Need help in interpreting the specs of Philips FW548C CD mini hi-fi system (1996)

sudokpr

Member
Joined
Sep 16, 2021
Messages
90
Points
18
Location
Bengaluru
Background
Hi, I am a newbie here. Starting my journey into the world of HiFi music
We have this "mini" hi-fi system from Philips which was bought in the 90's.
The input sources doesn't work (CD and Tape) but the AUX IN connected to any mobile works fine.
The speakers are working fine too.
I am exploring options to hook up an external DAC (with bluetooth) and play music via bluetooth. With all the latest Bluetooth codecs with higher bit rates, this should work fine for casual listening.
In case if I plan to upgrade the speakers, I wanted to understand the amplifier specs and found that the power rating is very low.
I wanted to confirm if my understanding is correct or not.


Philips FW548C specs
amplifier
• 1500 watts PMPO
• 2 x 100 watts, 2 x 15 watts Music Power
• 2 x 50 watts, 2 x 7 watts RMS,
10% THD, 6 Ohm, 1 kHz
Refer to the attached manual

If I have read this correctly, it is saying that the front channel peak power output is 100 watts with 15 watts RMS power. Please correct me if I am wrong.
For the front channels they mention it as "Music Power" whereas for the surround channels they mention as "RMS".
Is "Music Power" different than RMS?

If my understanding is correct, the power rating is too low for some of new speakers.
Most of the new speakers specs have a minimum recommended amplifier power to be 20 watts.

Should just go for a new mini amplifier (Aiyima, Topping etc.) and a new set of speakers?
Can anyone recommend a way to bringing this to life to play from sources of today's technology?

Picture for reference
Screenshot 2023-03-22 at 2.22.11 PM.png
 

Attachments

If you look at the THD it says 10% that's pretty high for a good music listening I think. seniors can help with more info on that, if you want to have a better listening then its better to go with a new amp and speakers
 
Background
Hi, I am a newbie here. Starting my journey into the world of HiFi music
We have this "mini" hi-fi system from Philips which was bought in the 90's.
The input sources doesn't work (CD and Tape) but the AUX IN connected to any mobile works fine.
The speakers are working fine too.
I am exploring options to hook up an external DAC (with bluetooth) and play music via bluetooth. With all the latest Bluetooth codecs with higher bit rates, this should work fine for casual listening.
In case if I plan to upgrade the speakers, I wanted to understand the amplifier specs and found that the power rating is very low.
I wanted to confirm if my understanding is correct or not.


Philips FW548C specs

Refer to the attached manual

If I have read this correctly, it is saying that the front channel peak power output is 100 watts with 15 watts RMS power. Please correct me if I am wrong.
For the front channels they mention it as "Music Power" whereas for the surround channels they mention as "RMS".
Is "Music Power" different than RMS?

If my understanding is correct, the power rating is too low for some of new speakers.
Most of the new speakers specs have a minimum recommended amplifier power to be 20 watts.

Should just go for a new mini amplifier (Aiyima, Topping etc.) and a new set of speakers?
Can anyone recommend a way to bringing this to life to play from sources of today's technology?

Picture for reference
View attachment 75969
If you look at the THD it says 10% that's pretty high for a good music listening I think. seniors can help with more info on that, if you want to have a better listening then its better to go with a new amp and speakers
 
@sudokpr
if you can manage to open the music system see which IC it uses for amplification. And from internet find out real performance of that IC. Usually power at 0.1 % distortion is acceptable to most people.
regards.
edit :
I checked the service manual. it has AN7164 IC in BTL mode with class G added circuit for more power when required by switching rail voltage. The ic max. power is 30watts at 0.3 % distortion.
 
Last edited:
Background
Hi, I am a newbie here. Starting my journey into the world of HiFi music
We have this "mini" hi-fi system from Philips which was bought in the 90's.
The input sources doesn't work (CD and Tape) but the AUX IN connected to any mobile works fine.
The speakers are working fine too.
I am exploring options to hook up an external DAC (with bluetooth) and play music via bluetooth. With all the latest Bluetooth codecs with higher bit rates, this should work fine for casual listening.
In case if I plan to upgrade the speakers, I wanted to understand the amplifier specs and found that the power rating is very low.
I wanted to confirm if my understanding is correct or not.


Philips FW548C specs

Refer to the attached manual

If I have read this correctly, it is saying that the front channel peak power output is 100 watts with 15 watts RMS power. Please correct me if I am wrong.
For the front channels they mention it as "Music Power" whereas for the surround channels they mention as "RMS".
Is "Music Power" different than RMS?
Hello sudokpr,

Several; points to be made on your post:

Philips FW548C specs
Philips FW548C specs

amplifier
• 1500 watts PMPO
• 2 x 100 watts, 2 x 15 watts Music Power
• 2 x 50 watts, 2 x 7 watts RMS,
10% THD, 6 Ohm, 1 kHz
Forget the 1500 Watts PMPO (Peak Music Power Output).... this is a fantasy spec created by marketing folks to sell their products.
No such (PMPO) specification exists formally, and it is usually 10 Times the Total RMS power of all channels put together.

