ICIETDIYEUR
Active Member
It's for a single mono block at full capacity
-
WANTED: Happy members who like to discuss audio and other topics related to our interest. Desire to learn and share knowledge of science required. There are many reviews of audio hardware and expert members to help answer your questions. Click here to have your audio equipment measured for free!
Fosi Audio V3 Amplifier Review
- Thread starter amirm
- Start date
It's for a single mono block at full capacity
Do you mean 2 V3 monos. If so it should come with the PSU filter and if so, will be fine. But this thread is for the stereo V3.
Yes, 2 V3 mono with filter.
Thank you
In general: Never use one PSU for two TPA3255 amps that are not syncronized. This is the same with many single supply D-amps.
You may not hear the sound this problem produces, but the amps will get hot with no load. Don't do it and no filter will help. Don't try to be smarter than Texas Instruments that designed it!
You may not hear the sound this problem produces, but the amps will get hot with no load. Don't do it and no filter will help. Don't try to be smarter than Texas Instruments that designed it!
they haven't arrived yet, if so I'll return them without trying them, I wouldn't want to break the speakers.
ICIETDIYEUR
Active Member
Wolf11Man write: "Don't try to be smarter than Texas Instruments that designed it!"
That's what I like to read because it's ALWAYS true
That's what I like to read because it's ALWAYS true
In most cases the speaker are not in danger. You should notice a cross oscillation with a high pitch from the tweeter.
Both amps have a very high working frequency, that is not critical at all, filtered at he amp output and inaudible. So low quality oscillators are used. In allmost any case two identical amps are a a few Hz appart. This difference produces audible sound if they share a single supply. You may only notice the two amps getting warm without a signal, while a single amp on the same supply will stay cold.
In China circumventing rules is concidered smart, western technical knowledge is seen as negotiable. If the consumer doesn't realize the fault, fine. If the product breaks, he is far away. So instead of using the TI sollution, they design a filter that tries to prevent the x-coupling over the power supply. Notice "tries to prevent". It may only push it down, but not remove it.
Sure one can try to compose some filter, but it will have influence on the direct flow of power to the amp board. Aside from extra part cost, there will be new negative effects.
The TI sollution only needs a change of connection, may be a "master-single-slave" switch and a two wire connection. You got to understand what you do, of course. Here is a link to the TI document how to do it right, for two or more amps of the TPA32xx family sharing one power supply. No Chinese filter shortcut mentioned!
Sorry Fosi Audio. If you don't do your homework, it is not unpolite to say it loud and clear.
Both amps have a very high working frequency, that is not critical at all, filtered at he amp output and inaudible. So low quality oscillators are used. In allmost any case two identical amps are a a few Hz appart. This difference produces audible sound if they share a single supply. You may only notice the two amps getting warm without a signal, while a single amp on the same supply will stay cold.
In China circumventing rules is concidered smart, western technical knowledge is seen as negotiable. If the consumer doesn't realize the fault, fine. If the product breaks, he is far away. So instead of using the TI sollution, they design a filter that tries to prevent the x-coupling over the power supply. Notice "tries to prevent". It may only push it down, but not remove it.
Sure one can try to compose some filter, but it will have influence on the direct flow of power to the amp board. Aside from extra part cost, there will be new negative effects.
The TI sollution only needs a change of connection, may be a "master-single-slave" switch and a two wire connection. You got to understand what you do, of course. Here is a link to the TI document how to do it right, for two or more amps of the TPA32xx family sharing one power supply. No Chinese filter shortcut mentioned!
Sorry Fosi Audio. If you don't do your homework, it is not unpolite to say it loud and clear.
ICIETDIYEUR
Active Member
Well said Wolf11Man
... but all class D amp distributors make mistakes
... but all class D amp distributors make mistakes
Well I would prefer to go with tried and tested. There are so many tpa3255 implementations, unless I have seen proper measurements I would not blindly buy them. Rather use unsymmetric inputs.
It is interesting that you recommend some random Ali express board and on the other hand critisize well known and tested brands. Even though I understand the point you make.
ICIETDIYEUR
Active Member
Why not?
The well-known and tested brands are also present on ALIEXPRESS.
There are other excellent technicians who are not necessarily with well-known brands...
The well-known and tested brands are also present on ALIEXPRESS.
There are other excellent technicians who are not necessarily with well-known brands...
I'm simply pissed off by people that call them selves "electronic designers" or "developer" and don't even understand a basic data sheet. There is even a Texas Instruments technical assistance in English and Chinese they could use...
It looks to me as if those well known audio brands are just doing the best copies they can find.
This golden board doesn't look as if it was made by anyone less capable than Fosi, Ayima or Sure/ Wondom. There is no clear concept in any of these brands products. No consequent handwriting in the design. It seems to me the good ones are sometimes done by accident, not because of serious development work.
For example there is a very cheap Sure board, that has a copper heat spreader under the aluminum heat sink. This very clever feature is not found under many "premium" boards from "well known brands". Sure/Wondom is usually known for mediocre designs, best used in vending machines and other noise producing gear, not high end audio products.
