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Terry, one thing I can say is that the Jim's board definitely looks as if he has had in his hand a copy of Greg's board, because the layout is practically identical from what I can see. My point being that the traces may even be spot on...negating some of the concerns of bad layout.
I think it's too close to be done just from internet photos, unless Jim is very good. Greg's has a ground plane across most of the spare space on the top surface of the board, but the Jim's one doesn't look like it does. Other than that, they look VERY similar.
Stu
I think it's too close to be done just from internet photos, unless Jim is very good. Greg's has a ground plane across most of the spare space on the top surface of the board, but the Jim's one doesn't look like it does. Other than that, they look VERY similar.
Stu
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I haven't seen Greg's board. For sure it is not an exact copy since it uses SC2240/2SA970 in place of BC546C/BC556C. They have different pinout so the trace layout has to be different. Paulo says his plays perfectly so it is probably some of my components that are causing the problem. I see pinnocchio used all Deans for his resistors. It will be interesting to see if that is audible. My parts should be here Tuesday so I'll see then if it is a parts issue.
Blessings, Terry
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You know the design is going to be sensitive to layout when the feedback compensation capacitor is specified as a small value and in a narrow range. The pcb parasitics and component intrinsic capacitances and inductances are going to be half the compensation story. Jim's Audio (who are the owners of that business ?) tried to clone the pcb by using the same parts layout (probably violating copyright at the same time) so that pcb parastics are likely to be close to the original - except for use of ground plane ?
Have any of you physically compared the two pcbs? Everyone keeps saying Jim's audio copied Greg's board yet they used different pinout parts. You throw around copyright infringment when Greg openly released the design to public domain. Jim's didn't make these boards until after Greg released the design. Im sorry I got involved with this one.
Give it a break. Changing the pin out on a couple of transistors does not make it a whole new PCB. Maybe Jim's Audio should be answering your numerous questions.
Jim sez:
"This is a very good sounding amplifier PCB, based on KSA GB150D. The schematic was recently released by the designer, and we were asked by some audiophiles to make the boards. So here are the long awaiting boards. While these are boards of our own, we try to adhere to the original component placement as to make the performance as optimize to original as we can."
"This is a very good sounding amplifier PCB, based on KSA GB150D. The schematic was recently released by the designer, and we were asked by some audiophiles to make the boards. So here are the long awaiting boards. While these are boards of our own, we try to adhere to the original component placement as to make the performance as optimize to original as we can."
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Terry,
I know you mean well - I think the misunderstanding here is the meaning of Public Domain. You can put IP into the public domain and still have it protected by Copyright. The New York Times is also in the public domain. But if Jim's Audio were to substantially copy it, they'd be shut down in short order for Copyright infringement. Copyright exists to protect public domain information. I can see that "Jim's" boards are cheaper - they did not invest any real effort in designing the pcb but took somebody else's design and applied minor modifications. Neither do they provide technical support. Can you really say you saved many $ when you take into account the time you are spending on this thing - Greg would have given you very good technical support. Anyhow, nothing personal, just sharing my thoughts on the applicability of Copyright in this case since Greg declined to put his pcb layout into the public domain for copying (he was asked) - so no, the pcb is not in the public domain but the schematic is. Anyhow, I'm not Greg's lawyer, just hoping to clarify what I think has been confusing.
http://en.wikipedia.org/wiki/Copyright
I know you mean well - I think the misunderstanding here is the meaning of Public Domain. You can put IP into the public domain and still have it protected by Copyright. The New York Times is also in the public domain. But if Jim's Audio were to substantially copy it, they'd be shut down in short order for Copyright infringement. Copyright exists to protect public domain information. I can see that "Jim's" boards are cheaper - they did not invest any real effort in designing the pcb but took somebody else's design and applied minor modifications. Neither do they provide technical support. Can you really say you saved many $ when you take into account the time you are spending on this thing - Greg would have given you very good technical support. Anyhow, nothing personal, just sharing my thoughts on the applicability of Copyright in this case since Greg declined to put his pcb layout into the public domain for copying (he was asked) - so no, the pcb is not in the public domain but the schematic is. Anyhow, I'm not Greg's lawyer, just hoping to clarify what I think has been confusing.
http://en.wikipedia.org/wiki/Copyright
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