Hi,
Ray, I mean no offense when I say this... but you'd be alot better off to read what's already been posted, start with the UCD180 thread, follow with the 400, when you're done those I can recommend a few others if you like.
Many of these questions are extremely basic and have little or nothing to do with hot rodding the modules, which we should get back to, it's branched off to many other aspects already, probably too many, but that should serve to stress the importance that the "basics" truly ought to be looked after before anyone ever considers modifying the modules, or it's mostly a waste of time.
Things like dual mono or true mono and all that are alot more geared to "help me with my dream amp" and what you'll find is that bank account is most likely what will determine that outcome long before what would be totally optimal. Design is about compromise, and I think hotrodding, so to speak, should be about making the very best out of what you already have.
With a little searching on the forum and on google (not just class d) youll find these kinds of questions are already answered tne times over.
As per Bruno finding the optimum value for whatever bypass cap, they already have and it comes with the module. Their "optimum" will often be different from that of your own, given that the goals are different in alot of cases, just like most cheap off the shelf commercial amps power supplies are "optimum" from their design perspective, they'll be far from optimum for you from a performance perspective. Why is that, you want to ask? Start searching.
I don't think I ever will give the exact value of cap that I used. In fact, I think I've said enough about it already 🙂
I'm more for promoting experimentation (of a factual /scientific nature) than providing a shopping list.
Best Regards,
Chris
Ray, I mean no offense when I say this... but you'd be alot better off to read what's already been posted, start with the UCD180 thread, follow with the 400, when you're done those I can recommend a few others if you like.
Many of these questions are extremely basic and have little or nothing to do with hot rodding the modules, which we should get back to, it's branched off to many other aspects already, probably too many, but that should serve to stress the importance that the "basics" truly ought to be looked after before anyone ever considers modifying the modules, or it's mostly a waste of time.
Things like dual mono or true mono and all that are alot more geared to "help me with my dream amp" and what you'll find is that bank account is most likely what will determine that outcome long before what would be totally optimal. Design is about compromise, and I think hotrodding, so to speak, should be about making the very best out of what you already have.
With a little searching on the forum and on google (not just class d) youll find these kinds of questions are already answered tne times over.
As per Bruno finding the optimum value for whatever bypass cap, they already have and it comes with the module. Their "optimum" will often be different from that of your own, given that the goals are different in alot of cases, just like most cheap off the shelf commercial amps power supplies are "optimum" from their design perspective, they'll be far from optimum for you from a performance perspective. Why is that, you want to ask? Start searching.
I don't think I ever will give the exact value of cap that I used. In fact, I think I've said enough about it already 🙂
I'm more for promoting experimentation (of a factual /scientific nature) than providing a shopping list.
Best Regards,
Chris
what to read
Well, this forum, I have read, and frankly it's to big to find out exactly some of the stuff you need to know. You can I guess do a search for the desired topic. It actually would be nice to post or to attempt to summarize the findings on the best hotrod mods for the UCD400. Obviously, some of the values and voltages can't apply for the UCD180. Anyway, that's all I have for now. Thanks, and let's get back to the mod info. Happy reading all.
Ray
Well, this forum, I have read, and frankly it's to big to find out exactly some of the stuff you need to know. You can I guess do a search for the desired topic. It actually would be nice to post or to attempt to summarize the findings on the best hotrod mods for the UCD400. Obviously, some of the values and voltages can't apply for the UCD180. Anyway, that's all I have for now. Thanks, and let's get back to the mod info. Happy reading all.
Ray
Hi cowanrg,
Well, you seemed to have summed it up. Mid to lower end. So if I were spending about $1400 to $2000, what would you suggest.
Well, you seemed to have summed it up. Mid to lower end. So if I were spending about $1400 to $2000, what would you suggest.
Hi Rick,
Well, reading your posts, don't know if any of the ideas expressed here would make a difference or not. The problem I have is suggesting for example that you drill four holes in your case and secure the transformer with tie wraps, rather tacty. And you want someone to spend $1400 or more. Although your ideas you mentioned on another forum are perhaps good ones, they unfortunately do not make for good servicing if something goes wrong. Now, you build one for yourself, that's different.
The other thing that is bugging is Chris really didn't poke any jabs at you at all. Please tell me how your last 2 posts for example contributed how we can improve the sonics of a "midfi" ampt to get past the compromises, and make 'em be highen pieces of gear. I think if you had come in here and just suggested some of the tweeks and shut up, you'd look less like a babbling fool. Am I saying you are, no. You obviously have some ideas to share, and this forum is for sharing ideas, not for your comercialization. . I'm done, and will not say any more. I'd rather learn from all of the great people out here, so I too can successfully build one of these amps, and do the job right the first time.
