burn in Beresford dac noise

[admin_exported]

Taken the plunge and got a Beresford DAC 7520 with the op amps upgrade.

Out of the box it's pretty impressive as it streams Spotify from my laptop to my amp which is what I wanted

The sound both in dynamics and detail can't compete with a Naim CDP , but I have to say that with only a few hours on the clock , , the Dac is punching well above it's weight and of course it gives unlimited access to a range of music on the internet.

But there are some early questions

a) Should there be the nosie of what sounds like signal interference and hiss coming from the speakers when I plug the usb into the laptop This noise disaappears when the music starts streaming , but it's disconcerting because I supsect it's still there, only the music has obscured it . Do I have some wires crossed OR is this a normal feature or is it a burn in issue ?

b) why is the gain on the dac small in comparison to the native sound coming from the CDP ie I have to turn the volume dial up to enjoy the same power as comes immediately from the CDP

c) I've got an upgrade PSU but before exchanging it for the supplied unit I need to know what this means on the instructions " please ensure that you select the correct polarity for the device to be used "

Here's to the magic of the dac

 

[PJPro]

peebs:

a) Should there be the nosie of what sounds like signal interference and hiss coming from the speakers when I plug the usb into the laptop This noise disaappears when the music starts streaming , but it's disconcerting because I supsect it's still there, only the music has obscured it . Do I have some wires crossed OR is this a normal feature or is it a burn in issue ?

This won't be burn in. An earthing issue maybe.....although this is usually described as a hum rather than a hiss?

peebs:

b) why is the gain on the dac small in comparison to the native sound coming from the CDP ie I have to turn the volume dial up to enjoy the same power as comes immediately from the CDP

Which line out are you using on the Beresford?

peebs:
c) I've got an upgrade PSU but before exchanging it for the supplied unit I need to know what this means on the instructions " please ensure that you select the correct polarity for the device to be used "

Does the PSU have a number of connectors which can be orientated such that the inner or outer contact of the DC power connector is live? My 7510 is positive on the inner connector...but double check for the 7520.

 

[Anonymous]

Thanks - so if it's an earthing problem what's the answer ? Hum / hiss ? Both and . .. I can even hear the mouse click when there's no music streaming. But when the music is playing - it;s heaven .

Line outs I'm using on the Beresford , 2 x rca ( Chord crimson ) from the L and R channels in the pre amp section to the rca inputs on the amp tape

Your third question stretches me ! The upgrade has a number 8 in total of power " tips " , there's also a " set voltage before use " on the psu

The instructions say that I will find a +/- symbol by the power supply unit . So I had a look at the Beresford supplied unit and saw this legend on it - c + . So that's all the stuff I think is relevant .

Do I simply swap the existing unit from the socket in the wall to the bac of the dac with the new one . Maplins are selling it . Switched Mode AC TO DC for general use 5/4A multi voltage

 

[PJPro]

I've got that power supply. I seem to remember getting a reply from Stanley on another forum where he stated that the standard PSU which comes with the 7520 is different to the one he used to ship with the 7510 and better than the Maplin PSU he recommended as an upgrade.

I've found the quote for you. Here's my question and Stanley's (forum name-Sensimilia) reply....

Posted by Sensimilia
Posted by PJPro
Stanley recommends a 12V, 5A, switched mode power supply (from Maplins) as a potential upgrade. Does the 7510 really need this much juice? If not, what is the requirement in terms of current?

I assume it is the 5A capability that leads you to make that conclusion? It never even crossed mind. A better choice than the Maplin's is an upgrade to the TC-7520 power supply. The DAC only needs less than 300mA.

So, if I were you I'd take the Maplin one back.

 

[Anonymous]

Thanks , I've been talking to Stanley overnight and this morning. He's very helpful .

I think you've got the measure of the psu stuff. The supplied psu with the 7520 is better than the 7510 which does improve that model Beresford.

But whether it's better than the Maplins one or identical to it,is I guess a matter of small margins and voltage current etc

However that's not what continues to bother me.It's the irritating noise/ hiss/buzz/ interference which remains a mystery !

It's not spoiling in any way listening pleasure once I've got the volume dials balanced.

