New Amp Day

A very nice birthday present right there Simon

Oh yeah, happy birthday.

They talk about over the hill being bad but when I peeked over quite a few years ago the view on the other side was quite acceptable

Happy birthday, and great present!

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Originally Posted by king casey

I think mine requires a valve replacement.

cheers, Mark.

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I was waiting on someone to pick up on that angle.

Happy 60th Simon. You truly are spoilt by your wife.

Cheers, Waz

Happy Birthday Simon.

Thanks for the birthday wishes.

Happy Birthday, Simon. A very thoughtful gift.

Quote:

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Originally Posted by Simon Barden

Unfortunately the vibrato circuit in the European model version is less than ideal. The original US version has a CdS opto-coupler in it, but as cadmium is banned under RoHS rules over here, they had to add an add-on solid state board to replace it.

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This made me really curious for some reason. The first thing that seems odd is that Cd would be banned in a tiny electrical component when there is an exception carved out for NiCd batteries. I wondered whether I can get CdS opto-couplers, since so many companies in the US follow RoHS guidelines? The answer seems to be "yes" Mouser lists 27 different ones. Impressive since they seem to be used in almost nothing but trem circuits.

Then I saw that the EU *did* have an exception for optocouplers if used in pro-audio equipment. However, it expired right about the time that your amp was made in 2013. That's a bummer, but also weird since the reasoning for having the exemption then seems equally valid now. Nevertheless the exemption expired.

Then I thought, isn't RoHS an EU requirement? So I tried to figure out why RoHS is still in effect for the UK...or if it will be after December... and then I saw that Australia is working on an FTA with the EU. Are we on a slippery slope toward a world wide ban of opto-couplers? I don't know, and now I have a headache.

I really must be trying to avoid doing my actual job...

RoHS
REACH
Prop 65
Conflict Minerals

... it's enough to give anyone a headache.

What I can't understand is why in this day and age, when you can get a great sounding tremolo pedal for US$20, they can't design an alternative circuit that works as well and is silent? Plenty of LED based optocouplers around. Or even add back in the extra valve stage that the optocoupler replaced.

FWIW I found a service manual for the amp here:

https://robrobinette.com/images/Guit...ice_Manual.pdf

Maybe one day you can replace it ;-)

The US version seems to be an LED based LDR. It is not at all clear to me what the PCB version even does...or why it needs the tube since it seems to have its own op amps... It's an order of magnitude more complicated than the US version.