and Andrew,
Preemptively, I don't want to hear any of your "the Americans don't know how to read what's written in front of them". So stuff it! 😀
Preemptively, I don't want to hear any of your "the Americans don't know how to read what's written in front of them". So stuff it! 😀
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O.K. Here is what I found as I stumble across home plate.
Removing C21 sounded thin with almost the same stage width. Very unmusical,dry and shallow. l much preferred the sound with C21 in place. Ah, I got him.
Tried the new C9/R10 swap and darn if it all didn't come back into place. Very well balanced across the spectrum, and clear. I heard a lot of the crackle at the beginning of the trombone section sforzandos and a lot more musicians taking breaths. The punch and extended bottom is all there and again the word "refined" applies to the upper registers.
At the end of thirty minutes one amp settled at 40 C and the other at 41 C. It is a new character of sound and I will continue to listen throughout the rest of the evening with several music styles.
I never would have believed cap/resistor orientation and placement could make such dramatic differences, but I'm fully convinced now.
Thumbs Up Mr. Inserra.
Removing C21 sounded thin with almost the same stage width. Very unmusical,dry and shallow. l much preferred the sound with C21 in place. Ah, I got him.
Tried the new C9/R10 swap and darn if it all didn't come back into place. Very well balanced across the spectrum, and clear. I heard a lot of the crackle at the beginning of the trombone section sforzandos and a lot more musicians taking breaths. The punch and extended bottom is all there and again the word "refined" applies to the upper registers.
At the end of thirty minutes one amp settled at 40 C and the other at 41 C. It is a new character of sound and I will continue to listen throughout the rest of the evening with several music styles.
I never would have believed cap/resistor orientation and placement could make such dramatic differences, but I'm fully convinced now.
Thumbs Up Mr. Inserra.
Final boards
After several hours (a real tour de force) of tiny details fixing and checking the gerbers I present you all the final boards:
I'll have a final check after one hour or two of relax and hopefully I'll order boards before midnight (local time).
I've uploaded all files (including gerbers) on the RC Google folder, if someone would do a double check in this two hours any help is welcome. 😉
I'm grateful to Bmcbob, Suburra and his batfriend for testing and to Metal for help in optimizing the PCB. 🙂
Thanks 🙂
After several hours (a real tour de force) of tiny details fixing and checking the gerbers I present you all the final boards:
I'll have a final check after one hour or two of relax and hopefully I'll order boards before midnight (local time).
I've uploaded all files (including gerbers) on the RC Google folder, if someone would do a double check in this two hours any help is welcome. 😉
I'm grateful to Bmcbob, Suburra and his batfriend for testing and to Metal for help in optimizing the PCB. 🙂
Thanks 🙂
Attachments
Great stuff, Dario. Now tell the truth, wasn't there the least bit of temptation to go forward with the C9/R10 swap to the new positions now that Bob has come along?
Slightly off topic.
All this discussion about C9, the coming disappearance of Black Gates, and the general problems, both sound and life, with typical electrolytic capacitors had me looking at alternatives at work today.
I'm just curious if anyone has any experience with these alternative technologies. Both of the links are for "polymer" capacitors which are a form of "solid" electrolyte caps. They appear to have longer life and typically lower ESR than the "liquid" electrolyte caps we are used to. That said, nobody seems to be using them for audio. Parts Connexion tried carrying the Sanyo OS-CON, which is of this family, but it appears no one liked them because they are not reordering.
The first is an aluminum - organic polymer cap, available from Mouser in 220 uF just like C9 for a buck or two. The second is a SMT cap using tantalum - organic polymer and also available from Mouser in 220 uF for a little more. I suspect the current limitations of the SMT might be a problem too.
RR70J221MDN1 Nichicon | Mouser
T520D227M006ATE007 Kemet | Mouser
Slightly off topic.
All this discussion about C9, the coming disappearance of Black Gates, and the general problems, both sound and life, with typical electrolytic capacitors had me looking at alternatives at work today.
I'm just curious if anyone has any experience with these alternative technologies. Both of the links are for "polymer" capacitors which are a form of "solid" electrolyte caps. They appear to have longer life and typically lower ESR than the "liquid" electrolyte caps we are used to. That said, nobody seems to be using them for audio. Parts Connexion tried carrying the Sanyo OS-CON, which is of this family, but it appears no one liked them because they are not reordering.
The first is an aluminum - organic polymer cap, available from Mouser in 220 uF just like C9 for a buck or two. The second is a SMT cap using tantalum - organic polymer and also available from Mouser in 220 uF for a little more. I suspect the current limitations of the SMT might be a problem too.
