[miserybeforethemusic]

Oh this will be a fun one for Team LittleBear:



Surprisingly usable as a true "portable," assuming one's pockets are large enough to fit the stack. Happy to report only one elastic band was needed to hold the SR25 and B4-X together and it doesn't wobble a bit. The silicone o-rings I put over the tubes (very carefully) seem to help with some of the ringing that motion would introduce. Takes it down low enough that you don't hear it when you're moving about. Totally cool that I can just put this down on a tabletop outside and go, though. Gives me a lot more use for the darn thing.

 

[samandhi]

Oh this will be a fun one for Team LittleBear:



Surprisingly usable as a true "portable," assuming one's pockets are large enough to fit the stack. Happy to report only one elastic band was needed to hold the SR25 and B4-X together and it doesn't wobble a bit. The silicone o-rings I put over the tubes (very carefully) seem to help with some of the ringing that motion would introduce. Takes it down low enough that you don't hear it when you're moving about. Totally cool that I can just put this down on a tabletop outside and go, though. Gives me a lot more use for the darn thing.

Makes me almost miss having stacks..... ALMOST.

 

[jrazmar]

Which one is harder to drive, a low sensitivity phone or a high impedance one? My F150c is both 85db and 150Ω. For me, it plays well with my phone driven using USB DAC dongles. I have several now but for the F150c, it goes well with the CX-Pro 31993 giving it more air and separation with smooth mids and sufficient bass impact. Just want to know if I'm getting the most out of it given I have no experience with dedicated portable and desktop amps or high-end DACs.

 

[WoodyLuvr]

Which one is harder to drive, a low sensitivity phone or a high impedance one? My F150c is both 85db and 150Ω. For me, it plays well with my phone driven using USB DAC dongles. I have several now but for the F150c, it goes well with the CX-Pro 31993 giving it more air and separation with smooth mids and sufficient bass impact. Just want to know if I'm getting the most out of it given I have no experience with dedicated portable and desktop amps or high-end DACs.

It really depends on how loud you are listening to your music.

Yes, the Seahf AWK-F150C 150Ω can be very hard to drive, from many mobile sources, but only after 95dB SPL.

As you can see just below the AWK-F150C only requires 1.22Vrms @ 10mW to reach 95dB SPL and one (1) volt would bring you in just a tad lower @ 93.24db SPL. Even if we use a rather needy headroom of let's say 25dB (which takes into account a hefty 15dB low bass requirement) you will still reach a significant listening level of around 68.24 to 70 dB which would really cover most situations (varying music genres and listening environments) just fine outside of a train station and/or heavy construction site. This is why they sound fine through your smartphone + dongle... they are more than likely getting enough power to be driven properly as designed.

One other worthy consideration to mull over is that earbud and IEM transducers (drivers) are very small and were purposely designed (even high impedance models) to play very well from modestly powered mobile sources. Quite a number of audio engineers, that specifically design such said transducers (drivers), have confirmed to me that the loss of fidelity due to power is usually less than 3% per 10dB which most human ears would have difficulty detecting as it usually occurs in the low bass region. The real issue rather is the resulting distortion because the driver's designed max power capability has been surpassed.

Now when one seeks to reach a level of 100dB SPL or greater in loudness this is where/when one will run into some "power issues" as well as the driver's design limitation being reached.

2.18Vrms @ 32mW is required to reach 100dB SPL... sustained listening at 75dB plus 25dB headroom equals 100dBSPL.

6.89Vrms @ 316mW is required to reach 110dB SPL... a very loud 85dB in sustained listening with 25dB of headroom (total of 110dB SPL). Note, that this may be reaching the driver's max power capability.

21.78Vrms @ 3,162mW (aka 3.2 Watts!) is required to reach 120dB SPL... which would most definitely be testing the driver's design specifications with grand distortion as a result... though at this point I would really have to question why anyone would be listening at sustained levels of 95dB or higher (95dB listening level + 25dB headroom = 120dB SPL).

 

[jrazmar]

Thank you for this very informative and detailed explanation. Although I'm not good at some of the technical terms, I could somehow understand the idea but not entirely on actual application specially that I only listen to music and not measure things. But this is really appreciated sir. I'm the type who listens to loud volume levels maybe 80% to 90% on a smartphone. Is there a way perhaps an app that could tell me how many decibels is my current volume? That way I can gauge which scenario above I am currently in.

 

[Ronion]

Oh this will be a fun one for Team LittleBear:



Surprisingly usable as a true "portable," assuming one's pockets are large enough to fit the stack. Happy to report only one elastic band was needed to hold the SR25 and B4-X together and it doesn't wobble a bit. The silicone o-rings I put over the tubes (very carefully) seem to help with some of the ringing that motion would introduce. Takes it down low enough that you don't hear it when you're moving about. Totally cool that I can just put this down on a tabletop outside and go, though. Gives me a lot more use for the darn thing.

I’ve found that I just needs to wear my Down jacket to prevent ringing while I walk. My grandfather used to say that you should work up a sweat every day to remain healthy. Well now I can do that just walking around my yard—which is about 3meters by 4 meters

 

[miserybeforethemusic]

I’ve found that I just needs to wear my Down jacket to prevent ringing while I walk. My grandfather used to say that you should work up a sweat every day to remain healthy. Well now I can do that just walking around my yard—which is about 3meters by 4 meters

I found rolling a couple of these over the tubes (very carefully) also helps a bit. If anything, it helps distribute the light from that tube glow. I used some of the leftover o-rings as a damper for my turntable's tonearm hahaha:


https://www.amazon.com/gp/product/B081G98QGX/ref=ppx_yo_dt_b_search_asin_title?ie=UTF8&psc=1

I got the 3mm wide, 8mm ID, 14mm OD gaskets. Could probably have stood to go a little thinner with a slightly larger ID to make it easier to roll over the tubes; just be sure to not break any of the leads connecting the tubes to their respective sockets.

