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fumac
01-04-2008, 09:47 AM
General Description
MCD stands for "MHz Class-D", a new branch of Class-D amplifier technology created by John Fu (Fumac) and Zhaolian Fu. This Class D amplifier technology operates at a relatively higher sampling frequency between 700kHz and 2.6MHz(factory selected).
This technology allows one to design amplifiers with excellent specification:
- High output power (up to 800w or higher),
- Very Low THD at full audio frequency (<0.00x%)
- Bandwidth 0-150kHz
- Small phase-shift
- Producing a Class-A alike sound.
All of these features can be achieved in a compact, cool running and environmental friendly circuitry. The superior sound quality suitable for wide variety of demanding applications.
Applications include:
1. HiFi audio
2. Active speaker
3. Professional amplifier
4. AV system
5. Ultrasonic high power AMP
MCD amplifier features two feedback paths (Figure 1). One is to produce the high frequency oscillation. The other is for audio frequency (AF) error feedback. This AF feedback includes the output filter to ensure load independent performance. By combining these two loops, One can create a system with both exceptional audio performance and technical indicators.
AF Error Feedback , Low THD
MCD has an audio frequency error feedback directly from the speaker terminal. This feedback can compensate distortion generated by the filter, so MCD can obtain a very low THD together with a very high power output.
The Higher The Sampling frequency ,
The More Detail
Previously, Class D technology ran below 100kHz. It was not fast enough for full-range (10Hz~20KHz) audio performance and most likely it was suitable for subwoofer (10Hz to 250Hz) applications only.
More recently, some Class D designers were able to increase the switching frequency to 200kHz-250kHz. This type of Class D amplifiers can produce close to audio full range (about 10hz-18KHz). Typically, these designs have great bass but poor treble. This kind of amplifiers can be found in home AV systems, sub-woofers, and medium class audio applications.
Bringing us up to date, there are some very good designs running at frequency in range 350kHz - 450KHz. Those are the very first designs that can reproduce the acceptable "full bandwidth" (10Hz~22kHz) with finesse.However, the large phase shift between bass and treble was a disadvantage in reproducing cohesive sound.
MCD runs at frequency between 700KHz to 2.6MHz (up to 6 times faster than other current technologies). It extends the amplifier bandwidth from below 0Hz to beyond 100KHz with a simple filter (150kHz Low Pass Filter). The high switching frequency makes all this possible.
The MCD will generate lower EMI, has lesser phase shift and a wider bandwidth than other Class-D amplifiers.

this is the datasheet of mcd-255:
http://www.mhzclassd.com/MCD-255%20datasheet(test%20version%201.1).pdf (http://www.mhzclassd.com/MCD-255%20datasheet(test%20version%201.1).pdf)
rg
fumac

edgewound
01-04-2008, 10:10 AM
It extends the amplifier bandwidth from below 0Hz to beyond 100KHz with a simple filter (150kHz Low Pass Filter).

DC in an audio amp....Excellent!!

This will be a boon to the reconing business.

Every home should have one....:applaud::D:bouncy:

timc
01-04-2008, 12:27 PM
Below 0 Hz.....thats gotta be a record.........

KromeDome
01-04-2008, 04:06 PM
Just the other day I was wondering what Bob Carver was up to lately...:p

fumac
01-04-2008, 04:32 PM
DC in an audio amp....Excellent!!

This will be a boon to the reconing business.

Every home should have one....:applaud::D:bouncy:


sorry
my english is not very well
is from 0 to 150k
you can take a look at the test pictures
thanks

fumac

JBL 4645
01-04-2008, 06:48 PM
Welcome to JBL fumac and happy new year. :)

Bugger I only clicked on the pdf file link, :banghead: I canít view it!!! So how much does this amplifier sale for, please say affordable because Iím a poor person, any pictures of this amplifier?

Why my Alesis RA300 have a frequency response from 10Hz to 50Khz. Not sure about my Marantz 1050 and 1030 I guess there dinosaurs.:(

So by having greater frequency response makes it easier for the recorded medium, to be heard in clear way?

Thanks. :)

fumac
01-05-2008, 04:57 AM
Welcome to JBL fumac and happy new year. :)

Bugger I only clicked on the pdf file link, :banghead: I canít view it!!! So how much does this amplifier sale for, please say affordable because Iím a poor person, any pictures of this amplifier?

Why my Alesis RA300 have a frequency response from 10Hz to 50Khz. Not sure about my Marantz 1050 and 1030 I guess there dinosaurs.:(

So by having greater frequency response makes it easier for the recorded medium, to be heard in clear way?

Thanks. :)

thank you JBL 4645
the pdf file can be downloaded
i have checked
if you need , mail me pls, and i will send the pdf to you

most of class-d amp have a poor frequency respond
and this will make the phase shift of treble ba large.
we also test it, the quite diffrent with 50k-3db and 150k-3db.

rg
fumac

hjames
01-05-2008, 06:20 AM
You really need to fix your PDF reader ... This is the 3rd time you couldn't download a PDF that was a perfectly working file.

