Godfrey - Correct, the 100nF capacitors were something that Alex added to the PCB layout. They're not needed, but it also doesn't hurt having them there. If anything, the amp will perform/sound better with the small 100nF capacitors installed. The location of the 1uF and 100nF should be as close as possible to T1, T3, T4, T5, and T6, which is exactly where they are right now.
10nF capacitors should be ceramic disc, that's what Goldmund uses.
You're absolutely right on your last point, experimenting will be a must for the builder. For example, in Goldmund Mimesis 3 amplifier, C3 and C5 are 8.2pF and they completely omit C6. This is all dependent on the layout of the board and how the amplifier is put together. So again, experimentation will be a must. By the way, these small capacitors should also be ceramic disc. That's what Goldmund uses.
10nF capacitors should be ceramic disc, that's what Goldmund uses.
You're absolutely right on your last point, experimenting will be a must for the builder. For example, in Goldmund Mimesis 3 amplifier, C3 and C5 are 8.2pF and they completely omit C6. This is all dependent on the layout of the board and how the amplifier is put together. So again, experimentation will be a must. By the way, these small capacitors should also be ceramic disc. That's what Goldmund uses.
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Do you mean the Goldmund inherent errors or just drawn something wrong accidentally?
Btw: Nagys, why do you post the same schematic again and again and again...?
It doesn't get better. Finally Alex improved the layout and now the ground should work. Nagys is stubborn but Alex seems willing to learn something.
I intervented here because I would have been sorry for all the subscribers to the group buy - but not for Nagys. He deserved a bad board.
Well you sanctioned the design a dozen times, look at the zeners and diodes on the drivers unless they are there for a reason other than clamping. Also D6 & D8 shorts the transformer every other half wave.
I trust that you are going to do all the experimenting and finalise the values before having the members throw their money into a group buy and cannot get it working the way it should.
Maybe the group buyers should insist on a money back guarantee should they not be absolutely thrilled with the outcome within seven days.
D6,D7,C15,C16 and D8,D10,C19,C18 are just basic voltage doublers. No errors here.
/Martti
Lee Knatta - I post the schematic everytime I talk about certain components so that it's easier for readers to reference it. I will continue to do so weather you like it, or not. The grounding scheme in Alex's latest PCB is what Goldmund does in their Mimesis series of amplifiers and those were the changes that I asked him to make. There's nothing to learn here, especially not from you.
Nico Ras - None of those are errors. Again, please see the schematic below. That is the Goldmund schematic, just because it doesn't apply to your understanding it doesn't make it automatically incorrect, or an error. Please stop confusing the potential builders. The schematic is the correct schematic of a Goldmund Mimesis 9.2 mono block amplifier. If you don't like it, please go build something else.
Any untested kit could require some changes, or experimentation (changing the value of the pF capacitors, soldering the ground points to different places on the ground plane, etc.). This should not be something that can be thrown together and expected to perform flawlessly. The potential builders should at the very least understand the basics of electronics. Otherwise they should not be a part of the group buy.
If this kit fails to work correctly for anyone it will be YOUR fault and lack of skill and lack of understanding in basic electronics.
Nico Ras - None of those are errors. Again, please see the schematic below. That is the Goldmund schematic, just because it doesn't apply to your understanding it doesn't make it automatically incorrect, or an error. Please stop confusing the potential builders. The schematic is the correct schematic of a Goldmund Mimesis 9.2 mono block amplifier. If you don't like it, please go build something else.
Any untested kit could require some changes, or experimentation (changing the value of the pF capacitors, soldering the ground points to different places on the ground plane, etc.). This should not be something that can be thrown together and expected to perform flawlessly. The potential builders should at the very least understand the basics of electronics. Otherwise they should not be a part of the group buy.
If this kit fails to work correctly for anyone it will be YOUR fault and lack of skill and lack of understanding in basic electronics.
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Nico Ras - I just read your last post... Your continuous useless input is quite annoying and unnecessary. Obviously you're against this circuit, why don't you go and build something you like? There are plenty of projects on this forum. Why waste your time here, unless you're trolling?
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There was a lot of argument about that a while ago, with most folks thinking those diodes and zeners are back-to-front. A truce was finally reached on the understanding that individual builders can put them in whichever way they see fit. I'm just glad the argument's over. On the up-side, if they are all inserted backwards, it won't actually break anything - there just won't be much protection for the mosfets.
No, that part's OK - they're part of a voltage doubler for each rail. Note the capacitor-coupling of the AC inputs.
I still don't regret pointing out severe mistakes in the layout that are mostly fixed now. You contributed absolutely nothing to this but showed you are completely clueless countless times.
I do pcb design for a living and know what I'm talking about.
Lee Knatta - What layout mistakes did you point out that are fixed now?
My concern regarding the grounding scheme was in post #861 and my suggestion for changes was in post #863.
Your input was in post #864.
Alex posted the updated PCB layout with my suggested changes (to mimic Goldmund more closely) in post #891.
Nothing you posted in #864 was incorporated. Your contribution is zero. If you continue to lie, I will continue to call you out on it.
My concern regarding the grounding scheme was in post #861 and my suggestion for changes was in post #863.
Your input was in post #864.
Alex posted the updated PCB layout with my suggested changes (to mimic Goldmund more closely) in post #891.
Nothing you posted in #864 was incorporated. Your contribution is zero. If you continue to lie, I will continue to call you out on it.
As for the diodes D2, D5, D3, and D4, that's how Goldmund connects them. Virtually all of the Goldmund schematics show them like that and you can see them connected the same way in my Mimesis 6 amplifier. Please see the picture bellow, they are right between the MOSFETS and the A1 module:
You can clearly see which sides are marked with the black Cathode ring.
An externally hosted image should be here but it was not working when we last tested it.
You can clearly see which sides are marked with the black Cathode ring.
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