There seems to be complete ignorance about these Light Dependent Resistor products. A word of warning really needs to be published about LDR based pre-amps. LDRs contain Cadmium gas which is lethal (kidney or liver failure) if eaten or breathed and is a long term serious health (Cancer) risk if just touched on a regular basis. Because of this it is illegal to import or sell these items within the EU as they are not RoHS or WEEE approved, so cannot be given a CE mark. This is true for both kits and built products.
Cadmium is a gas? Really?
This turns out not to be the case. http://uk.farnell.com/photo-light-dependent-resistors-ldr as one example.
Lack of knowledge is a dangerous thing, RoHS does not apply to components there is no import restriction. It is legal to supply components, but once those components have been built into PCBs or circuits then RoHS and CE and WEEE come into effect, this it seems is what people doesn't understand. I refer you to the posts by NRG on the subject at Art of Sound forum, a man who obviously has first hand experience of CE and RoHS. There was an exclusion that was negotiated by Marshall (Guitar Amps) as leader of an industry consortium which only applied to professional products and was specifically stated as such in the exemption clauses. It has now run out and has been refused to be renewed.
So at no point has a hi-fi LDR based passive pre-amp been legal to sell or import to the UK or EU - full stop. The wording in the directive is specific "once the product becomes available to be powered either from power supply, battery or inductance it becomes liable to RoHS regulations", and a kit is just that, it is "ready" to be powered.
When cadmium overheats and the device fails the Cadmium is released as a gas.
So at no point has a hi-fi LDR based passive pre-amp been legal to sell or import to the UK or EU - full stop. The wording in the directive is specific "once the product becomes available to be powered either from power supply, battery or inductance it becomes liable to RoHS regulations", and a kit is just that, it is "ready" to be powered.
When cadmium overheats and the device fails the Cadmium is released as a gas.
Thank you for your interest in our kit Richard. Mr Dunn IMO you need to ask those involved, which is good advice to you in future comments, before placing such misleading un-researched material on forums.
The National Measurement Office UK place themselves to interpret the ROHS directive and rather relying just on the EU interpretation we have sought their reply as well, which will be published here when it becomes available.
The EU I am pleased to advise have cleared the continued use of photoresistors for analogue optocouplers
Dear Mr Daly,
Thank you for your message.
The Commission Directive 2012/51/EU has enabled the use of cadmium in photoresistors for analogue optocouplers as an exemption from the ROHS directive. Therefore, indeed, the use of cadmium in photoresistors for analogue optocouplers is currently allowed as there are no other substitutes. We draw your attention in this context to the recitals of the Directive:
http://eur-lex.europa.eu/legal-conte...LEX:32012L0051
This new delegated Directive is based on the Recast of the RoHS Directive which entered into force in January 2013. The information relating to the recast of this Directive with the comments submitted during the public consultation is available on the following website of the Directorate-General for the Environment:
http://ec.europa.eu/environment/wast...e/index_en.htm
If you wish to voice your opinion on waste management issues and changes to the EU legislation, we invite you to consult the public consultations webpage on DG Environment:
Consultations - Environment - European Commission
We hope you find this information useful. Please contact us again if you have other questions.
With kind regards,
EUROPE DIRECT Contact Centre
EUROPA ? EU website | Choose your language | Choisir une langue | Wählen Sie eine Sprache - your shortcut to the EU!
A further letter addressed to the National Measurement Office UK asking as to any restriction applying to and relying on ROHS directives will be provided to this forum when it becomes available. It is likely in a similar manner to the EU reply that it will be found that there is no restriction to photoresistors for analogue optocouplers as there is currently no replacement or equivalent product available. If anything changes we at Stereo Coffee will be pleased to let you know. Are LDR pres the ultimate passive? - Page 11 contains further discussion.
Common sense applies to LDR's don't chew or smoke your LDR's. Further information discussing the encapsulated casings is at the above forum, which are entirely safe if used as supplied in our kits.
