Cambridge Audio Duo Phono Stage Review (Updated)

[Abdo]

I'm referring to the ground wire that has to go from your turntable to the Amp, not the mains power ground.

Right, left and ground should be coming out of your turntable.

I'm wondering what the noise will be when you've got the three wires between your turntable and your Amp connected.

It may be quieter with it all connected.

does not change when the Rega is connected, the noise signal is the same, and the Rega Planar 1 does not have a ground wire, just the RCA connectors and power cable.

 

[Doodski]

Yes, the MA6800's ground is well connected, the ground here is very good, straight from the energy company, everything is new. The Rega, as I showed in the video, is completely disconnected from the MA6800, even to see that the noise is generated by the MA6800 and not by the Rega.

Perhaps shorting the phono RCA inputs will reduce all that noise. <?> Is this safe for a phono preamp???

 

[Abdo]

Perhaps shorting the phono RCA inputs will reduce all that noise. <?> Is this safe for a phono preamp???

the noise is generated even with the phono (rega) disconnected.

 

[Doodski]

the noise is generated even with the phono (rega) disconnected.

Yes, but the phono preamp is still presented with noise at the input and it will amplify that.

 

[Abdo]

Yes, but the phono preamp is still presented with noise at the input and it will amplify that.

Yes, that's right. Now I just need an answer, is it worth putting a Cambridge Duo or MK3 in this system? (1 million dollar question..lol)

 

[Doodski]

Yes, that's right. Now I just need an answer, is it worth putting a Cambridge Duo or MK3 in this system? (1 million dollar question..lol)

The Duo tested very well here @ ASR if memory serves me correct. I will leave the answer to your question to somebody more knowledgeable regarding phono gear.

Review and Measurements of Cambridge Audio Duo Phono Preamp

This is a review and detailed measurements of the Cambridge Audio Alva Duo Phono Pre-amplifier. It is on kind loan from a member who purchased it and drop shipped it to me. The Duo costs USD $299 and includes Amazon Prime or free shipping from the company itself. Despite its budget price...

www.audiosciencereview.com

 

[LTig]

The Duo tested very well here @ ASR if memory serves me correct. I will leave the answer to your question to somebody more knowledgeable regarding phono gear.

Any competently designed phono preamp will add significantly less noise than even the best and cleanest vinyl contains. I would expect the Macintosh to be such a design.

A simple test is to play your cleanest record at the highest loudness level you can handle. Then listen to the noise at a pause between tracks. Lift the arm and listen to the change in noise. If its level drops significantly you're good and a better preamp won't improve SNR.

 

[Abdo]

Any competently designed phono preamp will add significantly less noise than even the best and cleanest vinyl contains. I would expect the Macintosh to be such a design.

A simple test is to play your cleanest record at the highest loudness level you can handle. Then listen to the noise at a pause between tracks. Lift the arm and listen to the change in noise. If its level drops significantly you're good and a better preamp won't improve SNR.

Thanks for helping.
Yes, when I raise my arm the noise decreases, I did as you explained. Between the bands, raise your arm.
Now a doubt still persists, could the sound quality with pre-phono (Cambridge duo) be improved?

 

[LTig]

Thanks for helping.
Yes, when I raise my arm the noise decreases, I did as you explained. Between the bands, raise your arm.

Ok, then noise is no problem seeking for a solution.

Now a doubt still persists, could the sound quality with pre-phono (Cambridge duo) be improved?

I wouldn't expect it. You have to compare the specs for freqency response. The input capacitance might play a role as well if it is high (more than 100 pF).

Edit: I just read the user's manual of the MC6800. The specs are fine so far and the description of the phono preamp sounds like a very competent design. I would not expect any improvement in sound quality. You might need the Duo if you switch to a low output MC pickup.

 

[Abdo]

Ok, then noise is no problem seeking for a solution.

I wouldn't expect it. You have to compare the specs for freqency response. The input capacitance might play a role as well if it is high (more than 100 pF).

Edit: I just read the user's manual of the MC6800. The specs are fine so far and the description of the phono preamp sounds like a very competent design. I would not expect any improvement in sound quality. You might need the Duo if you switch to a low output MC pickup.

Thank you very much for your reply. What worries me most is buying a product and then it not improving as expected.
And here in Brazil it's not like in the USA where you can simply return it if you don't like it. It's quite complicated here. So that's why I have to research well so I don't spend money on something that won't improve. I appreciate your response.

