Hi,
Guys anyone care to post the fully completed project info ?? Pictures,How to etc would be real good to read.
Alex saw your semi completed broads sometime back (Looks Awesome),did you finish it ? if so how does it sound ? have you used two transformers or what ??
Also if someone could throw some light on using a single transformer for the same,Please don't answer like "Its not meant to be and will not sound as prescribed BLAH BLAH"
I have received the files from generous Alex for this project and Am about to start,so before that I wish to know some stuff and also wish to know how it went for the people who have already done it.
Regards.
Guys anyone care to post the fully completed project info ?? Pictures,How to etc would be real good to read.
Alex saw your semi completed broads sometime back (Looks Awesome),did you finish it ? if so how does it sound ? have you used two transformers or what ??
Also if someone could throw some light on using a single transformer for the same,Please don't answer like "Its not meant to be and will not sound as prescribed BLAH BLAH"
I have received the files from generous Alex for this project and Am about to start,so before that I wish to know some stuff and also wish to know how it went for the people who have already done it.
Regards.
Noise on GM clone
Right at the start of this (long) thread it was pointed out by many the "cons" by the way Alex had let out its final proposals to the PCB. Critics (among others) went on:
1. The choice of voltage multiplier to VAS, and also that this was situated at the same print as the VAS.
2. Location of security circuit located on the same print as the VAS (in Alex's first proposal this circuit was laid out on a separate PCB).
There was some concern about possible noise that was the basis for this criticism.
Bigpanda says he is planning a revised edition of the PCB to Memesis 9. I allowed myself to give some thoughts to the forum from the experience I had with my two buildings of GM clones in # 1726, if a new PC was planning.
Niko, you have chosen a solution that greatly addressing the concerns that I have described above, but which to a certain extent could be realized on Alexs final PCB in a smart way.
(For any future builders of GM clone, I think you should show how you have taken all your ground connections).
Although I have chosen a different solution that works well, and where I did not experience any problems with noise: The voltage multiplier is removed. VAS has got its own separate power supply, on its own print, from its own transformer (the security circuit is still on the main board).
Eivind Stillingen
Right at the start of this (long) thread it was pointed out by many the "cons" by the way Alex had let out its final proposals to the PCB. Critics (among others) went on:
1. The choice of voltage multiplier to VAS, and also that this was situated at the same print as the VAS.
2. Location of security circuit located on the same print as the VAS (in Alex's first proposal this circuit was laid out on a separate PCB).
There was some concern about possible noise that was the basis for this criticism.
Bigpanda says he is planning a revised edition of the PCB to Memesis 9. I allowed myself to give some thoughts to the forum from the experience I had with my two buildings of GM clones in # 1726, if a new PC was planning.
Niko, you have chosen a solution that greatly addressing the concerns that I have described above, but which to a certain extent could be realized on Alexs final PCB in a smart way.
(For any future builders of GM clone, I think you should show how you have taken all your ground connections).
Although I have chosen a different solution that works well, and where I did not experience any problems with noise: The voltage multiplier is removed. VAS has got its own separate power supply, on its own print, from its own transformer (the security circuit is still on the main board).
Eivind Stillingen
Golmund clone
Small changes on the board that significantly affect the quality of the amplifier.DC coupled, Clarity, transparency at high signal levels. This is a very good amplifier.
Small changes on the board that significantly affect the quality of the amplifier.DC coupled, Clarity, transparency at high signal levels. This is a very good amplifier.
Attachments
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Nice work , I'm glad to hear you like it and sound better then other amplifier ...... also clear pictures 
Refering to my second amplifier , missing some parts , case and so on , some pictures I take this morning
Regards Alex.
Refering to my second amplifier , missing some parts , case and so on , some pictures I take this morning Regards Alex.
Attachments
Golmund clone
Some photos Golmund 9.2
Τhere is a small gap between heat sink and chassis. My opinion is that there is washers rubber between heat sink and chassis.
I wonder if someone knows a way that supports the transformers and the outer chassis legs .
Is the same screw that supports and transformers and outer chassis legs ?
The last photo is from construction ΝagysAudio.
Some photos Golmund 9.2
Τhere is a small gap between heat sink and chassis. My opinion is that there is washers rubber between heat sink and chassis.