If you choose to shatter the casings scrape back the lens cover and expose yourself to the resistive coating that is an entirely different matter, as is the disassembly of camera light meters, street lights, clock radios, alarm devices, night lights, outdoor clocks, solar street lamps and solar road studs and high powered loudspeaker voice coils, etc also containing cadmium sulphide.
The National Measurement Office UK place themselves to interpret the ROHS directive and rather relying just on the EU interpretation we have sought their reply as well, which will be published here when it becomes available.
The EU I am pleased to advise have cleared the continued use of photoresistors for analogue optocouplers
Dear Mr Daly,
Thank you for your message.
The Commission Directive 2012/51/EU has enabled the use of cadmium in photoresistors for analogue optocouplers as an exemption from the ROHS directive. Therefore, indeed, the use of cadmium in photoresistors for analogue optocouplers is currently allowed as there are no other substitutes. We draw your attention in this context to the recitals of the Directive:
http://eur-lex.europa.eu/legal-conte...LEX:32012L0051
This new delegated Directive is based on the Recast of the RoHS Directive which entered into force in January 2013. The information relating to the recast of this Directive with the comments submitted during the public consultation is available on the following website of the Directorate-General for the Environment:
http://ec.europa.eu/environment/wast...e/index_en.htm
If you wish to voice your opinion on waste management issues and changes to the EU legislation, we invite you to consult the public consultations webpage on DG Environment:
Consultations - Environment - European Commission
We hope you find this information useful. Please contact us again if you have other questions.
With kind regards,
EUROPE DIRECT Contact Centre
EUROPA ? EU website | Choose your language | Choisir une langue | Wählen Sie eine Sprache - your shortcut to the EU!
A further letter addressed to the National Measurement Office UK asking as to any restriction applying to and relying on ROHS directives will be provided to this forum when it becomes available. It is likely in a similar manner to the EU reply that it will be found that there is no restriction to photoresistors for analogue optocouplers as there is currently no replacement or equivalent product available. If anything changes we at Stereo Coffee will be pleased to let you know. Are LDR pres the ultimate passive? - Page 11 contains further discussion.
Common sense applies to LDR's don't chew or smoke your LDR's. Further information discussing the encapsulated casings is at the above forum, which are entirely safe if used as supplied in our kits.
If you choose to shatter the casings scrape back the lens cover and expose yourself to the resistive coating that is an entirely different matter, as is the disassembly of camera light meters, street lights, clock radios, alarm devices, night lights, outdoor clocks, solar street lamps and solar road studs and high powered loudspeaker voice coils, etc also containing cadmium sulphide.
I don't know if the cadmium can't be replaced, and I only read many LDR's contain cadmium, that is not the same as all LDR's contain cadmium? And there do seem to be replacements, maybe a bit more complex/bigger?
Being Dutch cadmium for me makes me remember the old Heineken cases, which if I am not mistaken still remain a problem to this day, cases were replaced in the eighties, they tried to separate 10.000 ton cadmium from the plastic around 2005, but a pile of waste was discovered in 2009 and it turned out the factory that would separate the cadmium from the plastic went bankrupt in 2007 LOL not sure if Heineken took it back or some other wastemanagement company was hired (to ship it to Africa, which often is the ultimate solution)
Being Dutch cadmium for me makes me remember the old Heineken cases, which if I am not mistaken still remain a problem to this day, cases were replaced in the eighties, they tried to separate 10.000 ton cadmium from the plastic around 2005, but a pile of waste was discovered in 2009 and it turned out the factory that would separate the cadmium from the plastic went bankrupt in 2007 LOL not sure if Heineken took it back or some other wastemanagement company was hired (to ship it to Africa, which often is the ultimate solution)
Attachments
Hi
I have written to Advanced Photonix with copy to Morten at Tortuga , to provide reply into any news of a audio grade ROHS compliant, rather than a ROHS exempted LDR, So I hope at the moment there is quite a bit of development to find a cadmium sulphide substitute. Of course our requirement being to equal or better the NSL32SR2s that we use at stereo coffee, and the NSL32SR3 that Morten uses.
