Products using lead free solder are harder to rework, especially if you use tools that are normally used with leaded solder. Turn the heat up a bit and use some liquid flux to get that lead free stuff flowing better.
Good luck with the smoke test 😉
Good luck with the smoke test 😉
Yes flux. Have been hunting allllll over for some. I'll have to order it online.
I'll need new Metcal tips to turn the heat up, the butane iron is brutal, got a mind of its own really. Will now reserve it for battery posts.
So, good news and bad news.
If you plan on building a stereo or multi channel amp with these, I don't know if you can space them out enough for the heterodyning to not be an issue. As given to me the modules are less than an inch apart I'd estimate, and I can hear the whistling from across the room next to a running computer.
Disappointing.
What am I going to do about that? Not a thing. My wires are cut to size so there's no spacing things out further.
Aside from that, the FC's have left it tainted. Fairly heavily colored. It was much better with the SAL's, and also with the tantalums. I'll endure them for the rest of the testing.
The good news is there's no smoke, and at least now that all is equal, I can finally evaluate it for imaging and such.
To be continued.
I'll need new Metcal tips to turn the heat up, the butane iron is brutal, got a mind of its own really. Will now reserve it for battery posts.
So, good news and bad news.
If you plan on building a stereo or multi channel amp with these, I don't know if you can space them out enough for the heterodyning to not be an issue. As given to me the modules are less than an inch apart I'd estimate, and I can hear the whistling from across the room next to a running computer.
Disappointing.
What am I going to do about that? Not a thing. My wires are cut to size so there's no spacing things out further.
Aside from that, the FC's have left it tainted. Fairly heavily colored. It was much better with the SAL's, and also with the tantalums. I'll endure them for the rest of the testing.
The good news is there's no smoke, and at least now that all is equal, I can finally evaluate it for imaging and such.
To be continued.
classd4sure said:Speakers lived.
Amps..
Dissection begins.
More later.
well good luck, I'm sure you'll sort em! Now wait for the moaning to begin😀
t. said:
Now wait for the moaning to begin😀
Thanks for that. I'm not so sure. I've come to the conclusion it's not my fault though. Being DOA when I first got it, I'm just alot more aggrevated right now to say the very least.
It blew in such a strange way.
I plugged it into a fairly hefty power bar that includes surge and EMI filtration... yes it has some Y caps... I know that's bad for sound quality, but it shouldn't be destructive in any way. The point of that was to get my source(pc) and amps all on a common main's branch and further reduce the noise floor to just the usual whistle.
It lasted 5 seconds plugged into that, powered up with the usual snap, heard the usual whistle hunting around, then both modules output 20Vdc on my speakers in one big blast, then another big blast, so I unplugged it, another big blast or two.
The negative rail of the op amp has ~3Vdc again Lars... all caps look fine and were installed properly, it played hard all morning (and better than ever), so I'll give a listening report later based on that experience..... far too aggrevated to say much of anything good about it at the moment. It's on the shelf. I'm highly disappointed. I gave it every possible chance!
I knew if something takes that much work to get reviewed, defnitly high risk. It really should be as simple as connect standard modules together and play. Leaving all the upgrades and mods for further discussion. Well...
It originally just had too much of a smoothed/silky fingerprint for my liking. I also found myself unable to comment on any aspect such as imaging /soundstage given the need to replace the input stage bypass caps on one of the modules because of DOA?!?
While I waited for a few things to happen ... so I could get cables/connectors to drive it fully balanced, a set of replacement caps for each module so they're at least all of the same variety, I did all I could to address the shortcommings of the power supply. I don't find 10 000uF is enough for my speakers. Snubbing the bridge rectifiers helps keep the HF hash at bay (and it did), etc.
It arrived in a sad state of affairs and I did what I could to fix it. I'm not a believe in ground lifts all over to try and make things immune to hum. To me it's just a soundstage/imaging killer, and so those got removed promptly.
EMI is high enough that they should never have been placed so close to one another, and I can't tell you if spacing them apart more would make a difference. It's unpleasant to hear them whistling if you manage to get the noise floor low enough though, perhaps a none issue with less efficient speakers.
Possibly with different input stage caps they should have been readjusted as well.... I honestly didn't even think to check the DC offset after I changed them this time, and I really should have.
Why I couldnt' review a smoothed fingerprint.... well, it's cute at first but it tires quickly when everything sounds the same. When I listened to it today from 7am to 12 noon, I wasn't tired of it at all, but I really dislike the fakeness the highs have from the FC bypass caps.. too squeezed, not enough air, seems off pitch or something, poor choice.
