howdy fumac, good to have you on board. there are a lot of Class D/T devices in the marketplace. What distinguishes your products. Can you provide more detail ?
vizion said:
hello vizion
MCD is different with other d-amps
the most different is :it's running at 1mhz, 2x to 10x speed than others
high speed can give us good solution
1. mcd band width.
most of class-d just can have a poor freq response
for example,
a class-d running at 100k, the response is about 0~1k.
most of this type just be used at bass boost.
a class-d at 400k, the response is about 0~40k.
this is a good one for audio,
but the phase shift is worst, large than 50DG at 20khz.
our MCD running at 1mhz
the freq response : 0~50k(0db), to 100k(-1db), to 150k(-3db)
the phase shift at 20khz is less than 10dG.
this is good for hifi audio
this give us faster sound than others,
this is quite different with others
perhaps u will ask , why others cant up to 100k or 200k
because if do, the pwm idle signal will be very large.
a picture for u
this is the first point
will go on
my English not well ,
if don't understand what i'm saying ,ask more pls
fumac
Attachments
Re: I like this amplifier
hello langtuhanoi
nice to heard about that u like this amp.
thanks
i will post some test pic for u . also will post how to use it to make a damp .
perhaps this can help u
too busy this days , will contiune ,but not sure when ,
sorry
rg
fumac
langtuhanoi said:
hello langtuhanoi
nice to heard about that u like this amp.
thanks
i will post some test pic for u . also will post how to use it to make a damp .
perhaps this can help u
too busy this days , will contiune ,but not sure when ,
sorry
rg
fumac
vizion
sorry for the delay
we have talk about the treble, on my last reply
some body say that not need up to 1mhz
we dont agree this .
because we can easy to know ( not technolegy saying)
bassboost ----50k~100k pwm---0~1000hz , just for bass
full rang system -----250k~500k pwm --0~18khz,or upto 22k, but poor treble, large phase shift at 10~20k, large than 40~60dg
so we need to goto 1mhz or 2.56mhz is better.
on this level ,
the frequncy respont upto 150khz-3db,
if upto 2.56mhz ,the frequncy respont will goto 500khz -3db ,
this will cause the zero phase shift at 20k
u can take a look , the good class-AB or class-A amp ,
they have a frequncy respont at 0~100khz ,or higher.
this will couse the treble sweet and fast.
we r now designing a class-A preamp
the frequncy respont is 0~1mhz -3db (have tested it )
then i 'd like to talk about bass
rg
fumac
sorry for the delay
we have talk about the treble, on my last reply
some body say that not need up to 1mhz
we dont agree this .
because we can easy to know ( not technolegy saying)
bassboost ----50k~100k pwm---0~1000hz , just for bass
full rang system -----250k~500k pwm --0~18khz,or upto 22k, but poor treble, large phase shift at 10~20k, large than 40~60dg
so we need to goto 1mhz or 2.56mhz is better.
on this level ,
the frequncy respont upto 150khz-3db,
if upto 2.56mhz ,the frequncy respont will goto 500khz -3db ,
this will cause the zero phase shift at 20k
u can take a look , the good class-AB or class-A amp ,
they have a frequncy respont at 0~100khz ,or higher.
this will couse the treble sweet and fast.
we r now designing a class-A preamp
the frequncy respont is 0~1mhz -3db (have tested it )
then i 'd like to talk about bass
rg
fumac
just one way to get a good bass:
huge current output and low output Impedance.
from class-AB, we can Parallel output stage to get a large output current,
most of class-D can output a huge current , this can make the speakers under control.
one of 400w class-d amp from another company ,
just have a 20A peak current.
mcd-255 can output 26A peak current, just 20mohm output Impedance.
perhaps some body think that not need 26A peak at just 250w output.
but we don't think so
sometimes u don't know how many current the speakers need.
at some spacial times,
an 8ohm speaker will down to 6ohm or 4 ohm ...perhaps 2ohm ...
because the speaker is a moving Coil inside Magnet, so it will output Inverter power to the amp.
this will Offset a part of the output current from amps.
so a huge output current is need ,
more is better than less.
Merry Christmas
rg
fumac
huge current output and low output Impedance.
from class-AB, we can Parallel output stage to get a large output current,
most of class-D can output a huge current , this can make the speakers under control.
one of 400w class-d amp from another company ,
just have a 20A peak current.
mcd-255 can output 26A peak current, just 20mohm output Impedance.
perhaps some body think that not need 26A peak at just 250w output.
but we don't think so
sometimes u don't know how many current the speakers need.
at some spacial times,
an 8ohm speaker will down to 6ohm or 4 ohm ...perhaps 2ohm ...
because the speaker is a moving Coil inside Magnet, so it will output Inverter power to the amp.
this will Offset a part of the output current from amps.
so a huge output current is need ,
more is better than less.
Merry Christmas
rg
fumac
howdy fumac,
i'm just a newbie. which is better to power class D amplifiers ? battery power, smps or transformers ?
i'm just a newbie. which is better to power class D amplifiers ? battery power, smps or transformers ?
Fumac,
I was send mail to you.
I don't see the back of this amplifier,
So, it have RCA, XLR balanced input or digital input SPDIF???