The Adobe Acrobat Reader for Windows is a free program, download it right from Adobe at - http://www.adobe.com/products/acrobat/readstep2.html

Now, to get back to the topic of this thread- it didn't sound like fumac has made the amp modules available in small quantities (1 or 2) for the DIY crowd. If he has, we'd all like to know where and for how much!



Welcome to JBL fumac and happy new year. :)

Bugger I only clicked on the pdf file link, I canít view it!!! So how much does this amplifier sale for, please say affordable because Iím a poor person.
any pictures of this amplifier?



Thanks. :)

fumac
01-05-2008, 09:23 AM
here is the detal of mcd-255

1. FEATURES
* High output power:
130W to 8ohm
250W to 4ohm
400W to 2ohm
* Super wide bandwidth: (All load, Power stage)
5Hz-50 kHz +0/-0.05dB
3Hz-100kHz +0/-1dB
2Hz-150kHz +0/-3dB
* Low distortion (20Hz-22kHz, 6 ohm, Power stage)
THD < 0.006% @ 100Hz, 1KHz, 7KHz, 1W
THD < 0.008% @ 100Hz, 1KHz, 7KHz, 10W
THD < 0.040% @ 100Hz, 1KHz, 7KHz, 130W
* Very low phase shift: <8 degree between 20Hz-22kHz
* Very low output noise: <18uV (20Hz-22kHz,AC power supply)
* Dynamic range: 123dB
* High sample rate: 1MHz (+/-60KHz)
* Very low switching residue at output: 0.08V@ 1MHz(typical)
* Very high output current: 26A peak
* Balanced or unbalanced input
* Input impedance:
Pre-amp: 15K ohm (unbalanced)30K ohm (balanced)
Buffer: 18K ohm
Power stage: 6K
* Gain: 30.5dB
Pre-amp stage: 6dB (before POT)
Buffer: 9.5dB (after POT)
Power stage: 15dB (class-d)
* Full protection:
Speaker protection
Over current protection: activated at 26A
Over voltage protection: activated at >+/-49VDC
* Soft-on/off function: No Pop noise
* Sleep function: Can be controlled by MCU
* Ripple rejection: 68dB
* High efficiency: 91% (at 250w rms)
* Very low idle power loss: 4W-6W
* Not need for external heat sink (if loading>4ohm and module has open air)
*Main Voltage:
DC: from +/-38V to +/-48V or alternatively,
or AC: 30v-0-30v
2. Applications
* HiFi audio
* Active speaker
* Professional amplifier
* AV system
* Ultrasonic high power amplifier
3.Other information
*Size:110mm x 100mm x 50mm
*Weight: 500g

fumac
01-05-2008, 09:28 AM
You really need to fix your PDF reader ... This is the 3rd time you couldn't download a PDF that was a perfectly working file.

The Adobe Acrobat Reader for Windows is a free program, download it right from Adobe at - http://www.adobe.com/products/acrobat/readstep2.html

Now, to get back to the topic of this thread- it didn't sound like fumac has made the amp modules available in small quantities (1 or 2) for the DIY crowd. If he has, we'd all like to know where and for how much!

----------------
hi hjames
perhaps it's my http sever mistake , sorry for that :)
the mcd-255 is for diyers. yes , any body can try it
the price is 95eur/channel .(not including shipping cost )
if need , send me a mail pls
rg
fumac

KromeDome
01-05-2008, 09:30 AM
Is this available to us as a module?
How much per unit?
Where do we buy it?
Do you have any samples available?

Thanks!

edit:internet collision

fumac
01-05-2008, 09:58 AM
Is this available to us as a module?
How much per unit?
Where do we buy it?
Do you have any samples available?

Thanks!

edit:internet collision

hello KromeDome
yes this is a module for diyers.
mcd-255: 250w to 4ohm, 95eur per channel (not including shipping cost)
you can buy it from me (email: fumac1*gmail.com * is @)
and then i shipping to you through tnt or ups.
no free sample. sorry
and the agent of spain is here:
http://www.eden-audio.com/shop/

rg
fumac

JBL 4645
01-05-2008, 02:32 PM
You really need to fix your PDF reader ... This is the 3rd time you couldn't download a PDF that was a perfectly working file.

The Adobe Acrobat Reader for Windows is a free program, download it right from Adobe at - http://www.adobe.com/products/acrobat/readstep2.html

Now, to get back to the topic of this thread- it didn't sound like fumac has made the amp modules available in small quantities (1 or 2) for the DIY crowd. If he has, we'd all like to know where and for how much!

Yeah I know, Heather, should I uninstall the present pdf file program and upload a new pdf file program, because I have a few pdf files saved on the pc that I call (home cinema technical files).

Thanks.:)

And thanks as well to you fumac that was comforting to know, how many amplifiers use higher speed rates that is to reproduce the recorded soundtrack, and just how many of them are affordable or how about budget models to prime expensive types?

Oh one more thing, anything on the (Damping Factor)?


