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AT-OC9 loading

Mr Pig

^'- -'^
About to try an OC9-MLII into the Aria phono stage. What would be the best settings to use?

The cart has a 0.4mV output and recommended load in 100 Ohm minimum.

Aria loading is:
70, 100, 150 or 400 Ohm

Gain is:
63.5 or 69.3 db

Capacitance is:
1000, 2000, 3200 or 4200 pf

Where should I start??

Fang queue :0)
 
I agree with the suggested settings as a starting point. I would also try 150 ohms. I do think capacitance does make a difference but its impact is more subtle; the impedance will have a bigger effect. Start with the lowest capacitance and adjust up by ear if necessary.
 
Really don't use vinyl much now days but I have an OC9MLii on an Audiomecca Romance with Romeo arm. I found it sounded slightly more open with higher resistance than 100R and used 240R so definitely try the 150R setting. The capacitance is more about defeating RF with an MC as some stages can pick up taxi coms etc. As said above it is much more critical with MM's where it affects the treble because of resonance with the high output impedance. Naim's MC boards (NA323) use from 1nF to 6.8nF IIRC
 
Thank you.

Why won't capacitance make any difference? Will it sound different with more resistance?
The cartridge source impedance is ultra low, just a few Ohms which makes them largely immune to capacitance and resistive loading. It can be impacted if you load at sub 100 Ohms but anything higher is just fine.

Very high levels of capacitance is sometimes used to control MCs with a large HF resonance, eg the very first Apheta.

Re the 2 gain settings available the lower is technically the best fit for the AT cart, however I'd use whichever gives you the most acceptable swing on the volume knob.
 
I’m using the same settings as for the Rega Ania. Note I’m using a OC9-XML, not a OC9-ML2.

I've just plugged it in with those settings too as that's the default. The box is very hard to access so I'll take the lazy option and try other setting later. 100 Ohms and the higher gain.

Straight away sound pretty good. No hint of the brightness the OC9 can exhibit but the characteristic lack of bass weight is present and correct. Don't get me wrong, it's not bass light and sounds well balanced and good. Just that other carts sound more solid at the bottom. Literally just set up though so can't really call it for a day or two at least.

The OC9-XML looks very like the ML II, all the specs look much the same. Cantilever isn't gold plated so a bit of cost cutting but I reckon they probably sound very similar. The ML II was slightly lower spec than the original OC9 on paper but it sounded better.

Audio Technica make feckin good cartridges.
 
I had AT33EV then the OC9 MLII then another 33EV I found the OC9 just a bit too lean with a very cool and blue tonal balance.
Much prefer the Hana SL I use now , warmer mids and fuller bottom end.
 
Colin,

Reading your post and as an Aria 3 user myself thought I would change the loading to 150 Ohms from 100 with my Hana ML out of curiosity (a needle is a good tool) and have to say really liking the result.
The sound seems more energised than before like going up a gear.Just played a couple of familiar tracks and big thumbs up.
Right time to get back on the sofa.... :)

Enjoy your OC9 -XML !
 
I have a AT OC9-XSL. It has a .4 output as well. I run it into the new Ryan Sound Labs adjustable boards for my Naim 82. I think I got the first set. My OC9 was too hot and overloading at 59db, which is the standard gain for the boards so Kit reduced the gain to 53db for me. That was much better. I found the sound best with loading set to 470 Ohm & the capacitance at a 1000. But now that the cart is broken in I may try the highest loading setting again, which I think is 560 Ohm. Previously, 560 made highs - like cymbals, stand out just a bit too much. Lower than 470 and it was a bit dull. It's interesting to hear how the loading changes the sound! I'm really happy with the new RSL adjustable boards. Found them to be an improvement over my Naim K boards. And Kit is great to work with!
 
I’d add a bit of weight to the headshell to get better bass. Blob of blutack is quick and dirty fix to try, brass finger nuts or AT weight cost effective longer term solution.
 
Enjoy your OC9 -XML

It's not mine. Or rather it used to be but I sold it to a friend when it didn't work on the RP10. Just borrowed it back to try on the new LP12, try to get an idea of what direction to go in cart wise. Because I know it so well it's a good reference.

Sounds good but think I'll go for something with more body. I will try 150 Ohms and lowering the gain but it's not overloading at all at the higher gain.

Had to put the Aria where the pre-amp used to be as the arm cable is too short. Cannot be removed without removing the turntable and three bits of Mana above it! Will have to flick the dip switches using a mirror.
 
How is the LP12 - RB3000 combination sounding now ?

There is a Hana ML in the classifieds here....low hours and a good price.... ;)
 


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