In response to an email I sent the following reply - since it gives a simple explanation of the use of the use of the boards I thought I would post it in the thread. Hopefully it is a correct explanation!!
The purpose of these boards is to reduce ripple which will exist after a simple rectifier / voltage regulator circuit in low-power applications such as pre-amps, dacs. When populated (I do not supply parts!) it acts like a very, very large capacitor.
The boards can be populated for Positive or Negative working, so if you have a simple power-supply of +12 volts (with say a 7812 regulator) then you would need to populate the board as a positive; similarly if the psu produces -12 volts (with say a 7912 regulator) then the board needs to be populated as per the Negative instructions (heed the warnings about orientation of the devices!!).
If you have a psu producing positive and negative rails then you need two boards one for each rail.
In most cases the Ripple Eater board will come after a regulator, if there is no regulator then Q1 and the rest of the current limiting circuit need to be populated.
If you have any further questions please do not hesitate to post them in the thread as there are some very technical people who have used the boards from the first group buy who will be able to say where and how they used these boards.
The small manual of the three lists all the components you will need for 'normal' operation - i.e between 5 volts and 35 volts (roughly) at about .5 amp.
Regards
Alan
The purpose of these boards is to reduce ripple which will exist after a simple rectifier / voltage regulator circuit in low-power applications such as pre-amps, dacs. When populated (I do not supply parts!) it acts like a very, very large capacitor.
The boards can be populated for Positive or Negative working, so if you have a simple power-supply of +12 volts (with say a 7812 regulator) then you would need to populate the board as a positive; similarly if the psu produces -12 volts (with say a 7912 regulator) then the board needs to be populated as per the Negative instructions (heed the warnings about orientation of the devices!!).
If you have a psu producing positive and negative rails then you need two boards one for each rail.
In most cases the Ripple Eater board will come after a regulator, if there is no regulator then Q1 and the rest of the current limiting circuit need to be populated.
If you have any further questions please do not hesitate to post them in the thread as there are some very technical people who have used the boards from the first group buy who will be able to say where and how they used these boards.
The small manual of the three lists all the components you will need for 'normal' operation - i.e between 5 volts and 35 volts (roughly) at about .5 amp.
Regards
Alan
CORRECTION
In trying to help I may have done the opposite 😱😱- as corrected by Will 😉:-
START OF CORRECTION
I've just seen the explanation of the JLH, and there is a slight oddity with it.
In most cases the Ripple Eater board will come after a regulator, if there is no regulator then Q1 and the rest of the current limiting circuit need to be populated.
The main reason for the current limiter is to protect the preceding regulator from the current draw on start up. The JLH capacitor multiplier can draw c200A of inrush current, which would cause severe strain on any PSU supplying it that does not have overload/sc protection built in. The LM317/78 types do, so no need for the CL, but the likes of a walt jung or a salas shunt would need CL protection. One thing Alex and myself have found is that leaving the CL in can create an extra layer of noise reduction (the saturated q1 acting as a resistor, and acting with the circuit capacitance, giving CR), giving a better overall sq.
The JLH as a whole also lowers PSU impedance, which is equally as important as reducing noise.
END OF CORRECTION
Thank you very much for that Will.
In trying to help I may have done the opposite 😱😱- as corrected by Will 😉:-
START OF CORRECTION
I've just seen the explanation of the JLH, and there is a slight oddity with it.
In most cases the Ripple Eater board will come after a regulator, if there is no regulator then Q1 and the rest of the current limiting circuit need to be populated.
The main reason for the current limiter is to protect the preceding regulator from the current draw on start up. The JLH capacitor multiplier can draw c200A of inrush current, which would cause severe strain on any PSU supplying it that does not have overload/sc protection built in. The LM317/78 types do, so no need for the CL, but the likes of a walt jung or a salas shunt would need CL protection. One thing Alex and myself have found is that leaving the CL in can create an extra layer of noise reduction (the saturated q1 acting as a resistor, and acting with the circuit capacitance, giving CR), giving a better overall sq.
The JLH as a whole also lowers PSU impedance, which is equally as important as reducing noise.
END OF CORRECTION
Thank you very much for that Will.
No problem Alan,
I just hope my explanation of the current limiter helping stands up to scrutiny, as I was techincally asleep when I typed it😛
I'd also like to post a link to a picture of one of the first round JLH, recently seen at work, out in the wild!
