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EQUIPMENT FORUMS >> ZP3 / ZMC1,2,3 >> Input Capacitance for ZP3?
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Message started by Scott R. on 04/28/20 at 18:31:19

Title: Input Capacitance for ZP3?
Post by Scott R. on 04/28/20 at 18:31:19

Greetings from Ashland, Oregon,

I was wondering if any of you know the input capacitance for the ZP3. I can't seem to find it in the manual or on the site. I don't want to choose a cart that doesn't pair well with the ZP3, and the input capacitance can be very important for some MM carts. I appreciate any insight that you may have.

Sincerely, Scott

Title: Re: Input Capacitance for ZP3?
Post by Ace-Tone on 04/29/20 at 16:19:48

Specs given to me by Steve:
47k Ohm
2v for full gain
42 db gain

Title: Re: Input Capacitance for ZP3?
Post by NormD on 04/29/20 at 16:38:24

I believe you mean 2mV for full gain.

Title: Re: Input Capacitance for ZP3?
Post by Archie on 04/29/20 at 17:07:48

By calculation, I think 4mV input yields about 1/2 volt output from the ZP3.

Title: Re: Input Capacitance for ZP3?
Post by Steve Deckert on 04/29/20 at 19:45:21

Hi Scott, welcome to the forums!

The ZP3 is around 50pF at it's input.

Thanks for asking : )

Steve

Title: Re: Input Capacitance for ZP3?
Post by Scott R. on 04/29/20 at 21:26:03

Thanks, Steve. Just what I was looking for!

Title: Re: Input Capacitance for ZP3?
Post by Archie on 04/29/20 at 21:36:20

What is the significance of the input capacitance number?

I see in the spec of MM carts around 150 to 300, or even 200 to 400 (Ortofon) but nothing is listed for MC carts. I've used Ortofon MM carts with the ZP3 with no issues and the 2M Black is often mentioned as used here in the Forum as well.

Title: Re: Input Capacitance for ZP3?
Post by Scott R. on 04/30/20 at 00:48:19

In simplest terms, input capacitance that is significantly higher than recommended creates a resonant peak that can creep into the audible range in the treble. Take a look at the first graph at the following link (http://www.hagtech.com/loading.html) - it shows how the resonant peak becomes more audible as the pF loading is increased. Don't worry - you don't need to understand any of the math to understand the graph.

50 pF is quite low, so the ZP3 shouldn't cause any issues regardless of the MM cartridge that you are using. Many MM phono stages use 100 pF as the default. The cabling that you use contributes additional loading, so the total of the phono stage and the cabling input capacitance should be within the recommended range for the specific cartridge that you are using.

MC cartridges are typically not sensitive to input capacitance. Rather, they are sensitive to the input impedance, and the recommended values are in the general range of 100-1000 ohms. For nearly all MM carts, the recommended input impedance is a standard 47K ohms.

Hope this helps, Scott

Title: Re: Input Capacitance for ZP3?
Post by Archie on 05/01/20 at 14:26:49

Thanks Scott, very helpful!