Right, get one and you can see where is the problem. I am using this one, cheap but serves the purpose well
ARM DSO203 Aluminium Nano 4 Channel Mini V2/Quad Pocket Digital Oscillo?scope.UK | eBay
The most obvious thing I can see is that the wires for your output stage smoothing caps are far too long! Even worse, one twisted pair is running right past the transformer while the other goes over your output wires. I'd start by moving those caps right back to where they belong.
Secondly, your HDAMs are bypassed but not much else has been improved. I'm not sure of the correct order here but you'll definitely want to look at improving op-amp power and output stage filter caps. Check for DC on your output too.
Look to upgrade servo PSU and 5v pre-reg cap to bring back some bass... The list is endless though...
Oh, one last thing: Make sure your HA op-amps are the genuine article and not the all-too-common Chinese rip-offs.
Ben
Oh yeah, you also might want to sanity check that output stage PSU. Is it feeding the correct voltage and is it good quality and beefy enough for the job.
Thanks for the tip, Brent. Do you think it was interference between the transformers themselves or the effects of them being wired to the PCB together? I still have longish wires on my servo transformers so can move it away and see if it helps. The output tx is mounted to the original KI bracket.
Thanks for the tip, Brent. Do you think it was interference between the transformers themselves or the effects of them being wired to the PCB together? I still have longish wires on my servo transformers so can move it away and see if it helps. The output tx is mounted to the original KI bracket.
Thanks ben im up to changeing a few caps and shortening them wires on the power supply caps but not really any good at this sort a thing. Did you notice the wires comeing from one of the input sockets on back as that is were another power supply is pluged in not sure what it poweres but its cb 14v dc power supply im useing
I noticed them. I'm assuming they're for the output stage. What power supply are you using exactly?
Also, this is probably obvious, but make sure those caps are wired the right way round. I imagine you would've had one pop by now if they were wrong, but that pink twisted pair carrying DC is an accident waiting to happen.
Also, this is probably obvious, but make sure those caps are wired the right way round. I imagine you would've had one pop by now if they were wrong, but that pink twisted pair carrying DC is an accident waiting to happen.
Hi ben its cb 14v dc 5 amp power supply. Im going to sort the power supply caps tommorow but i will let you know the value and make as thay might not be best for the job
CB as in radio? If so then I'd say it's very likely not up to the job. You want a good quality dual linear regulated power supply with a high VA rating. The original 7812/7912 regs have been removed from your player, so your op-amps are entirely at the mercy of whatever noise and ripple is present on that external supply. Brent sells some very nice looking, well spec'd external PSUs.
Alternatively you could go back in the box, but you're at a disadvantage there with everything being ripped out already so I wouldn't recommend it personally. If you've already broken out the box then I'd say roll with it.
Alternatively you could go back in the box, but you're at a disadvantage there with everything being ripped out already so I wouldn't recommend it personally. If you've already broken out the box then I'd say roll with it.
Hi ben yes its a cb radio power supply. Whats cheapest but fairly decent one ben. Could you post me a link to any on ebay please
I've actually got no idea where to get a cheap one that is good.
Personally I would probably just build one myself on veroboard from good components, as the basic circuit is fairly simple and can easily be found online. You'd need something in the order of some board + stand-off mounts, a decent toroid (e.g. Nuvotem brand from RS), a case, +/- regs, smoothing caps, an LED + resistor, switch, sockets, cables, fuse, rectifier/diodes. You can usually get pre-made bare PCBs on eBay to make it a bit easier.
If I wasn't confident to do that then I'd probably save up my pennies for something off the shelf like one of Brent's supplies, because it would at least be built with hi-fi audio in mind. Brent's are a bit more pricey but include low noise regs rather than your standard 78xx/79xx jobbies.
Personally I would probably just build one myself on veroboard from good components, as the basic circuit is fairly simple and can easily be found online. You'd need something in the order of some board + stand-off mounts, a decent toroid (e.g. Nuvotem brand from RS), a case, +/- regs, smoothing caps, an LED + resistor, switch, sockets, cables, fuse, rectifier/diodes. You can usually get pre-made bare PCBs on eBay to make it a bit easier.
If I wasn't confident to do that then I'd probably save up my pennies for something off the shelf like one of Brent's supplies, because it would at least be built with hi-fi audio in mind. Brent's are a bit more pricey but include low noise regs rather than your standard 78xx/79xx jobbies.
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Thanks ben i will have a look at brents then. Are the mean well power supplies any good and what would max voltage be
Thanks ben yes the mean well power supplys are a switch mode type. Reason i mensioned that brand is i have one for a 41hz amp i have. But i have just ordered a valve amp
I would consider reinstating the original circuitry. It's not difficult. You could download the service manual and upgrade pdf from ray's website. Then run through the op amp section in the upgrade pdf. This would reinstate most of the components then it should be a case of refitting a few wire links and job done.
This kit may help.....
http://www.siliconray.com/power-supply-for-jlh-headphone-amplifier.html
This kit may help.....
http://www.siliconray.com/power-supply-for-jlh-headphone-amplifier.html
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Thanks mcd99uk but i dont think i could build out like that and i dont think i could reverse the power supply mod thats been done. I have broke one cd 67 allready lol. There was a bloke on here in sheffield called simont who did the mods on my other player i had but not seen him post for a while
To be honest, carrying out DIY modding requires some very basic electronic know how and you need to read very basic circuit diagrams. Without these you will do more harm to your kits and the successful rate is very slim. If I were you I won't carry out DIY myself and will ask someone to do the job for me. From your uploaded photos the work carried out were not good at all. Sorry for being so blunt
To be honest, carrying out DIY modding requires some very basic electronic know how and you need to read very basic circuit diagrams. Without these you will do more harm to your kits and the successful rate is very slim. If I were you I won't carry out DIY myself and will ask someone to do the job for me. From your uploaded photos the work carried out were not good at all. Sorry for being so blunt
I totaly agree the work is shaby but im not guilty of it lol. I only fitted the opamps. I posted the pic to have the mods checked as i dont think the bloke knew what he was doing. I dont know any one else in sheffield who could have a look at it. As i said before i had another player before this and simont who was on here did all the mods on that and he knew what he was doing
If you want someone to help and do a decent job for you I would suggest you forget the existing CDP and try to bid a CD63 MKII KI from the Bay. There are a few people around here who can offer modding job. I think Brent and Lee are some of the examples. Search the web and I am sure you can find out more about their services. What you need to do is to send the CDP by courier and it will be returned when the modding work is done. Hope this can help.
To be honest highlander i had a 63se last that had been moded and i didnt think it was as good as the 67. Brent is not far from me docaster i think
Why buy an overpriced KI on eBay????? I can sell you a badge for £80 if you like!!!!! Thats terrible advise!!
That 67 is more than capable of equalling most DIY 63's if it get tidied up. Would you buy a new car because it needed a new tyre?
Get the main smothers back where they belong, get a large cap in the servo psu and swap the local caps as described a million times before......solid polymer on digital rails and Rubycon ZLh on analogue rails!
The only reason for going 63 over 67 is if you plan to run 2 clocks and use multiple discrete regs! Out the box the 67 out performs the 63 as its servo driver is regulated.
No point in buying a KI unless you want the badge, an SE is the same chassis just not copper plated (copper does look nice tho lmao!!) and the KI has a bigger toroidal transformer. By the time you've done the 1st round of mods, there's nothing in it!!!! In fact, you'd remove th better caps in the KI to replace with something 'better'!!
I'm also interested how Ben should use the scope to track down his mains hum???