers said:
As he says in the intro to those graphs,they are incredibly simplistic and take no account whatever of mechanical effects.
Click to expand...

indeed but as stated it’s a starting point and may help in getting where the OP needs to be
 
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