I have no idea why both modules went at the same time. I'll fix them if I can, I'd still be interested in trying them post filter feedback... but if I do get them fixed, they're going to get beaten on some 2$ subs for a good while first.
The actual listening report still to come. This is just a rough summation of my experience with it thus far. I suppose you could buy a worse amp, I'm positive there's far better.
While I waited for a few things to happen ... so I could get cables/connectors to drive it fully balanced, a set of replacement caps for each module so they're at least all of the same variety, I did all I could to address the shortcommings of the power supply. I don't find 10 000uF is enough for my speakers. Snubbing the bridge rectifiers helps keep the HF hash at bay (and it did), etc.
It arrived in a sad state of affairs and I did what I could to fix it. I'm not a believe in ground lifts all over to try and make things immune to hum. To me it's just a soundstage/imaging killer, and so those got removed promptly.
EMI is high enough that they should never have been placed so close to one another, and I can't tell you if spacing them apart more would make a difference. It's unpleasant to hear them whistling if you manage to get the noise floor low enough though, perhaps a none issue with less efficient speakers.
Possibly with different input stage caps they should have been readjusted as well.... I honestly didn't even think to check the DC offset after I changed them this time, and I really should have.
Why I couldnt' review a smoothed fingerprint.... well, it's cute at first but it tires quickly when everything sounds the same. When I listened to it today from 7am to 12 noon, I wasn't tired of it at all, but I really dislike the fakeness the highs have from the FC bypass caps.. too squeezed, not enough air, seems off pitch or something, poor choice.
I have no idea why both modules went at the same time. I'll fix them if I can, I'd still be interested in trying them post filter feedback... but if I do get them fixed, they're going to get beaten on some 2$ subs for a good while first.
The actual listening report still to come. This is just a rough summation of my experience with it thus far. I suppose you could buy a worse amp, I'm positive there's far better.
Munchausen Syndrome by Proxy?
Somebody do an intervention and get those amps to a safe place.
😀
Somebody do an intervention and get those amps to a safe place.
😀
ClasD4sure, I think it all went wrong from the moment you touched it, and I really did nothing but expect it to blow up in your face as it seems you dont know what your are doing - as Lars said you cant mess around with 4-layer boards like that, and I only feel sorry fore Lars, but I also wondered he was participating in something like this - module may be at fault, may be not, but this way we dont know anything - guys, you have to do something like this properly
Any review should be done with just the default product no matter whether you like it or not. Everyone want's to know how the original design is, whether it can be improved or not is really a different issue. I think this is just a lesson to be learned. Let's hope others will come up with some more objective reviews as the modules are shipped.
I knew there was still a chance others might beat you to a review. 😀
I knew there was still a chance others might beat you to a review. 😀
tinitus said:ClasD4sure, I think it all went wrong from the moment you touched it, and I really did nothing but expect it to blow up in your face as it seems you dont know what your are doing - as Lars said you cant mess around with 4-layer boards like that, and I only feel sorry fore Lars, but I also wondered he was participating in something like this - module may be at fault, may be not, but this way we dont know anything - guys, you have to do something like this properly
Come on guys, that's not a nice thing to say - we may or may not agree with the way Chris does things, but still...
At least for me it's been interesting - and informative - to follow his efforts, which I think he has done a great job of describing here.
Keep going Chris, I hope you can figure out how to get'em up and running again soon (maybe with a little help from Lars...).
/cdl
cdl said:
When one calls his efforts a review, and also supported by the manufacturer, the situation is different from just a person buying the product and reporting personal experience. If a good report cannot be successfully produced, it effects sales of the product. No matter what the original good intentions might there be. If I were in this situation, I would do the politically right thing. Right now all the discussion gives me a general impression that board is not designed for modifications or upgrades, it doesn't sound like it reproduces sound very well. It this the truth? Or is it just not built correctly?
I think the most simple thing is just for Lars to sent out a fully built unit he expects DIYers to have as a minimum and just let Chris do the listening. This will at least let others know what Lars preferences are regarding music reproduction.
soongsc said:
In principle I agree, but it didn't turn out like that (it's a prototype, DOA etc. etc.). And I believe Chris just promised to post his opinions and objective observations, which is just what he has done. And what do we have to gain from trashing his efforts, anyway?
The board not designed for modifications or upgrades...? Well, you're probably right there ... I guess that's part of the idea of buying ready assembled and tested modules rather than a kit or DIY from scratch. Not necessarily a disadvantage.
As for how well it plays ... well the guy Lars visited (from a Danish forum) with the very same prototype was happy enough about it - and he's very picky about sound. But there's really no knowing how the final version will sound in whatever setup it's put into... so those who have already ordered are playing on the dark horse anyway. As we are more or less every time, unless we buy a ready made product and get the option to bring it home and hear how the actual thing integrates into the rest of our system!
