Fosi Audio P4 Preamplifier Review

[Sokel]

View attachment 437043
I don't think so

Add a decent and safe analog VC to it and it will become expensive too, trust me.

 

[Calypso1]

Strange... is available on Amazon AU. Without going into it too much, I gather this could be something to do with current/pending international trade dramas.

eBay, seems to be available in general, US, AU, UK, DE etc.


JSmith

Out of stock in Amazon Canada right now but available to purchase.

 

[kemmler3D]

Really impressive for $80... the only complaint I can imagine is the non-internal power supply, but for the money and performance, complaints are just silly at this point. We are talking transparent audio gear for the price of a slightly exuberant bar tab.

 

[morillon]

remains the behavior, the l/r balance of the potentiometer to observe and measure

 

[amirm]

Maybe we need 2 user inputs: a rating for the engineering of the product and 1 for the value of the product.

The poll is not a scientific instrument. You can choose to use it however you like. When I recommend a product, I look at it as if I were in the market for one, would I buy it or not. I can consider the price in that, or not. You can do the same.

 

[Carl-Fosi Audio]

I spent $55 to replace my wiper blades yesterday… I know I could have done better…but maybe Fosi could do wiper blades next….with optional power supply of course to keep cost down.

Wiper Blades?

Seriously or am I misunderstand?

 

[Carl-Fosi Audio]

a "balance" is essentially useful, coupled with a mono function...
(I'm afraid that in recent decades it has been a bit forgotten balance/mono (or the funny forgotten function of the Denon 70s...."null balance"..useful))

Maybe you can help me remember.

 

[JSmith]

Wiper Blades?

I think it was just a bit of a joke, tied in with how cheap Fosi products are... as in I could get wiper blades or a new amp.

Whilst you're here, I did appreciate that in the marketing for the P4 that the whole opamp thing was toned down, just pointing out to customers that it is replaceable without going into other claims.


JSmith

 

[Carl-Fosi Audio]

I'd like to know if the P4 performance would be improved further (near maximum output) with a slightly higher voltage power supply? I mean, the opamp used should be easily able to use 15VDC rails.

Maybe it wouldn't make a jot of difference and may tax the electrolytic caps used, so forgive the probably numpty question (the use of the word 'numpty' is currently a kind of hot topic in the UK at this time )

Dont do that. A 15V power supply will damage P4.

 

[solderdude]

The internal 12V input DCDC converter usually only works between 10.8V and 13.2V input voltage so don't use anything other than a regulated 12V DC power supply.

 

[morillon]

Maybe you can help me remember.

?

 

[DavidM1]

Products are designed by engineers (science). Prices are set by marketers (not science).

I’ve never understood the prejudice against marketing. There is significant science behind good marketing and Fosi’s marketing has been very good. It’s not just pricing it is also through timing and availability of releases, product design and in their use of online promotion, engagement with social media and branding.

Fosi has gone from obscurity to prominence very quickly with products meeting or exceeding customer expectations. They are a case study in successful marketing.

 

[mike70]

I’ve never understood the prejudice against marketing. There is significant science behind good marketing and Fosi’s marketing has been very good. It’s not just pricing it is also through timing and availability of releases, product design and in their use of online promotion, engagement with social media and branding.

Fosi has gone from obscurity to prominence very quickly with products meeting or exceeding customer expectations. They are a case study in successful marketing.

marketers also use science (brain / social effects) and engineers can lie to sell a product (hiend niche?)

I think generally we use the "role" or the "bad behavior" as we need to proof our preconceptions.

Life isn't black or white, many colours out there.

 

[howard416]

No measurements for channel imbalance?

 

[xNORgate]

Thank you for the review.

FOSI designers will need a new challenge since they seemed to have mastered the DAC and PreAmp circuitry at reasonable costs.
May I suggest to FOSI brain-trust to get busy marrying their DAC-plus-PreAmp expertise and give us a proper ADC+DAC combo?
Some of us go either way but are also balanced!

 

[Carl-Fosi Audio]

Thank you for the review.

FOSI designers will need a new challenge since they seemed to have mastered the DAC and PreAmp circuitry at reasonable costs.
May I suggest to FOSI brain-trust to get busy marrying their DAC-plus-PreAmp expertise and give us a proper ADC+DAC combo?
Some of us go either way but are also balanced!

Give me more details please.

 

[Carl-Fosi Audio]

Is pre-out just hardwired to the RCA output or there’s more to it, eg it’s taken before tone controls?

Before tone controls.

 

[telemike]

Give me more details please.

If you could take the P4 and marry it with the V3 mono amps and ZD3 DAC in one larger chassis that would make a killer integrated amp

 

[Carl-Fosi Audio]

A set of Balanced input and out would cover it for a lot of peoples gear. It's small enough to place right beside a dac.

It would be much bigger than P4, the XLR is too large for such a small chassis.

 

[Watire]

For edification sake, would it be possible to compare the measured output of some current DACs direct and through the P4 ?