Basically every time I plug the usb into my laptop which is hooked up to the dac and my stereo amp I get this " noise " . It goes or rather is obscured and not heard when the volume control on the dac takes over from the amp volume control . But increase the amp volume without compensating with the Dac volume control and you can hear it . In other words the lower the volume on the dac control the greater the noise through the speakers. This is frustrating because I want to squeeze more volume out of the stereo amp- the dac volume only gets me so far. Anything passed 12 oclock on the amp volume and I can catch the noise so I crank up the dac volume.

When the streamed music quietens or changes track the noise is obvious.

So it seems to me that questionably a) the beresford is designed to boss the volume game which limits the loudness to the limit of the dac not the amp ?

b) Internet streamed music may have this element to it - the sound quality and signal is compromised in some way ?

c) When I exit Spotify or Windows Media altogether - the noise comes back big time ! Disappears when I turn the amp volume right down or the dac volume right up. It's as if there is a radio frequency noise ( that's a laymans attempt ) which fills the vaccuum created by the digital interface between the laptop , through the dac, into the amp and speakers

It's odd because even the optical mouse " squeaks " when I move the cursor like now over the screen !

BTW I don't get any noise problems with any other inputs/ outputs and I'm running a Tuner, the CDP, and I touch through the amp with peerless sound transmission.

I' ve tired isolating the devices causing trouble - ie the dac and laptop , by plugging in their pwoer supplies directly to the wall rather than running them off a block .

Final thought. I haven't fully explored this yet - I need to get a life . I will try the whole system through my pc.Maybe the problem is with the laptop- usb connection to the dac and will not be there with my pc.?

In the meantime , I'll go to Maplins !

Cheers and do feel free to comment .... any one else out there who is having to readjust expectations and live with this minor irritation.

Once the music is streaming and the dac volume is in control , it's heaven !

Peebs

 

[chebby]

I use the TC-7520 fixed output. (Not controlled by DAC's volume knob.)

I also use USB (to laptop) and get no hiss/hum/buzzes or anything similar with music playing or without.

I have turned the volume up high (with nothing playing) on all sources - including the DAC - to test for noise in the past and been satisifed there is none. (I do this whenever I buy a new component.)

Maybe your problem stems from a noisy laptop power supply. Mine (despite being a switched design) is evidently very well behaved. Mine is the standard Dell laptop PS with the rounded ends.

Try unplugging the laptop PSU completely at both ends (run laptop from battery) and see if the noise ceases.

 

[PJPro]

chebby:
Try unplugging the laptop PSU completely at both ends (run laptop from battery) and see if the noise ceases.

Yeap. That'd be my first suggestion.

 

[Anonymous]

to Chebby and the Pro - a thousand thanks , something so simple as that has done the trick ! No noise ....

But what do I do when the laptop battery runs out ! Do I need to get a quieter psu for the laptop and if so how ?

Still one unresloved issue and that is why the Dac volume control has to be at 9 o clock before the amp volume takes control ?

 

[Anonymous]

Chebby you are a genius ! And also a man of good taste as much of your signature system is my aspigrration .

I 'd argue with you about the speakers . I demoed pmc db 1's with the Nait xs and the CD 5X - I was blown away by the sound.

The XS has all the old virtues of Naim but adds a warmth and colour .

Bass extensions were remarkable from the dinky boxes , vocals were clear , separation was better than from the Nait 5i and CD 5i which I have also heard .

And yes I think such a system deserves better speakers than the DB 1's .

Overall the jump from Nait 5 i Cd 5 i is not massive but it is significant and the Xs , CD 5X upgrade and versatility path makes it the way to go if you are into Naim but sensibly so !

Having said that , the differences between the system I've got - B and W 685's Denon 2309 with the ASDW 3 network wirless dock and the CDP from the Pana BD 35 ( plus now the Dac ) ; and these others is not 2000 worth of difference IMO

I too got the op amps upgrade from Stanley on the strength of your forum comments , along with others. But why does nobody appear to review the 7520 and compare it with the Ca Dac Magic? With the small upgrade the 7520 is still cheaper than the Dac Magic and I wouldn't be surprised if it's just as good .

Any way , tell me what is the fixed out put on the Dac which you are referring to and why might there be part of the answer to my problem ?

