[guilford]

I'm brand new to turntables and was hoping someone might be able to help me out with what is likely a basic question. I'm looking at the specs for the Bryston BP-2 MM/MC 20 and trying to make sure that I get a cartridge that will work well with it.

The specifications for the MC-20 indicate that it provides a 1:10 step-up for MC cartridges up to 45 ohms - optimum 25 ohms with >0.3mV output

Once of the cartridges I am considering is the Hana SL with the following specs:
Output Level: 0.5mv/1kHz
Impedance: 30 ohms /1kHz
Suggested Load Impedance: >400 ohms

The output level looks like a suitable match, but my question is this: The MC-20 specs call for a cartridge "up to 45 ohms with 25 ohms being optimal". Are the MC-20 specs talking about the cartridge Impedance (in which case the Hana SL at 30 ohms would seem to be a reasonably good match) or the Suggested Load Impedance (in which case the Hana SL is not what I am looking for at >400 ohms).

Thanks in advance for any help with this vinyl newbie question. I'd like to go with the BP-2 to match the rest of my all-Bryston system, but want to make sure I understand the constraints on compatible cartridges.

[guilford]

I heard back from Mike Pickett at Bryston on this question and his reply was very helpful so I wanted to share it here in the hope that it may help others in the future with similar questions:

"The spec that mentions 'up to 45 Ohms' is referring to the impedance of the cartridge itself. This means that the Hana SL should match well.

The input impedance of the MM section of the phono stage is 47,000 Ohms, so the reflected impedance that the cartridge sees through the 1:10 transformer would be 1/100th of that, or 470 Ohms. This confirms that this would be a good match with the Hana."

So not only did Mike answer my specific question about the Hana SL, but he also gave me the tools I need to assess the suitability of other cartridges. I know Bryston makes great audio gear, but responses like this reinforce that it's the people behind the products that really set Bryston apart.

[gbaby]

I own the BP-2 and you should get the cartridge that better matches your turntable. The BP-2 will handle just about any moving coil cartridge except for the moving coil cartridge with an extremely low output, and even then, it may handle it with a step up transformer.

[TABARD]

Hi, If you are brand new to T/T's. Then you most likely do not know that the cartridge compliance needs to be matched to the T/T tonearm Effective mass. This is to ensure that the combination resonant frequency does not fall lower that 7hz (footfall & warpped LP sound) or higher than 14 hz (Base sounds)
The cartridge has a Shibata stylus & need extremely careful SRA (stylus rake angle) set up using a USB microscope to sound it's best.

Cheers & Happy Listening

[Stefan_DR3]

The BP-2 will handle just about any moving coil cartridge except for the moving coil cartridge with an extremely low output, and even then, it may handle it with a step up transformer.

Not true because the BP-2 does not have adjustable loading.  There will be an impedance mismatch and ringing in the audio signal, usually heard as sibilance.

I agree with Mike's advice and his math wholeheartedly, whether you are using a step-up transformer or not (I am).

[James Tanner]

Hi Folks,

My latest Newsletter deals with MC Transformers.

Email me if you want to be on the Newsletter List.

james

[gbaby]

I, too, own the BP2 mm mc. It will handle a moving coil cartridge as long as the output is .3 or .03 mv or better. Look for the specs on Bryston's web site.