Well, reading your posts, don't know if any of the ideas expressed here would make a difference or not. The problem I have is suggesting for example that you drill four holes in your case and secure the transformer with tie wraps, rather tacty. And you want someone to spend $1400 or more. Although your ideas you mentioned on another forum are perhaps good ones, they unfortunately do not make for good servicing if something goes wrong. Now, you build one for yourself, that's different.
The other thing that is bugging is Chris really didn't poke any jabs at you at all. Please tell me how your last 2 posts for example contributed how we can improve the sonics of a "midfi" ampt to get past the compromises, and make 'em be highen pieces of gear. I think if you had come in here and just suggested some of the tweeks and shut up, you'd look less like a babbling fool. Am I saying you are, no. You obviously have some ideas to share, and this forum is for sharing ideas, not for your comercialization. . I'm done, and will not say any more. I'd rather learn from all of the great people out here, so I too can successfully build one of these amps, and do the job right the first time.
Huh?
Ray,
What I said was try removing the steel bolt and cover and if you like the sonic results then you could always use wire ties to tie it to the chassis. I do not sell amps with wire tied transformers. I am on a DIY forum, so I am talking to the DIYers. I got the idea of the tie wraps from someone who brought his own amp over to my house and had removed the steel bolt and cover and used some wire ties....I think, a very good Idea. Was a PS Audio HC2A or whatever its called....pretty good amp with mods.
I don't know what your talking about "midfi" and all. If you read my posts and you are a tweaker then you might benefit from some of them...all my suggestions are things I have directly experienced...with my ears. I have never tried to sell anything here. My customers are not DIYers....duh!?!
And if you cannot see Chris's put downs and attitude then, I guess that is how you see it. I have gotten three emails from people who won't post here because of his attitude. He blasts anyone he does not like.....saying they are stupid, etc. Check out his latest drama on the Nuforce posts.
You guys have to decide whether you want an open forum or one that has a scary righteous critter running amok....you hold the power....I have voiced my objections over his attitude, but one dissenting voice will not a purring cat make. Peace, tolerance, joy, love and openness I wish for you all. You can differ in opinion without put downs, jabs, and personal attacks. But if someone acts out, then you should always call him on it. Only by making it obvious what is going on will there be any chance of change.
Ray,
What I said was try removing the steel bolt and cover and if you like the sonic results then you could always use wire ties to tie it to the chassis. I do not sell amps with wire tied transformers. I am on a DIY forum, so I am talking to the DIYers. I got the idea of the tie wraps from someone who brought his own amp over to my house and had removed the steel bolt and cover and used some wire ties....I think, a very good Idea. Was a PS Audio HC2A or whatever its called....pretty good amp with mods.
I don't know what your talking about "midfi" and all. If you read my posts and you are a tweaker then you might benefit from some of them...all my suggestions are things I have directly experienced...with my ears. I have never tried to sell anything here. My customers are not DIYers....duh!?!
And if you cannot see Chris's put downs and attitude then, I guess that is how you see it. I have gotten three emails from people who won't post here because of his attitude. He blasts anyone he does not like.....saying they are stupid, etc. Check out his latest drama on the Nuforce posts.
You guys have to decide whether you want an open forum or one that has a scary righteous critter running amok....you hold the power....I have voiced my objections over his attitude, but one dissenting voice will not a purring cat make. Peace, tolerance, joy, love and openness I wish for you all. You can differ in opinion without put downs, jabs, and personal attacks. But if someone acts out, then you should always call him on it. Only by making it obvious what is going on will there be any chance of change.
Hi Rick,
Well, so then, what do you do with these transformers What do you replace the plate with, and the bolt what do you use. I'm glad you don't do that with the tie wraps.
Can you give me a link to which NuForce forum?
Well, so then, what do you do with these transformers What do you replace the plate with, and the bolt what do you use. I'm glad you don't do that with the tie wraps.
Can you give me a link to which NuForce forum?
So Rick, these magic tips you recommend for the most part aren't even good enough to make it into your products, but apparently anything that is remains a "secret".
Someone brought over an amp that sounded good so you fell in love with the tie wraps you saw on it? I guess it never crossed your mind there was probably a better reason why it sounded as it did. You then apparently confused yourself with a placebo effect and all of a sudden that's sound advice, but not so sound that you'd actually use it?
You've been a member here since 2002, and have ~50 posts. A good portion of which were adds for your wares, in the appropriate section.
Now that your "tweaked" version of UCD has become your sole product,here you are, posting your little heart away, only with nothing meaningful. You're obviously not here as a contributor, and are simply a commercial leech off the DIY community, unwilling or unable to give back to it in any meaningful way.
Good tweaks are based on solide engineering and I'm sorry you can't seem to see that.
I'm also sorry you can't seem to grasp that "people of the forum" deserve sound engineering information in place of your marketing voodoo drivel which you're attempting to hype your products with here.
