[Alcophone]

Was there any information about what is different on the new PCB? or is this being chalked up to a bad component and not a design change?

Burson had a bad batch of PSUs that supposedly damage the boards, so in my case I'm getting a PSU and a PCB. But the review unit's PSU is fine, yet that unit buzzes as well, so I'm not convinced by that explanation.

Either way, there are already some differences in parts between the review unit and the one I bought.

Review unit (with Sparkos opamps):




Unit bought around Black Friday (with V6 Vivid opamps):

 

[raoultrifan]

Look about the same to me, just the polymer caps might be a different brand, but still same values, so...not sure what would be the differences then?

 

[Alcophone]

Look about the same to me, just the polymer caps might be a different brand, but still same values, so...not sure what would be the differences then?

I just noticed that some parts are different, but that's probably supply based. The board revision is the same. The biggest difference that I can see is that the capacitors (I'm assuming) below the RCA input and output (and the other ones of the same size) are marked as 25 V in the review unit and as 16 V in the new unit.

I'll post more pictures when I get the replacement PCB. Nothing I've been told indicates that there has been a board revision.

The PSU is a different one, though. Basically a 6 A version of the PSU that came with my review Bang.

Left: review unit, right: bought later

 

[Asahi Templar]

When I asked Burson about the noise issue they said it was an effect of the Max Current Power Supply. It has a hum around 60hz when powered on that gets pushed up to 170khz as it warms up making the noise go away. Its interesting that some people dont have the hum at all, perhaps it depends on the electrical setup in your home rather you get it or not. I didnt have the hum with the Play when I had it, only the Fun had it.

Will be interesting to see if newer PCBs eliminated the issue all together. I have a Playmate coming in the next few weeks which has even more MCPS than the Fun does so I will find out if it has the hum issue as well.

 

[Alcophone]

When I asked Burson about the noise issue they said it was an effect of the Max Current Power Supply. It has a hum around 60hz when powered on that gets pushed up to 170khz as it warms up making the noise go away. Its interesting that some people dont have the hum at all, perhaps it depends on the electrical setup in your home rather you get it or not. I didnt have the hum with the Play when I had it, only the Fun had it.

Will be interesting to see if newer PCBs eliminated the issue all together. I have a Playmate coming in the next few weeks which has even more MCPS than the Fun does so I will find out if it has the hum issue as well.

Both the Bang and the Fun have 4x MCPS, but there was no buzz that I noticed with the Bang (speakers instead of headphones, so maybe irrelevant).

While the buzz is less likely to occur when power cycling the unit after it has been running for a while, being able to fix it within seconds by inserting and removing a 6.35 mm to 3.5mm headphone adapter suggests it's not a temperature issue - although that trick didn't work with the unit I bought, only with the review unit.

The buzz happened at work, at home in the bedroom, and in the living room, with both a Furman PST-8 and an Audioquest Niagara 1000, over the course of several weeks. So I don't think it's related to power either.

When I contacted Burson's support email about this on November 18th, I was told "But it does seem to be a strange issue we have not had anyone else reported this issue yet."

 

[bunkbail]

Left: review unit, right: bought later

The one on the right is the same one as mine, doesn't work from day one. I'm still using the molex connector from my PC.

 

[raoultrifan]

In my review here: https://www.head-fi.org/showcase/burson-audio-fun.23238/reviews?page=2#review-20722 I was able to get some spikes coming from 50Hz mains and 2nd and 3rd harmonics...etc., but all are below -100dB, so definitely inaudible. I've also test FUN with 16 Ohms IEMs (100dB sensitivity) and heard no hum at all. Would you mind taking a RMAA and ARTA test to see exactly what's the frequency FUN is throwing on the headphone-out plug?

Meanwhile, I'll try to replicate your sort of defect on my FUN, but not sure I'll be able to. However, I'll use my scope and measure the +/-17V rails, just in case I can spot some strange spikes.

Technically, 50/60Hz should not be there, unless there's a ground issues (polluting ground or ground loop) or it gets induced by the surrounding cables. The MCSP works way above the audible range (>150 KHz) and even some of the lower harmonics might, hypothetically, get injected into the audible band, it will never hit the 50/60Hz noise, instead it will be somewhere between 10-20KHz (if any!). So RMAA and ARTA might help here, but please do a loopback first, then measure the FUN, so we can compare the hum noise induced from the surroundings with the noise from FUN's headphones-out.

