[Ronion]

My ETA was June 26, 2021. All of my other orders tracked quite well. AliExpress has even blocked me from contacting Venture Electronics through their website. They say my comment breaks the local law code. Whatever. They want to steal $26 from me I can live with it. It’ll just be my last order.

 

[baskingshark]

My ETA was June 26, 2021. All of my other orders tracked quite well. AliExpress has even blocked me from contacting Venture Electronics through their website. They say my comment breaks the local law code. Whatever. They want to steal $26 from me I can live with it. It’ll just be my last order.

In the logistics/delivery problems I've encountered buying from Aliexpress, I've had some sincere Aliexpress sellers willing to offer to refund you even within the validity period of the Aliexpress protecion period, once I showed them the logistics issue that the item wasn't even delivered/delivered wrongly. They won't even bother waiting for near the expiry period before processing the refund directly with Aliexpress. Those shops had my respect and I went back to purchase from them again in the future.

It is quite sad that this issue cropped up for you, I hope it gets sorted out soonish, but some of these sellers and sites are really penny wise but pound foolish when it comes to reputation and settling of logistics/refunds. And that may dissuade buyers from going back to their shop, or even avoiding the entire Aliexpress platform totally.

 

[WoodyLuvr]

Reading the A5 specs though, it looks like it has a 14.9v output!?!? I must be reading that wrong. Anyone know if that’s correct? I must be misunderstanding something. That sounds unrealistic.

That is Peak-to-Peak Voltage aka 'effective' voltage (Vpp)! You are thinking of Vrms which is "average" voltage or "actually seen" voltage in layman's terms. Fiio A5 Vrms is 5.29V (see below for more details).

It is 1.8V

No, the 1.8Vrms is a testing measurement only... after being leveled to 2Vrms for a High Performance Sine Wave @ 1kHz and 2.5Vrms analog input signal. This allows for consistency in testing across multiple devices but it is not always a "full" reflection of the device's capabilities nor the circuit's design considerations especially if "gain modes" are involved. Which in this case is indeed a factor to be considered as this 1.8VRms result was due to the ASR tester using FiiO A5's rather low "Low Gain" mode (which is intended for IEM/High-Sensitivity Headphone use).

I assure you that the A5 can easily output well over 1.8Vrms especially in High Gain mode... I should know I owned one . Gosh, even my little Meizu HiFi DAC HeadAMP PRO dongle, when "tricked", will output ~2Vrms with a thrust of 100mW @ 32Ω (13mW @ 300Ω).

I wish that both manufacturers and testers/reviewers would better (more clearly) explain these parameters as it often times can be unintentionally misleading and/or misunderstood (but since both analog signal source input values and headphone impedance/sensitivity ratings are all over the board I do admit it is extremely difficult for manufacturers to provide meaningful and consistent parameters that the consumer will experience in real-life).


FiiO A5 Parameters Provided by @FiiO
Supplied Power: +/-11V
Peak Output Voltage: 14.96Vp-p (Vpp = Peak-to-Peak Voltage)
Max Output Current: 250mA
Output Power @ 32Ω: > 800 mW (> ~5.06Vrms / > ~158mA)
Output Power @ 300Ω: ≥ 150mW (≥ ~6.71Vrms / ≥ ~22mA)
Output Impedance: <0.3Ω

Now FiiO has traditionally always been very conservative with their given parameters... meaning their products generally output greater numbers when "loaded" than shown on paper.


Here are the RMS values that we get via math:

14.96Vpp / 2 = 7.48Vp​

7.48Vp * 0.707 = 5.29Vrms​

250mA * 0.707 = 177mA rms​

RMS Voltage: 5.29V (probably occurring @ ~30Ω in High Gain)​

RMS Output Current: 177mA (probably occurring @ ~30Ω in High Gain)​

And this is what we get in actual "real-life" performance (the following are measurements of my A5 in "High Gain" mode taken by a professional audio engineer back in 2017. In regards to the line signal input: apologies, I am unable to read my terrible hand writing nor can I recall the value but it definitely was not something bizarre or out of the ordinary):

Output Impedance = 0.26Ω​

Output @ 16Ω = 2.89Vrms 522mW 181mA​

Output @ 32Ω = 5.32Vrms 885mW 166mA​

Output @ 150Ω = 5.87Vrms 230mW 39mA​

Output @ 300Ω = 6.79Vrms 154mW 23mA​

If I recall correctly when we tested at 600Ω impedance the output dropped drastically down to less than 1mW, if I am not mistaken, which is simply due to the amp's circuit voltage/current design limitations when driving headphones over 300Ω.


So you can see my FiiO A5 performed slightly better across the board than the given parameters provided by FiiO. All of my FiiO devices (E12A; A5; K3; BTR5) have been like this; performing better than advertised.

 

[furyossa]

That is Peak-to-Peak Voltage aka 'effective' voltage (Vpp)! You are thinking of Vrms which is "average" voltage or "actually seen" voltage in layman's terms.
Fiio A5 Vrms is 5.29V (see below for more details).

1.8V is a testing measurement only... after leveled to 2Vrms for a High Performance Sine Wave @ 1kHz and give a 2.5Vrms analog input signal. This allows for consistency in testing across multiple devices but it is not always a "full" reflection of the device's capabilities and circuit design considerations. I wish that both manufacturers and testers/reviewers would better (more clearly) explain these parameters as it often times can be unintentionally misleading.

FiiO A5
Supplied Power: +/-11V
Peak Output Voltage: 14.96Vp-p (Vpp)
Max Output Current: 250mA

Now FiiO has traditionally always been very conservative with their given parameters... meaning their products generally output greater numbers when "loaded" than shown on paper.

