[sdiy] Buzzing reverb

[harrybissell]

of course... an EARLY spring reverb tank would be about fifty to seventy-five
years old now....   :^P

(most modern tanks should be ok, otoh the wires are NOT very large gauge...)

H^) harry

"Roy J. Tellason" wrote:

> On Saturday 16 April 2005 10:06 pm, Steve Begin wrote:
> > It seems like if i move the tank somewhere else or even turn it around
> > inside the enclosure the buzzing is reduced drastically.
> > I got it really cheap but it's been buzzy right from the start, and it
> > would seem kind of crazy if it was just built this way.
> > Is there anything that could cause a spring reverb to become more sensitive
> > to noise from the power transformer?  (it looks like it's probably over 20
> > years old)
>
> A busted ground connection,  sound like.
>
> > If I can't find any other solution I'll probably just mount the tank
> > externally, but I'm curious as to how it got this way.
>
> Early reverb tanks had no strain relief on the wires going from the in/out
> jacks to the coils.  Bounce them around enough and you get a broken wire.
> Later tanks had a dab of glue or a small metal bit or something to take the
> stress off those soldered connections...
>
> > steve
> >
> > ----- Original Message -----
> > From: "Bob Weigel" <sounddoctorin at imt.net>
> > To: "Steve Begin" <trypannon at hotmail.com>
> > Sent: Saturday, April 16, 2005 7:52 PM
> > Subject: Re: [sdiy] Buzzing reverb
> >
> > > sure.  That means the tank is probably ok..barring any broken springs
> > > inside. Possibly then the problem is in the amp that picks up the signal
> > > from it. -Bob
> > >
> > > Steve Begin wrote:
> > >> Forgive me for asking, but how would you measure these impedances?  if i
> > >> have the spring tank unplugged and i measure across the rca connector i
> > >> get 200 ohms on both input and output.  Does this mean anything?
> > >> -steve
> > >>
> > >>
> > >> ----- Original Message ----- From: "Bob Weigel" <sounddoctorin at imt.net>
> > >> To: <synth-diy at dropmix.xs4all.nl>
> > >> Sent: Friday, April 15, 2005 9:59 PM
> > >> Subject: Re: [sdiy] Buzzing reverb
> > >>
> > >>> Yeah that's what I tried to say..not sure if my mail got through.
> > >>> Reverb cans OFTEN have problems with coil connections to leads (they
> > >>> fail in mexico to use strip-x or equiv to pull the enamel off the wires
> > >>> it appears..and they just solder and say a prayer.)  check again the
> > >>> impedences to the can. Input depending on can should be between almost
> > >>> nothing and a couple hundred ohms.  Output 20 to maybe 800. Most common
> > >>> ones I see in that kind of thing measure a DC impedence of 57 ohms on
> > >>> the in and 200 or thereabouts on the out.  If no connect on output
> > >>> you'll be amplifying an antenna. -Bob
> > >>>
> > >>> harrybissell wrote:
> > >>>> oooh... my bad
> > >>>>
> > >>>> I missed a clue.  If the Parametric EQ works without hum, but he
> > >>>> reverb DOES hum... its is very likely NOT a cap in the power supply
> > >>>> !!! Broken
> > >>>> wire, or EMI.  Or it could be a bad connection at, or insdie the
> > >>>> reverb tank itself. They usually use RCA connectors, famous for having
> > >>>> corrosion
> > >>>> etc...
> > >>>>
> > >>>> H^) harry
> > >>>>
> > >>>> jays at aracnet.com wrote:
> > >>>>> You haven't moved it next to something that has a lot of EMI have
> > >>>>> you?
> > >>>>>
> > >>>>> Reverbs are great for picking up AC hum from computer monitors and
> > >>>>> other units power supplies.
> > >>>>>
> > >>>>> Like Harry said, either bad caps or bad ground would be my guess
> > >>>>> after EMI. Usually linear power supplies aren't that bad to deal
> > >>>>> with.
> > >>>>>
> > >>>>> Jay S.
> > >>>>>
> > >>>>> Steve Begin wrote:
> > >>>>>> I have an Intersound PRV-1 Spring Reverb / Parametric EQ, and when
> > >>>>>> the reve=
> > >>>>>> rb section is switched on, there's a really loud buzzing sound added
> > >>>>>> to the=
> > >>>>>> output.
> > >>>>>> It does this regardless of whether or not there's an input present,
> > >>>>>> and the=
> > >>>>>> buzz would appear to be 60Hz.
> > >>>>>>
> > >>>>>> Would this mean it's likely one of the filter caps somewhere is
> > >>>>>> dead? If s=
> > >>>>>> o is there anything anybody can tell me about how I should go about
> > >>>>>> locatin=
> > >>>>>> g the offending capacitor?
> > >>>>>>
> > >>>>>> Thanks,
> > >>>>>> Steve=