"As the 2 x 4,700uF capacitors will need time to form, I have not done any in depth testing, but will do so when these capacitors have had time to fully form.
I expect this will take close to 72 hours, due to the size of the capacitors and the very low voltage involved . (<600mV)
Alex"
What exactly do you think the caps are doing during your "form" period? In a power supply?
Are you confusing this with the so-called "break-in" in audio applications?
I expect this will take close to 72 hours, due to the size of the capacitors and the very low voltage involved . (<600mV)
Alex"
What exactly do you think the caps are doing during your "form" period? In a power supply?
Are you confusing this with the so-called "break-in" in audio applications?
This is not the correct thread to be discussing the belief or not of capacitor forming, break-in or what have you. Please keep to discussion/information of the JLH PSRR, thanks.
No, I am not confusing this with "break in" in audio applications.
Many people have reported (myself includd) that the SQ of the equipment the JLH is being used with, has quite a few cycles of varying sound quality for around a typical 48 hours before stabilising. In fact, at some parts of the cycle, the SQ can sound quite poor, leading to the belief that something may have gone wrong with the equipment.
Jon's initial build for this PCB involved a JLH using the Current Limiter section. Jon reported a very heavy current draw from his dual regulated supply which was shown to be due to the 2 x 4,700uF capacitors in parallel.
In fact the 2SC5171 with the 33 ohm emitter resistor became very warm. When 2 x 2,200uF low ESR were fitted instead, there was no further problem. Normally, with 2 x 4,700uF in parallel, but relying on the internal current limiting of the voltage regulators, the same device is only a few degrees above ambient temperature. If using a JLH with 2 x 4,700uF low ESR electrolytics, it may be worthwhile "forming" the capacitors before use.
Note that not all brands of electrolytic cpacitors of this value exhibit this effect.
SandyK
Can any one suggest a replacement for the Suntan CD286 type EL's suggested in the BOM? Not seeing these from the usual vendors here in US. Looking at the impedence specs for each, (the suggested replacement) Panasonic FC seems nearly identical to CD286 at similar V, case size and value. It is the ESR that is the issue here?
Don't know how big a deal this is, but would like to hear what others hear upfront, seems to be important.
Don't know how big a deal this is, but would like to hear what others hear upfront, seems to be important.
I originally used Panasonic FM caps at the C4 locations in the JLH, and found the sound of the headphone amplifier I was using it with was 'thicker' with the FM's than with the Suntan caps when I swapped them out.
One option is to use a film cap at C6 to bypass you favourite 'normal' caps.
Jaycar, who are an Australian based electronics store, tend to carry Suntan caps, and have an online presence in the US. The part number is RE6306 2200uF Suntan Cap The picture does say Sanxion on the cap, but you should receive Suntan when they order. The sanxion caps are also pretty good. The other option is get an Australian mate to by some from the Jaycar store for you.
What I would say is that if you like how things sound using Panny FC caps at C4, then thats fine, and not to worry about it too much.
If you order from Jaycar, I can recommend the Headphone amplifier kit, KC5417 with the associated PSU KC 5418 if you fancy a play. With the right modifications, this amplifier is superb, and betters commercial amps many times its price. The original opamp is replaced with a LM4562 (lme49720) which can sound a little thin by itself. When the JLH is used, the sound changes for the better, bringing a superb bottom end, and improved clarity; it really wrings the best out of the 4562. This is what myself and many others found when using it. All the mods to this are detailed at the same forum as the support thread for the JLH, linked to previously by Jon.
One option is to use a film cap at C6 to bypass you favourite 'normal' caps.
Jaycar, who are an Australian based electronics store, tend to carry Suntan caps, and have an online presence in the US. The part number is RE6306 2200uF Suntan Cap The picture does say Sanxion on the cap, but you should receive Suntan when they order. The sanxion caps are also pretty good. The other option is get an Australian mate to by some from the Jaycar store for you.
What I would say is that if you like how things sound using Panny FC caps at C4, then thats fine, and not to worry about it too much.
