MOTM

I had a *long* debugging session with a customer building a MOTM-300 VCO 
from parts. Was dead in the water (no outputs). He had previously replaced 
*all* op amps, the MAT-02EH and the LM319. To no avail.

Them we started on the transistors. He noticed that he had 2 'batches' of 
2N3904s::  2N3904 - CJ22 and others marked  2N3904 - J04.

It turns out these have *different pinouts*. It's still an "2N3904" but not 
the proper EBC pinout! Which is...errr...NOT per JEDEC standard (the 2N 
means the part is supposed to be in a registered database) but I guess no 
one gives a rat's ass about JEDEC, JAN-TX and all those 'old fart' 
transistor specs.

So, *be very careful* buying 2N3904s, you want EBC pinouts. CHECK THE DATA 
SHEETS!

Paul S.

Hi Paul,

Is it possible these are "counterfeit / reject" transistors that have  
been badged
as 2N3904.....Seems highly unlikely there are 2 versions with  
different pinouts.

Graham

On 27 Feb 2009, at 06:47, Paul Schreiber wrote:

> I had a *long* debugging session with a customer building a MOTM-300  
> VCO
> from parts. Was dead in the water (no outputs). He had previously  
> replaced
> *all* op amps, the MAT-02EH and the LM319. To no avail.
>
> Them we started on the transistors. He noticed that he had 2  
> 'batches' of
> 2N3904s:: 2N3904 - CJ22 and others marked 2N3904 - J04.
>
> It turns out these have *different pinouts*. It's still an "2N3904"  
> but not
> the proper EBC pinout! Which is...errr...NOT per JEDEC standard (the  
> 2N
> means the part is supposed to be in a registered database) but I  
> guess no
> one gives a rat's ass about JEDEC, JAN-TX and all those 'old fart'
> transistor specs.
>
> So, *be very careful* buying 2N3904s, you want EBC pinouts. CHECK  
> THE DATA
> SHEETS!
>
> Paul S.
>
>
>

--Where did you buy these?

I've never heard of this problem: same PN and package having different
pinouts!
That's just WRONG!


> Hi Paul,
>
> Is it possible these are "counterfeit / reject" transistors that have
> been badged
> as 2N3904.....Seems highly unlikely there are 2 versions with
> different pinouts.
>
> Graham
>
> On 27 Feb 2009, at 06:47, Paul Schreiber wrote:
>
>> I had a *long* debugging session with a customer building a MOTM-300
>> VCO
>> from parts. Was dead in the water (no outputs). He had previously
>> replaced
>> *all* op amps, the MAT-02EH and the LM319. To no avail.
>>
>> Them we started on the transistors. He noticed that he had 2
>> 'batches' of
>> 2N3904s:: 2N3904 - CJ22 and others marked 2N3904 - J04.
>>
>> It turns out these have *different pinouts*. It's still an "2N3904"
>> but not
>> the proper EBC pinout! Which is...errr...NOT per JEDEC standard (the
>> 2N
>> means the part is supposed to be in a registered database) but I
>> guess no
>> one gives a rat's ass about JEDEC, JAN-TX and all those 'old fart'
>> transistor specs.
>>
>> So, *be very careful* buying 2N3904s, you want EBC pinouts. CHECK
>> THE DATA
>> SHEETS!
>>
>> Paul S.
>>
>>
>>
>
>
>


-- 
John Blacet

*I* did not buy them, the customer used the dreaded 'surplus store' in 
Silicon Valley.

Paul S.
/now understands today's meaning of 'surplus'


----- Original Message ----- 
From: "John Blacet" <blacet@...>
To: "Paul Schreiber" <synth1@...>; "MOTM List" 
<motm@yahoogroups.com>

Sent: Friday, February 27, 2009 9:24 AM
Subject: Re: [motm] Watch transistor pinouts!


> --Where did you buy these?
>
> I've never heard of this problem: same PN and package having different
> pinouts!
> That's just WRONG!
>
>
>> Hi Paul,
>>
>> Is it possible these are "counterfeit / reject" transistors that have
>> been badged
>> as 2N3904.....Seems highly unlikely there are 2 versions with
>> different pinouts.
>>
>> Graham
>>
>> On 27 Feb 2009, at 06:47, Paul Schreiber wrote:
>>
>>> I had a *long* debugging session with a customer building a MOTM-300
>>> VCO
>>> from parts. Was dead in the water (no outputs). He had previously
>>> replaced
>>> *all* op amps, the MAT-02EH and the LM319. To no avail.
>>>
>>> Them we started on the transistors. He noticed that he had 2
>>> 'batches' of
>>> 2N3904s:: 2N3904 - CJ22 and others marked 2N3904 - J04.
>>>
>>> It turns out these have *different pinouts*. It's still an "2N3904"
>>> but not
>>> the proper EBC pinout! Which is...errr...NOT per JEDEC standard (the
>>> 2N
>>> means the part is supposed to be in a registered database) but I
>>> guess no
>>> one gives a rat's ass about JEDEC, JAN-TX and all those 'old fart'
>>> transistor specs.
>>>
>>> So, *be very careful* buying 2N3904s, you want EBC pinouts. CHECK
>>> THE DATA
>>> SHEETS!
>>>
>>> Paul S.
>>>
>>>
>>>
>>
>>
>>
>
>
> -- 
> John Blacet
>
>

fwiw, mouser lists 2n3904s with two different pinout configurations - 
the 2N3904CTA variant has the collector on the middle pin.

