CR-2020 MC Loading Resistor

[zaskarx]

I'm considering buying an MC phono cartridge and would like to know if it is possible to update the MC phono stage in my CR-2020 to support 100 ohm loading for modern MC cartridges. Per the service manual, it is 10 ohms from the factory. I've been staring at the schematic and am struggling to determine which resistor(s) I would need to replace. I'm hoping someone more knowledgeable may be able to point me in the right direction. Thanks!

 

[Jygesq]

would it make a real difference in the sound? have you tried it the way it is now?

 

[zaskarx]

From what I've read the cartridge loading does make noticeable difference in sound - but I don't own an MC cartridge yet so I don't know for sure. I've read posts describing the swapping of phono stage resistors in other receivers and preamps, it could be that it isn't possible with the CR-2020.

 

[avionic]

I 'd give it a try first. I don't think you will have any issues with and LOMC cart. as is.

 

[Dr. Ear]

In the German "analog forum" exactly this question is discussed at a rather high level. The conclusion is that input impedance is a bit more than the first resistor in parallel which the pickup "sees". Please read this thread http://www.analog-forum.de/wbboard/...anz-50-ohm-ändern-für-dl-103-und-wenn-ja-wie/
Use a translator and you will find some useful information. Otherwise I agree with Avionic. My AT 33Sa (minimum load >100R) sounds just great on the A-S3000, (50 Ohms MC input impedance). It does not sound better with the 100R of my C-70 or C-80. Of course, there are certain cartridges which are known to sound more open or lively with higher loads, like the Denon DL103.

 

[zaskarx]

Thank you both for the advice and Dr. Ear thank you for posting the thread...very interesting read. I'll most likely buy the cartridge and give it a try.

I also have a Kenwood C2 preamp which if I can get working (I have a separate thread in the Kenwood forum for this) has a standard 100ohm MC setting. I'm in the process of recapping the 2020 after rebuilding the power supply which was in terrible condition. It'll be a race to see which one I can revive first!

 

[avionic]

In the German "analog forum" exactly this question is discussed at a rather high level. The conclusion is that input impedance is a bit more than the first resistor in parallel which the pickup "sees". Please read this thread http://www.analog-forum.de/wbboard/...anz-50-ohm-ändern-für-dl-103-und-wenn-ja-wie/
Use a translator and you will find some useful information. Otherwise I agree with Avionic. My AT 33Sa (minimum load >100R) sounds just great on the A-S3000, (50 Ohms MC input impedance). It does not sound better with the 100R of my C-70 or C-80. Of course, there are certain cartridges which are known to sound more open or lively with higher loads, like the Denon DL103.

The CR-2020 sounds great with my DL160 HOMC ..