RoHS gone MAD

P

Phil Allison

Guest
Hi to all,

I have a near new, Fender " Deluxe Reverb-Amp " on the bench.

This is a so called " Reissue " of a 22watt, all valve guitar amp first sold
back in 1965.

The circuitry is identical to the original except for one low cost component
that has been substituted .... like Vince Sorrenti famously says: I see
it, but I doooaann believe it !!!!

Inside the amp's chassis has been fitted an SMD board, about 50mm x 100 mm,
that does just *one* job - it replaces the usual CdS photo cell in the
tremolo circuit !!!!!

On the back of the SMD board, in copper, it says " ROHS TREMOLO ".

The 12AX7 valve responsible for the tremolo effect is still fitted and fully
wired - but the connections that usually go to the Ne2 lamp and the CdS
cell are now routed the SMD board instead.

The main IC on the SMD board is an LM13700 transconductance amp - plus a
TL072 and numerous transistors, caps etc. It does the job of mimicking the
CdS characteristic rather well.

But WHY ??

How much EVIL cadmium is inside one, tiny CdS cell ??

Remember: NiCd batteries are still being sold and still fitted to many power
tools - even in Europe.

How completely bonkers !!!!



..... Phil
 
Phil Allison wrote:
Hi to all,

I have a near new, Fender " Deluxe Reverb-Amp " on the bench.

This is a so called " Reissue " of a 22watt, all valve guitar amp
first sold back in 1965.

The circuitry is identical to the original except for one low cost
component that has been substituted .... like Vince Sorrenti
famously says: I see it, but I doooaann believe it !!!!

Inside the amp's chassis has been fitted an SMD board, about 50mm x
100 mm, that does just *one* job - it replaces the usual CdS photo
cell in the tremolo circuit !!!!!

On the back of the SMD board, in copper, it says " ROHS TREMOLO ".

The 12AX7 valve responsible for the tremolo effect is still fitted
and fully wired - but the connections that usually go to the Ne2
lamp and the CdS cell are now routed the SMD board instead.

The main IC on the SMD board is an LM13700 transconductance amp - plus a
TL072 and numerous transistors, caps etc. It does the job of
mimicking the CdS characteristic rather well.

But WHY ??

How much EVIL cadmium is inside one, tiny CdS cell ??

Remember: NiCd batteries are still being sold and still fitted to
many power tools - even in Europe.
Batteries are exempt from ROHS though.

How completely bonkers !!!!
You're not wrong.
ROHS is all about "reduction", not total elimination, strange that a single
CdS photocell would put you over.
Interestingly, Digikey actually sell some CdS photocells that are "ROHS
compliant by exemption", whatever that exemption means.

Perhaps the CdS cell wasn't replaced because of ROHS?, it might just have
been a discontinued part which they could not find a suitable alternative?
The board is ROHS compliant, because, well, that's what they all are these
days as standard.

I'm surprised marketing didn't get a hold of the "solid state" update...

Dave.

--
================================================
Check out my Electronics Engineering Video Blog & Podcast:
http://www.eevblog.com
 
"David L. Jones"


Batteries are exempt from ROHS though.

** Shame about the " Battery Directive ".

http://en.wikipedia.org/wiki/Battery_Directive

Note how NiCds are still allowed in power tools.



How completely bonkers !!!!

You're not wrong.
ROHS is all about "reduction", not total elimination, strange that a
single CdS photocell would put you over.
** The RoHS cadmium ban applies to the percentage ( max 0.01%) of cadmium in
any identifiable material or coating.

" The maximum permitted concentrations are 0.1% or 1000 ppm (except for
cadmium, which is limited to 0.01% or 100 ppm) by weight of homogeneous
material. This means that the limits do not apply to the weight of the
finished product, or even to a component, but to any single substance that
could (theoretically) be separated mechanically-for example, the sheath on a
cable or the tinning on a component lead. "

http://en.wikipedia.org/wiki/Restriction_of_Hazardous_Substances_Directive#Details


Interestingly, Digikey actually sell some CdS photocells that are "ROHS
compliant by exemption", whatever that exemption means.
** There is a general exemption for CdS photo cells used in professional
audio equipment (obtained by request from Marshall Amplification of the
K) - it expires end of this year - subject to review no doubt.

http://www.rohs.gov.uk/Docs/Exemptions%20without%20link%20backs/RoHS%20Exemptions%20-%20Cadmium%20(2).pdf

Makes what Fender have done impossible to comprehend.


Perhaps the CdS cell wasn't replaced because of ROHS?, it might just have
been a discontinued part which they could not find a suitable alternative?
** Bollocks.

The US market versions still have the CdS cells.

The SMD board is LABELLED: " ROHS TREMOLO " !!!


The board is ROHS compliant, because, well, that's what they all are these
days as standard.
** Massive red-herring.


I'm surprised marketing didn't get a hold of the "solid state" update...

** Not likely Fender will publicly reveal their premium priced "Re-issue"
models have a stinking SMD board hidden inside. Tube purists would all puke.




...... Phil
 
"Phil Allison" <phil_a@tpg.com.au> wrote in
news:7k9r8bF39eg4nU1@mid.individual.net:

Hi to all,

I have a near new, Fender " Deluxe Reverb-Amp " on the
bench.

This is a so called " Reissue " of a 22watt, all valve
guitar amp first sold back in 1965.

The circuitry is identical to the original except for one
low cost component that has been substituted .... like
Vince Sorrenti famously says: I see it, but I doooaann
believe it !!!!

Inside the amp's chassis has been fitted an SMD board,
about 50mm x 100 mm, that does just *one* job - it
replaces the usual CdS photo cell in the tremolo circuit
!!!!!

On the back of the SMD board, in copper, it says " ROHS
TREMOLO ".

The 12AX7 valve responsible for the tremolo effect is still
fitted and fully wired - but the connections that usually
go to the Ne2 lamp and the CdS cell are now routed the SMD
board instead.

The main IC on the SMD board is an LM13700 transconductance
amp - plus a TL072 and numerous transistors, caps etc. It
does the job of mimicking the CdS characteristic rather
well.

But WHY ??

How much EVIL cadmium is inside one, tiny CdS cell ??

Remember: NiCd batteries are still being sold and still
fitted to many power tools - even in Europe.

How completely bonkers !!!!



.... Phil
Is the fault in the tremolo section or somewhere else?
 
"GeoffC"
Is the fault in the tremolo section or somewhere else?
** The problem that I had to deal with was not related to the tremolo
circuit.

However, if that wacky SMD board ever fails, I know exactly what service
techs will do.



...... Phil
 
Phil Allison wrote:
"GeoffC"
Is the fault in the tremolo section or somewhere else?

** The problem that I had to deal with was not related to the tremolo
circuit.

However, if that wacky SMD board ever fails, I know exactly what service
techs will do.



..... Phil
LOL, probably replace it with a lamp and a CdS cell ...
 
On Oct 23, 1:41 pm, Swanny <swa...@nospam.org> wrote:
Phil Allison wrote:
"GeoffC"
Is the fault in the tremolo section or somewhere else?

** The problem that I had to deal with was not related to the tremolo
circuit.

However, if that wacky SMD board ever fails, I know exactly what service
techs will do.

..... Phil

LOL, probably replace it with a lamp and a CdS cell ...
Funny that :)
 

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