JLH feeding a USB
I just hope my explanation of the current limiter helping stands up to scrutiny, as I was techincally asleep when I typed it😛
I'd also like to post a link to a picture of one of the first round JLH, recently seen at work, out in the wild!
JLH feeding a USB
Last edited:
JLH RE Update.
Hi Alan,
Just a quick update as I hate leaving you in limbo: our AWOL member has been in contact and is now giving some thought to his requirements. I hope to be able to firm up shortly or we'll go without him - can't expect you to wait indefinitely
Cheers,
Dave.
Hi Alan,
Just a quick update as I hate leaving you in limbo: our AWOL member has been in contact and is now giving some thought to his requirements. I hope to be able to firm up shortly or we'll go without him - can't expect you to wait indefinitely
An externally hosted image should be here but it was not working when we last tested it.
.
Cheers,
Dave.
An externally hosted image should be here but it was not working when we last tested it.
Bruno,
Boards still available - please read the manuals (mini or large) for prices including post/packing and method of paying.
https://docs.google.com/fileview?id=...thkey=CKeD0ZkH is the mini-manual.
Regards
Alan
My 5 boards arrived safely, thanks Alan. Now I just need to research some transistor subs which will allow them to work at + or - 55v...
Regards,
Rob.
Regards,
Rob.
Hi Rob
Try the attached schematic. It is based on a +-55V JLH made and used by DIYAudio member Allan Pagan with his SC ULD amplifier..
You can use the original devices for everything except the LTP. 2SA970Bl are suitable for the -VE rail version at that location.
Alex
URL=http://img607.imageshack.us/i/jlh55vv2.jpg/]
An externally hosted image should be here but it was not working when we last tested it.
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Uploaded with ImageShack.us
You are correct. I should have mentioned that.
I am so familiar with this circuit that I sometimes forget to mention such important details! 😱
JLH RE BoM Help.
@ AlanElsdon (but don't let that stop anyone else from respoding 🙂 ),
Alan, the AWOL member of our mini GB has now decided not to go ahead so I can now confirm that our total requirement is eight (8) boards, all of the positive (+ve) variety. Please let me know how much we owe you and how you would prefer to be paid - I can offer fee-free PayPal, Bank Transfer or personal cheque.
Now the question: -
The only member of our group who knows which end of a soldering iron is which is having an extremely busy time with the other stuff in life ATM so I would appreciate some help with the BoM as I have also volunteered to source all the components. I know exactly which items to buy and where to buy them from but I have no idea how many of each are needed for each board so if someone could advise me that would be great. Thanks for any help.
Alan, if you would PM me with payment details I'll reply with my address details and confirmation of payment.
Cheers,
Dave.
@ AlanElsdon (but don't let that stop anyone else from respoding 🙂 ),
Alan, the AWOL member of our mini GB has now decided not to go ahead so I can now confirm that our total requirement is eight (8) boards, all of the positive (+ve) variety. Please let me know how much we owe you and how you would prefer to be paid - I can offer fee-free PayPal, Bank Transfer or personal cheque.
Now the question: -
The only member of our group who knows which end of a soldering iron is which is having an extremely busy time with the other stuff in life ATM so I would appreciate some help with the BoM as I have also volunteered to source all the components. I know exactly which items to buy and where to buy them from but I have no idea how many of each are needed for each board so if someone could advise me that would be great. Thanks for any help.
Alan, if you would PM me with payment details I'll reply with my address details and confirmation of payment.
Cheers,
Dave.
Dave,
All the info you need is in these documents - both technical and what/how to pay.
http://www.diyaudio.com/forums/grou...hood-ripple-eater-part-2-a-7.html#post2368243
The smallest document lists all the parts and how many of each is needed; the mini-manual gives all the payment details and how to build the boards; the full manual has all the details you need (but it takes a time to download!).
Alan
Boards sent today to cobo and kaoko.
I am glad to see boards now being delivered outside the UK.
I am glad to see boards now being delivered outside the UK.
Deliveries
I have received confirmation from 4 people that their boards have arrived - it is a bad time of the year for sending packages so I ask for your patience. I would also ask people who have received their boards to post this on the forum.
It will give us all a bit more confidence!!😀
Alan
I have received confirmation from 4 people that their boards have arrived - it is a bad time of the year for sending packages so I ask for your patience. I would also ask people who have received their boards to post this on the forum.
It will give us all a bit more confidence!!😀
Alan
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