DEVA Pro with Bluemini R2R--Combining the Best of the HIFIMAN Latest Developments

[samandhi]

Hi, I'd like to ask what is the specification of the battery inside, my hifiman bluemini has been used for a long time, I feel seriously aging, want to replace the suitable battery， thank u

That is a great question. One I had not considered to this point.

Also, looking at the pictures, it looks like, while not by any means impossible, the leads are soldered on to the board. The good news is that if you aren't able to solder this, a phone repair shop should be able to easily do it for very cheap.

P.S. Really though, this looks like a very simple solder job IMO.

 

[Denosha]

Hi, I'd like to ask what is the specification of the battery inside, my hifiman bluemini has been used for a long time, I feel seriously aging, want to replace the suitable battery， thank u

I've been wondering the same but haven't been able to find any info. The battery on my bluemini is toast, it's not holding charge beyond a couple of days. And usage time is probably around 4hrs or so, at best. I'm not sure why the battery died on me so fast as my usage isn't very heavy. Or could it be it doesn't like being charged by high-powered PD chargers?

 

[znthem]

That is a great question. One I had not considered to this point.

Also, looking at the pictures, it looks like, while not by any means impossible, the leads are soldered on to the board. The good news is that if you aren't able to solder this, a phone repair shop should be able to easily do it for very cheap.

P.S. Really though, this looks like a very simple solder job IMO.

Thanks for your advice. I'll ask a friend to check the battery in a few days. In addition, I would like to ask you, when using bluemini with devapro, what is the appropriate volume for you.
When I use Bluetooth mode to listen in a quiet room, I also need to adjust the volume to nearly 40 to achieve the right sound pressure.

 

[samandhi]

Thanks for your advice. I'll ask a friend to check the battery in a few days. In addition, I would like to ask you, when using bluemini with devapro, what is the appropriate volume for you.
When I use Bluetooth mode to listen in a quiet room, I also need to adjust the volume to nearly 40 to achieve the right sound pressure.

For me there is a bit of a void in the volume level "sweet spot" for me. I listen at about the same level, but less than that it is too quiet by a lot. Basically it seems as though the level increase isn't linear right in the area where it is too quiet and too loud for normal listening.

So, for my ears, I am not really able to achieve the optimum listenening level using the Blumini. But 40 seems close to correct. Remember that the Blumini has a tiny amplifier on it, and planar drivers are different than dynamic drivers. They rely on amperage rather than voltage to properly drive them. Because the Bluemini is portable they don't have a lot of current on tap.

Having said that, I don't see this as a problem because I think that they can get plenty loud for my ears. You just have to turn them to a higher volume level than you would think necessary because of it. Hope that made sense?!

 

[Denosha]

For me there is a bit of a void in the volume level "sweet spot" for me. I listen at about the same level, but less than that it is too quiet by a lot. Basically it seems as though the level increase isn't linear right in the area where it is too quiet and too loud for normal listening.

So, for my ears, I am not really able to achieve the optimum listenening level using the Blumini. But 40 seems close to correct. Remember that the Blumini has a tiny amplifier on it, and planar drivers are different than dynamic drivers. They rely on amperage rather than voltage to properly drive them. Because the Bluemini is portable they don't have a lot of current on tap.

Having said that, I don't see this as a problem because I think that they can get plenty loud for my ears. You just have to turn them to a higher volume level than you would think necessary because of it. Hope that made sense?!

i have the same problem listening using the Deva Pro on my Shield Pro, it's always slightly too loud or too quiet but most of the time it's around 30-40% for me as well. Personally i think as long as you're under 50% there's still plenty of headroom. And on amps without stepped attenuator type volume knobs, there usually is quite abit of channel balance at the lowest volume levels so i wouldn't want to "live" there either.

 

[TheFritz]

I've been wondering the same but haven't been able to find any info. The battery on my bluemini is toast, it's not holding charge beyond a couple of days. And usage time is probably around 4hrs or so, at best. I'm not sure why the battery died on me so fast as my usage isn't very heavy. Or could it be it doesn't like being charged by high-powered PD chargers?

Sorry. I didn't see the question on the Bluemini R2R battery specs due to the holiday season. Here you are:

The case is really easy to open and the cables to the battery are long enough to allow some soldering, so it should be a simple job to replace the two cells...

 

[Cooe]

You have to use a single 3.5 TRRS into the left ear up for balanced unfortunately, that is why the balanced bluemini works so they had no choice really

I know this thread is absolutely ANCIENT, but this is outright wrong!

(This was true on the OG Deva's which only had that left side 3.5mm TRRS jack, but not the Deva Pro's.)

The Bluemini's all use a balanced 3.5mm TRRS single jack input as that was the only way to get dual driver balanced output out of a dongle which only connects to one of the drivers! Otherwise you'd have needed to wire the Bluemini into both drivers, not just one side. But with the Deva Pro's additional 3.5mm TRS jack on the right driver you can use standard 2x 3.5mm TRS balanced cables with it JUUUUUUST fine! (In this case the left driver's 3.5mm input just functions as a standard TRS jack with the TRRS jack's 2nd output pole simply going unused.)

That is quite literally the ENTIRE REASON why HiFiMan added said right side 3.5mm TRS jack with the Deva Pro's!...

(Aka, so people could use their standard 2x 3.5mm TRS balanced cables that they likely already owned, instead of needing to buy a 1x 3.5mm TRRS balanced cable JUST for these cans, as you had to do w/ the OG Deva's.)

 

[Philliesfan]

I know this thread is absolutely ANCIENT, but this is outright wrong!

(This was true on the OG Deva's which only had that left side 3.5mm TRRS jack, but not the Deva Pro's.)

The Bluemini's all use a balanced 3.5mm TRRS single jack input as that was the only way to get dual driver balanced output out of a dongle which only connects to one of the drivers! Otherwise you'd have needed to wire the Bluemini into both drivers, not just one side. But with the Deva Pro's additional 3.5mm TRS jack on the right driver you can use standard 2x 3.5mm TRS balanced cables with it JUUUUUUST fine! (In this case the left driver's 3.5mm input just functions as a standard TRS jack with the TRRS jack's 2nd output pole simply going unused.)

That is quite literally the ENTIRE REASON why HiFiMan added said right side 3.5mm TRS jack with the Deva Pro's!...

(Aka, so people could use their standard 2x 3.5mm TRS balanced cables that they likely already owned, instead of needing to buy a 1x 3.5mm TRRS balanced cable JUST for these cans, as you had to do w/ the OG Deva's.)

The extra jack is to allow folks to use their after-market non balanced cables to feed each earpiece. If you use a generic balanced cable, you run into trouble because the left earcup’s jack is wired to a TRRS socket to allow the blue mini to drive each channel independently. A 1/8 mono or stereo plug into a TRRS jack will not work. The way those plugs connect inside a TRRS socket will link the live and grounds for each earpiece to both channels of your balanced amp and could cause damage to the amp. On a truely balanced set up, the live and ground are independent to each earpiece. Non-balanced or single ended amps use a common ground to both cups. You could avoid that shared ground issue by changing the 1/8 jack on the left earcup’s cable to a TRRS plug where the rings that link the balanced amp to the other cup are not used. But that would be a lot more work than just feeding from the left ear with a proper cable when running balanced. And soldering to a 1/8 TRRS jack is no joke. I have used SE cables to drive my Deva Pro and it works fine. But only from a SE amp like a Schiit/Nieche Piety or Cavelli-Drop CTH. When I want to go balanced, I use a 4.4 Pentagon to TRRS 1/8 single cable.