I expect mine in the next few days...
I have a tracking number so should not be too long in coming.
The boards do indeed look very good. I have a JFET tester (PEAK electronics DCA 75 semiconductor analyser) - hopefully that will get some numbers that can be validated. If not then no problem, the PCB's alone are worth Exhales asking price.
Package arrived a few minutes ago. The boards look good. Twelve TO-92 package devices were included, which are stamped "K170 BL 5A". I don't have a jfet jig to test the devices, and given their increasingly apocryphal origin, I'm inclined to source the fets elsewhere and call it a wash. If anyone tests these, I'd be interested in your results.
Cheers!
I have a tracking number so should not be too long in coming.
The boards do indeed look very good. I have a JFET tester (PEAK electronics DCA 75 semiconductor analyser) - hopefully that will get some numbers that can be validated. If not then no problem, the PCB's alone are worth Exhales asking price.
The diyAudio store thinks the DCA doesn't have the juice to measure jfets, if I understand this correctly:
"Note: The DCA Peak Atlas Pro semiconductor tester will give inaccurate results for testing these JFETs as it cannot provide adequate current during the test. Please refer to the user manual for more information on its specifications. This is a great tool but should not be used for testing high current / high voltage devices. "
JFET matching information – diyAudio Store
"Note: The DCA Peak Atlas Pro semiconductor tester will give inaccurate results for testing these JFETs as it cannot provide adequate current during the test. Please refer to the user manual for more information on its specifications. This is a great tool but should not be used for testing high current / high voltage devices. "
JFET matching information – diyAudio Store
I measured the IDSS of the devices the other day, using the method recommended in the diyAudio store link. The numbers I got are within spec for the k170BL, ranging from 10.12mA-11.52mA. Not enough data to declare them genuine, but it's not discouraging.
The IDSS match closely enough to create a couple sets of quads and two additional matched pair. The voltages I recorded were:
1.012
1.018
1.024
1.032
1.073
1.078
1.083
1.087
1.095
1.129
1.136
1.152
where 1V = 10mA
Fairly tight matching, the loosest group +/- 0.3mA as listed, with +/-0.17mA achievable. Not bad!
The IDSS match closely enough to create a couple sets of quads and two additional matched pair. The voltages I recorded were:
1.012
1.018
1.024
1.032
1.073
1.078
1.083
1.087
1.095
1.129
1.136
1.152
where 1V = 10mA
Fairly tight matching, the loosest group +/- 0.3mA as listed, with +/-0.17mA achievable. Not bad!
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I am not aware of anyone that has tested the TO-92 devices to be authentic. If you read this thread, you'll see the provenance is questionable, at the least. Extremely doubtful that the boards or devices were sourced from PassDIY, IMO.
The diyAudio store sells equivalent jfet devices.
Best of luck!
The diyAudio store sells equivalent jfet devices.
Best of luck!
Thanks Raoul.
Before I purchased I asked the seller and was told that they were originally bought from PassDIY.
On first inspection the Jfets do not look real to me at all (or at least not like the ones that came with the B1 that I got from PassDIY) but I have read posts about older 2sk170's that might look more like current fakes.....who knows? I will test them before using them, just wanted to confirm with the seller what they originally told me and to let anyone thinking of buying that this might be the case.
Before I purchased I asked the seller and was told that they were originally bought from PassDIY.
On first inspection the Jfets do not look real to me at all (or at least not like the ones that came with the B1 that I got from PassDIY) but I have read posts about older 2sk170's that might look more like current fakes.....who knows? I will test them before using them, just wanted to confirm with the seller what they originally told me and to let anyone thinking of buying that this might be the case.
Do you have a curve tracer to test the TO-92s? I'd be very interested in your results.
The leads on the TO-92 devices I received look straight and unscuffed, and unlikely to have been placed in a test jig. They were unmarked with measurements and not grouped. The IDSS range I measured was too wide (over the 1mA Pass tolerance) to use the devices interchangeably. I feel comfortable in declaring these non-Pass devices without your subtlety, if that is your concern.
