Meridian Unplugged - Powered by MrTechGuy.co.uk Forums Discussion Meridian - Systems MPMAX 221 with a turntable

rms is a good indication, but as VK say the peak to peak -means maximum negative and positive voltage -is important.

Robert

Robert,

Many thanks. I'm out of my depth here. I need to know what spec. numbers to look for in a new phono pre-amp to ensure compatibility and best performance with the MPMAX 221.

rms? peak to peak? volts?! All over my head I'm afraid...

Zander

You are getting into a very diifcult and unpredicatble area here. Read any of the many articles about turntable setup, particularly in Stereophile, and you will quickly realise there is no such thing as right.

Phono amps tend to have very large headroom (in my experience) to cater for badly - or well - mastered recordings. The modulation of the groove can cause relatively massive voltage swings and may overload many a line-level input - I believe the Audio Research reference stage can deliver up to 20v on the output. The 562 allows you to set a sensitivity to maximise the use of the bit-depth and minimise the chance of clipping. I have certainly had LPs cause clipping but on rare ocassions. I think this is why many phono stages have variable outputs.

But you also want to ensure that your phono stage is compatible with the particular characteristics of your cartridge - to me this would be of equal concern.

I think this all comes back to listening and auditioning. Buy the MPMax221 because it is a given you need it and it is particularly suited for your DSPs. Then audition a few phono stages until you find something you like the sound of. Then try it with a few torture tracks to see what it does and whether it can handle extremes in a manner you can live with.

look here
Point 1) show you different waveforms and defenitions

http://www.ese.upenn.edu/rca/instruments/HPfuncgen/WaveFormGen/WaveFormGen.html
or here
http://www.physics.mcgill.ca/webta101/ac/acbasics.html

here is an detail of the spec that show some data
http://www.phonostagepreamp.com/eragoldvphonostagepreamp.htmSpecification

Input range: 2mV to 10mV
Output (for input range): 252mV to 1,260mV (1.26V)
Maximum input: 39mV rms
Maximum output: 4.914V rms
Gain: 42dB (126) at 1kHz
Input impedance: 47k Ohms plus 100pf
Output (driving/source) impedance: 910 Ohm
Recommended load impedance: 10k Ohm or greater
Noise at output: -65dB CCIR Q-pk
Distortion: 0.02%
RIAA accuracy: <0.5dB
Channel balance: 0.2dB
Channel separation: 64dB

Robert

Out of interest, does anyone know what the phono stage sitting on top of the MPMAX221 in the brochure on Dunc's Meridian info is?

Since my 562v has the wrong phono stage in it (515 from memory) I used one of the Project Phono USB stages. I wasn't worried about 24/96 as that system only has 18-bit DSPs.

dpstjp

Robert,

as always, many thanks for your reply - most illuminating. 'Every day is a school day'.

OK - looking at the specs for that particular phono pre-amp, what am I looking for exactly to ensure that it, for example, would work (well) with an MPMAX 221?

Sorry for being dumb...

Zander

Hi

The 221 Datasheet you've linked to only shows two old 100 series components next to a turntable. They are the 104 tuner (top), and presumably the matching preamp of the day? Is this the page you're talking about?

Cheers

George

Matching cartridge output, gain in the phono stage to try and hit the input specification of the 221 is not going to be very easy? A highish output moving magnet cartridge such as the Rega/Goldring ones (6.5-7.5mV) average step up of several quality phono stages I've just looked up such as Rega ProJect and Graham Slee 100-120x would give you an output from your phono-stage of about 1V on a good day. If you need 2.2V to get full bit depth from the 221 it looks like you are likely to need another gain stage somewhere?

Richard,

I knew this was a good question :-)

Zander

It is. I presumed it was a phono stage given the context it was shown in.

Looks like M100 series ?
http://media.Meridian-audio.com/image-lib/imagebank/products/Museum/Meridian%20M10-100series.jpg

Robert

The first question I'd ask you is what cartridge are you using?

As for the 500 series;

the 562 has a 16bit ADC @ 44.1KHz
the 565 has a 16bit ADC @ 44.1KHz
the 561 has a 20bit ADC @ 44.1KHz
the 568 has a 24bit ADC @ 44.1KHz

Vinyl doesn't have a dynamic range that requires over 16bits, getting the level right (just below clipping on the ADC) is much more important.

It has been said that different recordings are at different levels, this is also true in the digital domain, hence the 518. A novel and quite elegant way of controlling the level into a ADC like the MPMAX221 would be a Meridian 101 (or 101B).

Using the 101(B) would give you an excellent phono stage and the ability to control the level into the ADC.

The 101 preamp is readily available second hand, has a nice small form factor and has a modular design so different cartridges can be accommodated.

I believe a 101 into a basic 562 would sound better than a non level controlled phono stage into the MPMAX221.

Steve.