Why my system becomes dull after sometime?

[sbenyo]

I am using a very good stereo setup: Accuphase P-300 with C-200 pre (both restored). Yamaha NS-1000 speakers (Clearday cables). All connected by sablon power cables to a ISOL-8 conditioner.

The DAC is connected to a PC using the sablon usb elite cable.

 

When it is at best the sound is just wonderful!! Every single note is clear and vibrant with crystal clear highs, amazing mid and very tight accurate bass (not booming).

 

There are some situations where the system become dull, like it is under fog. The bass becomes exaggerated, highs are not crystal clear and everything loses the sparkle I am hearing now.

 

I am not sure what causes this. It can happen without doing any changes and with no specific reason. I turn off the all system components every day except the ISOL power. Initially I suspected there is a power issue, so I upgraded all power cables and added the ISOL but this still happens. For now when it happens I try to disconnect everything include the ISOL for a few minutes. I am still not sure this resolves the problem, but after playing with some components on and off I am able to get back to perfect sound. The sequence is not yet clear to me.

 

I wonder if anyone experienced similar issue. It is really annoying because I don't really know what is the root cause and if the voodoo of disconnecting everything is the right thing to do (not sure if it helped in all situations). I don't mind having this issue as long as I knew what is the right solution to immediately resolve it when it happens.

 

[fas42]

A very familiar problem ... I suffered from this from a system that performed extremely well, 3 decades ago, and used the same technique to resolve it - I never properly solved what the precise cause in that case was, but I suspect very strongly that there was a buildup of static, somewhere, that was resolved by switching off - and switching back on again.

 

What to do about it ... ? Impossible to say unless one knows every possible detail of the rig, how it's set up, and the surrounding environment ... what I would do is very, very methodically, try altering only a single thing at a time - like switching off only one component, letting the supplies drain, switch back on again - has the problem cleared? Do this step by step, for every part of the system, and see if you can isolate the, hopefully, single item that alters the SQ back to normal.

[Account Closed]

Unless this happens with the exact same piece of music (and I do mean exact), it would be impossible to even say that there is anything wrong at all. If you are streaming and especially if there is wifi used anywhere in the chain, I would suspect network congestion issues to be the problem especially now with networks strained due to so many people working from home and kids at home all using the networks heavily. Also, try removing the power conditioner completely and just use a power strip.

[soares]

It happens. Not sure why, but I guess it is related to electric pollution. At night it happens rarely.

[One and a half]

8 hours ago, soares said:

It happens. Not sure why, but I guess it is related to electric pollution. At night it happens rarely.

I would agree.

@sbenyo , Take a note of the times when the music turns sour., random or during the day?

 

There's elements in the power conditioner that react with audio components and the line to create some very woolly effects, the swiss cheese effect and could do more harm than good.  The Accuphase devices have very little in the way of noise generating DSP actions and are classic amps that don't do that. 

 

Next step is to clean interconnects and connectors on the pre and power amp, and internal switches with Deoxit. It's unlikely the switches are wearing out, but are susceptible to dust entry, and that could also cause SQ problems from one moment to the next. My E-205 needs attention to the selector switch fairly regularly, the sound drops off or  just sounds 'off'.

[Killahertz]

I suspect a relay switch (probably in your amp) needs to be disassembled and cleaned with deoxit and fine sandpaper.  I just had to do this with one of my amps.

[ripples]

12 hours ago, sbenyo said:

connected to a PC

Instinctively i would worry about the PC (source) then go down the pipeline. Dont know if its online per wifi or cable (tidal/qobuz..) or local files and which player outputting to your usb ..anyway  when it happens see what you can analyze there. (reboot a pc or wifi is easy)

[davide256]

The fact that the problem goes away after a few minutes of idle time does sound like a possible overheat issue. Is the equipment,

in particular the amplifier, well ventilated?

Closed cabinets are a bad idea for hot running audio gear.

[sbenyo]

Thanks for all the suggestions!

 

Just to know, this has been like this for long time (more than a year). I did replace many things that I suspected on the way and it is still happening. All the power cables replaced and power conditioner was added just because I suspected there is a power issue. It happened before and still happening now so I don't think they are the problem.

 

Once I get it working well, I works like this for a few days, sometimes a week or more and then it happens again until I unplug everything and connect everything again. Strangely, the problem is not always fixed when everything is disconnected. Maybe I have to wait a bit for everything to drain or I did not disconnect all cables properly (not just the main power). 

 

I do tend to think this is related to the either the amp, pre or DAC. Next time this happens I will try to disconnect (and wait enough) only one component at a time to try and pinpoint the problem. It may also be there is more than one component affected.

[Killahertz]

I would put money on the output relay needs cleaning or replaced.

[davide256]

58 minutes ago, sbenyo said:

Thanks for all the suggestions!

 

Just to know, this has been like this for long time (more than a year). I did replace many things that I suspected on the way and it is still happening. All the power cables replaced and power conditioner was added just because I suspected there is a power issue. It happened before and still happening now so I don't think they are the problem.

 

Once I get it working well, I works like this for a few days, sometimes a week or more and then it happens again until I unplug everything and connect everything again. Strangely, the problem is not always fixed when everything is disconnected. Maybe I have to wait a bit for everything to drain or I did not disconnect all cables properly (not just the main power). 

