Thanks, you've spent a lot of time setting that out...
I'm struggling to make sense of the results tbh if we base what we see on standard opamps.
If we look at the good channel, we can see the 'Red' and 'Green' chips don't follow what would be the common opamp single or dual layouts. Pin 4 would have to the most negative (the neg rail) for either type and pin 7 or 8 the most positive. This means we can rule these out form being standard opamps.
IC3D White. Is that a typo 🙂 or is pin 4 really PLUS 13v on the good channel? If its a typo then those could be single opamps with supplies on 4 and 7 and pin 6 at zero volts.
Going back to the green chips at the input, if the design is DC coupled throughout then there is a chain of 'zeros' through the good channel chips. It looks like pins 1 and 4 are supplies to whatever those green chips are and that pin 2 and 7 might be the start of the signal chain at zero volts DC.
Could there be an issue right at the input? that is upsetting the DC voltages through the chain?
Has anyone any idea what those green chips could be, Could they be a transistor array and not an opamp?
It's worth not assuming they are faulty. Could there be an issue with another part immediately around the chip. Are those tantalum caps in a signal path or in a biasing network. Those are always suspect for going leaky.
According to the the same problem discussion in another forum, the green ICs could be the Elantec EL2002 buffers.
However, without tracing the wires around these chips it cannot be said this is the right IC for sure.
However, without tracing the wires around these chips it cannot be said this is the right IC for sure.
Hi, I have my ct100 some 15 yrs ago and had not been using for the last 8 yrs. I just tried using today it but while there are music being played, there are also distortions on both channels .. settings had been checked out for 2 different cartridges and I do not believe it is due setting error(s).
As it is dual mono and powered separately by 2 separate class A psu, what can cause such distortion of both separate circuitries in the ct100 as I expect failed component would only typically affects 1 channel and how can I check?
What can the unmarked 4 black tallest components be except capacitors in addition to the oscon 220uf 10v ones as it is mentioned that there is 2 stage regulations. I had ordered oscon replacement as old used and long time unused capacitor may have aged or dried up as well as with the distortion coming at about 10-15 second upon cold power on.
It is also strange if indeed that they are unfortunately capacitors as I cannot know what replacement to obtain to try repair it ...strange that it would be customised unmarked capacitors.
Thanks in advance and cheers.
Richard
As it is dual mono and powered separately by 2 separate class A psu, what can cause such distortion of both separate circuitries in the ct100 as I expect failed component would only typically affects 1 channel and how can I check?
What can the unmarked 4 black tallest components be except capacitors in addition to the oscon 220uf 10v ones as it is mentioned that there is 2 stage regulations. I had ordered oscon replacement as old used and long time unused capacitor may have aged or dried up as well as with the distortion coming at about 10-15 second upon cold power on.
It is also strange if indeed that they are unfortunately capacitors as I cannot know what replacement to obtain to try repair it ...strange that it would be customised unmarked capacitors.
Thanks in advance and cheers.
Richard
They look like caps of course although the markings (more clearly visible in the photos earlier in the thread) are not like any I've seen before. Could they be some kind of 'super cap' that has extremely high capacitance value (like back up caps) that are used across the rails. Normally those type of cap have voltage rating of only 5v though.
Dunno... perhaps try and identify if they are across the rails first of all. Also measure the voltage across them.
Dunno... perhaps try and identify if they are across the rails first of all. Also measure the voltage across them.
Hi Mooly, Tks ! Will measure the voltage across and try to identify if indeed over the rails.
Trying to know the capacitance will be to remove them to measure and guess its original value from highest ?
What brand if any of such "super cap" should I be looking out for as replacement ? Strange to me that dact bothered to somehow customised it with nle 17 marking which is its alternate model # to ct100 or probably production part no. to their cap supplier 😪
Tks again.
Trying to know the capacitance will be to remove them to measure and guess its original value from highest ?
What brand if any of such "super cap" should I be looking out for as replacement ? Strange to me that dact bothered to somehow customised it with nle 17 marking which is its alternate model # to ct100 or probably production part no. to their cap supplier 😪
Tks again.
Can't advice on that really as I never use or come across them. Given all the trouble smaller ones caused in years gone by (in backup applications) I'm not a fan of the things. I just have suspicions they would be prime candidates for deterioration.
Have a look on the likes of RS under Super Capacitor (also known as Ultra Caps). Looks like many of these are even lower voltage than 5 volt.
I doubt electrolytics have deteriorated that much in only 20 years, unless they were those notorius bad caps (badcaps.net). Given their true identity has been obscured there's no easy way to check other than pulling one and testing it. 40 years and I would buy aging as a possible failure mechanism, but many circuits will work without electrolytics, albeit sub-optimally, although some oscillate wildly.
