Can't find info on this part # anywhere :(

[snoof]

8  pin dip, marked JRC4028B.  No luck on Google.  it appears to be a reg 8pin opamp, but I can't be sure.  anyone know anything about this??

[Dagreb]

Is this any help?
http://www.4starelectronics.com/part_search/PartSearchResults.aspx
 
Search for 4028

[snoof]

when I search for 4028, 4028B I get references to a "1 of 10  decoder" 16 pin.

[Paul Perry (Frostwave)]

I found by googling that the CabTone cabinet simulator contains one of those chips, so if anyoen is familiar with that circuit..
but I suspect it is a decoder as Dagreb says, because many JRC chips are just other manufacturer's standard chips with the NJR prefix added (not always.. but the B for 'bufferd' is a strong CMOS hint!)

[snoof]

My hunch is that it's a opamp.  There is 3 of them in the crkt (Voodoo Microvibe) and there is no other IC's(cept for the wierdo one that has to do with the switching).

[Paul Perry (Frostwave)]

Snoof, which pin does the + voltage go to? If it is pin 14 it is prob a logic chip, if pin 11 it is prob an op amp

[goodrevdoc]

I would say it is a dual op amp. This is based on a crazy guess that i came up with just now. Checked out mouser digikey and the nte xref pages to no avail. A CMOS 4028 is a 16 pin device, but snoof said that this is an 8 pin dip. Check pins 4 & 8 for power and ground connections. If those are there, trace out pins 2 & 3 and 5 & 6.  if those seem like inputs, then look at pins 1 & 7. Those would be outputs on a standard dual OA.
-justin

[snoof]

yes it's def 8pn dip, not 14.  Power does go to p8, and grnd p4.  It's odd that that number doesn't show up anywhere though, maybe it's a custom OEM sorta thang.

[Paul Perry (Frostwave)]

Sorry for muddying the water. Clear missed the very first word in the post - EIGHT pin

[Mark Hammer]

Um, this might be an opportunity to say "welcome to the world of house numbers".

There is a distinct possibility that this number is unique to one manufacturer.  It happens.  Just TRY and find an EH-1048 in any supplier's catalog anywhere.

[Dagreb]

Um, this might be an opportunity to say "welcome to the world of house numbers".

There is a distinct possibility that this number is unique to one manufacturer.  It happens.  Just TRY and find an EH-1048 in any supplier's catalog anywhere.

This sort of thing happens in other manufacturing industries as well. Just to confuse the reverse engineer??