Fosi Audio P3 Preamplifier & Headphone Amplifier Discussion

[Deckard71]

Based on what I've read the P3 runs the tubes at a higher voltage than other similar units. What that means in the end I don't know and I've been torn about keeping the P3 versus the P1 I already had on hand. I'm leaning toward keeping the P3 because I like the detents for the tone controls and enjoy the sound I get from it paired with the V3. I'll insert the P1 before making the final decision. Hell, I may just keep both. That's part of the fun with these inexpensive units is that the costs involved are so small.

Please post your impressions vs P1. I have a P1 and I like it, I do not know if P3 is an upgrade (better SINAD) or it is just adding Bluetooth and headphone amp, as I don’t need these 2 things

BTW in the P3 you cannot decrease Bass and Treble, unlike in P1. In the P3 the neutral position is all the way left, and you can only INCREASE bass and treble. This is weird

 

[Deckard71]

Received today and performing the first sound tests, with headphones and at the output of the DO300.
Very good impressions.

Have you tried the Tube color sounds in the DO300? I am considering the DO300 for that feature. In the meantime I use a Fosi P1 to get that tubish sound from my DAC (Eversolo). I guess that you have tried but was not convincing enough for you, as you have bought the Fosi P3? Or maybe you have bought it for the headphones?

 

[GGroch]

BTW in the P3 you cannot decrease Bass and Treble, unlike in P1. In the P3 the neutral position is all the way left, and you can only INCREASE bass and treble. This is weird

That is not the way my works. Center/ straight up detent is neutral. That is the way it is advertised as well: The bass and treble controls boast central detents for tone-defeating.

 

[Deckard71]

That is not the way my works. Center/ straight up detent is neutral. That is the way it is advertised as well: The bass and treble controls boast central detents for tone-defeating.

Look at this

Fosi Audio P3 - Review | ThePhonograph.net

Fosi Audio P3 | Headphone Amplifier | Bluetooth Amp | Vacuum amp/pre-amp | Fosi Audio P3, a brand new headphone Vacuum amp from Fosi Audio. The Fosi Audio P3 might look small and innocent but the little guy is actually[...]

www.thephonograph.net

 

[GGroch]

Look at this

To repeat. That is not the way my P3 works. The center position detent is tone defeat flat. To the left subtracts bass/treble from flat. To the right adds treble/bass from flat. This is how the Fosi Product Page says it works.

It would be idiotic to put a center detent and -/+ if there was no center or - or +. Perhaps Phonograph.net got some weird pre-production sample. My tone knobs do not scratch either.

 

[NoMoFoNo]

Please post your impressions vs P1. I have a P1 and I like it, I do not know if P3 is an upgrade (better SINAD) or it is just adding Bluetooth and headphone amp, as I don’t need these 2 things

BTW in the P3 you cannot decrease Bass and Treble, unlike in P1. In the P3 the neutral position is all the way left, and you can only INCREASE bass and treble. This is weird

No I don't think that is the case with the tone controls. Someone posted that earlier but it's an error. Neutral detents are with the knob indictors pointed up and there is a strong physical 'indent' at that point. It's clear from listening that this is the neutral point and bass and treble can both be lowered or raised from this neutral point.

I'll post more once I try the P1 again before making a decision or I may keep both. I agree with posters who don't want BT or headphone jack, and the P1 is often available for less than $40, but the P3 is nicely done and sounds good too.

 

[MAXIminiME]

i can confirm - fosi support sent details on bass/treble characteristics - thephonograph review has a wrong statement - i can hear this also audible.

+- 12 bass
+- 6 treble

see attachment for turnover freq

 

[joqueval]

Have you tried the Tube color sounds in the DO300? I am considering the DO300 for that feature. In the meantime I use a Fosi P1 to get that tubish sound from my DAC (Eversolo). I guess that you have tried but was not convincing enough for you, as you have bought the Fosi P3? Or maybe you have bought it for the headphones?