And they won't need reforming as the unit has been regularly powered up (see the initial posting).
And they won't need reforming as the unit has been regularly powered up (see the initial posting).
Tks Naresh .. the trouble is that it is quite bad sounding and a bit bothersome with vinyl playback to do this for reforming.
I figure that having fresh new capacitors will not be a bad thing and granted that fairly accessible to proceed to recap.
Cheers.
Hey Mark,
Yes .. will get the oscon organic caps at 2nd regulation replaced and if it still fails, I will desolder these "super caps" and measure voltage applied to them to best guess available replacement as well to find out how badly they had deteriorated.
I am not the OP and my unit after being used for about 5 yrs were left completely unused for 8 yrs until earlier this week to find the distortion.
Suspected root cause being cap is due to about 10 secs from cold start being fine but distorts thereafter. What I cannot comprehene is that this is dual mono and strange that responsible component(s) fails for both channels .. with ICs especially remote. Just hope that it is batch issue or simply nature of especially organic caps from Oscon to fail all at once due to being used and then store for exceptional 8 long yrs.
Cheers 🤞🤞
Reduce the volume to about 60%, use a computer or similar source, let the caps reform, before that see if they are bulged or leaking.
And see if there is room for a slightly taller and thinner package, that may help ventilation.
Of course, a set of wires will help to connect to big caps fitted on the chassis, if they are too big to fit on the board.
And see if there is room for a slightly taller and thinner package, that may help ventilation.
Of course, a set of wires will help to connect to big caps fitted on the chassis, if they are too big to fit on the board.
To measure the DC voltage on the unknown capacitors, you must leave them in circuit and apply power.
You can't remove parts and assume the circuit will operate normally or safely without them connected.
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It seems unlikely to me that those big capacitors are supercapacitors (also known as ultracapacitors or electrochemical double-layer capacitors), but assuming they are:
Supercapacitors normally have a specified working voltage of 2.5 V to 2.7 V, sometimes 3 V. The 5.5 V memory back-up capacitors were really two of them in series. Larger supercapacitors are normally a single cell, the user can then connect them in series and add some voltage balancing circuit (although supercapacitor manufacturers also sell complete supercapacitor banks with built-in voltage balancing, but those don't look like the picture at all).
I looked into supercapacitor lifetime a couple of years ago, when I was doing some voluntary work for a clean energy company that unfortunately later went bankrupt. My conclusion was that there were many inconsistencies and unclarities in the data provided by the manufacturers, but all in all, Eaton and AVX appeared to be the brands with the best supercapacitor lifetimes. Their capacitors should last between 2.4 and 6 years at 45 °C, several times longer at lower temperatures. I ended up using 300 F, 2.7 V capacitors from Eaton (XV3550-2R7307-R), it was the first time I ever saw capacitors with values that high.
Hey Marcel,
Tks for the teaching !
Strange though to use them in consumer electronic circuitry at such "weak" 2.4 to 6 yrs at 45c 🥺
Owners of this CT100/NLE 17 phono preamp are reporting that they are still using their units after 2 decades.
Hope to get back soon on my finding as my unit is now with a friend while waiting for capacitors to arrive via digikey.
Cheers.
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Indeed. Like I wrote, I doubt if they really are supercapacitors; I can't think of a good reason why anyone would want to use four 2.7 V capacitors in a phono preamplifier.
By the way, the usual application of large supercapacitors is temporarily storing energy, for example when an electric vehicle brakes by using the motor as a generator. Storing the braking energy in the battery reduces the battery lifetime, but a supercapacitor bank can be charged and discharged as often as you like.
By the way, the usual application of large supercapacitors is temporarily storing energy, for example when an electric vehicle brakes by using the motor as a generator. Storing the braking energy in the battery reduces the battery lifetime, but a supercapacitor bank can be charged and discharged as often as you like.
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Just to correct some of the wrong info here.
The NLE brand is simply short for Niels Larsen Elektronik. The NLE-17 is his original Riia. He´s an old guy now, and the latest
communication I had with him, was on danish telephone number +45 45 88 44 12. (Don´t know, if he´s at all active anymore).
The DacT CT-100 is identical, but later produced by Danish Audio ConnecT, who bought the rights to produce it, after NLE
retired. They also switched from "through hole" to SMD.
I´ll dig in to try and reveal, what kind of opamps are used, since I know a couple of guys, who still use their NLE-17, but don´t keep
your hopes up.
