FM Acoustics 711 schematic

[amplidude]

Hi all.
Does any of you have schematic for the fm711 amplifier made by swiss fm acoustics?

 

[levinson mark]

711 schematic​

 

[llwhtt]

Anything on the 300A?

Craig

 

[levinson mark]

FM Acoustics 300

 

[llwhtt]

Thank you so much!!!! Now I'll compare to the schematic I drew years ago. Mine is an earlier version with the black input modules.

 

[levinson mark]

FM17420-MJL21194 ???

 

[mlloyd1]

thanks for sharing the images and schematics.
i always wondered what general topology they used.
i have to admit i was a little surprised by the use of a quasi-sym OPS in this day and age ...

 

[levinson mark]

FM-711

 

[adason]

I was wrong about that feedback, I did not notice it was drawn alt the way up.
Anyway, interesting output. If the boards would be available, i would try it.

 

[diyiggy]

Some noticed an important side of FM Acoustics sound is about their main transformer and huge smoothing cap....

 

[gage88]

Fm acoustics is very ingenious circuit. Many diagram were wrong in some forum. If one could not understand its knowhow,it would be a very crappy push-pull amplifier. It needs to adjust correctly.
There are two "black boxs" in every Fm acoustics power ampifier yet, they are made of five transistors. Of course, Fm acoustics are very clear amp ,if it were made correctly.

 

[analog_sa]

Fm acoustics is very ingenious circuit.

Please explain the ingenious part cause it looks rather pedestrian to me.

Every time i heard one of their amps it produced a very impressive sound, pretty much the way i would have wanted my big Jap amps to sound when i was a teenager, only they didn't. Power, control, fast transients. Today this wears me out quickly; it is a very competent high nfb sound but terms like relaxed or musical just don't come to mind.

 

[gage88]

Please explain the ingenious part cause it looks rather pedestrian to me.

Every time i heard one of their amps it produced a very impressive sound, pretty much the way i would have wanted my big Jap amps to sound when i was a teenager, only they didn't. Power, control, fast transients. Today this wears me out quickly; it is a very competent high nfb sound but terms like relaxed or musical just don't come to mind.

Oh,it was told by my Italy friend Mr.Martinelli Giovanni. He sent FMA some goods. Many diagram were wrong in some forum. he told me if it were so easy, same amp would be full of the market. But it is not real market situation. hehe.

 

[tiefbassuebertr]

According some guys FM Acoustics provide outstanding sonic quality with their power- and pre-amplifier models.
Unfortunately, no meaningful test reports can be found anywhere (e. g. stereophile).

Several internal parts are special made for FM acoustics (e. g. potted modules and TO-3/TO247 power output devices), additional no service manuals and circuit diagrams are published - that means a repair service is only possible at FM acoustics itself.
check out the internals of this pre-amplifier under
https://audiodripper.jp/used-audio/prepower-amplifier/fm-acoustics-fm245-used-preamp
in the attachments.
Furthermore there are only cheap standard parts in use - particularly concerning electrolytics, volume control and selector parts (push button switches, relay).
Last image from post #4 show burned power amp front end PCB (FM-1000). This limits reliability and life expectancy.

Is the sound quality of the genuine model (from this topic) "FM-711" exceptionally good and comparable to the Halcro DM38 ? - go to
https://www.stereophile.com/solidpoweramps/1004halcro/index.html
the not really very special circuit does not actually let expect that.
At the prices that are asked (as mentioned from FM acoustics for absolute precision handcrafted work and additional selection of used high precision parts) actually hard to believe.

- and what about the clones from far east ?
https://de.aliexpress.com/i/1005001810250125.html?gatewayAdapt=glo2deu

some other URL's
https://www.fmacoustics.com
https://www.cnet.com/tech/home-ente...o-an-audio-system-costs-as-much-as-a-ferrari/
https://www.diyaudio.com/community/...absolute-state-of-the-art.154067/#post1963472
https://www.diyaudio.com/community/threads/fm-acoustics.18556/
http://www.myav.com.tw/bbs/printthread.php?s=6687b0a34b584a425c456ac713c4efde&threadid=413907

FM300A clone
https://www.alibaba.com/product-detail/BRZHIFI-FM300A-FM-Acoustics-Original-99_1600427940161.html

P.S.: what means this term under
https://www.fmacoustics.com
"Make sure to use a music system or external speakers on computers and phones!" ?

 

[chchyong89]

My friend got an unit from aliexpress, and he said it "sounds very similar" to the original unit.. maybe he really heard one somewhere, idk...

I have listened to it once and here's some of my honest opinion to it:
High : Soft high, not glare like some of the amplifiers
Mid: a bit on the recessed side, I am expecting a bit more body from il dilvo voices...
Low: You are not getting a solid punch bass like other high damping factors amp, But overall bass present in a very soft and relax manner.

For my ears its a very good, comfort, relax sounding amp to live with, good for large genre of choices. But me as an electronics engineer myself, I can't stay with something with single layer PCB, it just look too 70th, I would rather get something else with better layout engineering efforts and better advancement of PCB fabrication works.

 

[Paroxod4]

Has anyone compared the clone Dartzeel and FM Acoustics with Aliexpress?

 

[cumbb]

Keep your feet on the ground: There is nothing unusual about these circuits, nor are the components and construction. And the sound also meets the expectations.
Don't be fooled by tinsel or glossy magazines or price tags;-)

 

[cumbb]

Has anyone compared the clone Dartzeel and FM Acoustics with Aliexpress?

"Dartzel": halfwave symmetrical pp circuit. Do look for Hiraga Classe A or Le Monstre. These will sound better. Or look for Nelsons pp-amps (F4, F5, F7?-)

 

[Paroxod4]

You probably need to be a cool specialist in order to determine the sound of the amplifier according to the scheme. The question is simple, in the subject, are there those who compared exactly the clones that the Chinese rivet in batches. In the original, they are one of the most expensive amplifiers in the world. I agree that there is nothing outstanding in the circuit (according to competent radio electronics), just like in Higara which they solder. I read the forums, I was not impressed. I have a clone of Dartzeel (the boards are not Chinese on the original parts) and a clone of Accupface 60. They play at a fairly high level. Almost all the circuits are simple, old compared to new brands, but they make music beautifully.The idea was to collect FM Acoustics.

 

[Tolik]

they are one of the most expensive amplifiers in the world.

There are very expensive collections on the fashion tv, made of insulation tape, garbage bags, garden meshes e t c.
It’s a vision of the author, and noting more from one side, and possibility for some people to show others, that they able to throw $10000 for insulation tape “dress” from the other side.