Hello. The first tests were done with the DO300. Even though it has filters, I use it in the basic setup, it's really an effect of the ESS DSP and I prefer that it only be dedicated to converting the signal. I'll be using it with the V3, but as there are always changes to the equipment, the micro size helps make it fast

 

[Deckard71]

Thanks. And did you find the Tube3 color mode effective? I think it is an interesting way to add the pleasant 2nd harmonics

 

[joqueval]

Hello.
@Deckard71
The differences in the ES9O39MSPRO's dsp are very subtle.
I hope to see the evolution with the warming of P·3
I have been testing with the balanced output of the DO300 direct to the active monitors and the rca output to the P3 and the same monitors.
Taking as a starting point that the signal from the DO300 is very good through the P3 in neutral position, a warmth is appreciated, which you can also adjust if you need with the tone controls.
@MAXIminiME Regarding the tone controls that you mention, it is true that they have positive and negative gain with 0 being the center.
In both the maximum and minimum positions the signal does not suffer distortion, something that reminds me of the equalization of analog mixing consoles.
At home I use D&R and Ecler mixers and they behave the same, you can twist the signal without degrading it.

 

[Deckard71]

Hello.
@Deckard71
The differences in the ES9O39MSPRO's dsp are very subtle.
I hope to see the evolution with the warming of P·3
I have been testing with the balanced output of the DO300 direct to the active monitors and the rca output to the P3 and the same monitors.
Taking as a starting point that the signal from the DO300 is very good through the P3 in neutral position, a warmth is appreciated, which you can also adjust if you need with the tone controls.
@MAXIminiME Regarding the tone controls that you mention, it is true that they have positive and negative gain with 0 being the center.
In both the maximum and minimum positions the signal does not suffer distortion, something that reminds me of the equalization of analog mixing consoles.
At home I use D&R and Ecler mixers and they behave the same, you can twist the signal without degrading it.

Thank you. I might try the P3. I like the P1, but as it is not so transparent, my brain is not in peace. But on the other hand I think that if we want the warmth and pleasure of second harmonics, which is a kind of (good) distortion, transparency is contradictory?

 

[joqueval]

Don't worry.
There are restless minds all over the world, myself included.
On the P1 you will surely notice a sound difference, but although everything is measurable, there are certain feelings that are not registered.
Why do I compare the P3 to an analog mixer?
Because the current digital tables are better in figures, in all of them, but it turns out that the classic analogue sounds with worse figures have a rounder, fatter and more enjoyable sound.
A very good tool to play with sound is DBX

 

[Deckard71]

I have just read this review in Amazon Germany:

I compared this back to back to a Fosi Audio P1, on my system: Dali Opticon 2 + Rotel A11 Tribute + Zen dac signature v2. I let the P3 burn-in for a day. I then started doing the A/B comparison, listening to the P3 first and, once I switched to the P1, I completely forgot about the comparison. The magic was back! So I listened to Grant Green - Born to be blue, just enjoying the music. I resumed the comparison with the stock tubes in each. First off, P1 sounds much louder than P3. When adjusting the volume on both units, P1 sounds better across the board: better dynamics and definition with a very nice soundstage depth. P3 sounds very average and a bit veiled. The sound is less open and a lot of the depth is lost with the P3. I then switched the tubes from P1 to P3 and from P3 to P1. With th 5654W, the P1 sounds warmer, hits harder, lower and it's softer on the highs. With the 6K4 the P1 is punchier, faster, has a bit more sparkle on the top end and voices are a bit more forward. I definitely prefer the 6K4 tubes. Now, the difference between the tubes is far less noticeable with the P3. It sounds average and a bit boring with both of them. It looks like Fosi Audio created a very average all-in-one unit with the P3. Get the P1, it's on another level when it comes to the sound quality.

 

[NoMoFoNo]

I've been listening to the P3 exclusively for a number of days, but based on the post above, will swap the P1 back in and do what the post above suggests, which is to listen with both the GE JANs and the generic 6K4s. It certainly seems possible that adding a headphone jack and BT to the P3 necessitated some changes/differences that might make the P1 more desirable for at least some listeners. One thing I wish they had kept in the P3 was the socketed op amps, that's for sure.