Any horizon news will be provided,
Cheers / Chris
Stereo Coffee apparently the best
Some comparisons of the stereo coffee against valve based active pre amp, ldr and switched attenuators.
http://theartofsound.net/forum/showthread.php?33176-Pre-Amp-bake-off-What-Happened
see post 1, 19, and 28 being contributions by the persons who were present.🙂
Some comparisons of the stereo coffee against valve based active pre amp, ldr and switched attenuators.
http://theartofsound.net/forum/showthread.php?33176-Pre-Amp-bake-off-What-Happened
see post 1, 19, and 28 being contributions by the persons who were present.🙂
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Here is reply from the National Measurements Office
Dear Mr. Daly
Thank you for contacting NMO Enforcement UK.
Your enquiry was:
I am an exporter from New Zealand of audio attenuator kits that use encapsulated LDR devices with part numbers NSL32SR2s , These encapsulated plastic LDR's are quite different to open face LDR's Cadmium sulphide is used in each for the variable resistive element, and aids the encapsulated part its excellent audio ability . The UK market for these DIY kits is individuals purchasing via ebay, and my website stereocoffee | 4 out of 5 dentists recommend this WordPress.com site The kits are then typically assembled and used by that individual, with assistance in DIY spirit given to others to assist them get their kit going. As such there is no ongoing manufacture involving on -selling Could you let me know if this style of sale contravenes any current legislation concerning ROHS expired items in the UK, and if not current any review date planned. I have concurrently written to the EU Case_ID: 0915122 / 1182429 asking them as to the current status of LDR's that have no available replacement part yet their ROHS exemption has expired. I would be most grateful for your reply. Regards
Our reply is:
No, providing that you establish which kind of economic operator you are (manufacturer, importer, authorised representative or distributor) and ensure that you comply with all of the requirements specific to you as detailed in the RoHS Directive.
We are currently looking at some alternatives to the NSL32SR2s which on our list is the
Fairchild H11F1M device. It is ROHS approved. 🙂
"The H11FXM series consists of a Gallium-Aluminum-
Arsenide IRED emitting diode coupled to a symmetrical
bilateral silicon photo-detector. The detector is electri-
cally isolated from the input and performs like an ideal
isolated FET designed for distortion-free control of low
level AC and DC analog signals.
Within the data are suggested connections for a isolated variable attenuator
"Distortion free attenuation of low level A.C. signals is accom-
plished by varying the IRED current, I F Note the wide dynamic
range and absence of coupling capacitors; D.C. level shifting or
parasitic feedback to the controlling function"
Cheers / Chris
Fairchild H11F1M device. It is ROHS approved. 🙂
"The H11FXM series consists of a Gallium-Aluminum-
Arsenide IRED emitting diode coupled to a symmetrical
bilateral silicon photo-detector. The detector is electri-
cally isolated from the input and performs like an ideal
isolated FET designed for distortion-free control of low
level AC and DC analog signals.
Within the data are suggested connections for a isolated variable attenuator
"Distortion free attenuation of low level A.C. signals is accom-
plished by varying the IRED current, I F Note the wide dynamic
range and absence of coupling capacitors; D.C. level shifting or
parasitic feedback to the controlling function"
Cheers / Chris
We have closed our eBay store as you can now buy direct from our own online store
stereocoffee | 4 out of 5 dentists recommend this WordPress.com site checkout is much the same via Paypal and in this case shoplocket
Cheers / Chris
stereocoffee | 4 out of 5 dentists recommend this WordPress.com site checkout is much the same via Paypal and in this case shoplocket
Cheers / Chris
First tests of the H11F1M, show it must have approx 500k resistance in series with its input, appears to suit series connection, rather than L pad. the forward voltage is lower than for a LDR at 1.3v.