 

I do tend to think this is related to the either the amp, pre or DAC. Next time this happens I will try to disconnect (and wait enough) only one component at a time to try and pinpoint the problem. It may also be there is more than one component affected.

The problem may also be outside the stereo entirely... next time it happens see whats running electrically, pay particular attention to heaters, hair dryers, etc.

[fas42]

5 hours ago, sbenyo said:

Once I get it working well, I works like this for a few days, sometimes a week or more and then it happens again until I unplug everything and connect everything again. Strangely, the problem is not always fixed when everything is disconnected. Maybe I have to wait a bit for everything to drain or I did not disconnect all cables properly (not just the main power). 

 

I do tend to think this is related to the either the amp, pre or DAC. Next time this happens I will try to disconnect (and wait enough) only one component at a time to try and pinpoint the problem. It may also be there is more than one component affected.

 

Yes, try and be as methodical as possible with trying changes. And even though this may be very hard to do, try and keep track of what may have done during the period prior to the SQ going off, even though the link to how the rig is performing may seem very tenuous - as people have noted, particularly pay attention to whether some electrical device, no matter what type, may have been activated, or its status changed.

 

Also, be completely consistent with how cables are organised - don't change how they are lying or arranged any more than necessary to disconnect and reconnect.

[One and a half]

Another possibility is a small signal transistor on the fritz.  As to which one is a methodical process.

[sbenyo]

There are some interesting insights. Heat can be an issue. I stack the amp and pre on top of the other so heat might be an issue.

I also believe that it may be relay switch and some cleaning may be needed. When this will happen again I will try to be very methodical on what I do to resolve it going component by component. Once I will be able to identify which component is problematic it may be easier to focus on the problem itself.

[sbenyo]

I have to say that since this last happened a few days ago, I am having the best sound I had from the system. Everything opened up and sounds crystal clear now. I hope it will stay like this and I won't have to go back to search for the problem. My magic sequence for now is to shutdown everything every day and before starting take the main electricity out for short time and then plug it back in.

 

If anything will change I will update...

[sbenyo]

I think I have enough ventilation. Currently the preamp is on top of the amp. This is not an unusual setup.

I don't have space to put them side by side. Maybe it will be better to switch so amp will be on top if this amp need more ventilation.

 

[EvilTed]

@sbenyo

 

Do you have vertical space?

You could try adding some anti-vibration pads between the pre and power, which will lift them up a bit.

Another solution which works very well for cooling between components is one of these.

I own one and used in a previous incarnation when space limited and had heat issues.

 

https://www.amazon.com/gp/product/B078PQJSRY/ref=ppx_yo_dt_b_asin_title_o07_s00?ie=UTF8&psc=1

 

This model that exhausts to the front is quieter then the ones that exhaust to the rear.

This model can be set to a pretty low fan level and still cool effectively.

I could never hear it in place while music was playing.

 

I'd get a thermometer first and check the temperatures.

They are around $20 on Amazon.

[sbenyo]

@EvilTed, I was just looking for feet solutions to increase the space between amp and preamp. I think this can help.

 

@Davide256, The system is not in a cabinet so I think it's quite ventilated, maybe except for the components on top of each other.

 

[davide256]

1 hour ago, sbenyo said:

@EvilTed, I was just looking for feet solutions to increase the space between amp and preamp. I think this can help.

 

@Davide256, The system is not in a cabinet so I think it's quite ventilated, maybe except for the components on top of each other.

 

Thx for the  picture. Consider some maple shade iso blocks  to raise the amp off the floor and/or separate the pre from the amp

for good ventilation + vibration isolation. Sets of 4 run $36 each.

 

https://shop.mapleshadestore.com/Mapleshade-Isoblock-Sets_p_1224.html

 

[fas42]

Yes, consider doing something that separates the the three components that are stacked on top of each other, starting with the amp, so there is distinct vertical separation between them - I would experiment with what I used to make the separation happen, and with ways to minimise vibration perhaps causing issues.

[GregWormald]

While the "stack" might not be unusual, IMO it is entirely likely to cause heat problems. 

Really, you need to get them separated more. 

As an experiment, put some spacers (maybe small blocks of 2"x4") between the components and then blow some air at them with a fan.

[Audiophile Neuroscience]

There are two time honored methods of fixing flaky electronic devices. a) Reboot by powering on/off. b) Boot, by kicking the device. While B sometimes works I can only really recommend A 😅

[Audiophile Neuroscience]

The conventional wisdom would be power supply issues and I'm not sure this has been as yet eliminated simply by adding a power conditioner (depending on how effective it may or may not be). I would adhere to the advice given about establishing associations or possible links to other electrical components running.

Re overheating, I have an infrared hand gun that reads out the temp of each component, including any part within the pc like sound card etc.

Pschoacoustic variation in pereption is another possibility but that would appear unlikely from your description of unplugging/replugging.

 

If overheating is eliminated and there appears no obvious power issue (like only when air con is running), my money is on your pc

[EvilTed]

Electronics, especially solid state sound and perform better if left on 24/7.

They will last longer too.

 

Tubes sound better turned on the morning you are going to listen and to my ears with my system, only get amazing after 1 hour or so of use. Some people say that heater voltages fluctuate a lot within the first hour, so I'm not sure.

 

Also get yourself a digital thermometer which reads with a laser.

That way you can measure the temps when things suck and then check the specs.

I wouldn't place a preamp on top of a power amp, if I could help it.

Too much EMI.