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Old 13th April 2011, 01:24 AM   #1601
wahab is offline wahab  Algeria
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Quote:
Originally Posted by jacco vermeulen View Post
Lo-D is Hitachi, it's Lo-D first, then Hitachi.
.
There s 2 versions /
HMA 7500
HMA 7500 MK2

GM is blatant (simplified) copy of the second one....
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Old 13th April 2011, 01:26 AM   #1602
tinitus is offline tinitus  Europe
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Originally Posted by CHARLIEB999 View Post
....or is mimicry the fundamental purpose here?
that was the intention of the thread starter, who is long gone

we have been through this a hundred times
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Old 13th April 2011, 01:55 AM   #1603
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Smile LO-D???

Quote:
Originally Posted by jacco vermeulen View Post
Lo-D is Hitachi, it's Lo-D first, then Hitachi.
GM is Goldmund.

The Project J12 is a monaural power amp that was manufactured overhere by Sphinx.
1st to come to mind for something that shares many characteristics with the Gioldmund (minus the retail price).
there you go with the LO-D!! what the hell is LO-D its Hitachi the same designer of your Goldmund device!!!! same company that makes the output devices for the GM!!! so the GM is LO-D too? what do you mean by LO-D? explain to me please?
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Old 13th April 2011, 02:25 AM   #1604
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Quote:
Originally Posted by CHARLIEB999 View Post
building it?
Wouldn't dream of it.

Sure, Mr Yvon knicked the basic outline straight from the Hitachi amp, too young at the time to have developed his own IP.
Still doesn't mean a stripped and tuned HMA will be an equivalent.
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Old 13th April 2011, 02:35 AM   #1605
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one of the nicest sounding amplifiers I have heard was designed by someone named "Bay" not too sure of spelling. but he was a japanese guy who had a workshop in a place near Cricklewood I seem to recall. was very good used 1 or 2 2SK135's that was it its entire semiconductor count. ran in class A on batteries only a few watts by modern standards this was around the end of the 80's. ran a business designing one off bespoke audio. good thread that may make. anyway
i at the request of a good friend ventured over to Cricklewood Electronics a short time ago coz he wanted to build his own amp for his recording studio monitoring. whilst there I purchased some components some carbon 3 and 5 watt resistors that I use in my own amps that I have not built for some years now but I can certainly build a "GM" with them I may look at some alternative semi's but have 100/200 BF469/470/471/472 etcvarious others for "front end" just not had the time to re-do the PCB as I cannoty find the old artworks but have a few PCB design progs to try ( I am more used to manual taping) so will knock up a few PCB's to make my non-inverted GM see what all the fuss is about. I do rather fancy using stabilised psu all rails throughout just need towork on the front end a little but should be really straightforward. not really into the hi-fi thing nowadays been there worn the T-shirt..... so will have to design some reference speakers too coz at present do not have any due to selling them all off but think I have a friend with some ATC 3 inch units I could beg or borrow as a basis for a design. also have some beautiful "Avell Linberg" TX's around 3Kva will give me close to 90v a few volts either way for each rail then I suppose put all of it up on here for all to see just not hear
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Old 13th April 2011, 02:46 AM   #1606
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Quote:
Originally Posted by jacco vermeulen View Post
Wouldn't dream of it.

Sure, Mr Yvon knicked the basic outline straight from the Hitachi amp, too young at the time to have developed his own IP.
Still doesn't mean a stripped and tuned HMA will be an equivalent.

not so sure as to the "nicked" it bit after all it was originally an application suggestion by Hitachi in the notes for the new wonder device called a MOSFET.

a device I have seen more badly understood and used very badly by hundred or more bad designers or companies that made them
I am now 52, been in this art, or discipline of knowledge since age 7.
i remember hitachi's press releases and the amps they made all of them. it is entirely possible to make a Hitachi HMA amplifier become a GM clone with little or no difficulty at all the GM is a clone of it with mods!!!!
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Old 13th April 2011, 03:37 AM   #1607
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I got this from the horses's mouth !

Lo-D stands for Low Distortion !

That's what Hitachi Audio School guys told me in 1980 !
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Old 13th April 2011, 09:18 AM   #1608
AndrewT is online now AndrewT  Scotland
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Quote:
Originally Posted by CHARLIEB999 View Post
...... I used to be a high end hi-fi reseller as well as being a very capable audio engineer.
"about me" is virtually empty.
Tell us about yourself.
Justify "engineer".
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Old 13th April 2011, 10:34 AM   #1609
Luke is offline Luke  New Zealand
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Quote:
Originally Posted by CHARLIEB999 View Post
not so sure as to the "nicked" it bit after all it was originally an application suggestion by Hitachi in the notes for the new wonder device called a MOSFET.

a device I have seen more badly understood and used very badly by hundred or more bad designers or companies that made them
I am now 52, been in this art, or discipline of knowledge since age 7.
i remember hitachi's press releases and the amps they made all of them. it is entirely possible to make a Hitachi HMA amplifier become a GM clone with little or no difficulty at all the GM is a clone of it with mods!!!!
Charlie relax The thread started by a guy who loved this amp so much he wanted to make it exactly the same, that's why its a clone. People bought into it and it became a group buy. You gotta remember that guys here make lots of amps, old ones new ones, simple ones complex ones. Its not a big deal if someone wants to make a goldmund clone is it?
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Old 13th April 2011, 06:21 PM   #1610
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thanks Luke that explains all to me at last. now I understand its purpose just for fun!!!cool runnings then GM cloners have fun bless up
ps love the end quote LMAO
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