🙂 cdl
Keep in mind that this was all intended to give us DIYers a preview of Lars' NCD. The fact that Lars chose Chris - the same Chris who is not shy about promoting the UcD modules he knows and loves - to do the preview audition shows that Lars has nothing to hide about his new modules. In fact, I admire him a little bit for that alone. Such an offer is rarely, if ever, made amongst audio equipment manufacturers.
tinitus said:ClasD4sure, I think it all went wrong from the moment you touched it, and I really did nothing but expect it to blow up in your face as it seems you dont know what your are doing - as Lars said you cant mess around with 4-layer boards like that, and I only feel sorry fore Lars, but I also wondered he was participating in something like this - module may be at fault, may be not, but this way we dont know anything - guys, you have to do something like this properly
So how many have you ordered? I also wonder why Lars would volunteer to send me a partially assembled amp with a non working module to share my experiences with. Obviously the first few aren't going to be that good. Do you suppose I should have simply sent it back right then?
All this whinning about modifications.... I don't even consider the removal of a few SMT ground lift resistors in order to optimize the grounding scheme as much as possible, like I'd do with any amp.
You'll find also that having enough capacitance in the supply (BHC T networks no less, not something I cut out of an old Pioneer receiver), is also simply done in the effort to implement a module as optimally as possible, same with the added snubbers and bleeder resistors, as I'd do for any amp, and as I'd done for the UCD modules.
As Brian mentioned you have to respect Lars to some extent for taking such a risk ... You don't really think he expected a typical stereophile review of me, do you? In turn I did all of the above in order to give his modules the best possible chance of measuring up to standards I've become used to with the UCD modules, which aren't something I'm in love with, but respect if not admire them for the caliber they truly are of based on design and implementation. However good they may be though, implementation is a "weak link in the chain" thing, so your job in "plugging them in" ought to be taken seriously. I call it standards. I don't believe I mentioned how they compare sonically either.
Obviously asking Lars to send along the replacement caps that he'd be implementing on production modules is also not a modification. I wonder if you moaners have even read the thread?
I'd think part of the reason I was chosen for testing them is because I have standards. If that's the case Lars got what he asked for and I don't feel the need to apologies for anything. I'm more ticked having done all that work to it, and only getting to listen to it for half a day, before of they both unexplainably ceased to funtion and repeatedly hit my speakers with high DC.
Oh, what I do consider a modification is deadbugging an opa627 in soic on the underside of the board. It's perfectly made for it.
Computers also aren't sold with the intent of having that "void if removed" sticker torn off, but you know you do it anyway.
About the picky Danish guy/Sound test. His standards I guess aren't my own. Remember a result of that sound test, Lars was seemingly near frantic about much a difference one particular type of RCA made. It seemed the amp had to be heard with that and that only to sound good??
Tinitaz, did you order some of that 😉
I admire Lars for trying to accomplish better performance in these class d amps. Personally, I am trying to decide which one to buy, the UCD180 or the NCD. Really don't have much time to try and debug amps.
I tried the AMP2 from 41Hz, not getting it running the first time really nothing to debug since it's all chips, the voltages measurement and symptoms changed over time for a few days until finally the 5V fuse just decided to burn from then on. I would have been happy if there were smoke somewhere so at least it would be possible to know what's bad.
I guess there was so much emphasis on being a fair and credible review that led lots of people to follow this thread with great expectations. Not trying to beat on anyone, but really, if a product for review is not in the right configuration, just return it and get the right configuration. Once you start tweaking on your own, we really don't know whether the results are typical for the product or whether the reviewer's tweak.
I tried the AMP2 from 41Hz, not getting it running the first time really nothing to debug since it's all chips, the voltages measurement and symptoms changed over time for a few days until finally the 5V fuse just decided to burn from then on. I would have been happy if there were smoke somewhere so at least it would be possible to know what's bad.
I guess there was so much emphasis on being a fair and credible review that led lots of people to follow this thread with great expectations. Not trying to beat on anyone, but really, if a product for review is not in the right configuration, just return it and get the right configuration. Once you start tweaking on your own, we really don't know whether the results are typical for the product or whether the reviewer's tweak.
Who's anyone? Have you read the thread? Is this your stereophile forum or ooooh silly me nooo it's DIYAUDIO. Return it and get the right configuration LOL... good thing I finished pukin last night.
It's fair and credible because it's not a review. You got what I promised. It seems you'd benefit from knowing which of your selections are best.... wouldn't be too political of me to tell you though.
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