[sdiy] Microphonic PCB

[karl dalen]

Ah, sorry, no i misunderstood i thought you had caps in there 
already and you did the ceramics, current caps! hehe :)

if the caps are just Bw limiting (10-30pF) they should
not cause any micro phonics.

Kd
> >
> >
> >
> >> Hi all,
> >>
> >> I'm scratching my head and wondering if anyone has
> some
> >> insight to help.
> >>
> >> I have a prototype made up using mainly standard
> SMD parts
> >> (the main components used are: 0805 resistors,
> 0805&
> >> 1206 ceramic multilayer caps, MLL34 silicon diodes
> and some
> >> dual shottkys, and SOIC TL074s)
> >>
> >> I am able to tap the PCB and hear it!
> >> (obviously not very good)
> >>
> >> Recently I was informed by Mr.G.Richter that SMD
> ceramic
> >> caps tend to be microphonic - you won't tend to
> notice it
> >> unless there is some amplification going on.
> >> Well, as the first stage of the PCB offers
> amplification I
> >> figured I should swap out the current caps and
> solder in
> >> some poly-box ones (no, it doesn't look all that
> neat!)
> >> The microphonics still remain..
> >>
> >> Are other parts microphonic?
> >>
> >> Cheers for any insight!
> >> Tom
> >>
> >> -- BugBrand LTD
> >> UK company No. 07199808
> >> VAT No. GB 988 2629 57
> >> 1 Ninetree Hill
> >> BRISTOL BS1 3SB
> >> United Kingdom
> >> www.bugbrand.co.uk
> >>
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> >>
> >
> >
> >
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> -- 
> BugBrand LTD
> UK company No. 07199808
> VAT No. GB 988 2629 57
> 1 Ninetree Hill
> BRISTOL BS1 3SB
> United Kingdom
> www.bugbrand.co.uk
> 
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