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Pearce BC-1: Help ID this IC Chip!!

Discussion in 'Amps and Cabs [BG]' started by pbass2go, Jun 25, 2008.

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  1. Jun 25, 2008 #1
    pbass2go

    pbass2go

    Dec 19, 2004
    Apple Valley, MN
    OK, so my trusty old Pearce BC-1 is acting up. No signal coming out of the main or mixer output. Good signal from each of the channel send to efx.

    Wiring diagram show a single IC Chip with the number 5534 on it as the mixer section. The chip has printed on it (in two lines) RC5534A and NC842. I cant tell if it is one number that runs onto the next line or if it is two seperate numbers.

    My local electronics supplier does not even recognize the RC5534 base number.

    Any electronic savvy TB'ers out there able to help?? :help:

    This amp has been great over the years and fairly simple to maintain. The only things that have failed are these chips. I had another chip in the limter circuit fail two years ago.

    I have the wiring diagram and layout in pdf form if anyone needs it also.

    Thanks,
    Rick
     
  2. Jun 25, 2008 #2
    bongomania

    bongomania Supporting Member Commercial User

    Oct 17, 2005
    PDX, OR
    owner, OVNIFX and OVNILabs
    No exact matches, but these will probably do the job:
    http://www.alldatasheet.com/view.jsp?Searchword=RC5534A
    Edit: actually, since the ones in that list end in "2A" and are dual opamps, it's possible your 4A ones are quad opamps. Check the schemo to see if there are four sets of in/outputs per chip (plus the power and ground pins).
     
  3. Jun 25, 2008 #3
    73jbass

    73jbass Supporting Member

    Apr 17, 2004
    Ellenwood,Ga.
    Both of mine have almost the same problem.Main out doesn't work,bit mixer out does. I have wiring diagrams and schematics if anybody needs them.
     
  4. Jun 25, 2008 #4
    pbass2go

    pbass2go

    Dec 19, 2004
    Apple Valley, MN
    That was my origional problem. I replaced the IC's in the limiter circuit and it cleared up. It was less than $10 in parts for the three IC's in the circuit so I changed all three out.
     
  5. Jun 25, 2008 #5
    pbass2go

    pbass2go

    Dec 19, 2004
    Apple Valley, MN
    On the wiring diagram, I see a gnd(pin 3), a +15(pin 7) and -15(pin4), single input with both cahnnel 1 and 2(pin 2), an out that goes through a capacitor and back in(pin 8 &5), a single line out(pin 6) and an unused line out (pin1)
     
  6. Jun 25, 2008 #6
    Thomas Peasley

    Thomas Peasley

    Jul 16, 2007
    New Hudson, Michigan
    This chip was made by both Raytheon and Fairchild under the base part number RC5534 and RC5534A. It is a rather specialized low noise linear op amp and was produced in a metal can as well as a plastic dual in-line package.You might try DigiKey Electronics or Mouser to see if they have any. Try to get the same chip if possible as the circuit may be designed for this particular part. Good luck!

    -Tom
     
  7. Jun 25, 2008 #7
    pbass2go

    pbass2go

    Dec 19, 2004
    Apple Valley, MN
    Thanks Tom. I appreciate your help.
     
  8. Jun 25, 2008 #8
    Rick Auricchio

    Rick Auricchio Registered Bass Offender Supporting Member

    Nov 27, 2007
    Cambria, CA (Central Coast)
    Neither digi-key nor mouser have the RC5534 part, but both have the NE5534 and other variants. As Tom says, there may have been slight circuit-design tweaks to match the RC part, but that appears to be unavailable. (If neither supplier has it...)

    The data sheet for the Fairchild part is at http://www.datasheetcatalog.org/datasheets/90/275663_DS.pdf . You can compare it against the NE part to see if it's virtually identical.
     
