GM120 diy amp

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Hi
I found very interesting and professionaly done diy GM120 amplifier .
What do you think about topology of this one ?

Unfortunately there is no PCB layout - maybe someone could make new PCB for that amp ?


Warning ! Forum is in chinesse...

link for GM120

Very sorry for poor english :eek:)
 

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The source of this schematic, if indeed it IS their schematic, is a company notorious for ripping off the designs, hard work, and creativity of others. Speaking as a member of this community, not on any official basis, I would encourage people NOT to visit that site or even consider spending a penny of money with them.
 
SY said:
The source of this schematic, if indeed it IS their schematic,
is a company notorious for ripping off the designs, hard work, and creativity of others.
Speaking as a member of this community, not on any official basis,
I would encourage people NOT to visit that site
or even consider spending a penny of money with them.

What company ??
And I promise I will not spend a penny!

With 'website', do you mean diyzone.net ??
If it is,
then is easy to avoid visiting links going there.
Besides, is too confusing with pages having "??????????" all over.
 
Ex-Moderator
Joined 2002
Every other project that I have seen coming from that site has been a copy of a commercial product or even another DIYer's project. The sole reason they exist is to make money unfairly from other people's work. I might even make an educated guess that one of the reasons that the service manuals from Pass Labs have been withdrawn is because of sites like diyzone.

Support them by buying their kits, and you are killing our hobby in the long term.
 
pinkmouse said:
Every other project that I have seen coming from that site has been a copy of a commercial product or even another DIYer's project. The sole reason they exist is to make money unfairly from other people's work. I might even make an educated guess that one of the reasons that the service manuals from Pass Labs have been withdrawn is because of sites like diyzone.

Support them by buying their kits, and you are killing our hobby in the long term.

Not every project, at least DZ has lincensed ULTIMA-PRE & POWER
from me since 2004, though the whole project has been delayed
about one year! :(

ULTIMA-POWER pdf as attached
 

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Visiting their site or not is not a big deal, just don't buy :p

Imagine a shop with tons of web visit but no sale, that must be quite amusing...


The GM120 in question is claimed to be of Goldmund in origin, but several other fellow DIYers in Taiwan had pointed out that the darn thing's circuit doesn't even look like Goldmund's.

I personally find that they often have some fairly wild circuit layout (wild as in wildcard, as you never know how bad it is going to be), and would really rather not touch it, even with a yardstick.


They have cloned or claimed to have cloned a lot of things, but IMHO the reason they are not sued yet is because maybe the original designer/manufacturer doesn't even consider their so called clone is even remotely like the original. :D
 
SY said:
Good thought, but they mostly haven't been sued because of where they are. That's probably why mtlin got a fee but the European, Aussie, and American engineers that have been ripped off haven't.


Well, IMHO mtlin12 didn't get much from them IIRC, but he was quite happy with them a while back and was championing for them then. Now I see a switch in his response to them, and maybe jumping boat after all that time, but anyways... back to the GM120...

Due to the design, the placement of the huge trannie, careful wiring is needed, and most builder who got GM120 was screaming... well, their speakers were humming that is, to the tune of your power company. It can be built to be quite, but one mistake in wire routing, then you'd be having a lot of fun with free music from your local power company. :D


And their cloned speaker, their first try was Response 2.5... which should be called DZ 2.5... the two speaker don't even weight anywhere close... MDF were totally costed down... and all I hear from DZ's 2.5 (powered by DZ's Aleph X) was music being turned into something quite chaoetic... it felt as if the sound was on the verge of becoming music, but not quite there... :devilr:
 
arthur said:
i don't visit and spend a penny from keces.com.tw
what a shame to insult his competitor


Keces does not sell kits anymore, nor am I working or helping them anymore.

And if you are not so blind as not being able to see something as far as your computer clearly, then you would be able to see that there are tons of people complaining about their products with regularity. All of them with one or more of symptoms below:

Poor layout.

Parts numbering all over the place. (See R10? now have fun finding R11)

Humming circuit

Oscillating power supply

Pre-amp with slower slew rate than your averge amp

Humming transformer

Tube amp with very weak circuit board that creak and bend whenever you remove or install a tube

Kits that comes with transformers so costed down that the transformer cannot provide the circuit with enough power due to overloading. (Personal experience on one of the few original kits that they sell.)

Circuits that are supposed to be isolated are built together and were affecting the normal operation of the kit (Their fabled CD PRO2).

Wrong component values that prevents the circuit from working (Their CD PRO2 kit again)

and more... If some of those DIYer that I know were to post here, the list will go on and on...


I'm not slamming them because I'm in the same business as them, because I'm NOT. I slam them simply because they put us in a bad light (Both DIYers and the people who lives in Taiwan), and because of his bad business practices.
 
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