Are the C32725's PNP or NPN? On-Semi and Fairchild datasheets indicate they are PNP  (BC327 range) but I've tested them out of an old Unison Research amp I'm fixing and they turn out to be NPN rather than PNP. Same goes for the C33725's (BC337) as spec'd as NPN but they test PNP in and out of the circuit.

They are old C32/33725 parts with the silver etched background on the TO92 transistors so apparantly the new BC327/337 range are modern replacements.

Is this a datasheet error (which I find it hard to believe to be across 3 manufacturers) or are the BC337/327 completely different to the C32/33725's?

 

 

Edited November 28, 201510 yr by DefQon

All BC parts I've ever seen are marked BC*** while something like this points to it being 2SC32725. 

Edited November 28, 201510 yr by spritzer

That was what I was thinking as well, although I can't seem to find any data sheet for a 2SC32725...

DefQon: Not sure if you you already know, but 2SCxxxx is an NPN BJT in the Japanese system (2SAxxxx is the corresponding PNP). BCxxx in the European system is a silicon small-signal BJT, but no mention of polarity.

//UFN

I'm going to order cut aluminum angles from OnlineMetals. Since I'm not too familiar with metallurgy: which alloy is preferred for attaching to heatsinks, the 6061-T6 or 6063-T52?

6061 is fine. Watch out you might not get perfectly straight or measured cuts. I would just order a bit shorter than the case depth to account for this.

3 hours ago, gepardcv said:

I'm going to order cut aluminum angles from OnlineMetals. Since I'm not too familiar with metallurgy: which alloy is preferred for attaching to heatsinks, the 6061-T6 or 6063-T52?

Great site! I was looking around for something like this a while back.

Another site to look at is speedymetals.com, though I don't know if they ship to Australia.

21 hours ago, UFN said:

That was what I was thinking as well, although I can't seem to find any data sheet for a 2SC32725...

DefQon: Not sure if you you already know, but 2SCxxxx is an NPN BJT in the Japanese system (2SAxxxx is the corresponding PNP). BCxxx in the European system is a silicon small-signal BJT, but no mention of polarity.

//UFN

Yes but there is no such thing as 2SC32 or 33725. All Japanese 2SC/2SA have a model designation between 2-4 digits, not 5. I'm wondering if anybody knows the manufacturer for the above general purpose NPN/PNP transistor.

On 11/27/2015, 8:38:27, DefQon said:

Are the C32725's PNP or NPN? On-Semi and Fairchild datasheets indicate they are PNP  (BC327 range) but I've tested them out of an old Unison Research amp I'm fixing and they turn out to be NPN rather than PNP. Same goes for the C33725's (BC337) as spec'd as NPN but they test PNP in and out of the circuit.

They are old C32/33725 parts with the silver etched background on the TO92 transistors so apparantly the new BC327/337 range are modern replacements.

Is this a datasheet error (which I find it hard to believe to be across 3 manufacturers) or are the BC337/327 completely different to the C32/33725's?

 

 

I've got some BC327-25 and BC337-25. The 337s look just like yours, above, but test out as NPNs (and the 327s are PNPs). I think they came from an ebay seller (Parts4You or something like that).

12 hours ago, Kerry said:

Another site to look at is speedymetals.com, though I don't know if they ship to Australia.

Oh yes, that’s looks really good.

Hopefully this will be useful to someone:

Genuine 2SA1486 from BDent (right in both pics) vs fake from SWL Electronics - Ebay (left in both pics).

V(BR) for genuine around 750.. fakes around 350.

The most obvious feature is the back-plate.

 

Also check the Vbr with a DY294 transistor tester.

It pays to pay a bit more to get genuine parts from reliable suppliers.

Its not worth trying to save a few cents in the end it will cost you more dollars and time to fix the project

I learn it the hard way in my KGSShv build a few years ago.

Some may find this interesting....