It looks to me as if those well known audio brands are just doing the best copies they can find.
This golden board doesn't look as if it was made by anyone less capable than Fosi, Ayima or Sure/ Wondom. There is no clear concept in any of these brands products. No consequent handwriting in the design. It seems to me the good ones are sometimes done by accident, not because of serious development work.
For example there is a very cheap Sure board, that has a copper heat spreader under the aluminum heat sink. This very clever feature is not found under many "premium" boards from "well known brands". Sure/Wondom is usually known for mediocre designs, best used in vending machines and other noise producing gear, not high end audio products.
ICIETDIYEUR
Active Member
LOL
ICIETDIYEUR
Active Member
People hi
For those who would be interested, I have 'transcribed' the 'MOD' used with the O-NOORUS D1 amplifier on this FOSI V3 STEREO amplifier which, although not having 'PFFB', has practically the same pattern and the same component values and which will allow you to improve the response curve in the high band of the amplifier whatever the load (4 or 8 Ohms).
Here is the diagram and indications ->
If you are having trouble reaching the locations to solder the 220pF capacitors on the top of the PCB then you can still do the following instead:->
Have a nice weekend
For those who would be interested, I have 'transcribed' the 'MOD' used with the O-NOORUS D1 amplifier on this FOSI V3 STEREO amplifier which, although not having 'PFFB', has practically the same pattern and the same component values and which will allow you to improve the response curve in the high band of the amplifier whatever the load (4 or 8 Ohms).
Here is the diagram and indications ->
If you are having trouble reaching the locations to solder the 220pF capacitors on the top of the PCB then you can still do the following instead:->
Have a nice weekend
What tube pre do you recommend and do you leave it on or turn it off when not in use?
ICIETDIYEUR
Active Member
LOL
Do you have some knowledge of electronics ?
Do you have some knowledge of electronics ?
No, I saw that the LED on the power supply no longer turns on, I also tried with another power cable, nothing to do, I will return them to Amazon.LOL
Do you have some knowledge of electronics ?
ICIETDIYEUR
Active Member
Which power supply did you use (DC voltage) as you only state 10A (current). What load (speaker impedance) did you use ? Did you use a preamplifier or a DAC with volume control for example to connect it ?
I used the 220V 10A power supply, first I connected the Wiim pro plus as a Pre, it didn't sound good, then I switched to a passive pre, much better.
The speakers are 4 ohm
ICIETDIYEUR
Active Member
It seems that you are unfortunately not the only one to have a bad experience with this amplifier reference at FOSI AUDIO if we observe the various customer complaints on a large number of internet forums...
AMIR has carried out the review of this device which seems quite decent but it seems to have somehow 'insisted' concerning the power supply to be used since we can see (added in red clearly visible) on the photo of the power supply that it is in 5A and not 10A.
Is it due to 'chance': I don't think so...
I had earlier in this post alerted about the use of a particular component used in the STEREO version of the V3 and it could be very likely that my remark is valid for this model:
this component called 'NTC' (see the picture below) seems to me 'too weak' to be used with a 10A power supply without taking the risk of its 'destruction'.
On your device, a simple test (with the volume at minimum) and this 'shunted' device would be enough to bring it back to life, I'm sure, and you could then gently increase the volume to the maximum to ensure that the amplifier works normally again.
Let's hope that it's only about that, otherwise 'it's much more serious, Doctor', and in this case FOSI would have to thoroughly review 'its copy'.
Unfortunately, I cannot be of much help to you in view of the distance that separates us, but it was with great pleasure
If I were you, as it was ordered on AMAZON, I would simply send it back since it is guaranteed and will no longer be so as soon as it has been opened.
Afterwards, I would ask myself several times the question of using an identical model, but that's just my humble opinion
Kind regards.
AMIR has carried out the review of this device which seems quite decent but it seems to have somehow 'insisted' concerning the power supply to be used since we can see (added in red clearly visible) on the photo of the power supply that it is in 5A and not 10A.
Is it due to 'chance': I don't think so...
I had earlier in this post alerted about the use of a particular component used in the STEREO version of the V3 and it could be very likely that my remark is valid for this model:
this component called 'NTC' (see the picture below) seems to me 'too weak' to be used with a 10A power supply without taking the risk of its 'destruction'.
On your device, a simple test (with the volume at minimum) and this 'shunted' device would be enough to bring it back to life, I'm sure, and you could then gently increase the volume to the maximum to ensure that the amplifier works normally again.
Let's hope that it's only about that, otherwise 'it's much more serious, Doctor', and in this case FOSI would have to thoroughly review 'its copy'.
Unfortunately, I cannot be of much help to you in view of the distance that separates us, but it was with great pleasure
If I were you, as it was ordered on AMAZON, I would simply send it back since it is guaranteed and will no longer be so as soon as it has been opened.
Afterwards, I would ask myself several times the question of using an identical model, but that's just my humble opinion
Kind regards.
Similar threads
- Poll