Here is what we get by math:

14.96Vpp / 2 = 7.48Vp​

7.48Vp * 0.707 = 5.29Vrms​

250mA * 0.707 = 177mA rms​

RMS Voltage: 5.29V​

RMS Output Current: 177mA​

And this is what we get in actual "real-life" performance (the following are measurements of my A5 taken by a professional audio engineer back in 2017):

Output Impedance = 0.26Ω​

Output @ 16Ω = 2.89Vrms 522mW 181mA​

Output @ 32Ω = 5.32Vrms 885mW 166mA​

Output @ 150Ω = 5.87Vrms 230mW 39mA​

Output @ 300Ω = 6.79Vrms 154mW 23mA​

If I recall correctly at 600Ω impedance the output dropped drastically down to less than 1mW if I am not mistaken which is simply due to the amp's circuit voltage/current design limitations for headphones over 300Ω.

So you see my FiiO A5 performed slightly better across the board than the given parameters by nji FiiO. All of my FiiO devices have been like this.

Thanks Mr @WoodyLuvr, even the manufacturer does not know this information

 

[Ronion]

I think my best bet for a positive response is through Venture Electronics. They seem to be good people who want to run an honest company, and not the fly by night type.

that’s awesome Woody! Thank you. The ASR measurements agree with your measurements, experience and calculations.

 

[WoodyLuvr]

Thanks Mr @WoodyLuvr, even the manufacturer does not know this information

They do but since both analog signal source input values and headphone impedance/sensitivity ratings are all over the board it is extremely difficult for manufacturers to provide meaningful and consistent parameters that the consumer will experience in real-life. Though I would whole heartedly agree that some manufacturers' given parameters are rather sparse and enigmatic leaving the customer thoroughly perplexed and wanting for more... LOL!

 

[Ronion]

Well, I’ve got another conundrum: my A5 is definitely the better amplifier technically speaking, but the little bear is generally more enjoyable even though it hides more details and it is less dynamic. It’s strange to me that I prefer more detailed, more dynamic speakers, but for some reason a less detailed amp sounds ‘better’. I haven’t had a moment of fatigue with it and though the A5 has never made me feel fatigue in the past, it now seems fatiguing. Audio is definitely a quirky hobby. My sense of hearing makes no sense at all I’m afraid. Maybe it’s just the new toy? It’s weird because I still enjoy my more detailed buds on the less detailed and dynamic amp. You can still hear all the same details on the little bear, they just don’t bring as much attention to themselves and they’re less clearly delineated. I wouldn’t try to hinder anyone from trying this cheap, battery powered tube amp.

 

[miserybeforethemusic]

Well, I’ve got another conundrum: my A5 is definitely the better amplifier technically speaking, but the little bear is generally more enjoyable even though it hides more details and it is less dynamic. It’s strange to me that I prefer more detailed, more dynamic speakers, but for some reason a less detailed amp sounds ‘better’. I haven’t had a moment of fatigue with it and though the A5 has never made me feel fatigue in the past, it now seems fatiguing. Audio is definitely a quirky hobby. My sense of hearing makes no sense at all I’m afraid. Maybe it’s just the new toy? It’s weird because I still enjoy my more detailed buds on the less detailed and dynamic amp. You can still hear all the same details on the little bear, they just don’t bring as much attention to themselves and they’re less clearly delineated. I wouldn’t try to hinder anyone from trying this cheap, battery powered tube amp.

I'm so glad you're over the moon with the B4-X. It should only get better with time.

The only other battery-powered amp that doesn't have a brain (like the Qudelix) is a Headroom Total Airhead. That little guy, on 4 AA batteries, can produce a wall of sound. Best hardware crossfeed ever, too.

But it's all fun and games until the battery runs out

 

[miserybeforethemusic]

Now this is a nice, mellow combo for a Sunday afternoon. The M2s foams are starting to get softer and more plush. Midbass is starting to round out, though there's still too much of a hump trough in the upper bass that's throwing my ears off. There's some really close moments with strummed acoustic guitars here until you realize some of the fundamentals aren't there. It's close, though, and really impressive if your ears aren't quite as spoiled.

For under $100, though, it's an amazing performance. I highly recommend

 

[Ronion]

Well, just that fast and Little Bear has developed intermittent crackling in the right side. I've tried different cables and sources and the problem remains. Sad because when it's not doing it, the sound is glorious.

 

[miserybeforethemusic]

Well, just that fast and Little Bear has developed intermittent crackling in the right side. I've tried different cables and sources and the problem remains. Sad because when it's not doing it, the sound is glorious.

May need to scrub the volume pot. With everything off and the battery disconnected, you can saturate a q-tip and run it around the volume knob. Give that knob a few swirls and let everything dry. It can help.

If not that, then might be the OPAMPs. Wouldn't be too sure how to troubleshoot it down to the component level.

 

[Ronion]

I will try cleaning the volu pot. When I first opened it, the volume pot was super smooth. Now it’s not…

 

[Ronion]

I found the problem! There are 2 adjustment screws near the base of the tubes. Twisted them a little and it's now perfect! The fix was actually in the manual. Believe it or not it actual sounds better than it did before due to less his is both channels.

 

[siderak]

Did laundry and discovered my missing RY4S’s as I was transferring the load into the dryer. The foams were still on.
I let them sit for 3 days and happy to report, they sound exactly as they did before a double cold cycle! I even compared them to an identical set.
Shocked.

 

[baskingshark]

Did laundry and discovered my missing RY4S’s as I was transferring the load into the dryer. The foams were still on.
I let them sit for 3 days and happy to report, they sound exactly as they did before a double cold cycle! I even compared them to an identical set.
Shocked.

This is called good QC check!

"Wash in" is the new Burn in!