hi! i've had my tangara for a couple of weeks now, and there've been some teething issues getting things to work smoothly. for example, it doesn't want to mount as a usb storage device and has a frustrating habit of rebooting itself during playback for whatever reason - but i figure these are firmware issues and should be sorted out over time, since the firmware's still in active development.
however, i have also noticed the audio output from the tangara's internal DAC has a quiet but noticeable hiss, kinda like an old compact cassette. there is no such hiss when listening over bluetooth, most likely because the tangara's DAC isn't being used. the hiss is also gone when no song is currently being played, but i assume that's simply because the tangara doesn't send anything over the headphone output at all when it's not playing a song.
i've tested the tangara with several sets of headphones, and then tested those headphones with my laptop, and it's definitely only a problem with the tangara's headphone output. so - is this a known issue? and is it likely to be a hardware problem? i'm not really equipped to test the internal components myself and track down anything faulty, i'm more of a software gal.
I noticed the same on my pair of Moondrop Chu II. There is a post on Crowd Supply that talks about the noise floor being picked up by such devices: https://www.crowdsupply.com/cool-tech-zo...io-quality. See "A Hack for Budget IEMs".
Perhaps this is the "hiss" you are talking about. It can be fixed by soldering two small resistors as described in the post.
Personally it doesn't bother me much, and it's only slightly audible during quiet parts of a song.
hmm, it's possible my test devices are in that second "easy to drive" + "very sensitive" group, but i'm not sure that's likely? i'm not using high-end audiophile gear: my regular headphones are just a pair of sony wh-1000xm4 noise cancelers, and i've also tested my tangara with extremely basic desk speakers like the logitech z150 set
i would've expected these devices to fall into the first "not very sensitive" category, since they're absolutely not targeted at the audiophile market, but maybe i'm mistaken? i did have a look at the spec sheet for the wh-1000xm4 but couldn't really work out how to compare it against that tangara blog post.
You might be quite surprised actually about the sensitivity of 'low end' headphones these days. In general AFAICT the industry trend here is using very sensitive but low quality speakers (or transducers or w/e... the bit that turns the AC signal into a noise you can hear!!), and relying on various tuning tricks to shift the frequency response into a sensible-looking curve. The spec you want to look for is some value in terms of SPL (in dB) per watt. SPL per volt is also fine if there's a nominal impedance listed for your headphones.
So far we've had a few folks reach out for support with an audible noise floor, and each time it's turned out that the Tangara itself has been operating fine (knock on wood). Happy to help you look into it further though! And of course soldering a couple of resistors into your mainboard will probably sort out your noise floor issues either way.
2025-06-17, 10:37 PM (Edited 2025-06-17, 10:57 PM by 01010111.)
I just got mine today. I knew about the potential for this white noise issue when I purchased it, but I was really surprised at how noticeable it is. I tested this with the following headphones: Sure 215, Sennheiser HD280, Sennheiser PX 200-II, and Sony MDR-EX650AP. The hiss is most noticeable on the Sure headphones. Which surprised me because they're the most expensive and high quality ones, and everything I read talked about "cheap" headphones being the worst offenders! I am able to hear the hiss on all my headphones.
Is the resistor mod the only workaround for this? What size SMD resistors do I need? The white noise is very unwelcome and distracting. Until I find a fix, the only headphones I can use with it are the PX 200-II because they have a built in volume control. But they don't block external noise at all. So, I feel like I can only use my portable music player at home where I don't need any sound isolation (unless my neighbors are being jerks, which is an every day occurrence).
edit: I think I found the resistors. I'm going to sleep on it and consider whether the risk of damage is worth it to avoid carrying around a dongle everywhere.
(2025-06-17, 10:37 PM)01010111 Wrote: I just got mine today. I knew about the potential for this white noise issue when I purchased it, but I was really surprised at how noticeable it is. I tested this with the following headphones: Sure 215, Sennheiser HD280, Sennheiser PX 200-II, and Sony MDR-EX650AP. The hiss is most noticeable on the Sure headphones. Which surprised me because they're the most expensive and high quality ones, and everything I read talked about "cheap" headphones being the worst offenders! I am able to hear the hiss on all my headphones.
Is the resistor mod the only workaround for this? What size SMD resistors do I need? The white noise is very unwelcome and distracting. Until I find a fix, the only headphones I can use with it are the PX 200-II because they have a built in volume control. But they don't block external noise at all. So, I feel like I can only use my portable music player at home where I don't need any sound isolation (unless my neighbors are being jerks, which is an every day occurrence).
edit: I think I found the resistors. I'm going to sleep on it and consider whether the risk of damage is worth it to avoid carrying around a dongle everywhere.
Are C15 and C6 still the right capacitors to solder the resistors to? It looks like the board layout's changed since the post about this on Crowdsupply.
We added dedicated footprints for this in our production runs; R3 and R8 are the ones you want to replace or solder over. We used an 0805 footprint so they'd be a little easier for folks to work with. Susumu RR-series resistors are a good pick, here's a digikey search for the relevant range: https://www.digikey.com.au/en/products/f...GTB16DUXaA
250 or maybe 100 ohms should be plenty. Worst case you can always stack a couple up.
2025-06-19, 10:18 AM (Edited 2025-06-19, 10:56 AM by 01010111.)
(2025-06-19, 03:07 AM)jacqueline Wrote: We added dedicated footprints for this in our production runs; R3 and R8 are the ones you want to replace or solder over. We used an 0805 footprint so they'd be a little easier for folks to work with. Susumu RR-series resistors are a good pick, here's a digikey search for the relevant range: https://www.digikey.com.au/en/products/f...GTB16DUXaA
250 or maybe 100 ohms should be plenty. Worst case you can always stack a couple up.
Thank you! Does it work using the same voltage divider circuit that was outlined in the post on crowdsupply? Those look significantly easier to work with in terms of size and location on the board.
Assuming the circuit worked the same as in the crowdsupply post and based on how much I had to attenuate the volume before the hiss became inaudible, I thought I'd need to reduce it between 20db and 30db. I tried some 50 ohm resistors. For my first time doing smd soldering, it was a success (even if it looks a little ugly). I installed the new resistors on top of the old resistors, because I don't have a hot air rework station. When I tested the results, I had to do a double-take. It was so close to how much I was attenuating the volume via dongle before, I had trouble believing it was that successful. It's now perfect.
For anyone that's successfully done this, it would be awesome if you posted pictures, or any more tips and tricks on the process! I have a lot of hiss as well, but the mod is intimidating.
(2025-06-29, 12:27 AM)redshift Wrote: For anyone that's successfully done this, it would be awesome if you posted pictures, or any more tips and tricks on the process! I have a lot of hiss as well, but the mod is intimidating.
I can solder through-hole components well enough. This was my first time soldering anything this small. Once it worked, I didn't bother trying to clean it up. I didn't have bridged connections, and it worked. So, I just buttoned it up and called it a day. The worst part for me are the volume buttons and screen protector. They do not line up at all during assembly, and the screen protector is EXTREMELY easy to scratch. I've attached the photo of my mod. I wish I could hide it under a "gore" tag.