Thank
I was send mail to you.
I don't see the back of this amplifier,
So, it have RCA, XLR balanced input or digital input SPDIF???
Thank
oklangtuhanoi said:
i dont talk about the biz of my amp here, so we can talk about it at eamil ,
rg
fumac
vizion said:
my choice: battery power, transformers ,others , smps
we r designing a strange smps for hifi audio, but too busy , have been delay.
after the smps ok , i cant tell u more.
rg
fumac
about the power supply
battery power is the best choice of any type amps, or preamp
a clean, Stability, high output current is the best for any amps.
but this will rise the cost and too heavy
so , we have another chose: the transformers
we use transformer for a long time , safe, also not very duty if we have very good Rectifying and filtering. also low cost, and high output current.
about the smps, light and easy to fit different voltage on the world, and high effect
but : duty, shorter life than transformer, low output current ,
a slow regulator loop.....
all this will harm the hifi audio.
so we need a different thinking to change this .
in fact a good smps is much expensive than a transformer.
rg
fumac
battery power is the best choice of any type amps, or preamp
a clean, Stability, high output current is the best for any amps.
but this will rise the cost and too heavy
so , we have another chose: the transformers
we use transformer for a long time , safe, also not very duty if we have very good Rectifying and filtering. also low cost, and high output current.
about the smps, light and easy to fit different voltage on the world, and high effect
but : duty, shorter life than transformer, low output current ,
a slow regulator loop.....
all this will harm the hifi audio.
so we need a different thinking to change this .
in fact a good smps is much expensive than a transformer.
rg
fumac
I was intrigued by the 1Mhz thing and contacted them about it. However per-channel samples are too much $$ for a quick test. Maybe they're concerned with people ripping off their design... Beats me.
EnvisionAudio said:
hello envision
nice to meet u here again
our price is same all over the world.
sure thing , in china many many products are at low price
but the price is deepened on the performance and function.
also depend on the No.
u are a designer and sale , if some body just calculate ur components cost then tell u a low price , do u happy?
good design, good price.
good sound , good price.
this is a rule in hifi audio market.
i think u do know this .
our mcd is a full function amp, not just a module
he (yes we call mcd--he) not just a power amp module
also include
over voltage protection
over current protection
speaker protection(we never break any speakers)
soft star,
No_pop on/off
sleep function.
balanced or unbalanced input
preamp use an op chip from BB(dip , can take out just by hand), any one can replace it with other type op .diyers can do test for chips.
also including input output pins for volume control
u can connet a pot or a "r-2r " volume control
not just this,
inside the board, there r a bridge and 3300ufx6 for power supply.
all this just xxeur for 250w output .
u just buy a transformer and connections that he can output good sound for u 🙂
if use other modules, u need to add manymnay other boards to make it run.
they need 😛ower board, speaker protection, also extent ion heat sink.
is mcd really expensive?
thanks
fumac
Attachments
fumac said:
No, you have explained more now. I got a couple picutres and many of those pictures have already been posted here. For example, I did not know that the power supply (except transformer) was included. Nor did I know that it has all those features. With the additional information, your prices seem much more reasonable.
Your amplifier does not need additional heatsinking?
Thanks!
EnvisionAudio said:
No extra heatsink required in Fumac's modules, confirmed.
I already talked with him about this.
hi EnvisionAudio
sorry for that i have no pdf now,
because i want the words in pdf is true,
so need time to check and check it .
also , my English is not well , so delay, sorry for my mistake.
Nor did I know that it has all those features.
----------------------------------
the most important feature is that he can singing with a good sound for u .
low Distortion ,balanced and nature sound.
Your amplifier does not need additional heat sinking?
---------------------------------
yes, keep it in a open air place, u needn't add heat sinking .
the best chose is :
Transfer the heat to ur case (even a steal case, the best is an Aluminum case),
then u can keep it in a closed box.
the idle power of mcd is about 4w~6W(depend on the working Voltage)
if u want him to drive 2ohm load , then u need buy a fan for him.
we just sale it as a 250w version,
but he can output more than 380w at low load(our OC protection is 26A peak, so can drive low load ).
sorry for that i have no pdf now,
because i want the words in pdf is true,
so need time to check and check it .
also , my English is not well , so delay, sorry for my mistake.
Nor did I know that it has all those features.
----------------------------------
the most important feature is that he can singing with a good sound for u .
low Distortion ,balanced and nature sound.
Your amplifier does not need additional heat sinking?
---------------------------------
yes, keep it in a open air place, u needn't add heat sinking .
the best chose is :
Transfer the heat to ur case (even a steal case, the best is an Aluminum case),
then u can keep it in a closed box.
the idle power of mcd is about 4w~6W(depend on the working Voltage)
if u want him to drive 2ohm load , then u need buy a fan for him.
we just sale it as a 250w version,
but he can output more than 380w at low load(our OC protection is 26A peak, so can drive low load ).
zox2003 said:
hello zox2003
nice to meet u
we r now finding the agent of our moduls in usa
if u do need the mcd, send me a email
thanks
fumac
Kooka said:
thanks kooka
u are the first user of mcd-II outside china
thanks for ur trust
keep touch
fumac
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