MM/MC Phono Stage and Cartridge matching

[guest147]

Gents and Ladies,
Can anyone please help with some guidance on MM/MC Phono Stage and Cartridge Matching. I have posted something on this before but currently have an Ortofon 2M Red which I am using with a Little Bear T8 phono Amp and also a Denon DL103 which even with the T8 in MC mode causes background hum. I suspect this to be due to poor matching.
While I am quite fond of the T8/Ortofon setup, I would like to be able to utilise the Denon cartridge and need some information about how best to match this. I worked as an electronics technician in another life so can probably revive some of those skills with a bit of study. I am therefore considering a DIY kit, possibly valve if I can stretch to something decent but wonder if there is a guide somewhere on the Web that describes how to match load and output voltage. Also any good recommendations on suitable clone designs would be great.
If anyone can point me in the right direction please?

 

[rothwellaudio]

... also a Denon DL103 which even with the T8 in MC mode causes background hum. I suspect this to be due to poor matching.

Even with it in MC mode? The implication seems to be that MC mode would have less hum. No, MC mode has more gain, therefore any hum at the input will be amplified more.

The Ortofon 2M is straightforward. It's a moving magnet cartridge requiring a 47k load impedance and gain of about 40dB.
The Denon is a low output moving coil requiring a load impedance between about 100 ohms and 400 ohms and gain of about 60dB.
The hum you're experiencing could be due to the turntable/arm/cartridge wiring rather than the phonostage itself.

 

[Tiver]

To look at things a little more on the front end be sure the MC gain hum isn't a simple interference issue. Makes sure you interconnects are routed cleanly and do not cross over power cords. See if the T8 has a variable hum issue when you touch it or pick it up slightly while playing. Try swapping interconnects if you have any alternates.

Looking at the interconnects routing and connections are the simplest first steps to make and many times are found to be the culprits. OTOH, there are reviews on the MC section of the T8 that are not very favorable. It is worth a shot before spending money on another preamp.

 

[sqlsavior]

Good suggestions here. If the T8 is near other electronics, try moving it farther away by itself.

I would suggest an SUT to go with your Denon. IME, they always sound better than inexpensive MC stages, and you already have the cartridge. Get a 10:1 turns-ratio step-up transformer, and it will work with 90% of the MCs out there, and with any MM phono preamp.

 

[guest147]

To look at things a little more on the front end be sure the MC gain hum isn't a simple interference issue. Makes sure you interconnects are routed cleanly and do not cross over power cords. See if the T8 has a variable hum issue when you touch it or pick it up slightly while playing. Try swapping interconnects if you have any alternates.

Looking at the interconnects routing and connections are the simplest first steps to make and many times are found to be the culprits. OTOH, there are reviews on the MC section of the T8 that are not very favorable. It is worth a shot before spending money on another preamp.

Thanks and I will try this.
I am aware the T8 is basic and had planned something better in the future and fancied building a valve stage, possibly an EAR clone.

 

[twiiii]

People wonder why chose to use High output Dynavector MC's. No hum and no circuit matching issues. yes I do have a Mcintosh MP100 phono to line level pre-amp that can do all the matching and loading for MC or MM cartridges. I use it to get a better sound than the phono section of my C-34 Mcintosh pre-amp. I might have gotten the sound I wanted by changing cartridges or tone arms in the lower midrange and upper bass, but then I might be having noise issues, too. The High output Dynavectors negate those issues. If I want XX-2 low-output in the future I am already set up for it. The Mac MP100 has a digital output which I use to feed my CD recorder, too. It makes it easy to dub records with no fuss or muss. If I want to use analog processors I can do that also.

 

[Grenadeslio]

I have one, had the same issue, contacted the manufacturer, he suggested several modifications, none of which worked, I finally gave up. This was several yrs ago so maybe apples and oranges.

 

[guest147]

I have one, had the same issue, contacted the manufacturer, he suggested several modifications, none of which worked, I finally gave up. This was several yrs ago so maybe apples and oranges.

That's what I figured. I like the Denon DL103 for several reason even though it is not bleeding edge. First it tracks well, second it works with some of my older worn vinyl and produces little noise (in a previous setup) and finally I like the way it sounds. Granted this was when I used valve amps but I am certain if coupled with a decent Phono stage I can get good sound from it.
This is also partially why I think a tube phono stage is the way to go, though experience has shown me I won't get away with a budget stage amp and will need to splash out a bit. For best bang for pound (British terminology ) a decent DIY amp, possibly a clone kit would serve me well. Anyone have ideas on what good kits are available or decent designs I could build from scratch?

 

[guest147]

Even with it in MC mode? The implication seems to be that MC mode would have less hum. No, MC mode has more gain, therefore any hum at the input will be amplified more.

The Ortofon 2M is straightforward. It's a moving magnet cartridge requiring a 47k load impedance and gain of about 40dB.
The Denon is a low output moving coil requiring a load impedance between about 100 ohms and 400 ohms and gain of about 60dB.
The hum you're experiencing could be due to the turntable/arm/cartridge wiring rather than the phonostage itself.

 

[guest147]

Thanks and yes I have checked headshell and wiring and though not swapped the arm I tried it on my old SL1500 with same issue. The problem arose when I got the T8 so that is favourite at the moment. I previously had an ifi which I sold to get the new table but it worked well in that setup. Also my Ortofon MM works fine with the T8 so it looks to be either phono cable run or the T8. I have just rewired it so will try again in the morning to see if it works better and post if it's improved any.
It could be a faulty T8 MC stage as I am reluctant to point at the cartridge as it worked fine before.

 

[Grenadeslio]

That's what I figured. I like the Denon DL103 for several reason even though it is not bleeding edge. First it tracks well, second it works with some of my older worn vinyl and produces little noise (in a previous setup) and finally I like the way it sounds. Granted this was when I used valve amps but I am certain if coupled with a decent Phono stage I can get good sound from it.
This is also partially why I think a tube phono stage is the way to go, though experience has shown me I won't get away with a budget stage amp and will need to splash out a bit. For best bang for pound (British terminology ) a decent DIY amp, possibly a clone kit would serve me well. Anyone have ideas on what good kits are available or decent designs I could build from scratch?

The same cartridge, a Denon DL301 works great with the phono stage in my pre. The only reason for the Little Bear I was attempting to use it with my Kenwood integrated amp that doesn't support MC cartridges, went another route.

 

[E.Man]

I had a LB 8.1 which is a different thing but it was shocking with MC even with SUT.

Got a proper one from ProJect.

 

[guest147]

Y

I had a LB 8.1 which is a different thing but it was shocking with MC even with SUT.

Got a proper one from ProJect.

Up it was just a temp thing until I get something decent. I sold my old iFi Phono as I bought a Sony PS-6750 refurb. I have wanted one of these since I had my old Sony PS-X7 which was missing bits, bad lid etc but sounded incredible. I am a sucker for high quality DD tables and the Sony is stunning even through the T8.