I wonder if someone knows a way that supports the transformers and the outer chassis legs .
Is the same screw that supports and transformers and outer chassis legs ?
The last photo is from construction ΝagysAudio.
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Goggle is your enemy.
http://www.hifido.co.jp/photo/10/704/70454/f.jpg
http://www.hifido.co.jp/photo/10/768/76802/d.jpg
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Thanks Jacco !!!
From what I see I make the explanation:
The front legs have nothing to support the transformers and that transformer caps are based to chassis with screws and washers rubber.
Now, regarding the center rear leg supports the chassis, but at the same point comes to support for mechanical grounding reasons the heat sink with central bolt
Do you want confirm it ?
regards Nikos
From what I see I make the explanation:
The front legs have nothing to support the transformers and that transformer caps are based to chassis with screws and washers rubber.
Now, regarding the center rear leg supports the chassis, but at the same point comes to support for mechanical grounding reasons the heat sink with central bolt
Do you want confirm it ?
regards Nikos
The front "leg" is a threaded rod, to mount the adjustable feet, it goes through a hole in the chassis.
On the inside, there's a sub-chassis for each transformer, isolated from the chassis with rubber damper rings, secured from the bottom with 4 Allen bolts (plus metal washers and the same white rubber rings)
The mechanical grounding thing, similar to how the heatsinks are attached to the chassis (standard damping & isolating routine : heavy & sturdy on flexible & light)
As you can see from the picture, the "leg" is not positioned in the center of the two outer bolts, it's attached to the transformer platform.
The center "leg" is mounted to the aluminum angle that holds the output devices, with the Allen bolt that's visible from the top.
The large square shaped opening in the bottom for the center leg makes it easier to mount the heatsink assembly to the chassis.
The transformer caps are secured to the chassis with the 4 smaller screws (no washers/rings).
Much more elaborate construction than the Nagys one (huge difference in retail price)
(using sub-chassis is how i build amps for the last couple of decades, copycatted it from opened-up Goldmund models at audio shows)
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GOLMUND MIMESIS 9.2 CLONE
Mr Jacco
Thank you very much for explanation.
I think your photos are from the model Mimesis 8
----The transformer caps are secured to the chassis with the 4 smaller screws (no washers/rings).----
I think these four small screws are to support the board.
Mr Jacco
Thank you very much for explanation.
I think your photos are from the model Mimesis 8
----The transformer caps are secured to the chassis with the 4 smaller screws (no washers/rings).----
I think these four small screws are to support the board.
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Duhh, stupid me. (would also have been stupid of Goldmund if they had done that)
MM9, not MM8.
The Mimesis 8 has the front legs attached to the chassis, see picture you posted.
In the MM9, the front ''legs'' are under the transformer(caps)
=> http://www.hifido.co.jp/KWgoldmund/G1/E/90-10/C10-53992-76802-00/
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Jacco
So as I understand so the front legs based on the sub-chassis and pass the vibrations in the leg.
Τhe screw from the leg does not touch at all in the main chassis.
But this way they charged full weight the sub-chassis
The four smaller screws with metal washers and the same white rubber rings afford to keep all the weight;
I wish we had a photo of the overturned transformer.
regards Nikos
So as I understand so the front legs based on the sub-chassis and pass the vibrations in the leg.
Τhe screw from the leg does not touch at all in the main chassis.
But this way they charged full weight the sub-chassis
The four smaller screws with metal washers and the same white rubber rings afford to keep all the weight;
I wish we had a photo of the overturned transformer.
regards Nikos
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jacco vermeulen; On the inside, there's a sub-chassis for each transformer, isolated from the chassis with rubber damper rings, secured from the bottom with 4 Allen bolts (plus metal washers and the same white rubber rings)
[/QUOTE]
What type of white rubber is this?
The MM9.2 amp weights 65 kg, any specific Shore A or B (hardness) used?
Shore Durometer Hardness Testing of Rubber and Plastics
[/QUOTE]
What type of white rubber is this?
The MM9.2 amp weights 65 kg, any specific Shore A or B (hardness) used?
Shore Durometer Hardness Testing of Rubber and Plastics