The specs you have posted for the amplifier state that it claims to deliver 50 Watts RMS each to the Front Left & Right Channels + 15 watts each to the 2 rear Channels.

Total Power Delivered: 50+50+15+15 = 130 Watts RMS Total, into a 6 Ohm speaker load, with 10% Distortion.

Actually even this will most probably not be delivered simultaneously, with all channels driver, that that's another story! :rolleyes:

Hiten has done some great digging and identified the AN7164 IC used for amplification.

This IC delivers a max of 47 Watts into a 8 Ohm load, so 50 Watts into a 6 Ohm speaker is a reasonable extrapolation.
The IC operates in Bridge Mode. You need not concern yourself too much with this, just that the Bridge Mode allows 4x the power to be delivered from the power supply voltage. its an internal matter between the IC and the circuit designer. The consumer need not be concerned, except for the fact that in a Bridge Mode amp, BOTH speaker terminals are 'Live' and one of them cannot be grounded. In your system, all the wiring, including to the speakers is internal, and Not user configurable.

Your system is, as you have correctly said, Good for casual listening. The amp & Speakers have been chosen for optimal results, and if I may..... I would term the setup as "Low Fi".

I would not advice U spending money on external speakers to attach to this setup. Stay with this setup, or replace it completely (new amp + Speakers + Source), for an upgrade.

Yes you can attach an external BlueTooth receiver. Should work well.
 
The specs you have posted for the amplifier state that it claims to deliver 50 Watts RMS each to the Front Left & Right Channels + 15 watts each to the 2 rear Channels.
This clearly explains the amplifier specs.
So both the Front and the surround channel specs are written on the same line. For some reason my brain thought that the first line is for the front channels (Peak and RMS) and the second line is for the surrounds. 🤦‍♂️

Thanks a lot for your inputs @musiclovr @Hiten and @IndianEars 🙇‍♂️
 
You guys are super smart. Similarly, can you look into the following amp circuitry for the SONY MHC RX90, vs. the Philips FW 750C, the FW 395C and the MHC RX99? Which one has better internal circuitry? I have heard the RX90 and the RX99 and I find they sound great, the FW philips series have even more refined sound quality.

Its hard to get to hear sound from a brand new one these days, do these amps loose "quality" and "strength" over time? For e.g. the RX90 below sounds fantastic!






Hello sudokpr,

Several; points to be made on your post:

Philips FW548C specs
Philips FW548C specs


Forget the 1500 Watts PMPO (Peak Music Power Output).... this is a fantasy spec created by marketing folks to sell their products.
No such (PMPO) specification exists formally, and it is usually 10 Times the Total RMS power of all channels put together.

The specs you have posted for the amplifier state that it claims to deliver 50 Watts RMS each to the Front Left & Right Channels + 15 watts each to the 2 rear Channels.

Total Power Delivered: 50+50+15+15 = 130 Watts RMS Total, into a 6 Ohm speaker load, with 10% Distortion.

Actually even this will most probably not be delivered simultaneously, with all channels driver, that that's another story! :rolleyes:

Hiten has done some great digging and identified the AN7164 IC used for amplification.

This IC delivers a max of 47 Watts into a 8 Ohm load, so 50 Watts into a 6 Ohm speaker is a reasonable extrapolation.
The IC operates in Bridge Mode. You need not concern yourself too much with this, just that the Bridge Mode allows 4x the power to be delivered from the power supply voltage. its an internal matter between the IC and the circuit designer. The consumer need not be concerned, except for the fact that in a Bridge Mode amp, BOTH speaker terminals are 'Live' and one of them cannot be grounded. In your system, all the wiring, including to the speakers is internal, and Not user configurable.

Your system is, as you have correctly said, Good for casual listening. The amp & Speakers have been chosen for optimal results, and if I may..... I would term the setup as "Low Fi".

I would not advice U spending money on external speakers to attach to this setup. Stay with this setup, or replace it completely (new amp + Speakers + Source), for an upgrade.

Yes you can attach an external BlueTooth receiver. Should work well.
 
Its hard to get to hear sound from a brand new one these days, do these amps loose "quality" and "strength" over time? For e.g. the RX90 below sounds fantastic!
ALL amps degrade in Sound Quality to some extent, due to ageing of the electrolytic capacitors used in the Power Supply and often used at the output stage, in lower cost products such as this
 
Back
Top