Thanks.:)

edgewound
01-05-2008, 02:42 PM
hello KromeDome
yes this is a module for diyers.
mcd-255: 250w to 4ohm, 95eur per channel (not including shipping cost)
you can buy it from me (email: fumac1*gmail.com * is @)
and then i shipping to you through tnt or ups.
no free sample. sorry
and the agent of spain is here:
http://www.eden-audio.com/shop/

rg
fumac

Will you be showing product at the CES show in Las Vegas Jan.7-10, 2008?

If so....where, please?

JBL 4645
01-05-2008, 02:45 PM
Will you be showing product at the CES show in Las Vegas Jan.7-10, 2008?

If so....where, please?

HmmÖ

fumac
01-05-2008, 07:15 PM
And thanks as well to you fumac that was comforting to know, how many amplifiers use higher speed rates that is to reproduce the recorded soundtrack,
and just how many of them are affordable or how about budget models to prime expensive types?

Oh one more thing, anything on the (Damping Factor)?


Thanks.:)

hi JBL 4645
1.Damping Factor is depend on the power supply and the filter caps of power.
so you can control the Damping Factor by diffrent transformer and add more caps
we have test : if we use 350VA a transformer and add 30,000uF caps , the Damping Factor is about 180~220(diffrent load will be diffrent).

2. about high speed amp:
many top audio amps have a very high speed .for example goldmund etc
high speed is very good to the dynamic and Accurate sound.

thanks
fumac

fumac
01-05-2008, 07:17 PM
Will you be showing product at the CES show in Las Vegas Jan.7-10, 2008?

If so....where, please?

hello edgewound
one of our design(odm for euro company) will do show at the ces show
because the nda, so i cant tell you the name of them.

rg
fumac

JBL 4645
01-05-2008, 07:35 PM
hi JBL 4645
1.Damping Factor is depend on the power supply and the filter caps of power.
so you can control the Damping Factor by diffrent transformer and add more caps
we have test : if we use 350VA a transformer and add 30,000uF caps , the Damping Factor is about 180~220(diffrent load will be diffrent).

2. about high speed amp:
many top audio amps have a very high speed .for example goldmund etc
high speed is very good to the dynamic and Accurate sound.

thanks
fumac

fumac

Thank you for replying to that, I only understand a little of this technical stuff regarding amplifiers, thou I have learned how to pick up good buys, the (damping factor) on my Alesis RA300 is (200) I remember someone telling me about 6 or 7 years ago that the high the number the better, or more controlled the bass is with tighter bass, something like that?

fumac
01-05-2008, 07:42 PM
fumac

Thank you for replying to that, I only understand a little of this technical stuff regarding amplifiers, thou I have learned how to pick up good buys, the (damping factor) on my Alesis RA300 is (200) I remember someone telling me about 6 or 7 years ago that the high the number the better, or more controlled the bass is with tighter bass, something like that?

yes
higher damping factor is more controlled the speaker
but in hifi amp of uk, they dont like too higher damping factor
because they want the bass softer.
rg
fumac

JBL 4645
01-06-2008, 12:32 AM
yes
higher damping factor is more controlled the speaker
but in hifi amp of uk, they dont like too higher damping factor
because they want the bass softer.
rg
fumac

fumac

Well Iím sure the new amplifiers that brought last year, granted they came out early 2000ís I only need a few more of them to (phase out) delete my Marantz amplifiers.

One other thing does this new amplifier come with any cooling fans built into it or does it run super cool, even at high output levels, within its technical tolerance levels? I sure must of the other Die Hard JBL members are eager to get there hands on it for test drive, with some dynamic mixes. :applaud:

fumac
01-06-2008, 12:45 AM
fumac

Well Iím sure the new amplifiers that brought last year, granted they came out early 2000ís I only need a few more of them to (phase out) delete my Marantz amplifiers.

One other thing does this new amplifier come with any cooling fans built into it or does it run super cool, even at high output levels, within its technical tolerance levels? I sure must of the other Die Hard JBL members are eager to get there hands on it for test drive, with some dynamic mixes. :applaud:

i use jbl speakers too ,:)
our amp does not need fans when you drive a load speakers > 4ohm
because the efficiency of the mcd-255 is about 91%.
thanks
fumac

yggdrasil
01-06-2008, 04:30 AM
Hi Fumac.

I have placed a few orders in china, and have had varying luck with regards to shipping cost, all dependent on the sellers preferences. For our convenience can you please set up shipping cost examples for europe and the us?

fumac
01-06-2008, 05:18 AM
Hi Fumac.

I have placed a few orders in china, and have had varying luck with regards to shipping cost, all dependent on the sellers preferences. For our convenience can you please set up shipping cost examples for europe and the us?

hi yggdrasil,
nice to meet you
we use
ups to euro :first 0.5kg, 17eur, other 0.5kg 6euro per 0.5kg,
DHL to usa : first:0.5kg, 16eur, other 0.5kg 5euro/0.5kg
the weight of 2xmodule is 1.2kg(including pakege).
so to euro is 29eur, to usa is 26eur.

rg
fumac