C2500 static noise & upgrade to Auralic?
 

Hi All,
Late last year, one speaker started emitting static noise audible from 1 m or even from my listening position. After swapping all cables, plugging the power cord into the power conditioner instead of to the wall directly and substituting another speaker, and the noise is still there. A qualified McIntosh tech checked the C2500 and confirmed there were no issues to it. The tubes were fine as well.
What could be the cause? I am tempted to swap the original tubes for Gold Lions to see if this would solve the problem. How do you bias the new tubes?

This has also set me thinking whether I should upgrade the set to C2700 or the Auralic Altair G2.1. I loved the Mac tube/SS combo and on the other hand, need to upgrade my Node 2i streamer so the Altair seems like a good preamp/streamer combination option, especially with the excellent reviews I have read so far. I will likely have a home audition soon for this which will help with making a decision.

Does the C2700 have the same capability as the G2.1? The THD seems way higher.

Any advice please?

Have you tried to use a different amplifier ? Don't be so quick to blame on the C2500. Actually try to plug in a headphones to the C2500 first and see if you can hear that static noise.

Isn't the headphone section on its own discrete circuit? If so, that may not offer a true diagnosis. I second the suggestion to try a different amp if at all possible or bring your preamp to a friends house and see if it duplicates on his/her system.

Perhaps take it to your dealer and let them plug it into one of their systems.

Before you change components you should find the source of the problem. When you say "swapping cables" you should be also swapping channels. If it is the pre and one of its channels has become noisy, you should be able to move the noise from one speaker to the other by swapping channels.

Best

Charles

I agree with the others that you should diagnose first, shop second. When you get around to shopping...

Both the Auralic and the C2700 are fine components, but not really comparable. The G2.1 is a streamer/DAC with a preamp tacked on. The C2700 is primarily a preamp with a DAC tacked on--no streamer! The THD of the G2.1 is lower likely because it is SS vs the the C2700 tubes, so I would not use this number to compare the two. You really need to listen to both. You might also consider components that have less redundancy between them so that all your $ is going where it will serve you best.

Thanks for all your replies.

Yes I am going to bring my C2500 to the store to test if there is the same noise. Also will do a home audition of the Auralic if possible.

Fully agree both the C2700 and Auralic are designed for different purposes. Yes also agree C2700 is tube preamp and therefore the THD would be higher; probably sound more analog than digital SS preamp.

If I were to keep the C2500, what would be a good option for streamer? I think the DAC on the C2500 might be outdated.

I am almost exclusively ripped CDs, my only streamer is a Bluesound Node 2i, but this is not up to the caliber of the rest of your system. Aurender into a Yggrdrasil comes to mind quickly as a combo that would match your other components.

I brought my preamp to a store and it was hooked up to their speakers. The static noise was still audible albeit not as audible as on a BW diamond tweeter.
The store manager said this is normal and other tube preamps he had also had the same noise. Even when the volume was turned up and when the source was changed, the static noise stayed the same.
I have to get used to this from now.

Hmm - that doesn’t sound right to me…I had a c2500 some time ago hooked up to B&W speakers and never had an audible noise from the speakers. There are quite a few owners of Mac pre amps here who can share their thoughts as well but something seems amiss to me and the dealers comment about this being ‘normal’ may be true for noisy power delivery but not the pre amp itself from my experience at least…

Yes I wondered about that too. When I bought the set, I never heard the noise till late last year it started. Tried DeOxit on all the cables and it is still there. But on the D3s, the noise is clearer than other speakers.