Jlh psu
C37
Although possible, it has not been tried. You would most likely need to reduce the value of the 33 ohm resistor as well, to increase the available "correction"current which is normally around 16mA.
You may be better off as several have done, just using it to supply the front end only.
Alex
C37
Although possible, it has not been tried. You would most likely need to reduce the value of the 33 ohm resistor as well, to increase the available "correction"current which is normally around 16mA.
You may be better off as several have done, just using it to supply the front end only.
Alex
Hi Andrew, I did not say it was in this thread, but found a hint that sparked my curiousity in this onewere the JLH ripple eater was briefly discussed two years ago. But it's a comment only one sentence long you made at that time. I could be wrong. Anyway, on another forum (rockgrotto) there is a mention from someone else that a user adapted it for a 100 W amplifier ? ( Have to search for this one)
Regards,
Thomas
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I went back and read the context of my "try it" statement.
I was saying that the ripple eater may be able to operate at 5Apk.
That is quite different from saying "it could be configured for 5A".
I am not an advocate for regulators in the power supply of the output stage of an amplifier, except when it is a ClassA output stage that truly draws constant current from the PSU. Most ClassA do not meet this condition.
The problem with regulated supplies for amplifiers is the range of currents that the amplifier demands of it's PSU. 100W into 8ohms can be as high as 14Apk. 200W into 4ohms can approach 28Apk. There is some evidence that the peak transient demand can be even higher.
There are few if any regulators that can react quickly enough to current levels in the tens of amperes and back down to the tiny quiescent currents drawn during quiet moments..
A linear supply consisting of transformer + bridge rectifier + smoothing caps can and does meet that sort of demand without a sweat.
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JLH Ripple Eater
"Anyway, on another forum (rockgrotto) there is a mention from someone else that a user adapted it for a 100 W amplifier ? - C37"
C37
There is no mention of that in RockGrotto, only that it has been used to supply the front ends only of a 100W/Ch. amplifier with +-55V supply rails.
DIYAudio member awpagan has done that.
Alex
"Anyway, on another forum (rockgrotto) there is a mention from someone else that a user adapted it for a 100 W amplifier ? - C37"
C37
There is no mention of that in RockGrotto, only that it has been used to supply the front ends only of a 100W/Ch. amplifier with +-55V supply rails.
DIYAudio member awpagan has done that.
Alex
Wow. Merci beaucoup les amis. It is true that i found back and re-read the thread in rockgrotto wich says " In fact, Pagan (Allan) has a modified JLH working at + and -55V with a 100W /Ch. Power amplifier's front end supply" which you wrote, sandyK. Sorry for my mistake.
However, i still feel my original post had almost all necessary precautions included, such as " I think that" and all questions marks needed and i asked if it could be configured for a power end. Andrew responded in a pedagogical kind of way which i very welcome, and after you have written "Although possible, it has not been tried". I do feel i get strangely flamed in this thread? Because i am ( obviously) a noob asking questions? did i do anything obviously wrong? If so, Mes excuses, et je m' en vais
JLH Ripple Eater
C37
i am sorry if you got that impression. It was certainly not my intention.
IIRC, Andrew originally suggested that the JLH may be useable at much higher currents using higher powered devices.
However that would entail using much more robust devices with heatsinks and a new PCB.
The original published design only gave details in the chart for use with a maximum current limit of 100mA. Neither did the original article as published show the use of the design without it's integral current limiter.
As you can see, we have substantially improved on those limitations.
Andrew is of course correct in what he said, and the JLH will do a fine job when used to supply the front end of an amplifier, and leaving the power output end to either a very well regulated high current supply in the case of a 15/20W Class A design, and a normal bridge rectifier and capacitor supply for Class AB amplifiers.
Alex
C37
i am sorry if you got that impression. It was certainly not my intention.
IIRC, Andrew originally suggested that the JLH may be useable at much higher currents using higher powered devices.
However that would entail using much more robust devices with heatsinks and a new PCB.
The original published design only gave details in the chart for use with a maximum current limit of 100mA. Neither did the original article as published show the use of the design without it's integral current limiter.
As you can see, we have substantially improved on those limitations.
Andrew is of course correct in what he said, and the JLH will do a fine job when used to supply the front end of an amplifier, and leaving the power output end to either a very well regulated high current supply in the case of a 15/20W Class A design, and a normal bridge rectifier and capacitor supply for Class AB amplifiers.
Alex
Hi,
The current BOM values using the current limiter will give 650mA. We reckon that perhaps 1A might be the max with the limiter bypassed, but you'd need to bear in mind trace thickness/width. The Ripple Eater has been used very sucessfully in headphone amps and DACs. As the BOM stands, it's a low voltage, low current device. With changes alluded to above, it can do 55V, at low current, but I haven't tried this.
Hope that helps.
Jon
The current BOM values using the current limiter will give 650mA. We reckon that perhaps 1A might be the max with the limiter bypassed, but you'd need to bear in mind trace thickness/width. The Ripple Eater has been used very sucessfully in headphone amps and DACs. As the BOM stands, it's a low voltage, low current device. With changes alluded to above, it can do 55V, at low current, but I haven't tried this.
Hope that helps.
Jon
Order is in!
Hi Everyone,
I have just placed the PCB order. It'll take a month or so for the boards to arrive with me. I will then build and test a pair to validate the boards and also to finish the build manual. Once this is done, I will post ordering and payment details. I will be using PayPal in GBP for payment as this is easy for me to track and means you get your order in the post. I will also "Zone" postal costs, so you know what that'll cost you above your board order.
Finally, I'll be posting a few Ts and Cs that you will agree to if you order - in short, if you kill yourself (with 15V!) or set fire to your house, or drop hot solder on your most sensitive parts because you like nude soldering, or whatever, it'll be your own fault!
This'll be an easy build. We'll tell you where to get your parts, what's recommended, and how to test your boards. How you employ them is up to you, but we have had great results with the Jaycar Headphone amp and the SC DAC.
Cheers
Jon
Hi Everyone,
I have just placed the PCB order. It'll take a month or so for the boards to arrive with me. I will then build and test a pair to validate the boards and also to finish the build manual. Once this is done, I will post ordering and payment details. I will be using PayPal in GBP for payment as this is easy for me to track and means you get your order in the post. I will also "Zone" postal costs, so you know what that'll cost you above your board order.
Finally, I'll be posting a few Ts and Cs that you will agree to if you order - in short, if you kill yourself (with 15V!) or set fire to your house, or drop hot solder on your most sensitive parts because you like nude soldering, or whatever, it'll be your own fault!
This'll be an easy build. We'll tell you where to get your parts, what's recommended, and how to test your boards. How you employ them is up to you, but we have had great results with the Jaycar Headphone amp and the SC DAC.
Cheers
Jon
If you wish to follow the progress of order #1201, please click here:
status - Online Spreadsheets - EditGrid
Jon
status - Online Spreadsheets - EditGrid
Jon
Hi All,
Sorry - more detail.
Our order number is 1201. They are currently producing order number 1187. So you'll see when our order is in production and then when it has shipped. Allow 2 weeks for it to get to me - a couple of days to test build a set or two and complete the build manual - and then we'll be live.
How's that?
Jon
Sorry - more detail.
Our order number is 1201. They are currently producing order number 1187. So you'll see when our order is in production and then when it has shipped. Allow 2 weeks for it to get to me - a couple of days to test build a set or two and complete the build manual - and then we'll be live.
How's that?
Jon
- Status
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