Fosi Audio P3 Preamplifier & Headphone Amplifier Discussion

[Fosi Audio]

After the successful launch of our previous mini stereo amplifier, V3, we received significant attention and recognition from members. Thank you all!

As a brand committed to designing and developing products based on user feedback and demands, Fosi Audio swiftly responded to customer suggestions and feedback. We promptly assembled our team of engineers to embark on the development of our next-generation vacuum tube preamplifier and also a headphone amplifier, the P3, which belongs to the same series of V3. We'll reveal the development process information about it and collect your suggestions!

First, we'd like to share the concept map of this new preamplifier.

 

[JSmith]

Why using tubes?

I'd like a well priced preamp that measures very well, not using any tubes and with XLR... my feedback 2c.


JSmith

 

[brandonhall]

Agree about the tubes. I know they are popular on Amazon though. I love XLR as much as the next guy, but I understand not including them since this unit is a match for the RCA only amplifier. Nearly all these low-cost preamp/DACs include a remote.

 

[Steven Holt]

Thank you for sharing this. Lines are nice and clean, very elegant. I would like to see a DAC in in, though.

 

[Fosi Audio]

More details

 

[Fosi Audio]

Why using tubes?

I'd like a well priced preamp that measures very well, not using any tubes and with XLR... my feedback 2c.


JSmith

Can share your thoughts about why you do not like the tubes?

 

[JSmith]

Can share your thoughts about why you do not like the tubes?

To me in 2023 it's simply unnecessary and a waste of time unless using the most premium tubes and excellent design.

Being a company that makes affordable products, I don't see that happening... so I'd be concerned about distortion and noise levels coming from such a preamp.

Can you share preliminary test measurements?


JSmith

 

[Fosi Audio]

To me in 2023 it's simply unnecessary and a waste of time unless using the most premium tubes and excellent design.

Being a company that makes affordable products, I don't see that happening... so I'd be concerned about distortion and noise levels coming from such a preamp.

Can you share preliminary test measurements?


JSmith

Sure, we'll turn to our R&D team for the preliminary test measurements and share them with you.

 

[TonyJZX]

i think this isnt the type of device that this place likes

firstly... heaps of people hate tubes

2ndly... this is basically a tube stage buffer.... there's no switching, granted this isnt a line stage preamp as such, just in and out

3rdly... this place does not value bluetooth input, ESPECIALLY incongruous because its bluetooth then buffered by tubes!


this would suit a particular clientele, just not here

eg. if you made a plain line stage preamp with say 4-5 rca inputs and dual outputs w/ remote and maybe even add a BT input, people would be more receptive

 

[PiobGuy]

@Fosi Audio My thought I'd this, why not make this preamp/headphone amp with a switch to bypass the tubes? This way you have one device to please many. For me, sometimes I like the effect of a tube buffer, sometimes I don't. Also, I think 2 inputs and no Bluetooth would be better received. Keep up the amazing work!

 

[TonyJZX]

i appreciate seeing these new devices however i feel like ASR pidgeon holes themselves into certain genres

they love dacs, they love simple amps

there's a tuibe preamp sort of like this...

ebay find: MIAOLAI SA-1000 tube stage pre-amp w/ dual outputs

https://www.ebay.com/itm/175482568999 i literally LOL'ed at this one also in black https://www.ebay.com/itm/285074330772 its another one of those chinese design masterpieces slash frankensteins that ends up being completely bonkers again, how do they do it for the money? also translation...

www.audiosciencereview.com

the reason i like this one is that it encloses the tubes, i'm not a fan of exposed tubes

and yes i agree, a tube bypass button would be good

that SA-1000 would be perfect if it had bypass and a remote... and actually worked properly.

 

[Zek]

Can share your thoughts about why you do not like the tubes?

The problem with the tube is that the anode voltage must be at least 150-200V, where the tube works most linearly. This is not possible with a 12V preamplifier adapter.
If you want to make a real preamplifier, it should have at least 2-3 inputs, one of which should be balanced, and two outputs (balanced and unbalanced).

 

[Dzontra1007]

Agree with others, we don't need another tube preamp with bluetooth. Cut the costs use the same case as V3 with holes for cooling, also simple design classic preamplifier in A class if possible with quality components like V3.
I would like to see a simple switch selector in the front big volume button and two small ones for tone control. For inputs one optical and two RCA... and thats it.. price under 100 USD and success is quarantined


Something like this, its affordable and based on NAD 3020 design ..
Just found this amazing item on AliExpress. Check it out! RSD2,121.66 15%OFF | Fully Discrete Tone Board Preamp Pre-amp Volume Adjustment Pre-amplifier Tone Controller For Amplifier Board Refer UK NAD3020

https://a.aliexpress.com/_mPpPFkG

 

[TurtlePaul]

@FosiAudio

Since you are monitoring this forum, any thoughts on making the v4 using a compound amp so you can get opamp-like SINAD with post-filter feedback to remove the load dependance?

 

[Fosi Audio]

@FosiAudio

Since you are monitoring this forum, any thoughts on making the v4 using a compound amp so you can get opamp-like SINAD with post-filter feedback to remove the load dependance?

Yes, we have the thoughts. We'll probably make a monoblock similar to V3 but without load dependence first.

 

[abc1234]

Yes, we have the thoughts. We'll probably make a monoblock similar to V3 but without load dependence first.

It would be nice to have features like XLR input, 12v trigger as well

 

[Dzontra1007]

Yes, we have the thoughts. We'll probably make a monoblock similar to V3 but without load dependence first.

I would be interested in monoblocks but maybe with some other TI chip like TPA3221 which requires less voltage 24v vs 48v for 3225 an can deliver up to 200w. Much easier to supply it with 24v/10A integrated or external power supply

 

[ampguy]

no tubes, TRS or XLR balanced inputs, outstanding specs.

 

[Joe Smith]

Solid state monoblocks capable of clean 100 - 125 wpc at 8 ohms would definitely be of interest, also a SS preamp that would allow for multiple inputs, with a remote. These would be like a less expensive version of a Schiit Vidar x 2 plus a Sys preamp. At a much lower cost, I am sure. Say in the $150 range for a monoblock and $200 for the preamp, that would be a nice package for $500 all told.

I'm not into tubes...there are so many tube buffer like objects out there already...

 

[gafortiby]

May I suggest that you (Fosi) make two different products? There is a reason why Schiit makes the Magni AND the Vali and sells them both.
1. Preamp with tubes.
2. Preamp with no tubes.
Then tube-lovers and tube-haters will each have reasons to your products.

I don't want tubes because:
1. I want to stack and I don't want a lot of heat. The P3 looks like it would stack perfectly with V3. So I don't want something HOT sticking out the top.
2. Is this really a 100% tube amp? I'm guessing you are using the tube just for one of the stages, which means I don't get 100% of the tube sound anyway.
3. Tubes wear out. I don't want to replace burnt tubes.