 

[samandhi]

I found rolling a couple of these over the tubes (very carefully) also helps a bit. If anything, it helps distribute the light from that tube glow. I used some of the leftover o-rings as a damper for my turntable's tonearm hahaha:


https://www.amazon.com/gp/product/B081G98QGX/ref=ppx_yo_dt_b_search_asin_title?ie=UTF8&psc=1

I got the 3mm wide, 8mm ID, 14mm OD gaskets. Could probably have stood to go a little thinner with a slightly larger ID to make it easier to roll over. The tubes to bend a little; just be sure to not break any of the leads connecting the tubes to their respective sockets.

What are the adjustable POTs on that thing for? Calibrations? It looks like you have one POT, for the left tube at 1oclock, and the right one at 12 oclock?!

 

[miserybeforethemusic]

What are the adjustable POTs on that thing for? Calibrations? It looks like you have one POT, for the left tube at 1oclock, and the right one at 12 oclock?!

Yep, they're biasing adjustments for the OPAMPs and tubes. That's the before. They're matched now.

 

[Ronion]

Okay, so my VE Zen Lite arrived today and I just foamed them up and plugged it into the balanced end of Qudelix 5K. These are some HiRez buds for certain! Even with AAC over Bluetooth these things are exposing things in the midrange with more detail than I’ve ever heard. Very layered soundstage as well. From memory not as huge as the M2s pro, but layered and enveloping nonetheless. Bass doesn’t seem as deep, nor is the trebles as prominent but I can’t help but love this signature. The comfort of this shell is a new level for me. It’s definitely cool when you put a but in your ear for the first time w/o any experimentation and it wows you. If no amp/source sounds better than this I’ll be fully satisfied, but I’m sure a few of them will. The Little Bear with HiRez (redbook or better) files should one up with as well as the A5. My gut tells me these guys are a A5 mate… Time will tell.


I’m in a place now where I have several buds that I love. Time to get rid of ones I won’t use.

 

[samandhi]

Awesome! I like that you have adjustments for those...

 

[Ronion]

Yep, they're biasing adjustments for the OPAMPs and tubes. That's the before. They're matched now.

Mine were making a crackling noise until I moved those around a bit. Then I adjusted them for channel balance and life is beautiful. I really love the what this amp adds to the music.

 

[nymz]

Okay, so my VE Zen Lite arrived today and I just foamed them up and plugged it into the balanced end of Qudelix 5K. These are some HiRez buds for certain! Even with AAC over Bluetooth these things are exposing things in the midrange with more detail than I’ve ever heard. Very layered soundstage as well. From memory not as huge as the M2s pro, but layered and enveloping nonetheless. Bass doesn’t seem as deep, nor is the trebles as prominent but I can’t help but love this signature. The comfort of this shell is a new level for me. It’s definitely cool when you put a but in your ear for the first time w/o any experimentation and it wows you. If no amp/source sounds better than this I’ll be fully satisfied, but I’m sure a few of them will. The Little Bear with HiRez (redbook or better) files should one up with as well as the A5. My gut tells me these guys are a A5 mate… Time will tell.


I’m in a place now where I have several buds that I love. Time to get rid of ones I won’t use.

If those are mini Zen 2.0, you're in for a ride. They love power and sources. Very nice detail. Mine got more bass with more power. Enjoy the ride!

 

[Ronion]

I believe they are essentially mini Zen 2(don’t quote me on that). I’m completely pumped up about these. Going to take them hiking with the dog right now, but tonight we are doing the Little Bear, JDS Atom, and the A5. Both battery amps are charging as I type. This is going to be a good, good night thank you!

 

[miserybeforethemusic]

Okay, so my VE Zen Lite arrived today and I just foamed them up and plugged it into the balanced end of Qudelix 5K. These are some HiRez buds for certain! Even with AAC over Bluetooth these things are exposing things in the midrange with more detail than I’ve ever heard. Very layered soundstage as well. From memory not as huge as the M2s pro, but layered and enveloping nonetheless. Bass doesn’t seem as deep, nor is the trebles as prominent but I can’t help but love this signature. The comfort of this shell is a new level for me. It’s definitely cool when you put a but in your ear for the first time w/o any experimentation and it wows you. If no amp/source sounds better than this I’ll be fully satisfied, but I’m sure a few of them will. The Little Bear with HiRez (redbook or better) files should one up with as well as the A5. My gut tells me these guys are a A5 mate… Time will tell.

Oooh nice! Playing around with the first set I can confidently run foam-less. I'd even venture to say they sound bigger than the M2s Pro, but I did just pop them in my ears. Definitely need some more time with them, but I will say they're unique. Very unique.



Oh, and speaking in terms of fit and tonality, these plopped right in from the beginning and were good to go. That BA adds a really interesting tonality; almost like the stage didn't necessarily grow wider, but seems to extend down a really long hallway. It's not necessarily realistic, but it's definitely fun and different from the rest of the stable. Unfortunately, I think these were originally priced out of most people's consideration (Headfonics said they were £119 at the time they reviewed) and probably just fell below the radar. They're tons of fun, though, and I have to give a massive thank you to @samandhi for the care package. Been going through a bit of a rough patch, so this will help provide a little respite for the time being.

Thanks bud