BTW - liked your recent " ear " piece and the " rant " of a couple of weeks ago on the old OPPO blu ray !!!

 

[Anonymous]

Just a quick thought on this - given that you and Chebby have solved my noise problem -

could I use the Maplins psu for my laptop ?

 

[PJPro]

peebs:
Just a quick thought on this - given that you and Chebby have solved my noise problem -

could I use the Maplins psu for my laptop ?

Maybe. But then again, maybe not. You have to match the PSU to the voltage and current required by the device you wish to power.

I suspect your lappie will require more volts than the Maplin PSU can supply. Moreover, your laptop may require AC rather than DC.

 

[Anonymous]

probably not then ? but it does need resolving and preferably without the need to buy a new laptop !!

 

[PJPro]

No probably not.

Not sure what to suggest really. What did Stan say?

 

[Anonymous]

Stan told me to turn down the digital volume on the laptop

so you guys went one better - take the power supply away !

But it's not a long term solution ...

 

[link]

peebs:
Any way , tell me what is the fixed out put on the Dac which you are referring to and why might there be part of the answer to my problem ?

there are two outputs at the back of the dac, one is variable which can be used as a pre amp and volume control dependant of the dac itself and the other one is fixed which is not controlled by the dac volume knob but solely by the amp.

 

[PJPro]

peebs:
Stan told me to turn down the digital volume on the laptop

so you guys went one better - take the power supply away !

But it's not a long term solution ...

No, you want the volume on the PC up to maximum.

Use the fixed output, as suggested in the previous post.

Then you need to try and identify a quiet power adaptor. Any luck, someone else will have done that already.

Please post the make and model of your laptop and the details on the PSU provided with it.

 

[PJPro]

Alternatively, you could try something like this.

Or, use an optical connection between your laptop and DAC.

 

[PJPro]

But I can't be 100% that either of these will fix the noise.....I'm assuming you have a ground loop problem.

 

[PJPro]

Or there's this.

 

[PJPro]

Another option is to remove the earth/live wires in the USB cable. You don't need this as you are not powering the device you are connecting to through the USB cable.

See this thread for details.

You might even be able to a USB cable without the power wires?

 

[Anonymous]

Thanks for hanging in there on this with me !

I have gone for the fixed option- stronger and immediate volume . Still getting all the sounds of mouse click, misrosoft sounds and of course the " buzz " - all of which goes when I take away the laptop psu ac adapter (!) and go battery .

Have contacted Asus the laptop manufacturer about replacement psu and a battery .

For your interest the Model is WJC 2 001P and the AC adapter is ADP90SB BB.

I've googled the models and found similar but not exactly compatible units for the adapter psu. Can't track a battery match.

I thought of the optical connection - do I take the SPDIF out from the front of the laptop to the equivalent input on the dac ? what 's the exact cable I need ?

What if I have the same problem - because I still need to power supply my laptop and don't want to drain my battery all the time !

Thanks

 

[PJPro]

The optical approach should eliminate any electrical connection....so no ground loop (assuming that is the problem). For a direct connection between laptop and DAC your laptop needs to support SPDIF.....this is usually through the headphone socket.

If it does support SPDIF, then you'll need a Toslink cable with a mini Toslink adapter. If it doesn't support SPDIF, then you could go for a usb to optical adapter like this and then connect this new device via a toslink cable to the DAC.

By the way, why do you want to change your battery?

 

[Anonymous]

why would the optical approach solve the grounding problem ? I still have the psu adpater which I think is the cause because .....

my battery is not re charging properly and it only has 3 hours at max - when you are on the internet for a few hours its draining !

 

[chebby]

Try plugging in the laptop PSU to a different extension and wall socket than the hifi & DAC.

Also I suggest getting a Tacima CS 929 extension for your hifi. (But as I suggested, plug the laptop PSU in somewhere else.)

[Edit] I have posted this alternative to your laptop PSU on your other thread. It has the same output (19V, 4.7A, 90Watts). It may clear things up a bit.

 

[PJPro]

peebs:
why would the optical approach solve the grounding problem ?

With an optical connection there is no shared ground, i.e. there is no electrical connection. It's simply light.

But try chebby's suggestions first.