Is it possible to hook the DAC board and the SPDIF output board together to the Upstream Pro board, even if it takes a little soldering? I ordered the Upstream Pro board, the DAC board and the SPDIF output board and realized that there’s only one header for eithetr of the expansion boards.
–Manfred
Hi Manfred,
I would say yes, it should work or very surprised if it didn’t.
You will need to split out the SPDIF, ground and +ve from the 7 pin cable out of the Pro board and share the ground and +ve supplies to both boards.
Let us know how you go with the modifications.
Steve1
Hi Steve,
thanks for the quick reply. I was thinking in the same direction.
I will give it a try and share my experience.
–Manfred
Hi Manfred but why do you want to do that?
The HD DAC has an analog out (simular to the pro, it has an analog in and also a spdif in.
Ald all the internet radio spotify etc dig inputs aswell
So i woukd yse the pro in another room for another speaker and make it multiroom.
Hi Manfred,
How did you go, did it work okay?
Steve
Hello Steve,
thanks for the note and sorry for the late feedback.
Status is that I put the SPDIF board on the back burner since I first have to tackle a minor, yet annoying EMI issue. Due to the lack of space in the housing, I had to put the Upstream Pro board on top of the analog board, which results in a periodic (~1s) “ticking noise” that is barely audible but is nonetheless annoying. When I’m done with that, I’ put in the SPDIF output board; I’m very confident that it will work out fine. I will keep you guys updated.
–Manfred
Could you maybe place a earthed metal sheet between the boards? This should (hopefully) block EMI.
I’ve done that already; it’s a lot better than without it, but I’m still not entirely happy. My idea now is to put whole board in a customized metal box. Otherwise,the performance is great.
– Manfred
Hi Manfred,
Any chance of a couple of photos?
Steve
Hello Steve,
The whole contraption is supposed to be a headphone amp (WHAMMY by Wayne Colburn from Pass Labs) with an integrated UpStream Pro board . The input can be switched from external to the internal soruce, additionally, it can be hooked to an external stereo to serve as a streaming client.
I lined the underside of the FR4 carrier board with aluminum tape that connects to the housing via the left notch in the side panel. The UpStream board has a power supply of its own. All the ground lines lead to the central ground lug left of the IEC connector.
Unfortunately, the op amp that’s responsible for the voltage gain is located directly underneath the UpStream board; however, the difference the aluminum tape has made gives me the hope that a better shielding might eliminate the remaining EMI. I wonder what it is: Periodic click, roughly about 1/s.
–Manfred
Hi Manfred,
That long I2S cable might be an issue, other forum members have had success in reducing noise by wrapping the I2S cable with aluminium foil.
It might be worth a try.
Steve
Hi Steve,
I’ve disconnected the cable on the board side, no difference…Noise floor is virtually non-existent, it’s just that faint “tick…tick…tick…”, pretty much like an old fashioned bomb timer lol
Of course, when the UpStream is booting up, there’s a lot going on, but I can live with that.
–Manfred
Hi Manfred,
Just to confirm, you say that you remove the I2S cable from the Pro board but the noise (tic tic) continues?
Hi Steve,
yes, that’s correct. Whether the I2S cable is connected or not makes no difference at all. Nothing but moving the UpStream board does.
–Manfred
This reminds me of an issue that Ernst @KolfMAKER had with one of his mini boards, he found that rotating it made a difference to interference.
Is there another position within the enclosure that you could try moving it too?
Steve
Hi @homme_de_terre / Manfred and @Steve1 ,
Just hopping into the topic, responding to Steve’s reference to one of my older threads on the forum.
My issue was a ‘ticking’ noise, but it was quicker than one tick per second. Maybe like 4 or 5 per second, which made it sound more like a ‘ripple’ noise.
First I also thought it was an EMI problem. And I experimented with all types of foil. Sometimes it helped, but it was never completely gone.
In the end I found out that the Mini uses a MCU-chip with an integrated DAC. In fact the MCU handles all the ADC/DSP/DAC/BT functions, so a system-on-one-chip design. If you remove the top board of the Up2Stream Mini, the MCU/DAC chip is visible.
The fact that MCU and DAC are combined in one chip, makes it sensitive to pick up noise and create the ripple.
I then tested by adding the optional DAC board. This one by-passes the DAC in the MCU/DAC combination. And the result I found …. ripple completely gone.
More info about my search, tests and results can be found here: Up2Stream Mini & Ripple problem ? - #36 by KolfMAKER
Hi @KolfMAKER and @Steve1
thanks for chiming in. Your analysis makes a lot of sense. I’m sure now that the source is the MCU. I don’t have any interference when I hook the external DAC to my main stereo. It’s just that, unfortunately, I put the UpStream board directly on top of the gain stage of my headphone amp. The reason why I did it was that wanted to keep access to the Ethernet port/USB ports and analog in and out. Last night I wrapped the whole thing in aluminum foil, but the ticking has been persistent. When I move the board a little to the back, it becomes dead silent; so I’m afraid I’ll have to sacrifice the ports.
Do any of you guys have an idea if the Upstream HD would be a significant step up in terms of audio performance and EMI?
I could reuse the Pro for a different project, find a bigger case and integrate the HD instead of the Pro. I sure would like to have aptX HD.
–Manfred
Hi Manfred.
I guess you mean the Up2Stream HD DAC?
This one.
The HD DAC board has a different DAC than the Mini, a better quality DAC. This board has a dedicated chip for MCU and a dedicated chip for the DAC. You can see that on the picture below.
Because both chips are separated, I am close to 100% sure, you will not encounter your ticking/ripple issue with this board.
Hi Ernst and @Steve1 ,
I took the plunge and ordered the HD DAC. The 15% mother’s day discount helped me to make the decision:-)
I will have to find a larger housing because it definitely won’t fit in the Hammond enclosure, but that one is already too crowded with the UpStream Pro and the additional power suppl.
I will keep you guys posted.
Thanks again for your valuable input,
–Manfred
Hi @KolfMAKER and @Steve1 ,
Finally, here’s my update on the Upstream Pro vs. Upstream HD DAC:
First of all, the “ticking” noise issue is history. I have been able to cram the larger board on top of the analog board in the already tight housing.
The contraption is dead silent now, the audio quality of the HD DAC seems to be significantly superior.
Additionally, with the Upstream Pro and 24bit/192kHz signals from Qobuz, I had occasional dropouts and track-skipping issues which are entirely gone now.
At the current price of $149 I’d have bought the HD DAC to begin with, but back then, it was still $249, which seemed to be too steep of a price difference to me.
Bottom line is, I think the HD DAC is significantly superior to the Upstream Pro + external DAC, at least if you want to stream uncompressed HD content, not to mention aptX HD BT, which I yet have to test.
Thanks again for your valuable input.
–Manfred