How does the thickness of the copper traces compare to your authentic B1 boards?
The leads on the TO-92 devices I received look straight and unscuffed, and unlikely to have been placed in a test jig. They were unmarked with measurements and not grouped. The IDSS range I measured was too wide (over the 1mA Pass tolerance) to use the devices interchangeably. I feel comfortable in declaring these non-Pass devices without your subtlety, if that is your concern.
How does the thickness of the copper traces compare to your authentic B1 boards?
I don't have a tracer, just going to do what I think you did....9V IDSS test to see if they are even in the ballpark. I did a quick comparison with the authentic B1 board. It looks like the copper is much thicker on the B1 boards. Looking online, Exhale's Pearl boards are missing the manufacturers logo (which are on the B1). These boards might work just fine but I will have to double check them with the schematic before even thinking about stuffing.
I would think the Pass boards have 2oz copper. These Pearl boards are not that. The gerber files are available from PassDIY. Looks like >$10 worth of Chinese boards for $80+shipping. That said, I imagine the boards will work fine. If authentic jfets are purchased through diyAudio, the total cost is basically a wash vs the authentic boards. The red flags were there; can't win them all
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Hmmm...we’ll, I grabbed a set after the “last pair” post.
When I originally inquired, the response to my question about whether the jfets were offered with the boards was a no as I said.
When I inquired this time, I was told the response was due to “frustration”.
Perhaps that was due to being scrutinized for offering $200 board/jfet sets for $88 shipped, who knows?
I just hope the circuit checks out on the boards at this point. I have plenty of genuine 2sk170bl in the 10-11ma range sorted into a bag that have no purpose if those will work.
When I originally inquired, the response to my question about whether the jfets were offered with the boards was a no as I said.
When I inquired this time, I was told the response was due to “frustration”.
Perhaps that was due to being scrutinized for offering $200 board/jfet sets for $88 shipped, who knows?
I just hope the circuit checks out on the boards at this point. I have plenty of genuine 2sk170bl in the 10-11ma range sorted into a bag that have no purpose if those will work.
I'm not sure if the Pearl 2 gerbers are available on passdiy now; I only found
a link to the B1 gerbers.
Per post #247, the Passdiy boards are 3oz copper:
https://www.diyaudio.com/forums/pass-labs/156397-pearl-25.html#post2242674
I ordered a set from Passdiy a few years ago and they jfets were
well matched. I believe they were 2sk370BL (smaller package
version of 2sk170)
a link to the B1 gerbers.
Per post #247, the Passdiy boards are 3oz copper:
https://www.diyaudio.com/forums/pass-labs/156397-pearl-25.html#post2242674
I ordered a set from Passdiy a few years ago and they jfets were
well matched. I believe they were 2sk370BL (smaller package
version of 2sk170)
Three ounces is a lot of beef!
The gerbers have been available by request in the past. See post #1018 here:
Building a Pearl 2
The gerbers have been available by request in the past. See post #1018 here:
Building a Pearl 2
Yes I would agree that based on your pictures of what you received Mazzer that the jfets are fakes.
It’s ultimately on us I suppose. I was skeptical to begin with because of the conflicting information that surfaced regarding what was offered in the sale.
It seemed like things were going in the right direction when Raoul and you posted pics that you received the packages as promised, so I went for the set still being offered.
As is always the case it seems...too good a thing is too good a thing.
It would be easier on us at this point if the seller would step up and explain the source of the boards and tell us at least if he had them made from Gerber files requested from PASS.
It’s ultimately on us I suppose. I was skeptical to begin with because of the conflicting information that surfaced regarding what was offered in the sale.
It seemed like things were going in the right direction when Raoul and you posted pics that you received the packages as promised, so I went for the set still being offered.
As is always the case it seems...too good a thing is too good a thing.
It would be easier on us at this point if the seller would step up and explain the source of the boards and tell us at least if he had them made from Gerber files requested from PASS.
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