OPEN SOURCE DIY Mic Project - ORS 87 - Stripped Down u87

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How about a less chaotic trace routing overall? And what's the purpose of those "coupling pads" between the various sections of ground?
 
Please put the correspondence scheme of version v1.1 one more time
I'm thinking about creating two versions, one with multiple options (as V1 and V1.1), and the other one with no open options, even R* won't be there. Makes sense?
 
And... now that you mention about version 1.2, what additional changes would you like to have?
I expect to update it next weekend.
Regards!
I would make GND present all around, up to the edge and as extended as possible inwards, close to the other traces, except for the jFET input area. Thus the PCB would connect its GND to the body with the help of screws.
...more to come 😀
 
I'm thinking about creating two versions, one with multiple options (as V1 and V1.1), and the other one with no open options, even R* won't be there. Makes sense?
Yes, but...
You could create even more confusion among beginners.
If you let someone uninitiated make a decision on their own, they will most likely make the worst decision.
Then @Khron has to 'fight' with them, to explain clearly and quickly things learned over the years.
 
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[...] JLCPCB is one of the most popular [...] They all have the "$5 for 5-10pcs of (up to) 100x100mm 1/2-layer boards" deals, so whatever differences might only show up in the shipping options / costs.

Very much this is what I see. I sent a PCB (for BM-800 with these footprints) to JLCPCB and it cost me US$3.50 with shipping included to Mexico, whereas with @homero.leal's shared project on PCBWay it would cost me US$10.11, almost three times as much. Neither option is bad, but JLCPCB is definitely a better option for some.
 
That's with their $2-first-order promotion, and the cheapest / slowest shipping option, I'm guessing?

Yes: Their cheapest shipping option (10-12 business days) is US$1.50; next is US$17.80 (3-5, 4-6 business days); and then US$18.60 (4-7 business days).

What's interesting is that it's a "special offer" that just appears there all the time with small boards. This was not my first order, and now that I'm trying to order the same Gerber files it also applies the "special offer". I don't know the dynamics of their offers, but I'll gladly take the discount.

Another thing to add is that this option (US$2.00) is cheaper than buying 5 perf boards from Ali (US$2.13) with similar shipping time frames. Oh, the economics.

On subject, thanks to all who have shared so many insightful comments on their builds. This build has been a fantastic learning experience!
 
Yes, but...
You could create even more confusion among beginners.
If you let someone uninitiated make a decision on their own, they will most likely make the worst decision.
Then @Khron has to 'fight' with them, to explain clearly and quickly things learned over the years.
Ok. What coupling cap (between FET and Transformer) do you think will be the best for beginners?
 
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2N3819 JFET N-channel pinout.jpg
Regarding this drawing for almost 20minutes, I've just realized I've had pinned reversed my JFET from the beginning..
I can't believe it !!! :cool::cool::cool:
 
Ok. What coupling cap (between FET and Transformer) do you think will be the best for beginners?

Probably a box film cap - lasts virtually forever (electrolytics are so-and-so, and are +/-20% tolerance to begin with; 5% films are the same price as 10% ones).

Later edit: Oh, and you can't install them the wrong way around, either! 😁
 
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Ok. What coupling cap (between FET and Transformer) do you think will be the best for beginners?
In the upper right corner are the candidates with the best measured esr and loss.
They all sound very good, with extremely
small differences,flavors, probably imperceptible in the mix.
🥁
The winner is the one left in the test circuit.
He is a repeat offender. 😀
He won in several tests/circuits.
Doesn't measure the best, but sounds exceptional with all transformers tested (huge or tiny core)
I made numerous comparisons, repeated on different days, having different moods.
✨
 

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Probably a box film cap - lasts virtually forever (electrolytics are so-and-so, and are +/-20% tolerance to begin with; 5% films are the same price as 10% ones).

Later edit: Oh, and you can't install them the wrong way around, either! 😁
What about the big 1uf cylindrical film?
 
In the upper right corner are the candidates with the best measured esr and loss.
They all sound very good, with extremely
small differences,flavors, probably imperceptible in the mix.
🥁
The winner is the one left in the test circuit.
He is a repeat offender. 😀
He won in several tests/circuits.
Doesn't measure the best, but sounds exceptional with all transformers tested (huge or tiny core)
I made numerous comparisons, repeated on different days, having different moods.
✨
Ok, this will be the one! Thank you very much @micolas!
So, as a summary:
  • Remove HI-Z traces
  • Add ground plane connecting to body using the screws
  • Remove redundant/multiple options
  • Use WIMA MKS-4 1uf cap
Ugly coupling pads will remain :) . They do make a difference.
 
What about the big 1uf cylindrical film?
The yellow cylindrical film capacitor (probably polypropylene) offered the most Hi-Fi sound in the test, a little more 'smile', very clean, but slightly reducing the mids, mid-highs specific to U87.
I would use it in C800, C12.
The electrolytics produced a more nice pronounced saturation, a U87 for Rod Stewart 😀.
The tantalum sounds nice, balanced, but I removed it for personal reasons.
 
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