 

http://www.hificollective.co.uk/components/an_tantalum_nonmagnetic.html?utm_source=Audio+Cap+Customer&utm_campaign=6f352989ac-Newsletter23_12_2015&utm_medium=email&utm_term=0_7186968816-6f352989ac-318768309&mc_cid=6f352989ac&mc_eid=6adaa47f65

5 hours ago, wink said:

Some may find this interesting....

 

http://www.hificollective.co.uk/components/an_tantalum_nonmagnetic.html?utm_source=Audio+Cap+Customer&utm_campaign=6f352989ac-Newsletter23_12_2015&utm_medium=email&utm_term=0_7186968816-6f352989ac-318768309&mc_cid=6f352989ac&mc_eid=6adaa47f65

Looks very nice except for the eye watering price! But let me do a BOM for my next Carbon build

Looking at the website. Anybody used these soft start/dc filter modules?

Any good?

 

http://www.hificollective.co.uk/components/newclassd-soft-start.html

Does anyone know a good source for female 5-pin pro-Stax connectors?  

1 hour ago, Blueman2 said:

Does anyone know a good source for female 5-pin pro-Stax connectors?  

I recommend this ebay item. this teflon socket is very very... yes! very...  tight！
http://www.ebay.com/itm/280935223236?ssPageName=STRK:MESELX:IT&_trksid=p3984.m1555.l2649&rmvSB=true

That's just the pins and they are easy to open up.  Well a bit tedious when I had to do that to some 500 sockets... 

17 minutes ago, spritzer said:

That's just the pins and they are easy to open up.  Well a bit tedious when I had to do that to some 500 sockets... 

You mean the tail screw is easy to loose, right？
Put some solder on it can fix the problem, only do that after you screw up tightly!

The nut isn't a problem when attached to a PCB.  The issue is is the pressure of the pin as they grip too much.  They need to be opened up to the correct pressure

marginally related, but...

Does anyone know if a PCB fab will honor asymmetric ring sizes, as long as the annular ring specifications are met? So, basically I want the minimum ring size for the hole on the top of the PCB, but a significantly larger ring on the bottom? I don't see why not, I could accomplish the same thing with a ground pour and the subtracting from the solder mask...

Since the top and bottom copper are separate layers in the Gerbers, I don't see why not?

Since the top and bottom copper are separate layers in the Gerbers, I don't see why not?

So, my tool wouldn't do this, so I had to create a ground pour and attach it to each pin in the bottom, then subtract the solder mask via a pin swell parameter. I used the minimum annular ring on the part itself. I am getting the Gerbers ready to quote, so we will see.

Dumb question, but anyone ever had problems with standoffs? I have some Keystone standoffs I bought from Mouser awhile back that I just tried out and none of the threads feel very smooth/precise when I screw them in. Two of them can't even be screwed into another standoff from the same package... I tried forcing it in one and now it's stuck (no swt jokes, please).

Since the top and bottom copper are separate layers in the Gerbers, I don't see why not?

So, my tool wouldn't do this, so I had to create a ground pour and attach it to each pin in the bottom, then subtract the solder mask via a pin swell parameter. I used the minimum annular ring on the part itself. I am getting the Gerbers ready to quote, so we will see.

Ok, ordered. Interestingly, I ran it through OSH Park to see if they would kick anything back, and their board rendering showed the increased pin mask swell on the top as exposed copper, even though under the solder mask swell on the top there isn't any copper. That's odd.

I ended up ordering from PCB Way, as I got better lead-time and 2 more boards. Chose immersion gold, next step up in board thickness and 2 oz copper, and blue - the last three options best OSH. The FR4 spec that OSH uses was considerably more, not sure the what the Tg difference really entails. Shouldn't matter for my use.

I was tempted to have them delivered to me in China, but didn't want to risk mail routing issues.

I couldn't use Elecrow or Seeed because I exceed their width for their prototype (my boards are 12.5" wide) options. I still will use Elecrow for assembly though and maybe for another daughter board I need to whip up next.