Does the volume knob on your amp wiggleing? Mine is rock solid.If you do not bother too much about the wiggle in the volume knob, you won’t be disappointed.
Does the volume knob on your amp wiggleing? Mine is rock solid.If you do not bother too much about the wiggle in the volume knob, you won’t be disappointed.
I’ve one myself, and have used one of a friend, both with a wiggling volume knob. This has been acknowledged by Fosi as something that should be considered ‘normal’, i.e. not a reason to send it back.Does the volume knob on your amp wiggleing? Mine is rock solid.
I’ve one myself, and have used one of a friend, both with a wiggling volume knob
Tb10d.I need something like this for a pair of ATMOS speakers. I was just about to pull the trigger on this, thinking that for about a hundred bucks I would not find anything better, when I though "I wonder if Fosi makes something that measures as well, but without the bluetooth." A Quick Look at their product lineup and I think the answer is "no, they don't" but am I missing something?
Yes, you're missing out on the fosi V3, slightly better performance in terms of noise and distortion, more power, no BluetoothI need something like this for a pair of ATMOS speakers. I was just about to pull the trigger on this, thinking that for about a hundred bucks I would not find anything better, when I though "I wonder if Fosi makes something that measures as well, but without the bluetooth." A Quick Look at their product lineup and I think the answer is "no, they don't" but am I missing something?
Tb10d.
Yes, you're missing out on the fosi V3, slightly better performance in terms of noise and distortion, more power, no Bluetooth
Don't forget about the new ZA3 as well.....buy one now for stereo and one later to set up a mono-block system....Jes sayin'I'm guessing the V3 is the slightly better choice for me
That looks interesting/promising. I'll probably get a v3 with the 48v power supply for now, since I need something "immediately," and if I am happy with it for my Atmos use, that ZA3 (if it performs well based on objective criteria, etc) may also be in my future. The key will be whether they get something more linear this time, because it would need to be neutral with a speaker that is 14ohms in the >5khz region, like the following. (My use for now is with speakers that are less challenging.)Don't forget about the new ZA3 as well.....buy one now for stereo and one later to set up a mono-block system....Jes sayin'
Don't forget about the new ZA3 as well.....buy one now for stereo and one later to set up a mono-block system....Jes sayin'
You may have saved me from a mistake. Can you tell me what's going on?The za3 mono mode is utter nonsense... Just don't connect second input in the v3 and you'll get same ...
Nothing particularly serious, simply the mono mode of the Za3 provides very little more power than the stereo mode, and the gain can be trivially attributed to the fact that the power supply can concentrate on a single channel, which is why the same effect is obtained by connecting just one channel of the V3 and therefore using all the current that the power supply makes available for just one channel.You may have saved me from a mistake. Can you tell me what's going on?
Fair enough. The V3 with 48v power supply and the variable line output (ie, 2024 version) is about $100 direct from Fosi at present, so its hard to argue about value, that's for sure, and I have one on the way.Nothing particularly serious, simply the mono mode of the Za3 provides very little more power than the stereo mode, and the gain can be trivially attributed to the fact that the power supply can concentrate on a single channel, which is why the same effect is obtained by connecting just one channel of the V3 and therefore using all the current that the power supply makes available for just one channel.
I currently believe that even using it only as a power amp, the V3 offers better value than any product out there.
Amir does not test that I'm afraid.I was curious whether something in the measurements show that you can consume almost all the power in a single channel if you want to. I haven't learned where to find that objectively in the measurements amirm posts. I would like to learn how to see that.
Curious BT20A Pro High Temperature Issues...
I have three BT20A Pro amps. One was purchased with the Fosi provided standard power supply (can't remember if it was 32v or 36v). Two were purchased with Fosi provided 48v power supplies.
When idling or running on the standard power supply the amp is just slightly warm to the touch. But when simply idling (or playing) on 48v they become so hot that I'm reluctant to touch them. I swapped the PS's around to see if the heating problem was due to the amps or due to the PS voltage. The heating issue clearly followed the 48v supplies. Based on this exercise it is clear to me that 48v causes extremely high idling temperatures. Whereas idling or running on the standard (32v or 36v) supply the case temps are just slightly above ambient.
I then noticed that 48v idling temps would drop to ambient if I simply unplugged one of the two RCA input cables. Didn't matter if it was left or right side. With both RCA's connected, idling temps would soar to "do not touch" territory. But disconnecting one RCA would cause idling temps to drop again.
I tried this on all three amps and identical behavior was observed on all of them.
My audio source is a Denon DNP-800NE Music Streamer which passes through a Fosi P1 tube preamp (Denon > P1 > BT20APro).
Same high temp behavior is observed when connected directly to the Denon (ie without the P1 in the loop: Denon > BT20APro) and persists whether the Denon or the P1 are powered on or off.
This got me to thinking that the RCA's from the P1 and/or the Denon may have a shared ring/ground (I have not yet confirmed this as several other probjects are taking the priority at the moment).
Question: Could such shared ring/ground on the RCA cables cause the BT20A Pro to run such high temps when running on 48v PS? But not on the lower 32v/36v PS?
Has anyone else observed similar behavior with their BT20A Pro on 48v? And does unplugging one of the RCA's cause the idling temps to drop?
Rgds...
- John
To be fair, he says drilling the holes addressed the problems. Holes are cheap to drill. Seems like regardless of use the holes are an improvement so @FosiAudio should consider adding ventilation to future cases, or connecting the heat sink directly to the case so that it's not air gapped (Aiyima does this).I believe that the problem is not the thermal resistance of a small 100 euro domestic amplifier.
I think the problem is that you intend to use this little amp as if it were a professional power amp for outdoor parties, it is not and you shouldn't expect it to for 100 Euros.
I suggest you orient yourself on the excellent Behringer A800, which is certainly much more suitable for your use case.
https://www.audiosciencereview.com/...behringer-a800-stereo-amplifier-review.10499/
Any recommendations?a power bar with a12v trigger
I'll speculate he's talking about power strips designed to sense if a PC is on or off (by AC current draw), and turn other outlets on the same strip on or off with the PC. Might work if the upstream equipment draws enough power. There are solutions to rig something sensing audio input on/off, like the Radio Labs ST-ACR2, but that's more than the amp itself, and needs more stuff to make it work for this.Any recommendations?