:-S

>*I* did not buy them, the customer used the dreaded 'surplus store' in
>Silicon Valley.
>
>Paul S.
>/now understands today's meaning of 'surplus'

i am just about to build a 300 and a 310 and i want to be sure to get
the right parts...   for the 2n3904 is the mouser #512-2N3904CTA? 

also anyone have the proper # for the ferrite bead?  i have seen a few
sizes now and am wondering which is the right one.

thanks
patch 

--- In motm@yahoogroups.com, Jason Proctor <jason@...> wrote:

>
> fwiw, mouser lists 2n3904s with two different pinout configurations - 
> the 2N3904CTA variant has the collector on the middle pin.
> 
> :-S
> 
> >*I* did not buy them, the customer used the dreaded 'surplus store' in
> >Silicon Valley.
> >
> >Paul S.
> >/now understands today's meaning of 'surplus'
>

Get this one:

512-2N3904TF

Paul S.


----- Original Message ----- 

From: "patchdub1972" <patchdub@...>
To: <motm@yahoogroups.com>
Sent: Friday, February 27, 2009 8:53 PM
Subject: [motm] Re: Watch transistor pinouts!


>i am just about to build a 300 and a 310 and i want to be sure to get
> the right parts...   for the 2n3904 is the mouser #512-2N3904CTA? 
> 
> also anyone have the proper # for the ferrite bead?  i have seen a few
> sizes now and am wondering which is the right one.
> 
> thanks
> patch 
> 
> --- In motm@yahoogroups.com, Jason Proctor <jason@...> wrote:
>>
>> fwiw, mouser lists 2n3904s with two different pinout configurations - 
>> the 2N3904CTA variant has the collector on the middle pin.
>> 
>> :-S
>> 
>> >*I* did not buy them, the customer used the dreaded 'surplus store' in
>> >Silicon Valley.
>> >
>> >Paul S.
>> >/now understands today's meaning of 'surplus'
>>
> 
> 
> 
> 
> ------------------------------------
> 
> Yahoo! Groups Links
> 
> 
> 
>

thanks paul!

any chance someone has mouser#s for the 300 and 310 that they could post? 

for me, getting the right parts from mouser has been the biggest
challenge with building modules.  ics and caps are the most confusing,
i am not sure what i am looking at and there seem to be so many
variations. 

if anyone has anything they wouldn't mind sharing that would be most
appreciated!

thanks
patch     


--- In motm@yahoogroups.com, "Paul Schreiber" <synth1@...> wrote:
>
> Get this one:
> 
> 512-2N3904TF
> 
> Paul S.
> 
> 
> ----- Original Message ----- 
> From: "patchdub1972" <patchdub@...>
> To: <motm@yahoogroups.com>
> Sent: Friday, February 27, 2009 8:53 PM
> Subject: [motm] Re: Watch transistor pinouts!
> 
> 
> >i am just about to build a 300 and a 310 and i want to be sure to get
> > the right parts...   for the 2n3904 is the mouser #512-2N3904CTA? 
> > 
> > also anyone have the proper # for the ferrite bead?  i have seen a few
> > sizes now and am wondering which is the right one.
> > 
> > thanks
> > patch 
> > 
> > --- In motm@yahoogroups.com, Jason Proctor <jason@> wrote:
> >>
> >> fwiw, mouser lists 2n3904s with two different pinout
configurations - 
> >> the 2N3904CTA variant has the collector on the middle pin.
> >> 
> >> :-S
> >> 
> >> >*I* did not buy them, the customer used the dreaded 'surplus
store' in

> >> >Silicon Valley.
> >> >
> >> >Paul S.
> >> >/now understands today's meaning of 'surplus'
> >>
> > 
> > 
> > 
> > 
> > ------------------------------------
> > 
> > Yahoo! Groups Links
> > 
> > 
> > 
> >
>

Hey Patchdub! Will Bill and Elan to the RESCUE!!!!! I'll attach the files.


MOTM300BOM.xls - Will/Bill style BOM, very detailed
MOTM310BOM.xls - Will/Bill style BOM, very detailed

MOTM-310 µVCO.xls - Elan Hickler style BOM... mine BOM is different in
a few ways:
-Solder not listed
-Diodes, Transistors, and Op-amps are combined under Semiconductors
-Carbon Film 5% is replaced with Metal Film 1%
-Synthtech extra parts are indicated with pink text
-Assumes you are not buying Synthtech mounting rails.

great!! thank you very much!!  very much appreciated


--- In motm@yahoogroups.com, Argitoth <argitoth@...> wrote:
>
> Hey Patchdub! Will Bill and Elan to the RESCUE!!!!! I'll attach the
files.

> 
> 
> MOTM300BOM.xls - Will/Bill style BOM, very detailed
> MOTM310BOM.xls - Will/Bill style BOM, very detailed
> 
> MOTM-310 µVCO.xls - Elan Hickler style BOM... mine BOM is different in
> a few ways:
> -Solder not listed
> -Diodes, Transistors, and Op-amps are combined under Semiconductors
> -Carbon Film 5% is replaced with Metal Film 1%
> -Synthtech extra parts are indicated with pink text
> -Assumes you are not buying Synthtech mounting rails.
>

I found errors in my 310 BOM. Some of the resistors were not 1% metal
film and I just didn't notice the 291 in place of the 271. Also, the
LT1013 dual op amp should be ordered from digikey LT1013CN8#PBF-ND