[gimmeheadroom]

That makes sense now (I should have clicked beforehand). Maybe I missed it, but if you have an RME, what do you need the Fostex for?

I have several DACs including the RME, the Brooklyn DAC+, and an Oppo 205. But I also have more than one apartment and the battery on my Chord Mojo is dying after almost 4 years. I want to get a cheap but good desktop DAC that doesn't need a battery.

 

[340519]

I'm just a normal member here if that is even possible

It's a link to a pic of my desktop setup in the headfi thread.

Lol normal.

 

[Rickster1515]

Hi All

I am new here, i actually interested with Fostex HP A4BL, but i use my Ipad pro for music playing, can i connect my Ipad to this dac/amp via usb input? Do i need to update the software if i use my ipad?
Thanks

 

[Yevgen Chupak]

Hi All

I am new here, i actually interested with Fostex HP A4BL, but i use my Ipad pro for music playing, can i connect my Ipad to this dac/amp via usb input? Do i need to update the software if i use my ipad?
Thanks

iPad has headphone jack. So you can use 3.5.mm to Single-Ended input on Fostex.

 

[KingFiercer]

Fostex has no analog inputs, only RCA line out and headphone outs. Inputs are only optical toslink and USB. USB can work through OTG with android devices, but I don't know about Apple. By the way, I like the sound from the computer with Win10 more than from the android smartphone. I think using bluetooth in iPad to connect to bluetooth DAC (something like TOPPING DX7 Pro) is not a bad option.

 

[Rickster1515]

Fostex has no analog inputs, only RCA line out and headphone outs. Inputs are only optical toslink and USB. USB can work through OTG with android devices, but I don't know about Apple. By the way, I like the sound from the computer with Win10 more than from the android smartphone. I think using bluetooth in iPad to connect to bluetooth DAC (something like TOPPING DX7 Pro) is not a bad option.

 

[Rickster1515]

I finally had a chance to try the HP A4BL at my local shop. I use the iphone X connected to the Usb In and it works fantastic. Clear sounding and tonally balance. The balance xlr is indeed amazing with the small dac amp and balance output. Love this little unit.

 

[Audioboxer]

Hi everyone, I know this topic hasn't been bumped in a while but as a recent owner for the HP A4BL I have a question about speaker popping when using USB.

I have my PC connected via USB and a set of Edifier speakers and headphones coming off the Fostex. Everything with the headphones is fine. The speakers however have an issue with the passive speaker out of the powered pair making loud pops any time windows volume is changed, or there is a windows sound or even when skipping through a youtube video. It happens with an older set of powered Yamaha speakers I have as well.

I went and bought a powered USB hub and then also a USB cable with double ferrites on it. Still doing the same thing with the left speaker (passive one). I have an AV Link ground loop isolator coming today I'm going to add between the phono output from the Fostex that goes into the speakers. Last thing I have to try.

Does this sound like a grounding issue, or is it something else to do with phono output going to powered speakers?

Optical obviously works fine, but I'd rather crack the USB conundrum if I can lol.

Cheers!

 

[davehutch]

Hi everyone, I know this topic hasn't been bumped in a while but as a recent owner for the HP A4BL I have a question about speaker popping when using USB.

I have my PC connected via USB and a set of Edifier speakers and headphones coming off the Fostex. Everything with the headphones is fine. The speakers however have an issue with the passive speaker out of the powered pair making loud pops any time windows volume is changed, or there is a windows sound or even when skipping through a youtube video. It happens with an older set of powered Yamaha speakers I have as well.

I went and bought a powered USB hub and then also a USB cable with double ferrites on it. Still doing the same thing with the left speaker (passive one). I have an AV Link ground loop isolator coming today I'm going to add between the phono output from the Fostex that goes into the speakers. Last thing I have to try.

Does this sound like a grounding issue, or is it something else to do with phono output going to powered speakers?

Optical obviously works fine, but I'd rather crack the USB conundrum if I can lol.

Cheers!

I'm just throwing this out there because it rings a small bell with me about a potential grounding issue. I had a static discharge issue when using metal IEMs so I wrote to Fostex (my UK dealer) and they sent me a grounded power supply. Issue solved.
Here's a phot of PS if that helps at all

 

[Audioboxer]

I'm just throwing this out there because it rings a small bell with me about a potential grounding issue. I had a static discharge issue when using metal IEMs so I wrote to Fostex (my UK dealer) and they sent me a grounded power supply. Issue solved.
Here's a phot of PS if that helps at all

Oh, good idea. My UK plug from them has ferrite cores wrapped around both sides, but it's not a grounded power supply. I purchased from Amazon so I dunno if Fostex UK will send anything. Maybe with an invoice.

Can you let me know the email/site you used for contacting them? https://www.fostexinternational.com/docs/distributors/index.php?group=Europe There is a UK based email here.

I'll update on whether the isolator does anything later when it arrives.

 

[davehutch]

Oh, good idea. My UK plug from them has ferrite cores wrapped around both sides, but it's not a grounded power supply. I purchased from Amazon so I dunno if Fostex UK will send anything. Maybe with an invoice.

Can you let me know the email/site you used for contacting them? https://www.fostexinternational.com/docs/distributors/index.php?group=Europe There is a UK based email here.

I'll update on whether the isolator does anything later when it arrives.

