[raoultrifan]

@belgar, I assume you did changed the USB cable, right?

Given the input received from @belgar, I left my CV2+ for about 4 hours powered ON, then I took my middle finger, I mean "digital" thermometer, and started doing some temperature measurements inside the CV2+. One thing's for sure, the inside air is not moving, because there're no holes and not ventilation with the outside, but it should not exceed 40C inside (25C room temp.). I found the ESS chip to be warm-to-hot (it wasn’t over 50C, out of the max. 70C recommended by manufacturer) and the PGA2310 pretty hot (above 50C for sure, but below 70C). The XMOS chip was only warm, below 40C, so there's absolutely nothing inside the transport card to overheat for sure.

So from three chips tested I got, from warm to hot: XU208 (estimate 40C) < ES9018S (estimate 50C) < PGA2310 (estimate 60C).

However, just to be 110% I’ll be on the safe side in the future, I installed three heatsinks inside the CV2+: one on the XMOS transport chip, the second one to the ESS DAC chip and the latest to the TI volume control chip.

vs.

vs.

Of course, this is not a recommended mod, because I wasn't able to identify any overheating components inside CV2+ and @belgar found no root-cause for his issue yet. This mod it's just fun to do it, nothing else.


Now that I took out the transport and DAC boards, I got some more pics and a bit of detailing with what I found inside:

On left of board, ST LD1117 linear power regulators for 1.2V and 3.3V for the DAC chip: https://www.st.com/resource/en/datasheet/cd00002116.pdf, on top the 0.1ppm 100 MHz TCXO

Foxconn USB connector, the SO8 chip M25P40 Micron flash memory on top: https://www.micron.com/~/media/documents/products/data-sheet/nor-flash/serial-nor/m25p/m25p40.pdf, the well-known XMOS XU208 chip (U30870C10): http://www.xmos.com/download/private/XU208-128-TQ64-Datasheet(1.9).pdf and the three quartz:24.000 KHz, 24.576 KHz and 22.570 KHz .

I see no data isolation between the XMOS chip and the 5-pin header connected to DAC board (probably the the I2S), so any kind of USB protection placed in front of the USB plug might help in preventing unwanted jitter increase or power spikes while plugging/unplugging USB cord, but also when powering the device ON/OFF (or the attached computer). Ground loops might also be lowered, if exists, by using a device in front of the USB plug. By "device" or "protection" I'm referring to something like Schiit Wyrd or a similar and cheap equipment, but even a decent HUB with it's own power adapter could help as well (not the cheapest one), even if the transport chip takes the power from inside CV2+. A simple HUB root in front of the USB transport might minimize USB noises coming from the computer and will decouple somehow the transport from the computer. However, this is not an USB isolation, at least not for the data lines. However, such a device might not improve anything in the audio chain, so it’m more like a nice-to-have actually (mostly for those with ground-loops).

The ES9018S 8-channels DAC chip has a DNR of 129 dB per channel when working in 8-ch. mode and 135 in mono mode (all channels paralleled) and a THD of -120 dB and its max. power consumption should not exceed 100 mW and the operating temperature: 0 to 70C. However, the heatsink I placed on top of it will help in reducing the dissipated heat, although not needed given the measured temps. hence I don't think any manufacturer did that.

BTW, check the bypassing caps from behind the ESS chip and the bottom of the DAC board:

Bypassing capacitor for the ES9018S DAC chip.

Pretty nice layout and lot of ground plane on the DAC chip left-side.

 

[belgar]

I'm impressed @raoultrifan! I wished I was that handy with hardware!

Yes, I not only tried different computers but also different wires. Australia is far away from my studio so I wanted to rule out any other issues before shipping it

Your discovery may well be the answer, thanks. I never have any issue when running it for just a few hours, and so far it always came back to life.

 

[raoultrifan]

1. When you see that your CV2+ has this issue again, after a 5 seconds power cycle, does the issue is still present or music is singing again?
If possible, get the top cover off and power it OFF, then immediately check with your finger the XMOS and ESS chips temperature (power OFF the device first!)? Just please touch the top case first, then the plastic top case of the chips, but not the board pins (to be sure there will be no electrostatic discharge).

2. Also, while issue is present, what happens if you get the top cover off and let it cool down, while powered ON? Will the CV2+ be seen by the computer and able to play songs again (without power cycle)?

I will also try using the IR thermometer I have, but given the very small chips, it might be difficult to "focus" the thermal cell on the correct spot, not mentioning that after taking the cover off in about 10 seconds temps are lowering immediately, so measurements may not be precise, this is why I used my finger instead of IR thermometer actually. At 60C I am unable to keep my finger for more than 5 seconds.

 

[Sound Eq]

I re bought the Burson conductor V2+, I wonder if any of you suggest to buy a good power cord, or is the stock one good enough. I once auditioned the audo gd nfb27 and changing the power cord did wonders to the sound. If you think that changing the power cord would be something beneficial which one would you suggest, to add more body to the mids

Since its been almost over a year, can I ask did any of you do any mods, or recommend anything to do or add to the V2+

 

[devilboy]

Just curious, what headphones will you use with the Burson? Also, will you use its DAC or do you have your own?

 

[Sound Eq]

Just curious, what headphones will you use with the Burson? Also, will you use its DAC or do you have your own?

I will use the meze empyrean and i have as well the cord qutest

 

[devilboy]

Yes, that Meze looks very nice.
I'm interested to know how you like the Chord Qutest vs the DAC in the Burson.

 

[raoultrifan]

Default power cord will do just well. I don't think there are any easy mods available to CV2+, but perhaps other headfiers might have a different oppinion.

 

[Sound Eq]

Hello everyone, I have tried these parameters of Audirvana on mac with my Burson V2 + and I feel them fantastic, try them and report here thanks!
Good music!

i never understood what those settings do, but sounds good to me following your settings

do others have other recommendations to try

its so strange that i prefer the sound from burson alone than hooking to it the chord qutest as a dac, so so strange

 

[Milan01]

Why Is strange to prefer your burson alone than with the chord ? It depends to your preferences, the synergy, not the price
But what differences have you heard ?

 

[Sound Eq]

Why Is strange to prefer your burson alone than with the chord ? It depends to your preferences, the synergy, not the price
But what differences have you heard ?

this is the strangest thing, with qutest as a dac the dynamics went south, and bass became less, and the sound became thin, which is something I did not expect at all. Using the burson alone was way better in everything

 

[devilboy]

So I assume you haven't heard the Burson with any other dac besides the Chord?
I'm thinking of adding a Metrum DAC.
I've had four already, but never with the Burson.

 

[Sound Eq]

So I assume you haven't heard the Burson with any other dac besides the Chord?
I'm thinking of adding a Metrum DAC.
I've had four already, but never with the Burson.

i just tried it with qutest, unless something is wrong with the interconnects I am just surprised why with burson alone the sound is more dynamic and fuller, it really by itself is a great dac amp, so I am totally surprised

i will try other interconnects and mojo and ifi black label tomorrow

 

[up late]

it seems like you have underestimated the cv2+ or overestimated the qutest or both

 

[Zojokkeli]

i just tried it with qutest, unless something is wrong with the interconnects I am just surprised why with burson alone the sound is more dynamic and fuller, it really by itself is a great dac amp, so I am totally surprised

i will try other interconnects and mojo and ifi black label tomorrow

Let us know how it goes. I'm using Mojo at the moment, but upgrading my CV2 to CV2+ or upgrading my Bifrost Uber to Multibit are on my mind.