One thing I can say for certain is, that the 4 capacitors are ordinary "lytics". Nothing to do with supercap´s or other conspiracy
theories 🤣. Probably just standard 2200/4700-25 volt capacitors of good quality😉
The NLE brand is simply short for Niels Larsen Elektronik. The NLE-17 is his original Riia. He´s an old guy now, and the latest
communication I had with him, was on danish telephone number +45 45 88 44 12. (Don´t know, if he´s at all active anymore).
The DacT CT-100 is identical, but later produced by Danish Audio ConnecT, who bought the rights to produce it, after NLE
retired. They also switched from "through hole" to SMD.
I´ll dig in to try and reveal, what kind of opamps are used, since I know a couple of guys, who still use their NLE-17, but don´t keep
your hopes up.
One thing I can say for certain is, that the 4 capacitors are ordinary "lytics". Nothing to do with supercap´s or other conspiracy
theories 🤣. Probably just standard 2200/4700-25 volt capacitors of good quality😉
Hi Boydk,
Just awoke from an afternoon nap to these good information especially for me on the 4 unmarked black capacitors .. thanks a million and a step towards more possible replacement if indeed the cause of distortion of my unit by usual e caps unlike some exotic "super capacitors".
Do not know of 2200-4700uf to be measured but 25v is indeed very likely the case as rare excellent* instruction did mentioned +/-16v regulation 🥳🥳
http://www.dact.com/html/phono_stages.html
Neil must be a proud man to have left this decades old legacy product that I had ABed with ultra expensive FM Accoustic's fm122 gen 1 and found on par in my build from this kit ... with added advantage of matching close to perfection of any cartridge requirement.
Read also that there was even improved version NLE 22 coveted but unheard in this part of the world and even rare in Europe and that several hiend audio mfgr then simply used repackaged NLE17 and sold them 5-10 times more with added psu, chassis etc.
Cheers.
* schematic and bom would have been perfect
Just awoke from an afternoon nap to these good information especially for me on the 4 unmarked black capacitors .. thanks a million and a step towards more possible replacement if indeed the cause of distortion of my unit by usual e caps unlike some exotic "super capacitors".
Do not know of 2200-4700uf to be measured but 25v is indeed very likely the case as rare excellent* instruction did mentioned +/-16v regulation 🥳🥳
http://www.dact.com/html/phono_stages.html
Neil must be a proud man to have left this decades old legacy product that I had ABed with ultra expensive FM Accoustic's fm122 gen 1 and found on par in my build from this kit ... with added advantage of matching close to perfection of any cartridge requirement.
Read also that there was even improved version NLE 22 coveted but unheard in this part of the world and even rare in Europe and that several hiend audio mfgr then simply used repackaged NLE17 and sold them 5-10 times more with added psu, chassis etc.
Cheers.
* schematic and bom would have been perfect
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Mine built into a conrad johnson step up xformer hv2 that I ripped out the inards and used it to match then excellent and musical premier 14 preamp that I sold with much regrets some 15 yrs ago ... missed it till now 😭😭
The ct100 is housed in a lead box with both the cj casing and lead box laden with expensive thick umetal sheets and damping matetials while the psu are class A for linearity and fast response 😍😍
Plan is that if I still fail to solve the distortion issue, I will hunt down and replace the complete nos ct100/nle 17 still available from 1 or 2 sellers now with relief that 8 populated aged e capacitor replacement is possible .. tks to Boydk and others here 🙇♂️🙇♂️🙏🙏
Cheers.
PS: Still unsure nor understand why these unmarked capacitors of same 8mm diameter like those oscon caps but much taller and seemingly customised with NLE marking at expected greater cost while Oscon ones are clearly marked ? Size for 2200uf and impossible 4700uf ?? 😰
The ct100 is housed in a lead box with both the cj casing and lead box laden with expensive thick umetal sheets and damping matetials while the psu are class A for linearity and fast response 😍😍
Plan is that if I still fail to solve the distortion issue, I will hunt down and replace the complete nos ct100/nle 17 still available from 1 or 2 sellers now with relief that 8 populated aged e capacitor replacement is possible .. tks to Boydk and others here 🙇♂️🙇♂️🙏🙏
Cheers.
PS: Still unsure nor understand why these unmarked capacitors of same 8mm diameter like those oscon caps but much taller and seemingly customised with NLE marking at expected greater cost while Oscon ones are clearly marked ? Size for 2200uf and impossible 4700uf ?? 😰
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Oops ... even latest Panasonic miniature FR series at 2200uf 25v is 12.5mm diameter at 30mm tall where height is still manageable without boxed top cover against existing 8mm diameter ones .. 4700uf 25v of even today's miniaturisation stands no chance of fitting. 😰
The oscons are just 220uf albeit 10v at 8mm diameter x 10mm length 🤔
The oscons are just 220uf albeit 10v at 8mm diameter x 10mm length 🤔