DIY phonostage.

[Bksabath]

Sure.
It might be a while though.
I'm not renowned for my blistering pace.

Blisters on finger tips

I would be also interested in the low range 337 and have quite a few 327 on that range that once I am done I am willing to swap /resell

Will you also do a third pass ,this time using pliers and same room temperature, before they go on the board ?


Where did you get them from? can you also give me supplier part number ,as I said before it is pot luck to get the right batch, and this time look like you got the right ones.

[RothwellAudio]

Back at it.
Finishing up the first pass through the BC-337.
So that's 1000 each BC-337 and BC-327 filtered for 400-450 range.


Bench by Martin Fay, on Flickr



Measured by Martin Fay, on Flickr

And second pass of the BC-337 now complete - looking good for a better than 1% match in the 430 - 450 range with about 150 pieces in this range to choose from.

Second pass on the BC-327 yet to go.

Well done on having the stamina to do so many measurements. However, I should point out that the meter you have seems to be measuring at just one current drain. That's fine and will give some level of matching, but the next level up in terms of matching would be to measure the Hfe at the current drain they'll see in your circuit. Better than that would be to also make a measurement above and a measurement below the operating current to get a crude measure of the shape of the curve. The ultimate in matching would be to measure the actual curve rather than just one point on the curve.

[mac72]

Well done on having the stamina to do so many measurements. However, I should point out that the meter you have seems to be measuring at just one current drain. That's fine and will give some level of matching, but the next level up in terms of matching would be to measure the Hfe at the current drain they'll see in your circuit. Better than that would be to also make a measurement above and a measurement below the operating current to get a crude measure of the shape of the curve. The ultimate in matching would be to measure the actual curve rather than just one point on the curve.

DCA75 Pro is capable of curve tracing as far as I know

[mac72]

Sure.
It might be a while though.
I'm not renowned for my blistering pace.

Time is not an issue, after few months I managed to built PSU , at this pace I should be done just before I retire .
I have 500 of each transistors but haven't opened Mouser cardboard box yet, couple months since receiving .
Obviously I'd need find a way to compensate you for time you've spent testing them .
Keep in touch

[howlindawg]

Better than that would be to also make a measurement above and a measurement below the operating current to get a crude measure of the shape of the curve. The ultimate in matching would be to measure the actual curve rather than just one point on the curve.

I think I'll wait for the final selection before going to those lengths.
2000 curves might be a bit too much, even for my OCD.


Peak-337 by Martin Fay, on Flickr

Will you also do a third pass ,this time using pliers and same room temperature, before they go on the board ?

The second pass was already at a reasonably consistent room temp (mid twenties) and without touching so should be pretty close.

Where did you get them from? can you also give me supplier part number ,as I said before it is pot luck to get the right batch, and this time look like you got the right ones.

Mouser but it really is pot luck batch to batch.
I just got lucky that the outliers of my samples overlapped in the usable range.
327s are clustered between 390 and 450 - mostly around 400.
337s are clustered between 450 and 490 - mostly 460-480.
Fingers crossed I get matching 327s on the second pass.

Mouser No: 512-BC32740TA
Mfr. No: BC32740TA
Desc.: Bipolar Transistors - BJT PNP -45V -800mA HFE/630

Mouser No: 512-BC33740TA
Mfr. No: BC33740TA
Desc.: Bipolar Transistors - BJT NPN 45V 800mA HFE/630

I'd definitely be up for swaps within the usable ranges.

Time is not an issue, after few months I managed to built PSU , at this pace I should be done just before I retire .

I've had my psu built and tested years ago (literally!) but have been too unwell until recently to continue with the build.
Brain Tumors suck!

[Bksabath]

WP_20170821_21_10_52_Pro.jpgHi Martin
same results here
The PNP are in range
The NPN are a pain in the ...
I have a batch from Rapid those are low from 300 to 350
batches from mouser are hi they start from 460 and go all the way up to 600

I have ordered today a further 1000 from Farnell instead of the tape (TA) I am going to try the BU there may be a bit more span
Same as you
I am using the DCA Pro on the first page (component testing) that seems to be a bit faster for the first pass
I will do the last pass before they go on the board whit the curve tracer function

[sq225917]

Howling, you've gotta do curves for the input stage. Trust me.

[sq225917]

Before you ask, 8mA

[howlindawg]

Howling, you've gotta do curves for the input stage. Trust me.

I do Simon and I will.
I should have all the 430-450 whittled out now so that's the easy part done then.

Results not as good as expected.
150 337 in the 430-450 range
50 327 in the 430-450 range (hundreds in the 400-430 range!)

looks like I'll being ordering a few hundred more 337s then.

[RothwellAudio]

DCA75 Pro is capable of curve tracing as far as I know

I stand corrected, thank you. I that case, curves would probably be worth doing, at least after narrowing down the selection by single point measurements.