 

[Snowzy]

I have just read this review in Amazon Germany:

I compared this back to back to a Fosi Audio P1, on my system: Dali Opticon 2 + Rotel A11 Tribute + Zen dac signature v2. I let the P3 burn-in for a day. I then started doing the A/B comparison, listening to the P3 first and, once I switched to the P1, I completely forgot about the comparison. The magic was back! So I listened to Grant Green - Born to be blue, just enjoying the music. I resumed the comparison with the stock tubes in each. First off, P1 sounds much louder than P3. When adjusting the volume on both units, P1 sounds better across the board: better dynamics and definition with a very nice soundstage depth. P3 sounds very average and a bit veiled. The sound is less open and a lot of the depth is lost with the P3. I then switched the tubes from P1 to P3 and from P3 to P1. With th 5654W, the P1 sounds warmer, hits harder, lower and it's softer on the highs. With the 6K4 the P1 is punchier, faster, has a bit more sparkle on the top end and voices are a bit more forward. I definitely prefer the 6K4 tubes. Now, the difference between the tubes is far less noticeable with the P3. It sounds average and a bit boring with both of them. It looks like Fosi Audio created a very average all-in-one unit with the P3. Get the P1, it's on another level when it comes to the sound quality.

I agree, the P3 is quite basic, and the sound quality, unfortunately, doesn't meet my expectations, so I didn't keep it. It's a pity because the V3 is excellent. Even though I'm not a big fan of the Aiyima brand, the T6 Pro tube works wonderfully well with Soviet 6*1 tubes.

 

[Deckard71]

I agree, the P3 is quite basic, and the sound quality, unfortunately, doesn't meet my expectations, so I didn't keep it. It's a pity because the V3 is excellent. Even though I'm not a big fan of the Aiyima brand, the T6 Pro tube works wonderfully well with Soviet 6*1 tubes.

I looked at the Aiyima T6 but Bluetooth, DAC, headphone amps… are things I do not need. I hope someone will release a bit higher end tube preamp, ideally without transistors, just tubes. Of course I would be willing to pay 5x times

 

[Snowzy]

I looked at the Aiyima T6 but Bluetooth, DAC, headphone amps… are things I do not need. I hope someone will release a bit higher end tube preamp, ideally without transistors, just tubes. Of course I would be willing to pay 5x times

Yes, indeed, the T6 has many features, some useful and some not, depending on individual preferences. I use it a lot with Bluetooth. The P1 seems interesting and very affordable. The op-amps are replaceable, which piques my curiosity to compare it with the T6. I don't understand why Fosi didn't follow the path of the P1 by improving it and integrating it into a casing with a design similar to the V3. From what I can see, the P1 receives a lot of positive feedback

 

[NoMoFoNo]

As noted above I swapped the P1 with LME49720s and GE JAN5654W into my main system yesterday, driving my V3, to compare it to the P3 that I've been using over the last couple of weeks. I swapped the P3 back in today and will return the P1, which I had for several weeks before the P3 arrived.

My thoughts are that the P3 sounds more natural to my ears (and eyes). I like the way it looks better, which we all know makes a difference in sighted listening. Fosi has decided to increase their aesthetics and objective performance recently, instead of cranking out the same pieces along with Aiyima, Doug, FX Audio and other Chinese makers, and I appreciate that Fosi notes better objective performance of the P3 over the P1. My impression when re-inserting the P1 was that it sounded a little less natural, perhaps a touch bloated in the bass and less open up top (subjectively), although no doubt I couldn't pick one from the other in DBT.

I like them both, but I decided to keep the P3. It sounds great, looks more polished and I like to support what Fosi is doing at this point. The P3 is my keeper in this case.

 

[joqueval]

Today I have carried out tests with the P3 and the MC101 (Chips: TI TPA3116-Power: 100watts x2@4Ω - PSU-24V 4.5A),
Here the P3 did sound a little flatter, but in this case the difference in sound corresponds to the amplifier.
With the V3 the sound is fuller and the variation in tone adjustments is deeper.
That indicates that the P3 in each amp/speaker configuration will get a different result.

 

[JimFarrell29]

Hi folks. Near the beginning of the thread I posted how my first P3 failed some 15 minutes after trying it out.
Fosi support were great and sent me a new one, but eventually I tracked down the fault to a tiny smd capacitor which was loose. Fosi were kind enough to send me the capacitor values.
So armed with the correct values I eventually replaced two of the smd caps and the issue (no power) is fixed. If anyone has a similar problem and wishes more details please let me know.
I'm unreasonably pleased with myself, as I have never worked with tiny smd components before.