BL3207 no marking

[matopotato]

Hi,
I hope someone knows how to determine the pinout on a BL 3207 as it has no indicator on it.



Many thanks in advance

[Mark Hammer]

Um, then how can you be certain it's actually the chip it purports to be?  Where did you source it from?
Is there any marking on the bottom that might suggest where pins 1-8 are?

[matopotato]

I bought it from Banzaimusic in Germany. They seem to deal with legit parts.
The bottom says H8 encircled in the middle. But no leg indicator.
Is there some way to breadboard and determine some of the pins?

[matopotato]

I goes in to the EMV2 by DrAlx.



I guess if I chance it, and turn power on I might fry it, right?

[duck_arse]

the observed standard method convention for marking chips is to have the numbering running left to right, to the right of the pin 1 pip. so your pictured would be pin 1 lower left, if following this not-a-standard.

but - NatSemi used to mark their pip-end with a white band many years back, I dunno if that was for indications, tho. [is that a paint band on the right hand end?]


edit for the word I wanted.

[matopotato]

Thanks!
The right side is not much of draw. More like missed paint or something.







Orher end/side

[duck_arse]

I'd get onto banzai, ask them for info. they need to identify "the right way", otherwise it's not fit for purpose.

[I couldn't tell if that "band" was inked or a chamfer - turns out neither.]

[matopotato]

I'd get onto banzai, ask them for info. they need to identify "the right way", otherwise it's not fit for purpose.

[I couldn't tell if that "band" was inked or a chamfer - turns out neither.]

Thanks, doing that.
One leg fell off. Not good quality but not 100% if it was broken from the start or not. It was bent and straighten out broke it effortlessly. I mean it was not good from the start.

Are there any ways to figure out pinout on say a breadboard setup? Or will 180 deg mistake always result in frying?

[ElectricDruid]

Are there any ways to figure out pinout on say a breadboard setup? Or will 180 deg mistake always result in frying?

According to the MN3207 datasheet, I think you'd get away with it. I'd test it at 5V though, to reduce the risk. The "aboslute maximum ratings" in the datasheet are -0.3V to 11V. Reversing the power supply doesn't exceed that, so it *should* be ok.

Like Duck said, I'd assume pin 1 was bottom-left with the writing the right way around.

[Mark Hammer]

One leg fell off.

First thing that came to mind was the Cook & Moore "Tarzan" sketch.
https://www.youtube.com/watch?v=lbnkY1tBvMU

[DrAlx]

 Sorry but that chip looks fake. Go to ebay.co uk and search for EMV2. Against the listing there are some gutshots of a sample build with a real BL3207. I bought mine from Banzai but several years ago. I don't know where Banzai are sourcing them now. All the BL3207 I have seen look like the one in my build.
Disappointing. I have never had a problem with fakes from Banzai before.

It should look like this

https://www.retroamplis.com/WebRoot/StoreES2/Shops/62070367/5643/2C48/BA27/598F/18FD/C0A8/2BBA/5C42/BL3207_ml.jpg

[PRR]

> never had a problem with fakes from Banzai

Some years back, people reported 3080 VCA chips in Banzai kits which did not work.

[ElectricDruid]

Sorry but that chip looks fake.

DrAlx might have a point. It doesn't look anything like the known-good examples I have:

[Mark Hammer]

Given what's involved in producing an IC, as well as the continuing disappearance of the DIP form-factor, and replacement by SMD, I can't see any manufacturer investing in the manufacture of a "dentless" chip.  On the other hand, the re-legending of chips is less costly to achieve, and if one can score a batch of dentless chips to relegend how you see fit....

Still, there are all manner of oversights by ostensibly dependable manufacturers.  I've told the story before, but it bears repeating.  A friend asked me to see what was up with his Diamond Memory Lane pedal.  He had two of them, and left them both with me to detect the issue.  One was perfectly fine, but the other had an annoyingly audible whine.  Thinking it may have been one of the many trimmers inside being mis-set, I wrote to Diamond's tech support to help ID-ing them.  A few e-mails back and forth, and in the process, I mentioned that the whine didn't start until the pedal had been powered up about 5 minutes or so.  That rang a bell for the tech, and he said that they had received, and mistakenly installed, a batch of 3-pin 1A regulators, early on, that had really thin heat fins, and I should look for that.  The pedal provided three different supply voltages, and looking inside I could see that one of the regulators had an unusually thin heat fin.  The other two were regulation thickness.  I removed it, installed one of proper thickness, and the problem went away.  Bear in mind we're talking about a reputable pedal manufacturer, not some guy in his dorm room, that ordered parts from a reputable distributor, manufactured by a reputable semi-conductor provider (NatSem).  The pedal lacked, and really didn't need, any ventilation, and the regulators were not sinking any heat buildup against the enclosure.  But the thinness of that regulator (and I suppose the current draw for that voltage) resulted in it getting warm and drifting off-spec.

The moral of the story is that the manufacturer took its eye off the ball, as did the distributor, and eventually the pedalmaker.  All trusted everything was AOK.  Could an honestly-manufactured BBD suffer a similar fate?  Well, it's certainly not a common one, but it could happen.  Stick it into a socket, in the orientation suggested by the legending, and see.

[bluebunny]

It doesn't look anything like the known-good examples I have:

The picture on the Banzai website doesn't look anything like your known-good examples, Tom!

[matopotato]

It doesn't look anything like the known-good examples I have:

The picture on the Banzai website doesn't look anything like your known-good examples, Tom!

I nitice there is more if a dot on Banzai page than on my specimen.

[bluebunny]

That just looks likes a moulding mark, rather than a proper divot.

[matopotato]

That just looks likes a moulding mark, rather than a proper divot.

Agree, but it is more than I got. And aligns with what Tom suggested.

[ElectricDruid]

It doesn't look anything like the known-good examples I have:

The picture on the Banzai website doesn't look anything like your known-good examples, Tom!

Well...I dunno!

Mine came from our own puretube (Ton) who graciously shared 100 with me so I'd be able to continue to send people Flangelicious pedals (I ran out of my stash of old MN3207s).

[matopotato]

I would like to try and set my IC up with 5V and then what?
Can I just measure pins for voltages, and if anything "reasonable" then I can try in the build?
If the pinout is reversed with 5V test, I would not get any readings on the pins?
Some BL3207 datasheets have application examples, but for this one I find either is is in Japanese, or not much of examples to go by.

If I go by what Tom and others suggested and put it in with pin 1 down to left when reading text "normally". And put it into the circuit, it should get 9V, so then re-measure for more proper readings?

IF it is fake, how can one tell?
I am guessing there is some scale to fake. From nothing happens at all, to a small whine in specific conditions?

I have logged a case with Banzai support. I have no reason to think they would consciously engage in selling fake. That would have a huge impact on their business fast. And the other stuff they delivered was good. Mark Hammer's post also suggests to give them the benefit of a doubt until they reply at least.
The BL3207 was 6.58 Euro (~USD), which is cheaper than my other source, Das Musikding (7.50 Euro), but they have MN3207 or V3207, not the BL.