We obtained fairly useless volume range although it was reproducing audio quite well when at high volume, signal side resistance was at 3.5k Will see how it develops,
We obtained fairly useless volume range although it was reproducing audio quite well when at high volume, signal side resistance was at 3.5k Will see how it develops,
Have to start by saying thanks to Chris for his remarkable patience and unmatched customer support. Then...this is for some of those unbelievers who prefer to pay for marketing and hype instead of investing in good/value audio...Give it a try...there is not better money spend than this...
Finally I will be soon telling you a bit more about my experience with the Stereo Coffee and the fun process of it's integration with and old vintage receiver, stay tuned! Diego
Finally I will be soon telling you a bit more about my experience with the Stereo Coffee and the fun process of it's integration with and old vintage receiver, stay tuned! Diego
Due to popularity we have also reopened the eBay store,
stereo coffee items - Get great deals on items on eBay Stores!
and have listings there for the single and three input models. 🙂
Hello everyone. This is my first post on DIY Audio and want to let you all know how delighted I am with my recently completed Stereo Coffee LDR preamplifier.
About 4 months, I was looking for a passive preamplifier to compliment my stereo system which consisted of Quad ESL57's, Quad 303 power amplifier and a pair of Dulci EL84 valve monoblocks. I researched the possible options available when a close hi-fi friend suggested I also add a Stereo Coffee LDR preamp to the list, which he had earlier heard in one of his friend's system and was most impressed.
I had never met Chris or had any form of contact with him until now. Luckily, he lived only an hours drive from me and so I made contact with him. A home audition was arranged. Chris bought over a demo unit and immediately upon hearing it, I knew this was a very special product. I wanted one without even thinking twice, which is unusual for me as I always like to mull things over before making a decision. Having seen my system, Chris suggested converting a Quad 33 to an LDR preamp, as this would compliment nicely my vintage Quad system. I thought this was a great idea and have spent the past few months carrying out the conversion
I have attached pictures of the converted Quad 33. I modified the rear panel to accept RCA plugs. I opted for a 3 input LDR board as I listen CD's and the radio. So, on the rear panel there are 3 pairs of RCA input sockets and 1 pair of RCA output sockets. Next to the output sockets is a socket used to plug a DC power block into for recharging the12 volt battery inside the chassis.
On the front panel, an LED battery indicator is used where the "Quad" light originally appeared. The red LED continues to shine until the time the battery needs recharging, when it then changes to blue. The charging circuit is activated by pressing the "cancel" switch. To deactivate charging and return the preamp back to use, the "10K" switch is pressed. The "disc","radio1" and "radio2" switches are used for the inputs.
I carried out the mechanical alterations, whilst Chris provided the necessary circuits. He also checked the conversion when it was completed to make sure everything was in order.
It's been an amazing project with fantastic results. I couldn't be happier. The music from my hi-fi system is the best it has ever sounded and this is in no small way due to the Stereo Coffee preamp. It's a top quality product and it"s been a pleasure to have met Chris who is a really lovely guy and was always on hand to assist.
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Cheers,
Baldev.
About 4 months, I was looking for a passive preamplifier to compliment my stereo system which consisted of Quad ESL57's, Quad 303 power amplifier and a pair of Dulci EL84 valve monoblocks. I researched the possible options available when a close hi-fi friend suggested I also add a Stereo Coffee LDR preamp to the list, which he had earlier heard in one of his friend's system and was most impressed.