If you order from Jaycar, I can recommend the Headphone amplifier kit, KC5417 with the associated PSU KC 5418 if you fancy a play. With the right modifications, this amplifier is superb, and betters commercial amps many times its price. The original opamp is replaced with a LM4562 (lme49720) which can sound a little thin by itself. When the JLH is used, the sound changes for the better, bringing a superb bottom end, and improved clarity; it really wrings the best out of the 4562. This is what myself and many others found when using it. All the mods to this are detailed at the same forum as the support thread for the JLH, linked to previously by Jon.
Just for fun, a couple of pictures of previous versions of the JLH ripple eater.
Version 1 of the current board. No room to lie caps down. I use these in my Class A headphone amp, 20V@100mA. Uses the current limiter.
The original JLH, used in over a hundred (I think) modified Jaycar headphone amps. Main difference between this version and the two most recent versions is that it lacks the optional C6 by-pass cap, allowing the use of non-low esr cap, and R5 is not present on the collector of Q2.
It was thanks to SandyK that we got introduced to this lovely little circuit, and there are pictures from his builds that show older types of the JLH ripple eater.
An externally hosted image should be here but it was not working when we last tested it.
Version 1 of the current board. No room to lie caps down. I use these in my Class A headphone amp, 20V@100mA. Uses the current limiter.
An externally hosted image should be here but it was not working when we last tested it.
The original JLH, used in over a hundred (I think) modified Jaycar headphone amps. Main difference between this version and the two most recent versions is that it lacks the optional C6 by-pass cap, allowing the use of non-low esr cap, and R5 is not present on the collector of Q2.
It was thanks to SandyK that we got introduced to this lovely little circuit, and there are pictures from his builds that show older types of the JLH ripple eater.
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A few lucky Aussies got to use some of these beautiful limited run, dual PCBs
designed and supplied by well known DIYAudio member Greg Erskine.
designed and supplied by well known DIYAudio member Greg Erskine.
An externally hosted image should be here but it was not working when we last tested it.
There are still boards left, but orders are coming in steadily. Ordering info is in the Mini or Full manuals. Don't delay, order today!
Thanks for your support, everyone.
Jon
There are still boards left, but orders are coming in steadily. Ordering info is in the Mini or Full manuals. Don't delay, order today!
Thanks for your support, everyone.
Jon
Thanks Jon, Just paid for 2 boards
Hot Cakes!!
Hi Everyone,
I've just finished packaging the latest batch. I'll be running these up to town this afternoon (missed the Village Post Office this morning due to the large amount of orders!!).
Many thanks for your support, and especially those who have generously donated over and above!!
Just to let everyone know: I have just 106 of these boards left. It sounds like a lot, but I'm packaging up around 70 per session.
If you order by 1800 UK time today, I will package these up tonight and post them on my way to work tomorrow morning. I'm not going to be able to process any orders until Saturday, otherwise. That means postage on Mon 2nd Aug.
This GB will CLOSE on Wednesday 4th Aug, unless boards sell out before then (which I think they will).
Final accounts will be posted thereafter, when all receipts are in and numbers crunched. If in the unlikely event there are leftovers, these will be offered for sale again in October. But, I think these will ALL be sold very soon.
Don't delay, order TODAY!!!
Thanks again for your support!!!
Cheers
Jon
Hi Everyone,
I've just finished packaging the latest batch. I'll be running these up to town this afternoon (missed the Village Post Office this morning due to the large amount of orders!!).
Many thanks for your support, and especially those who have generously donated over and above!!
Just to let everyone know: I have just 106 of these boards left. It sounds like a lot, but I'm packaging up around 70 per session.
If you order by 1800 UK time today, I will package these up tonight and post them on my way to work tomorrow morning. I'm not going to be able to process any orders until Saturday, otherwise. That means postage on Mon 2nd Aug.
This GB will CLOSE on Wednesday 4th Aug, unless boards sell out before then (which I think they will).
Final accounts will be posted thereafter, when all receipts are in and numbers crunched. If in the unlikely event there are leftovers, these will be offered for sale again in October. But, I think these will ALL be sold very soon.
Don't delay, order TODAY!!!
Thanks again for your support!!!
Cheers
Jon
Recieved, thanks!! And your boards are in the post as we speak!!!
I've had a count up. We have only 90 boards left, folks.
This will most likely be the ONLY run of these, so don't miss out.
Cheers
Jon
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