In reality only some transistors can be surface mount on a Class AB design like the LTP, current mirrors, or cascocoded transistors.
Any part that has significant current through it and high voltage across it won't be able to run cool enough without a heatsink because of this surface mount parts can't dissapate as much power and there are limited options for attaching a heatsink. There are very few parts that are adequate for a Class AB design once you get to the VAS.
There could have been more use of surface mount resistors and capacitors but there was significant push back going to surface mount and those aren't the parts that are in short supply.
Jeremy
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Hi Everyone,
New video is up;
PCB unboxing.....
These are some really nice boards. đź‘Ś
Dont forget there is a giveaway for a set of Green EF3-3 boards.
Good luck!
And a big thankyou and well done to the design team, you guys have really done a a great job on these PCBs.
- Daniel
New video is up;
PCB unboxing.....
These are some really nice boards. đź‘Ś
Dont forget there is a giveaway for a set of Green EF3-3 boards.
Good luck!
And a big thankyou and well done to the design team, you guys have really done a a great job on these PCBs.
- Daniel
It's funny here. Please don't layout your own, 'cause the very best is here. Oh! sorry, our layout will not be published (plz don't ask).
I give full respect to what the project team have done, especially to @stuartmp who manages it to happen.
Any improvement the team made is of course IP of their own. Therefore the team has the right to decide whether / what they are willing to share back to the public forum. And even more, the team has the right to cash grab for the their effort.
The reason of parts shortage is a so strange story, at least to me.
I don't see any impact on GB participants' part sourcing by publishing a schematic with only component values but specific vendor model.
The team has the right to make money by selling their fine-tuned PCBs and recommended BOM. Knowledge is money.
But, if the team is willing to share the improvements, I just don't understand why not NOW.
We are not sharing it now for one simple reason. Lets say there is only 300 Q1, Q2 ideal transistors available and we publish what they are. Then someone (a single person or company) goes out and purchases all 300 and places a further order for 5000 it could be a very long time before the members of the thread who have paid for their boards can build the amplifier with idea components.
Please be patient and know we are trying to look after all the GB members.
As far as a cash grap. I can assure you its far from that. I ask all members that we stop discussing this group buy process in that manner.
I'm not trying to argue. But..
A schematic like your #1225 post can not make things like you said happen.
You contribute circuit improvements to everyone in this thread. Those who can't wait or who wants their own ways can benefit, TODAY.
I do think some people here are willing to try available but not ideal transistors on their own. Here is a DIY forum.
I think everyone in GB is willing to be silent about the recommended BOM, for the reason you indicated.
Until the day you think everyone in GB is well satisfied, keep your recommendation undisclosed.
I believe it's a good idea for everyone here.
At the end, you have the right to choose what's the best for you. I respect your choice, your effort, your contribution ( to ostripper's incomplete job )
m2c
This is a high performance amplifier and what makes it high performance is the component we have selected, the schematic (amplifier topology) and the pcb layout.I do think some people here are willing to try available but not ideal transistors on their own. Here is a DIY forum.
If people choose to use un tested parts that's up to them. But when the smoke comes out. If could reflect badly on the amplifier if their not honest about the fact they used un tested parts.
In time when we have more feedback from all the early adopters we will have more information and more confidence on what works and what doesn't. But for now I recommend sticking to the BOM supplied. It takes alot of time and dedication to build an amplifier. Taking shortcuts on components is simply not worth it.
Depending on the component performance will certainly suffer.
Any company could undertake that process now, and you'll be waiting in any case......has nothing to do with a few hobbyists on forum building a couple of amplifiers.
Treating the BOM and schematics as classified government secrets because a few hobbyists need to access a global supply chain of transistors seems a little far fetched.
Can you see why people seem a little sceptical of the motives ?
Appreciate your frustration but our priority is still to support those who followed and supported the thread and then purchased the boards (sight unseen).
This is the reason why I removed myself from the GB. Without knowing what I’m committing to, thats a no go.
There is always tyre kickers wasting peoples time. People wanting something for free without earning it. The people involved have sacraficed hours and hours to make this a reality. Now to me if I sacrafice my personal hours I think of the time I'm not spending with my family. So if for example 1000 hours have gone into the amp then that's 25 work weeks solid for 1 individual.
Im excited to see how the amp goes and by all reports there is nothing on the market that can be bought retail that can even compete.
Im excited to see how the amp goes and by all reports there is nothing on the market that can be bought retail that can even compete.
Hi Stuart,
I'm in contact with Gianluca at Modushop about having these extra holes milled, he is asking if the dxf file could include the heatsink outlines? Measurements provides by Gianluca for the 5U 200 heatsink is 200x210 (2 heatsinks per side).
Is this something you could add?
Thanks
Chris
I'm happy to do that. I added the current dxf file to the Dropbox the other day.
Is Gianluca not able to pick-up on the existing UMS holes then plot out the new ones?
All the dimensions are there he should be able to do this no worries.
If not, let me know and I'll update my file.
Btw, I have no skin in this game, I've invested my time in a SMD version of ostrippers spooky amplifier.
I'm just pointing out the excuses of not releasing the BOM or schematic seem a little melodramatic.
If you could just add the holes we have to drill to the drawing (even the old ones already used for the UMS heatsinks) and the outlines it would be perfect. The reason I am asking for this is we are going to drill all the holes in a single time, we are not going to get an UMS heatsink and add these new holes as there could be problems with tolerance
If this is your prevailing attitude then the entire forum would cease to exist.
What you're describing is a commercial venture, remember this is a DIY audio forum.
If the expectation that people should be paying for this amplifier design, then maybe this thread should be moved to the Vendors forum, thus the justification for not releasing any information would be mutually understood.
My viewpoint is of someone watching from afar.....
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All the holes new and old are clearly shown in the dxf fileIf you could just add the holes we have to drill to the drawing (even the old ones already used for the UMS heatsinks) and the outlines it would be perfect. The reason I am asking for this is we are going to drill all the holes in a single time, we are not going to get an UMS heatsink and add these new holes as there could be problems with tolerance