RR70J221MDN1 Nichicon | Mouser
T520D227M006ATE007 Kemet | Mouser
Thanks Jac 🙂
To tell the truth, no.
I think it's nice to have the option so all builders can try both configs for an extended time.
If a general agreement will be reached RTM boards will have only one of the two configs for layout cleanliness.
Polymers are OK for supply/decoupling tasks, but not so good in the signal chain because they have very high, uncontrolled and probably nonlinear leakage current.
Separated at birth?
Bill,
you're scaring me...
watching the PCB I was thinking...that trace seem a perfect antenna...
😀
Bill,
you're scaring me...
watching the PCB I was thinking...that trace seem a perfect antenna...
😀
Attachments
If you get that R10/C9 swap in there, I'd like to get a set of boards too.Bill,
you're scaring me...
watching the PCB I was thinking...that trace seem a perfect antenna...
😀
Is the alternate ground selection in the new board?
1 day delay
Sorry guys, 2:00AM here and I'm too tired to make the order, it was a LONG day and I don't want to make errors.
All is ready, including gerbers, all uploaded to the google folder.
Hi George,
YES the PCB can accomodate both C9/R10 configurations but NO the ground selection switch is gone, it was part of beta boards and since the GND config was better is gone.
Let me know if you still want boards via PM.
Sorry guys, 2:00AM here and I'm too tired to make the order, it was a LONG day and I don't want to make errors.
All is ready, including gerbers, all uploaded to the google folder.
Hi George,
YES the PCB can accomodate both C9/R10 configurations but NO the ground selection switch is gone, it was part of beta boards and since the GND config was better is gone.
Let me know if you still want boards via PM.
Attachments
PCBs are just been ordered
Just ordered the PCBs from PCB-Proto (Italy).
The Eagle files and Gerbers sent to production have been uploaded to the RC Google Folder.
PCBs will be shipped to my home in about 15 working days.
Just ordered the PCBs from PCB-Proto (Italy).
The Eagle files and Gerbers sent to production have been uploaded to the RC Google Folder.
PCBs will be shipped to my home in about 15 working days.
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Thanks for adding the mouser import tool column to the BOM. It makes the copy and paste process really easy. I am going to process my order later today. Does anyone recommend ordering anything else from mouser that is not on the BOM other than chipquick?
You're welcome. 🙂
While it should be all OK I've yet to do the final check.
I would wait a couple of day more 😉
Apart the Chip Quik kit (Mouser 910-SMD1NL) an interesting article to order, if you want to experiment, is the SIL sockets strip (Mouser 506-510-AG90D).
In addtion, for whom is interested, I can include in the PCBs package (no additional shipping is required) some hard to find parts that are better sounding than Mouser BOM parts:
Elna package:
4 Elna RJHs
4.5€
ERO package:
2 NOS ERO KP1834 10nF (polystirene film/foil)
2 NOS ERO KP1834 150pF (polystirene film/foil)
2 NOS ERO KC1850 1000pF (polycarbonate film/foil)
4.5€
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Ok I will wait a couple days. Thanks for the reminder about the sockets, it was somthing I visualized but it just totaly escaped me.
I would be interested in the caps too if you want to send me a payapl request. Thanks again Dario!
I would be interested in the caps too if you want to send me a payapl request. Thanks again Dario!
You're welcome. 🙂
Both packages?
A quick note:
I still have to deep test KC1850s, not 100% sure they're better than FKP2s, they're part of the package as free bonus.
Elna Package
- SoIL4x4
- SoIL4x4
Jac, you're still interested in Elnas?
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Dario,
Yes to the Elna's. I'm not at home at this moment. When I get home, I'll check my list. I may be interested in the other caps too. I'll contact you then.
Also, regarding C9, I recall the lead spacing is 5 mm. What is the diameter of the pad on the board? Is that a via just left from the first C9 pad?
The reason for all these questions is that I'm thinking about trying something unusual for C9 on one of my builds. Mouser has a Niobium Oxide cap, 220 uF, 6.3V that I think I can find a way to fit. The specs are interesting, although I have no idea of how it will sound. Just out of curiousity, I'm looking for the next option when Black Gates are gone.
Yes to the Elna's. I'm not at home at this moment. When I get home, I'll check my list. I may be interested in the other caps too. I'll contact you then.
Also, regarding C9, I recall the lead spacing is 5 mm. What is the diameter of the pad on the board? Is that a via just left from the first C9 pad?
The reason for all these questions is that I'm thinking about trying something unusual for C9 on one of my builds. Mouser has a Niobium Oxide cap, 220 uF, 6.3V that I think I can find a way to fit. The specs are interesting, although I have no idea of how it will sound. Just out of curiousity, I'm looking for the next option when Black Gates are gone.
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