etoastw said:
Oh, I know -- don't worry, it's not getting too hot (I've been checking) -- I can't run it at high volumes anyway. Those thick aluminium slabs that my modules are on seem to be fairly effective heatsinks. (for other people reading, my modules are slightly different to the standard ones).
And the case is arriving soon
Still sounding good; my next effort is to find a decent source. I might have to buy a decent(ish) USB soundcard or something.
good etoastw, show you a pic of the preamp on board
we are doing research at preamp,
found that the thd of ne5532 is better than the op2134,
just because i cant find the new ne5532 here,
so i cant replace the op2134 with ne5532,
(i cant use 2nd hand components at mcd modules)
you can try to do it , ne5532 is cheap
we will do other researching of preamp.
happy Chinese new year
rg
this picture is +/-15v reg, 1k load, 6v rms output. 3x gain.
Attachments
alfsch said:
thanks alfsch
i'm doing a research of 20 types opamp, to test the charater of opamps running at diffrent loading, voltage and others.
but this is a topic of a hifi Magazine, perhaps will post after the Magazine sale.
thanks for your Proposal, could you tell me a list of op that you want to know about ?
rg
fumac
kittikun said:
hi kittikun
1. more output power : 420w at 1%(thd)
2. separate preamp and power amp.(you can take out the sub board of preamp.)
3, the power supply will be better(-10db noise lower).
4.less thd (pls ready the picture, test BW=30k)
because we got a set of ap system, so we can make it better .
rg
fumac
hi kitikun
mhzpower module datasheet with ap test
mhzpower-4 , 420w to 4ohm
http://www.mhzclassd.com/mhz-power 4 datasheet ver 0.4.pdf
pls down load
fumac
mhzpower module datasheet with ap test
mhzpower-4 , 420w to 4ohm
http://www.mhzclassd.com/mhz-power 4 datasheet ver 0.4.pdf
pls down load
fumac
Hi Famac,
The design looks very nice with very high specification. I like the wide bandwidth with very low distortions. The good thing is everything seems to be on board, including the thermal protection. I notice that this module can received only single end input. Can it accept balanced input?
Regards,
Kittikun
The design looks very nice with very high specification. I like the wide bandwidth with very low distortions. The good thing is everything seems to be on board, including the thermal protection. I notice that this module can received only single end input. Can it accept balanced input?
Regards,
Kittikun
kittikun said:
the mhzpower module is just the power stage . not including the preamp. also not including the buffer amp.
why we need the balance input , because we need a very low noise floor,
but , we have very low noise floor now . you can get the noise floor from the fft of data sheet.
(we use a normal transformer to test our amp, no regulate power supply , no 20k filter between class-d and AP system,
most of other damp testing is powered by regulated power supply and including a 20k filter between damp and AP)
most of amp is unbalance inside the case. because we hard to control the volume and hard to balance the gain at full balanced path (diy ).
some oen not like op-preamp(me too), i don't like to use a very good preamp(tube or class-A design),then to a op-amp then to power stage.
so we can use this one as:
source----> volume control -->class-A preamp---> mhzpower.
there are no more un-need opamp inside.
if we use a opamp to make the balanced input(like mcd-255 and other class-d modules ), the signal path will be very loog:
source----> volume control -->class-A preamp---> unbalance to balance ---->balance input(op inside the class-d)---> class-d amp
so mhzpower is good to some one good at diy. because they need to design the power supply and preamp and volume control.
simple is the best
rg
fumac
Hi Fumac,
In the MCD250 spec sheet, there is a soft power switch; namely, ¡°N104 enable pin¡±; used to powering on/off the module.
My plan is to build an integrated amp with full remote control. My remote control kit has a power on/off relay and it is controlled by the remote controller.
Instead of using the soft switch, can I use the relay to do a hard turn on (and off) of the amp? ie., leave J18/J19 open and supply power to the toroidal transformer.
In the MCD250 spec sheet, there is a soft power switch; namely, ¡°N104 enable pin¡±; used to powering on/off the module.
My plan is to build an integrated amp with full remote control. My remote control kit has a power on/off relay and it is controlled by the remote controller.
Instead of using the soft switch, can I use the relay to do a hard turn on (and off) of the amp? ie., leave J18/J19 open and supply power to the toroidal transformer.
PeterLeest said:
nice to heard about you are doing your project.
about the n104, this is a control pin for power down the power stage of MCD, if you have a remote control for the on/off, you can let the n104 keep opening, soft star inside MCD is funtionabel.
will have no pop noise when you turn on the power.
can you pose your pictures here ?
i like to take a look at your works
and how about the sound
rg
fumac
momoto said:Hi Fumac,
me is atmel wong
hello wong ,
nice to meet you here
"me is ...." saying is wrong English
you should say : i'm ....
but take it easy ,
most of the guy here are Friendly,
i'm not good at English too,
but they never laugh at my words
after you read more English here ,
you will be better
rg
fumac
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