Fosi Audio P4 Preamplifier Review

[gvl]

Before tone controls.

Thank you. Can you please also clarify the input impedance value? It’s missing from the specs.

 

[trevor_bartram]

Motorized volume control & input selection relays for a paltry $80, incredible. Surely a Wiim beating integrated will be the next step, follow the money!

 

[xNORgate]

Give me more details please.

Analog plus digital I/Os (balanced ADC+DAC) would allow and provide flexibility in doing EQ, even for those who wish to use 'cheater' cables between RCA/XLR I/Os.

I'd fundme that project, without giving you grief for throwing in different opamps; that I'd never entertain to use. What do you think?

 

[Njoy]

@Fosi Audio What is the input impedance?

 

[elshaddai]

I wonder if/when we'll ever see a high-pass filter from @Fosi Audio - either on an amp or preamp with a sub out. Seems odd not to have the option yet.

 

[gvl]

@Fosi Audio What is the input impedance?

It has been asked multiple times already but they are not responding, which probably means it’s low.

 

[xevman]

It has been asked multiple times already but they are not responding, which probably means it’s low.

I'd assume the same aswell, dropping from 2vrms to 1vrms input from my wiim didnt result in much of a change in volume

 

[Njoy]

Thank you. Can you please also clarify the input impedance value? It’s missing from the specs

Oh,I didn't see your post.No matter how low it is,they should mention it.Topping does.

 

[Ropeburn]

If it says 24-36V, then you can only use 24-36V power supply, but not 48V.


How do you use the 4-8 channels then?

@phoenixdogfan probably meant input channels, but I can think of how I'd use 4 output channels: 2 for mains, 2 to subwoofer(s). If mains have a basic adjustable 24db/oct highpass option, plus mono sum switch for sub outs, it would turn this thing into a true market gap filler, even if it cost 200 or 250. Make it 300 if they added selectable XLR/RCA in and out. Won't be as tiny anymore, obviously, but who cares.

Seriously, an affordable, good quality stereo preamp with simple but effective analog subwoofer management is perhaps THE biggest market gap I see right now.

 

[Carl-Fosi Audio]

Thank you. Can you please also clarify the input impedance value? It’s missing from the specs.

10.1kΩ-60.1kΩ

 

[Ropeburn]

10.1kΩ-60.1Ω

Do you mean 10 kOhm input and 60 Ohm output impedance?

 

[Carl-Fosi Audio]

Do you mean 10 kOhm input and 60 Ohm output impedance?

10.1kΩ at max volume and 60.1kΩ at minimum volume.

 

[gvl]

10.1kΩ at max volume and 60.1kΩ at minimum volume.

Thank you, these are sane values I think.

 

[Talisman]

In the next products I would like to see a high pass filter with a sub output, as the A5 from douk audio did.
And then, even if I know that many do not care, a good old "loudness" button to click in the evening for low volume listening, audiophiles have campaigned against it, but in all the amplifiers and preamplifiers in which it was not there I have always missed it

 

[Njoy]

10.1kΩ at max volume and 60.1kΩ at minimum volume.

Thank you.Will order one.

 

[Carl-Fosi Audio]

In the next products I would like to see a high pass filter with a sub output, as the A5 from douk audio did.
And then, even if I know that many do not care, a good old "loudness" button to click in the evening for low volume listening, audiophiles have campaigned against it, but in all the amplifiers and preamplifiers in which it was not there I have always missed it

Thank you for your suggestions, HPF will be released soon, keep an eye on our new products.

 

[morillon]

It's just one of the most common successes encountered in audio...anyone with a little experience knows it or has been confronted with it...

i just ask...

without balance the subject is sensitive....

 

[OG_Tiredofthe_BS]

It's just one of the most common successes encountered in audio...anyone with a little experience knows it or has been confronted with it...

i just ask...

without balance the subject is sensitive....

Ok. Were you planning on purchasing this unit and doing research?

 

[morillon]

Ok. Were you planning on purchasing this unit and doing research?

just registered to "attack" me like this... amazing...
no comment..

 

[antcollinet]

Come on with the BS, man. You're just being an insufferable know-it-all looking for reasons to complain.

This is a great product at a great price.
.

Please keep personal insults out of it.

Not what we do here.