Yamaha CA-2010 - MC Impedance

[sydbar81]

I'm trying to ascertain the specification of the MC Impedance for the CA-2010.

Service manual states 10ohm impedance, 50μV sensitivity.

I'm considering a Audio Technica OC9-mlii and am not sure if I need a SUT. I spoke with Audio Technica and they seem baffled by the spec listed for the CA-2010 and stated that it was unusually low for a head amp. Yamaha support was unable to confirm either how this value is determined.

Audio Technica stated that I need 20ohm for a SUT, 100ohm for a head amp. Has anyone out there tried this pairing or anything similar?

 

[mbz]

Service manual states 10ohm impedance, 50μV sensitivity.

Same as the CA-1010.

The input impedance will be derived from R101 and IC101 (proprietry)

 

[Balifly]

I'm trying to ascertain the specification of the MC Impedance for the CA-2010.

Service manual states 10ohm impedance, 50μV sensitivity.

I'm considering a Audio Technica OC9-mlii and am not sure if I need a SUT. I spoke with Audio Technica and they seem baffled by the spec listed for the CA-2010 and stated that it was unusually low for a head amp. Yamaha support was unable to confirm either how this value is determined.

Audio Technica stated that I need 20ohm for a SUT, 100ohm for a head amp. Has anyone out there tried this pairing or anything similar?

The output for the cartridge is:

0.4 (mV at 1 kHz, 5 cm/sec)

You should be able to use the CA-2010 MC phono as is, without an additional of SUT.
http://www.audio-technica.com/cms/cartridges/8e67b15a2a48de4e/index.html

 

[sydbar81]

Just figured I'd give an update.

The oc9 is here and I'm spinning the first record.

It is confirmed it sounds fantastic straight in to the ca-2010. Have been running a Signet TK5E for the last couple years, seems to have the same playback level.

I am just blown away by this thing right out of the gate with no break in. Holy crap.

I have a pair of yp-d71s set up and have a at130e body on the way. Once I decide on a stylus I have some fun a/b ahead of me!

 

[sydbar81]

Well... Curiosity/obsessiveness got the better of me when this NOS AT630 SUT popped up on that auction site.

Will provide A/B notes once I'm confident the cartridge has a full break in.

 

[sydbar81]

I spent a month running the OC9-MLii through the AT630 SUT, and have now bypassed it and am funning straight to the amp.

The easiest way to describe this change is as if I'd pulled huge wads of cotton out of my ears. The SUT seems to have veiled the range, the highs now soar, the bass has slam and the image now has depth.

I still do not understand how this is, considering that the input spec is dramatically out of the preferred range for this cart from AT.

Same as the CA-1010.

The input impedance will be derived from R101 and IC101 (proprietry)

mbz - I don't have an electrical background, could you explain what this means?

 

[mbz]

mbz - I don't have an electrical background, could you explain what this means?

The input impedence/resistance is what the incoming signal sees.

Looking at the schematic, the incoming signal has a choice between
the path through R101 and the path to IC101 pins 3&4. The key resistance
will be that of IC101, the datasheet may give some indication.

Simplifications are resistance/ESR from C101,3 is very small. Also
no signal flow through R109,111 since they are large (voltage rail)

 

[cdfac]

I spent a month running the OC9-MLii through the AT630 SUT, and have now bypassed it and am funning straight to the amp.

The easiest way to describe this change is as if I'd pulled huge wads of cotton out of my ears. The SUT seems to have veiled the range, the highs now soar, the bass has slam and the image now has depth.

I still do not understand how this is, considering that the input spec is dramatically out of the preferred range for this cart from AT.

I have a suspicion that Yamaha incorrectly measured or calculated their input impedance into MC on some of these integrateds. My A-1 also quotes 10 Ohms, but I know of a lot of people using carts successfully that wouldn't seem to fit with that low of an impedance.