I'm in the UK and spoke to a guy called Nigel at fostex@scvdistribution.co.uk
He needed the serial number of my amp so sounds like they were changed at some point. Best of luck

 

[Audioboxer]

I'm in the UK and spoke to a guy called Nigel at fostex@scvdistribution.co.uk
He needed the serial number of my amp so sounds like they were changed at some point. Best of luck

Mine came pre-loaded with firmware 1.10 (it's written on the box), so I don't know if that is classed as the latest batch. The plug does have a ferrite core wrapped at the plug base and another at the end going into the unit. So either they've upgraded to this plug or I presume your original plug was like this?

I'll email them anyway. Still waiting on my Amazon delivery to test the isolator. If it works it works, but I'll still see if I can snag another plug.

edit - lol the AV isolator from Amazon makes things worse?! So thats going back. It introduces hum and noise that wasn't there before. Head-scratching. I'll see if I can get another plug.

 

[davehutch]

Mine came pre-loaded with firmware 1.10 (it's written on the box), so I don't know if that is classed as the latest batch. The plug does have a ferrite core wrapped at the plug base and another at the end going into the unit. So either they've upgraded to this plug or I presume your original plug was like this?

I'll email them anyway. Still waiting on my Amazon delivery to test the isolator. If it works it works, but I'll still see if I can snag another plug.

edit - lol the AV isolator from Amazon makes things worse?! So thats going back. It introduces hum and noise that wasn't there before. Head-scratching. I'll see if I can get another plug.

Does sound more like a grounding issue. My mains plug is a full 3-pin plug with all pins (inc. each) metal. An IEC connector connects to the transformer unit.

 

[Audioboxer]

Does sound more like a grounding issue. My mains plug is a full 3-pin plug with all pins (inc. each) metal. An IEC connector connects to the transformer unit.

Yeah I emailed them about a plug, so we'll see if they can send me one

While it's the 'wrong' thing to do, I plugged my speakers into the headphones output and there is no speaker pop. So it's just coming off the phono output from the Fostex. I guess that's to be expected though as I don't have any issues with headphone usage.

For anyone who understands audio and hardware a LOT better than a newbie like myself, is this because the phono output is more powerful or something? Or more susceptible to grounding issues? As my speakers are active and no external amp is being used I presume the Fostex being powered and my speakers being powered is where the grounding issue is occurring.

I'm enjoying learning more about grounding issues, ferrite cores, audio humming/buzzing and more but at the same time it's a massive headache for a newbie that up until now when it comes to PC audio use I've only ever engaged with motherboard sound output (or a few years ago now I had a dedicated Xonar soundcard).

Never really had any issues with audible hum, buzz or pops with TV sound systems or even my record player that's hooked up to a Cambridge Audio amp and Roth speakers.

Bought this DAC for headphone use on PC as part of a big PC upgrade I done earlier this year, so it's been my first real headache with audio. I mostly use headphones but the pop on the passive speaker when not using headphones is just that annoying. It's a right piercing sound that is pretty unpleasant

My PC speakers aren't the most expensive, being a mid-range Edifier pair which only cost not too far north of £100, but for me it's enough as PC speaker use will mostly just be the odd YouTube video or the likes. They have a subout so I was planning on adding a sub in the not to distant future just to improve the lows a bit. Until then though I want to figure out how to sort this issue I have between the Fostex and the speakers. As I mentioned earlier I tested things with a Yamaha NX-50 powered set of speakers my PC audio was running through for the last few years and those too had the popping issue. So it's not as if my Edifier low-end speakers are faulty or anything. No pops from them either when hooking up to the motherboard sound directly.

What I find interesting and I have no knowledge of why it happens is the speaker popping only happens with the left speaker. On both the Edifier and Yamaha sets I have tried that is what I'd call the passive speaker. The right speaker is powered, where the volume control and power control is. A single phono output is used to connect the left speaker to the right. I guess that's just how it can happen? Is it anything to do with the passive speaker being the last "item" in the chain???

 

[Audioboxer]

I managed to scramble together some odds and ends power supplies/plugs from around the house off of other devices. Every single one of them still results in the passive speaker with a big pop any time a YouTube video is seeked through, or sound first comes out the speaker. None of my power supplies are rated as powerful or the same as the one dave posted above though.

Still, making me doubt if it's even the power supply now... Has anyone else got powered speakers hooked up to the phono outputs on this DAC? I genuinely think I've done everything I can at the PC end from getting a powered USB hub to using a ferrite attached USB cable.

The troubleshooting for me comes at the phono out point, there is no issue at all using headphones with the DAC over USB. Optical is obviously fine with headphones AND speakers. But I've read that before now, any issues with all of this just use optical...

I don't know enough about any of this to have experience to know if its the power supply, USB or something else. Optical works fine which makes me think its USB, but I've tried hooking up an AV isolator and it just made things worse. Most people online say when they went to an external USB hub it did the trick. Would rather not spend £50 on this and it's not USB https://www.amazon.co.uk/iFi-iDefen...rds=usb+noise+isolator&qid=1620053951&sr=8-18

I've hooked everything up via my laptop when it has its power coming from battery and I still have the issue.

What makes me more confused is most people online talk about hum and buzz when its a ground loop issue. My issue is a very sharp loud pop noise that comes out of one speaker only, the passive speaker in the powered speaker setup. As tested this is across two different powered speaker brands.

My PC and laptop are Windows 10 so it's not like I can try Mac over USB. My phone is a Galaxy S20 and I gave it a brief go hooking up over USB via a USB A to C adapter but I couldn't figure out how to make sound pass through the Fostex over USB or even know if it's possible with an Android/Galaxy phone (I read someone else mention doing it with an iPhone).

I wouldn't rule out something being faulty in my HPA4-BL phono outputs, but I don't think it's that.