I'll send you some dual opamps whose part numbers have been sanded off and painted over with different colored paint. You won't know which is which and I won't tell you the ones that are, or are not, in your batch.
First batch of opamps ordered from Mouser. Adapters and paint ordered from Amazon. Testing jig designed. Will soon be able to communicate total price (divided by two) to listening panel volunteers. As described above, money is refunded in full and you keep all opamps forever, after listening evaluations AND RANKINGS are published here.
I use Chipquik solderpaste and a hot air rework station for SMD parts.
I also use Chipquik solderpaste with the tip of a toothpick place a small dab of paste on the solder pads. Place the IC or chip part on the pads with the solder in place. With the hot air slowly warm things up, the flux in the paste will begin to sizzle a little and the solder will melt and flow. The part will center up on the pads.
You also can solder with your soldering iron. Hold the part in place with tweezers. Place a little dab of solder on the tip of the iron, then place the tip of the iron on the leg of the part. Just the right amount of solder will flow or wick between the part leg and the solder pad. Move on to the next pads.No sweat! Get a thin solder, something below 0,5mm. It is very easy to overdo and add too much solder to the connection.
Inspect, if you end up with a solder bridge a little solder wick and your soldering iron will remove the excess solder.
Thanks DT
Well, I just explained it a few posts ago in bigger detailYou also can solder with your soldering iron. Hold the part in place with tweezers. Place a little dab of solder on the tip of the iron, then place the tip of the iron on the leg of the part. Just the right amount of solder will flow or wick between the part leg and the solder pad.
Inspect, if you end up with a solder bridge a little solder wick and your soldering iron will remove the excess solder.
Thanks DT
Yes it works well even for the flat pack parts with many legs to close together to solder individually,Well, I just explained it a few posts ago in bigger detail
solder wick removes the excess solder
@Mark Johnson
not to throw a spanierd into the works but I was thinking about paint colours identifying chips...
it might be worthwhile avoiding single colour IDs. you don't want the characterizations of the chips "coloured" by the means of identifications.
"the red amp produced a warmer sound while the blue chip was clinical"*
Jackson Pollack could help... splatter and take a photo with your phone.
just sayin'
* of course this never happens in audio!
not to throw a spanierd into the works but I was thinking about paint colours identifying chips...
it might be worthwhile avoiding single colour IDs. you don't want the characterizations of the chips "coloured" by the means of identifications.
"the red amp produced a warmer sound while the blue chip was clinical"*
Jackson Pollack could help... splatter and take a photo with your phone.
just sayin'
* of course this never happens in audio!
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Build Documentation Update -
Version 1.0c attached. Minor revision, but has important changes to the umbilical.
Online Build Guide updated to reflect this.
Online guide coming along nicely, slowly fine tuning and optimizing. It's absolutely good enough to use right now, so don't wait.
Version 1.0c attached. Minor revision, but has important changes to the umbilical.
Online Build Guide updated to reflect this.
Online guide coming along nicely, slowly fine tuning and optimizing. It's absolutely good enough to use right now, so don't wait.
Attachments
I received my SS7815 and SS7915 Sparkos regulators and got surprised that they looked at bit different as pictured at the web.
I asked just to be sure I should only use heat paste and no insulator pad.
I got this answer (just so you know that the new design is easier to use):
"Yes, we have been using the plastic tabs for awhile now. It eliminates the need for the insulator and prevents guys from shorting the tab to grounded heatsinks and blowing fuses if the insulator is missing or not installed correctly.
We didnt update the photos of the devices on our website.... We should probably do that at some point."
I asked just to be sure I should only use heat paste and no insulator pad.
I got this answer (just so you know that the new design is easier to use):
"Yes, we have been using the plastic tabs for awhile now. It eliminates the need for the insulator and prevents guys from shorting the tab to grounded heatsinks and blowing fuses if the insulator is missing or not installed correctly.
We didnt update the photos of the devices on our website.... We should probably do that at some point."
That mouse is awesome. It's from a company called Lunar Artifacts out of Great Britain, and there's a matching wireless charging station too. The underside is polished aluminum, and looks and feels like some of the later Star Wars thingies. As an architect, I'm a sucker for a beautiful object...
And in case anyone is curious, my wife thinks I'm an idiot. And she doesn't understand my love of making cool **** for listening to music either.
And in case anyone is curious, my wife thinks I'm an idiot. And she doesn't understand my love of making cool **** for listening to music either.
I thought I read or heard that they don't need to be matched. Did I misread or mishear? I have Toshiba K170 BL that range from 9.7 to 9.85. Should I contact punkydawgs? I don't want to cut corners on this one!...as of this writing, eBay seller "punkydawgs" has genuine Toshiba and sells matched octets...
Build Documentation
@6L6 and @rhthatcher and @wayne ...
Gentlemen - great docs. My I ask a question about the BOM...
2sk209GR or 2sk170BL
Why the different Idss classification?
I now have a matched octet of 2sk170BL's. 7.65mA +/- 0.01mA
I recovered them just recently. 'Bought them a dozen years ago for the original Pearl, got sidetracked, and misplaced them.
I'm having second thoughts about soldering the SMD parts; I used solder SMD parts, but now... Youth Deficit Syndrome may present challenges.
Are my 2sk170BLs suitable for the Pearl 3 ? (Or save them for Pearl 4 ? )
Many thanks,
Tony Z
Gentlemen - great docs. My I ask a question about the BOM...
2sk209GR or 2sk170BL
Why the different Idss classification?
DIfferent packages has different power dissipative capabillities.
@6L6 and @rhthatcher and @wayne ...
Gentlemen - great docs. My I ask a question about the BOM...
2sk209GR or 2sk170BL
Why the different Idss classification?
I now have a matched octet of 2sk170BL's. 7.65mA +/- 0.01mA
I recovered them just recently. 'Bought them a dozen years ago for the original Pearl, got sidetracked, and misplaced them.
I'm having second thoughts about soldering the SMD parts; I used solder SMD parts, but now... Youth Deficit Syndrome may present challenges.
Are my 2sk170BLs suitable for the Pearl 3 ? (Or save them for Pearl 4 ? )
Many thanks,
Tony Z
Not to worry,
Take a look at the P3 schematic. The parallel jfets are in series with 750 Ohm R1 and form a voltage divider between R1 and the parallel jfets. The higher the Idss of the jfets the more current they try to draw causing a larger voltage drop across R1 and reducing the voltage drop across the jfets resulting in a reduction in current drawn.
Next consider the jfet drain resistors further reducing the bias point current.
My guess is that the 7.65 Idss jfets will only draw 0.40 * 7.65 ma each for a total of ~ 12.25ma.
Someone with an operational P3 can confirm this with a voltage drop measurement across R4, R5, R6, or R7.
Thanks DT
I believe you will fine using what you have. Running a little bit more current should not make that much of a difference. From my limited electronic knowledge a GR in theory should be a fraction bit quieter but I would not think enough to make a sonic difference that 98% of us would hear. I am sure I will be corrected if wrong.@6L6 and @rhthatcher and @wayne ...
Gentlemen - great docs. My I ask a question about the BOM...
2sk209GR or 2sk170BL
Why the different Idss classification?
I now have a matched octet of 2sk170BL's. 7.65mA +/- 0.01mA
I recovered them just recently. 'Bought them a dozen years ago for the original Pearl, got sidetracked, and misplaced them.
I'm having second thoughts about soldering the SMD parts; I used solder SMD parts, but now... Youth Deficit Syndrome may present challenges.
Are my 2sk170BLs suitable for the Pearl 3 ? (Or save them for Pearl 4 ? )
Many thanks,
Tony Z
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