  9. Jun 25, 2008 #9
    BassmanPaul

    BassmanPaul Inactive

    Aug 25, 2007
    Scarborough Ontario Canada
    5534 is a standard quad OP amp. It can me replaced several choices. Any marked 5534 will be suitable, price on-line is a couple of bucks or less. You could upgrade to an OPA627. Better OP amp but more expensive.

    Paul
     
  10. Jun 25, 2008 #10
    Passinwind

    Passinwind I know nothing. Commercial User

    Dec 3, 2003
    Columbia River Gorge, WA.
    Owner/Designer &Toaster Tech Passinwind Electronics
    Nope, it's a standard-pinout single.
     
  11. Jun 25, 2008 #11
    Bofee

    Bofee

    Aug 19, 2005
    Grass Valley, CA
    I've pm'd both pbass2go and 73jbass regarding the BC-1 documentation offered. I've been looking for it for a while.
     
  12. Jun 25, 2008 #12
    pbass2go

    pbass2go

    Dec 19, 2004
    Apple Valley, MN
    PM returned and docs sent to your e-mail.

    Rick
     
  13. Jun 25, 2008 #13
    pbass2go

    pbass2go

    Dec 19, 2004
    Apple Valley, MN
    I could not find it at either digi-key or mouser either.
    Thanks for the data sheet. I will search for the data sheet for the NE5534 form the suppliers. I am not 100% what I am going to be lookign for though. I am able to t/shoot to a bad component and replace, but never learned all the in's and out's of circuit design. (should've gone to college like mom wanted)

    Thanks,
    Rick
     
  14. Jun 25, 2008 #14
    Rick Auricchio

    Rick Auricchio Registered Bass Offender Supporting Member

    Nov 27, 2007
    Cambria, CA (Central Coast)
    As Paul said, you should be able to simply pop in another 5534 variant.

    Changing to a different part could be troublesome, because op-amp circuits can get into ultrasonic feedback depending on the values of the other components in the immediate vicinity. Stick with the 5534.
     
  15. Jun 25, 2008 #15
    Passinwind

    Passinwind I know nothing. Commercial User

    Dec 3, 2003
    Columbia River Gorge, WA.
    Owner/Designer &Toaster Tech Passinwind Electronics
  16. Jun 25, 2008 #16
    pbass2go

    pbass2go

    Dec 19, 2004
    Apple Valley, MN
  17. Jun 25, 2008 #17
    Rick Auricchio

    Rick Auricchio Registered Bass Offender Supporting Member

    Nov 27, 2007
    Cambria, CA (Central Coast)
    Not with the RA prefix, which was what I meant. The NE and others, yes.
     
  18. Jun 25, 2008 #18
    pbass2go

    pbass2go

    Dec 19, 2004
    Apple Valley, MN
    So, any varient of 5534 should work? If so, I do see it on digi-key. I downloaded the data sheet and will go over both to see if I can read any significant difference.

    That would be sweet. :hyper:

    Thanks again,

    Rick
     
  19. Jun 25, 2008 #19
    68Goldfish

    68Goldfish Supporting Member

    Nov 4, 2006
    Port Orchard WA
    Wow, I have the same problem with my BC1. I've traced it down to something wrong in the limiter section, I guess. Only one of my outputs work. It's been some time since I hooked it up so I don't remember which one still worked. I'm watching this thread for sure because that is a great amp. It's been with me for years. Have you guys seen this? I came across this a while ago but havn't really looked into anything. http://members.aol.com/DBmElect/pea...but you could probably just cut and paste it.
     
  20. Jun 25, 2008 #20
    Passinwind

    Passinwind I know nothing. Commercial User

    Dec 3, 2003
    Columbia River Gorge, WA.
    Owner/Designer &Toaster Tech Passinwind Electronics
    Over the years I've used a boatload of these chips, although mostly the dual variant, ie NE5532, NJM5532, RC5532, etc. I've never observed a lick of meaningful performance difference in any of 'em unless they were defective. But I still always check my results on an oscilloscope to look for parasitic oscillations, and you might want to do the same.;)
     
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