You are right about something, but these amplifiers have been manufactured for a long time and users respond well. Confuses that many write about the old circuitry. 3M electrical tape is also praised.🙂
I have bought several of the FM clones over the course of the last 6 yrs. After the first purchase I was very impressed, especially for the cost.
I did a ton of research on the Chinese language sites as well as Baidu. For starters it should be understood that all the items on Aliexpress or Baidu are NOT all the same. There are several small shops making clones and some are somewhat "Boutique" if there is such a thing in China, and some just make poor quality look alikes.
What I did find is that the FM modules have proven difficult to replicate, however the module in the entry level Preamp FM155 was cracked with great success and that was my first purchase which unfortunately skewed my perception of the quality of China gear. Several Baidu sits recently claim they have cracked the latest 19200 HR modules as earlier ones had some noise when SE outs were used.
Most of the gear is single ended with the modules being Balanced to SE converters that have good rejection. The amps are not bridged and use a SE signal.
There is a "House" sound to FM gear that is spacious and gives outstanding vocal reproduction. I have heard better low bass and slam but the midrange is really special.
I did find a shop based in Beijing ( Oak Leaf )that makes very good units but they are expensive and bought a 222MK2 Phono stage from them.
The 711 schematic has a special high breakdown diode that gets subbed for a regular diode and that is the only thing I can find in good power amp clones other than matching of transistors and their branded power transistors. They also use 2 bridge rectifiers which gives lower forward resistance and is a ground loop breaker.
The PCB's have been cloned for identical layouts as well.
The FM amps are quasi complimentary like the Phase Linear and JLH amp so they do not use complimentary NPN / PNP outputs.
FWIW I sold my Levinson ML333 and kept the FM711 clone.
I did a ton of research on the Chinese language sites as well as Baidu. For starters it should be understood that all the items on Aliexpress or Baidu are NOT all the same. There are several small shops making clones and some are somewhat "Boutique" if there is such a thing in China, and some just make poor quality look alikes.
What I did find is that the FM modules have proven difficult to replicate, however the module in the entry level Preamp FM155 was cracked with great success and that was my first purchase which unfortunately skewed my perception of the quality of China gear. Several Baidu sits recently claim they have cracked the latest 19200 HR modules as earlier ones had some noise when SE outs were used.
Most of the gear is single ended with the modules being Balanced to SE converters that have good rejection. The amps are not bridged and use a SE signal.
There is a "House" sound to FM gear that is spacious and gives outstanding vocal reproduction. I have heard better low bass and slam but the midrange is really special.
I did find a shop based in Beijing ( Oak Leaf )that makes very good units but they are expensive and bought a 222MK2 Phono stage from them.
The 711 schematic has a special high breakdown diode that gets subbed for a regular diode and that is the only thing I can find in good power amp clones other than matching of transistors and their branded power transistors. They also use 2 bridge rectifiers which gives lower forward resistance and is a ground loop breaker.
The PCB's have been cloned for identical layouts as well.
The FM amps are quasi complimentary like the Phase Linear and JLH amp so they do not use complimentary NPN / PNP outputs.
FWIW I sold my Levinson ML333 and kept the FM711 clone.
Here is the Beijing Oak Leaf Seller that I got my FM222mk3 from.
https://item.taobao.com/item.htm?id=567101802896
It was a PITA to find these again as my new PC doesn't have all the old cookies, history or logins.
You may have to create a Taobao account which is difficult because some of the language is in graphics which text translation does not see.
On Taobao there are some sites w reviews as well as Baidu conversations.
The Weillang shop is generally regarded as good solid sound and the first ones to get good cracked modules. I got my FM155 from Weillang.
I bought an FM711mkII from Queenway but they are not coming up.
http://www2.erji.net/forum.php?mod=viewthread&tid=2113130.
Lots and lots of Chinese language threads as they seem obsessed with cloning expensive gear.
I will open the units and take some pics over the weekend.
https://item.taobao.com/item.htm?id=567101802896
It was a PITA to find these again as my new PC doesn't have all the old cookies, history or logins.
You may have to create a Taobao account which is difficult because some of the language is in graphics which text translation does not see.
On Taobao there are some sites w reviews as well as Baidu conversations.
The Weillang shop is generally regarded as good solid sound and the first ones to get good cracked modules. I got my FM155 from Weillang.
I bought an FM711mkII from Queenway but they are not coming up.
http://www2.erji.net/forum.php?mod=viewthread&tid=2113130.
Lots and lots of Chinese language threads as they seem obsessed with cloning expensive gear.
I will open the units and take some pics over the weekend.
I wanted to build a clone of FM 711 on such boards. After reading reviews about the original amplifier, which is a soft, relaxing tube amplifier, I refused in favor of 60+. There is nothing super unusual in the circuit, and the price is more than 2 times more expensive. Marketing and promotion of another Swiss one (read Dartzeel), which I also have. Has anyone built a clone of this amplifier and compared it with something else?
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I have the Dart Zeel as well and i would NOT call the FM soft by any measure. I call the Dart soft And sluggish actually. I also spent a bit w real Dart Zeel amps. The Dart is much closer to tube sound than the FM. the FM is a lot like the Goldmund sound with slightly thicker bass.
I have a Dartzeel 108 clone and an Accuphase A60 clone. Until I raised the quiescent current of the 108, it played as you write. Now both give out a very decent drive and the music is almost indistinguishable. It’s not correct to compare with tube ones, I dealt with them about 40 years ago, I forgot like a bad dream. We played tube amplifiers only on guitars. This is my opinion, I don’t force it on anyone.
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If your clone has a power supply of 46-48V DC at a mains voltage of 230V, with large radiators you can set the base resistors R23/R24 to 15-10 ohms (I have 11 ohms). If possible, control the temperature (I think 60-70 degrees) and find the best option based on distortions. I’ll give you a link to the forum, there’s a lot of interesting stuff there. Good luck.
https://www.diyaudio.com/community/threads/dartzeel-amp-schematic-build-this.134362/
https://www.diyaudio.com/community/threads/dartzeel-amp-schematic-build-this.134362/
It is he?https://www.diyaudio.com/community/threads/diy-class-a-b-amp-the-wolverine-build-thread.385920/ Which Dartzeel did you compare with? Original or clone? If my memory serves me, there are about 8 Chinese clones. Not all of them are good, since there are modifications that cannot even be compared with budget ones. And not all of them have good components, may the fans forgive me Aliexpress. But since the topic is about FM, which is praised, it would be an interesting comparison with Wolverine.
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