C2500 static noise & upgrade to Auralic?

[PeterMusic]

Originally Posted by Exsg

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.

No disrespect to you, but...Baloney. A C2500 and B&W speakers should not have audible static. I'd find a new preamp...and a new dealer.

A bit more background on me--I had B&W 805s connected to my C22 (which I believe has identical architecture to a C2500 or C2600, less the DAC) and MC275 for 4 years.

[Exsg]

Originally Posted by PeterMusic

No disrespect to you, but...Baloney. A C2500 and B&W speakers should not have audible static. I'd find a new preamp...and a new dealer.

A bit more background on me--I had B&W 805s connected to my C22 (which I believe has identical architecture to a C2500 or C2600, less the DAC) and MC275 for 4 years.

I am really puzzled as well. I did not notice any noise before so there should not be any audible static. The unit was tested by an authorised McIntosh repairer who was deemed one of the best in the country and came back with no issues with unit or tubes.

I swapped the D3s to my 805s and the static was still there but much less audible at the same volume. I had to go much nearer to the speaker to hear it. As mentioned before, the static noise is the same regardless of the gain volume.

Don't wish to let go of the C2500 unless it is to upgrade to C2700 but this latest model is around 3 years old now too. I think it might be better for me to upgrade to a streamer dac instead.

[Thedo]

I also have the C2500 going to the MC501s or the MC275 VI depending on my mood and I hear absolutely Nothing when there is no music. BTW, my speakers are Sonus Faber Amati Anniversario

[W9TR]

Some simple troubleshooting is in order. No need to go to a store or buy new stuff. Although buying new stuff is always fun!


Swap interconnects left to right between the preamp and power amp. Does the problem move?

If yes it is the preamp or something connected to it. If no it is the power amp.

Disconnect everything from the preamp and turn the volume all the way down, but leave the preamp connected to the power amp. Is the noise still there? If yes it is the preamp. If no, it is something connected to the preamp. Reconnect each item until you find the offending one.

If yes, buy a replacement set of tubes or better yet swap unused tubes (for example from the MM or MC phono section, whichever you are not using) into the noisy channel and see if the problem goes away. If yes, it is a tube. If no then get the preamp serviced.

It is most likely a tube - they get noisy and fail all the time.

Happy hunting,

Tom

[Levitator]

Good advice [emoji106]

[Exsg]

Yes I have tried that before. Unplugged everything. The moment the preamp is connected to the mono amp, the hissing starts.
I think it is the tubes too but I am puzzled the tech said the tubes are fine and need not be replaced. I wonder if he cleaned the contacts for the tubes but he is an expert.
In which case, if I replace the tubes, should I go to Gold Lions or change back to the stock tubes?

[Cohibaman]

I had a similar noise problem with my C2300. I could actually watch the preamp and amp needles move.

It turned out to be an APC uninterruptible power supply I’m using on my salt water fish tank. If I unplug the UPS, the noise goes away.

[W9TR]

Originally Posted by Exsg

Yes I have tried that before. Unplugged everything. The moment the preamp is connected to the mono amp, the hissing starts.
I think it is the tubes too but I am puzzled the tech said the tubes are fine and need not be replaced. I wonder if he cleaned the contacts for the tubes but he is an expert.
In which case, if I replace the tubes, should I go to Gold Lions or change back to the stock tubes?

Gold Lions are a safe bet and likely less expensive than the original McIntosh tubes. If you are not using either the MM or MC Phono Preamps then you may be able to swap in those tubes to see if the problem goes away.

Tube testers don’t check for noise or microphonics so it’s likely the tech tested the tubes and they checked out fine.

[Exsg]

Originally Posted by W9TR

Gold Lions are a safe bet and likely less expensive than the original McIntosh tubes. If you are not using either the MM or MC Phono Preamps then you may be able to swap in those tubes to see if the problem goes away.

Tube testers don’t check for noise or microphonics so it’s likely the tech tested the tubes and they checked out fine.

Can I swap the tubes myself? Does the tubes need biasing? How do I know which tubes to swap?
I have Prima Luna as well and it was easy to change.

[Thedo]

Originally Posted by Exsg

Can I swap the tubes myself? Does the tubes need biasing? How do I know which tubes to swap?
I have Prima Luna as well and it was easy to change.

Yes, you can swap the tubes yourself. Just need to be patiently remove the top cover and remove the tubes. You can do a search on this site or on the web to find out the exact steps needed to do so. Normally, you do not need to adjust the bias after you swap or replace the tubes in your C2500. I swap in and out different tubes brands in my C2500 quite a few times and I did not need to do anything afterward. My C2500 still sound fine and there is no noise at all.