I had never met Chris or had any form of contact with him until now. Luckily, he lived only an hours drive from me and so I made contact with him. A home audition was arranged. Chris bought over a demo unit and immediately upon hearing it, I knew this was a very special product. I wanted one without even thinking twice, which is unusual for me as I always like to mull things over before making a decision. Having seen my system, Chris suggested converting a Quad 33 to an LDR preamp, as this would compliment nicely my vintage Quad system. I thought this was a great idea and have spent the past few months carrying out the conversion
I have attached pictures of the converted Quad 33. I modified the rear panel to accept RCA plugs. I opted for a 3 input LDR board as I listen CD's and the radio. So, on the rear panel there are 3 pairs of RCA input sockets and 1 pair of RCA output sockets. Next to the output sockets is a socket used to plug a DC power block into for recharging the12 volt battery inside the chassis.
On the front panel, an LED battery indicator is used where the "Quad" light originally appeared. The red LED continues to shine until the time the battery needs recharging, when it then changes to blue. The charging circuit is activated by pressing the "cancel" switch. To deactivate charging and return the preamp back to use, the "10K" switch is pressed. The "disc","radio1" and "radio2" switches are used for the inputs.
I carried out the mechanical alterations, whilst Chris provided the necessary circuits. He also checked the conversion when it was completed to make sure everything was in order.
It's been an amazing project with fantastic results. I couldn't be happier. The music from my hi-fi system is the best it has ever sounded and this is in no small way due to the Stereo Coffee preamp. It's a top quality product and it"s been a pleasure to have met Chris who is a really lovely guy and was always on hand to assist.
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Cheers,Baldev.
Hi baldevpatel.
Your links don't work!
I'm in the process of building my second LDR from Chris into an old Leak preamp so am interested in seeing your efforts.
Bought another kit off Chris so I could keep my first untidy rig going until the new one is finished.Love it.
Your links don't work!
I'm in the process of building my second LDR from Chris into an old Leak preamp so am interested in seeing your efforts.
Bought another kit off Chris so I could keep my first untidy rig going until the new one is finished.Love it.
Hi,
My apologies for the links not working. I'm a newbie on this forum, so some teething problems I guess.
Hopefully I now have it sorted.
Pictures should follow.
Cheers,
Baldev.
My apologies for the links not working. I'm a newbie on this forum, so some teething problems I guess.
Hopefully I now have it sorted.
Pictures should follow.
Cheers,
Baldev.
Custom Building
Being a DIY kit the stereo coffee is very adaptable to more inputs, having two outputs switched or unswitched or other variations. Suiting every connfiguration of audio system so far we have done:
Balanced kit with three inputs
Single input with two outputs
Three inputs with two outputs
Six inputs and two outputs
Two inputs and a stereo output
Our standard products remain as Single Input kit with stereo output, and three Input with stereo output which are very popular.
Cheers / Chris
Being a DIY kit the stereo coffee is very adaptable to more inputs, having two outputs switched or unswitched or other variations. Suiting every connfiguration of audio system so far we have done:
Balanced kit with three inputs
Single input with two outputs
Three inputs with two outputs
Six inputs and two outputs
Two inputs and a stereo output
Our standard products remain as Single Input kit with stereo output, and three Input with stereo output which are very popular.
Cheers / Chris
Hi
I have just completed another successful stereo coffee build into a quad 33 ( my own )
4 inputs and facility for tape out. For rear plugs I used a 5 pin locking plugs and sockets
that fit perfectly.
The power supply uses the original Quad transformer extracting 16VAC, this then supplies
the electronics salon LT1963 regulator board with ultra low noise 12vDC out.
Complementing the FM3 tuner in the wooden sleeve housing both, it looks and sounds wonderful
some images in a few days to follow.
Cheers / Chris
I have just completed another successful stereo coffee build into a quad 33 ( my own )
4 inputs and facility for tape out. For rear plugs I used a 5 pin locking plugs and sockets
that fit perfectly.
The power supply uses the original Quad transformer extracting 16VAC, this then supplies
the electronics salon LT1963 regulator board with ultra low noise 12vDC out.
Complementing the FM3 tuner in the wooden sleeve housing both, it looks and sounds wonderful
some images in a few days to follow.
Cheers / Chris