 

[Wayne C]

Just bought one of these phono stage and headphone amplifiers could someone advise on this issue. Connected my High Output Moving Coil to the moving magnet input to listen via headphones but the volume is incredibly low.

The Phono stage specs says the following

Moving Coil input recommended 0.3 - 1mv
100ohm/100pf loading.
Sensitivity for Nominal Output
3.35mv MM
305uv MC

My cart is a Benz Micro silver which is 2mv output and 47 ohm loading

Does that mean this cartridge is incompatible with both MC due to being 2mv ( 1mv above the recommended ) and MM due to it being 2mv when the nominal is 3.35mv?.

On MM I can hardly hear anything at 75% of full rotation of the volume dial

Any advice please

 

[JeremyFife]

What happens when you connect your TT to the MC input?

 

[Wayne C]

What happens when you connect your TT to the MC input?

The volume increases with a bit of background hiss but it says recommend 1mv max on the moving coil input. Do you think I should look to getting an alternative!. As nothing can be altered on this phono at all?. With the sensitivity on MM saying 3.35 I guess my 2mv MC is too low?. Thanks for your help. I have always used this cart on MM on my other proper amplifiers?.

On MC it seems to be distorting a little to be honest?.

 

[JeremyFife]

Hopefully some of the other members with deeper experience of cartridge matching can help - out of my ken I'm afraid. Good luck

 

[lowdef]

The volume increases with a bit of background hiss but it says recommend 1mv max on the moving coil input. Do you think I should look to getting an alternative!. As nothing can be altered on this phono at all?. With the sensitivity on MM saying 3.35 I guess my 2mv MC is too low?. Thanks for your help. I have always used this cart on MM on my other proper amplifiers?.

On MC it seems to be distorting a little to be honest?.

Your cart sounds like it's in the no man's land of output - high output moving coil (I have one like this - Osawa Satin M18BX). Send the Cambridge back and grab something like the Schiit Mani. You can then tweak the settings to match. The MC stage of the Cambridge is all wrong for your Benz (impedance and max input voltage), and the MM input doesn't have enough sensitivity.

Schiit Mani 2 Review (Phono Stage)

This is a review and detailed measurements of the Schiit Mani 2 phono preamplifier. It was sent to me by the company and costs US $149. Naturally the unit looks like other Schiit products and seems to even have the previous Mani skin given the lack of "2" designation in the front. Fortunately...

www.audiosciencereview.com

 

[Wayne C]

Your cart sounds like it's in the no man's land of output - high output moving coil (I have one like this - Osawa Satin M18BX). Send the Cambridge back and grab something like the Schiit Mani. You can then tweak the settings to match. The MC stage of the Cambridge is all wrong for your Benz (impedance and max input voltage), and the MM input doesn't have enough sensitivity.

Schiit Mani 2 Review (Phono Stage)

This is a review and detailed measurements of the Schiit Mani 2 phono preamplifier. It was sent to me by the company and costs US $149. Naturally the unit looks like other Schiit products and seems to even have the previous Mani skin given the lack of "2" designation in the front. Fortunately...

www.audiosciencereview.com

Thanks for that information I will send it back appreciated , on MM you have to turn the volume control to around 95% of it’s travel just to get volume of a minute movement on the dial on my benchmark Dac. I bought the Cambridge as the headphone option was what I needed only as wasn’t using it to attach to main system. I just wish other manufacturers made a phono stage with headphone option like this but I don’t think there are any or at least I can’t find any?.

 

[lowdef]

Mobile Fidelity make one (UltraPhono), but you'd be much better off with the Mani plus a separate headphone amp of your choice.

 

[ivanj]

One might also consider the Parks Audio Waxwing; this has very flexible gain and loading. Or the Michael Fidler Pro solutions.

 

[LTig]

[..] on MM you have to turn the volume control to around 95% of it’s travel just to get volume of a minute movement on the dial on my benchmark Dac.

The Duo has a gain of 39 dB, a factor of almost 100, so with 2 mV input you get close to 200 mV on the output. This is 20 dB (factor 10) below the CD "standard" of 2 V.

 

[ivanj]

Thanks for that information I will send it back appreciated , on MM you have to turn the volume control to around 95% of it’s travel just to get volume of a minute movement on the dial on my benchmark Dac.

Which Benchmark DAC do you have?