Signal/Noise Ratio (50 Hz hum nose is lower then -102 dB)
​

I sill do again this above test, loopback vs. FUN, just to see if I can spot same issue on mine, after playing a lot with POWER-ON and POWER-OFF, then plug/unplug the headphones, like some said here that might "help" in getting the defect to manifest.

 

[Eiffel]

That remembers me the high amount of hum I had with my first Play unit - they changed it later with a different revision one.
I suspected mostly the PSU brick as with it I got biggest hum. Connected to PC - even with the worst PC PSU I had, the hum was barely audible. But I was unable to use different brick, even a more powerful one.

 

[raoultrifan]

I only had noise with V1.6 of PLAY with really sensitive cans (16 Ohms IEMs, AKG K550, Beats Solo 2). I got no noise with Grados, AKG K701, Byerfdynamic DT880 (600 Ohms), HE-560, T50RP-mk3. However, there are lot of amps not being compatible with sensitive cans, but I'm glad PLAY V2.1 and higer did fixed that. I do hope the FUN issue will get fixed, too bad I can't replicate it on mine (or too good, depends how you see this).

 

[DjBobby]

No noise at all on my Fun, dead silent after the powers switch climbs up to 170Khz.
With the Play there was some digital noise and whining. Probably the dac section was too close to the analogue, or not enough shielded because the noise was also present through RCA line out.
I have a feeling that the Swing paired with the Fun could be my end game for long time.

 

[raoultrifan]

I was able to do some in-depth tests today to mu FUN and found no hum-noise, not even with my 100 dB sensitive 16 Ohms IEMs. However, with volume to the max. there's a slight background noise, somehow similar in amplitude with Objective2 with a gain of 2.5-3X.

Instead, I found an interesting thing: RCA-outputs are a little bit suffering of 230V mains hum injections, but in a very small amount of less than -110 dB, so definitely inaudible, unless connecting a very powerful speakers amplifier with volume to the max.

Could you please confirm the noise you guys hear is there only on the 6.3mm jack and without any device connected to the RCA plugs (IN & OUT)?
Also, if you touch the 6.3mm metallic plug of your headphones, if the hum-noise decreasing/increasing in amplitude?
Is the noise still there is volume to the min. and no RCA cables connected to IN or OUT of the FUN?

FUN RCA-max-volume: power outlet vs. isolation transformer
(50 Hz and few of its higher harmonics are present when powered directly from mains, but inaudible to normal listening levels)


FUN headphones-max-volume: power outlet vs. isolation transformer (not much difference)
​

 

[escalibur]

I wonder if with no inputs connected and volume to the min. the same noise is still present. If not, try increasing the volume (no input source connected) and see if noise appears.
If still noise, perhaps a new PSU might help? Maybe a computer desktop +12V to try out?

It's odd because I have absolutely no noise with FUN nor with BANG. Fan tested with 100dB sensitive 18 Ohms IEMs, BANG tested with 90dB/mw/1m speakers.

I've received replacement PCB from Burson and now my FUN works as it should. Old PCB definitely had some contact/ground issues as the AMP was working well if you were lucky enough to eliminate the noise with switching it off and on in addition to PSU barrell roll.

Now I will take some time to get to know this beast before writing my FUN review.

 

[raoultrifan]

@escalibur is it the same PCB version? Are you able to spot any differences?

When I asked Burson about the noise issue they said it was an effect of the Max Current Power Supply. It has a hum around 60hz when powered on that gets pushed up to 170khz as it warms up making the noise go away. [...]

I was able to see those 50 Hz and higher harmonics with my scope, but it only lasts for 2-3 seconds or so.

 

[Alcophone]

New PCB and PSU. Will try tonight.



Guess where the PSU was.

 

[raoultrifan]

I can't spot any differences, same PCB rev., same components values...odd. However, I'm glad issue has been resolved.

BTW, can't remember if the noise was still there with the old PCB if NE5534 were installed, instead of solid-state opamps.

Glad issues have been resolved!