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Phono stage input capacitance list.

catman

catman

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G'day all, I was just thinking about input capacitance and loading, and I realised that a lot of commercially made phono stages either do not publish input capacitance figures and/or are quite high, making them unsuitable for some otherwise very good MM phono cartridges (like the Shure M97xE). 220 picofarads seems to be a popular value, although too high for the M97xE when tonearm wiring and interconnect cable capacitance are added into the equation.

My ANT Kora's input capacitance is 100 picofarads, a pretty well ideal value, and my TCC TC-750 is 220 picofarads (factory default value), which I have changed to 100 picofarads.

If the input capacitance is low, one can always add capacitors, but generally it is not easy to change, if the input capacitance is already too high without 'surgery', although using shorter interconnects might be an option.

Anyway I was thinking we might compile a list of various phono stages input capacitance (if available), as this will definitely help with optimal cartridge capacitance loading. The value might be gleaned from a circuit diagram. Regards, Felix aka catman.
 
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Hey Felix:

A great idea, but a daunting task, as you point out-many equipment makers do not disclose the capacitance of the devices they sell. These items would have to be idividually tested. I do not own the necessary equipment to test myself, so I would not, at this time, be able to add to the database.

Conversely, I would love to have this data available when I consider purchases :yes:
 
OK, If you want to start a data sheet.

DB Systems

Input sensitivity for 1 volt output:

1.8mv into 47K and 100 pf
 
Yes it would be very helpful. I've been waiting on Emotiva to respond to an email on this question. I've also been waiting on Ultimate Cables to reply about the capacitance of their phone cables. This is often the dark side of the new direct sales in audio model, email-only customer service that often sucks, but not always, Schiit is great BTW. I need to add capacitance to get in the 400-500pf range for a V15 lll. I also need a new RCA phono cable w/ the male 5 pin DIN for the Grace 707. I will probably splice a known RCA interconnect to my Grace din cable rather than patronize a company with crappy service. Sorry for the rant Felix, but at least it's on subject.
 
My Phonomena has two stated dip-switch settings:
200 and 300 pF. Now, I have no test equipment to see what the true values across the whole thing are. I set it on 200, which may not even affect my LOMC cartridge, but does suit the Stanton moving-iron model I use.
 
G'day all, many thanks for the contributions so far. I think that it is quite important to get good information on this subject as the effects on a 'high inductance' moving magnet cartridge upper frequency response can be very significant! :yes: Regards, Felix aka catman.
 
Emotiva USP-1 MM phone in is 47k ohms (published) and 100 pF per Nick at Emotiva over the phone. He says that also applies to the MC input so its 240 ohms and 100 pF.
 
G'day all, yes receivers and integrated amplifiers are welcome in the list too. :yes: Regards, Felix aka catman.
 
Well, if receivers are welcome; this is my Sony STR-GX9ES receivers' phono section. I see the 330pf to ground through the 330 ohm resistor. Is the 330pf the total phono section capacitance? If so than that seems pretty high. Someone more knowledgeable than me can hopefully correct me if I'm wrong.

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G'day mate, interesting on putting the capacitor in series with resistor like that. I don't think I've seen that done before. :yes:

The resistor will modify the capacitance value seen by the cartridge slightly but not by too much, I expect.

Yes the input capacitance will be 'around' 330 picofarads a rather high value (by present day standards). I wonder when that amp was designed/made? :scratch2: If it dates from the 1970's that's probably ok as many of the Shure's back then recommended 400 to 500 picofarads of input capacitance for example. Regards, Felix aka catman.
 
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The Musical Fidelity V-LPS was measured by a German magazine to have 74pF capacitance.

The Parks Audio Budgie is stated to have ~ 50pF.
 
Yamaha C80: 47k ohms at 2.5mV , switch for 220pF and 330pF. 2 Phono inputs, phono 1 is MM or MC, phono2 is MM only.

Harman Kardon HK 825: 47k ohms at 2.2mV and 130pF . Switch for normal, +100pF, +200pF, +300pF. 2 phono inputs, separate button to select MM or MC.
Manual states if cart is 200pF or less, to use normal setting, for 200-300 pF switch to +100 setting, and so on.
 
ART USB Phono Plus Project Series 47k/100pf (Phono), Pioneer SX-255R Receiver 220pf(Phono)
 
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Denon AVR-2106

Denon AVR-2106

Input sensitivity/Impedance = 2.5mV/47K
The spec sheet does not specify the input capacitance but I looked at the schematic and there is a 220pF cap going from the phono input to gnd for each channel. So I am going to take this to mean that the input capacitance it 220pF. I just want to add that the caps go to gnd after the input resistors.
 
catman said:
G'day all, yes receivers and integrated amplifiers are welcome in the list too. :yes: Regards, Felix aka catman.
Click to expand...

FWIW I'm using a Linn Kairn passive preamp for phono stages with MC Dennon and Supex carts with really low outputs into the auxillary of this KW1100U.
Inky quiet backgrounds, amazing sound quality and no caveats so far. :rockon: :rockon:
 
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