Better luck on a more commercial forum.
Someone brought over an amp that sounded good so you fell in love with the tie wraps you saw on it? I guess it never crossed your mind there was probably a better reason why it sounded as it did. You then apparently confused yourself with a placebo effect and all of a sudden that's sound advice, but not so sound that you'd actually use it?
You've been a member here since 2002, and have ~50 posts. A good portion of which were adds for your wares, in the appropriate section.
Now that your "tweaked" version of UCD has become your sole product,here you are, posting your little heart away, only with nothing meaningful. You're obviously not here as a contributor, and are simply a commercial leech off the DIY community, unwilling or unable to give back to it in any meaningful way.
Good tweaks are based on solide engineering and I'm sorry you can't seem to see that.
I'm also sorry you can't seem to grasp that "people of the forum" deserve sound engineering information in place of your marketing voodoo drivel which you're attempting to hype your products with here.
Better luck on a more commercial forum.
Gentlemen, please do not start it again 🙁
I've seen this hapenning in other forums but never in this wich I, and maybe all of us, consider "our" thread 😡
This is an open forum. Everyone is able to post his impressions here. The poster deserves attack-free replies. This is good manners.
I wish you a good weekend 🙂
Mauricio
I've seen this hapenning in other forums but never in this wich I, and maybe all of us, consider "our" thread 😡
This is an open forum. Everyone is able to post his impressions here. The poster deserves attack-free replies. This is good manners.
I second that!
I wish you a good weekend 🙂
Mauricio
BHC TNetwork caps
I found the BHC caps at DNM for 23-25 pounds each. I think that's about $36 US. Of course, by the time you ship them from England they will be much more. Looking further, I think Aerovox picked them up for the States. We'll see on that one on Monday. I have a call in to them. So if any of you folks in the UK could do a bit of research for us all, most apreciated. Thanks.
Ray
I found the BHC caps at DNM for 23-25 pounds each. I think that's about $36 US. Of course, by the time you ship them from England they will be much more. Looking further, I think Aerovox picked them up for the States. We'll see on that one on Monday. I have a call in to them. So if any of you folks in the UK could do a bit of research for us all, most apreciated. Thanks.
Ray
BHC caps
I've just placed an order for the 10,000uF 63v t-network caps at DNM (4 pole + slit foil combined) and should have them next week. From my experiments with various tripath amps I realise that the power supply significantly affects the sound of a class D amp, but its difficult to audition all the different caps. The Rubycon's have a good reputation and look good on paper but too hard/expensive to get a hold of.
So I went for one of the most expensive options but at least I know that there is a good chance it will sound decent.
For those stateside who want to try a similar cap (although about the same price) try the Jensen 4-pole, Chris has a couple of these and is pleased with them.
BTW - Denis at DNM is really helpful at explaining the ins and outs of these caps for anyone who is interested.
Regards,
Dean
I've just placed an order for the 10,000uF 63v t-network caps at DNM (4 pole + slit foil combined) and should have them next week. From my experiments with various tripath amps I realise that the power supply significantly affects the sound of a class D amp, but its difficult to audition all the different caps. The Rubycon's have a good reputation and look good on paper but too hard/expensive to get a hold of.
So I went for one of the most expensive options but at least I know that there is a good chance it will sound decent.
For those stateside who want to try a similar cap (although about the same price) try the Jensen 4-pole, Chris has a couple of these and is pleased with them.
BTW - Denis at DNM is really helpful at explaining the ins and outs of these caps for anyone who is interested.
Regards,
Dean
The datasheet is pretty good too, if you know anything it doesn't mention after having discussed it with him why not say so here already.
These caps are hardly expensive considering what they are and what they do. Consider the black gate alternative for instance. That, is expensive.
Be sure to feed them well with some good rectifiers. No sense going half way with it now.
BTW it was the BHC T-networks from Lars Clausen that sold me on the 4 pole technology. I just went with Jensen 4 poles for more uF and to save ordering them the UK. Partsconnexion is just a few hours away I think. Very similiar sound, BHC perhaps is more neutral.
The problem with parts connexion is their packaging of them.. less than ideal for what you'd consider to be gold, probably get them with a few scratches. Very careless of them. If you order clamps with them make sure you specify they don't throw them in the same bag with the caps at least. May as well have your expensive parts looking nice, rather than second hand junk out of someone's tool box.
These caps are hardly expensive considering what they are and what they do. Consider the black gate alternative for instance. That, is expensive.
Be sure to feed them well with some good rectifiers. No sense going half way with it now.
BTW it was the BHC T-networks from Lars Clausen that sold me on the 4 pole technology. I just went with Jensen 4 poles for more uF and to save ordering them the UK. Partsconnexion is just a few hours away I think. Very similiar sound, BHC perhaps is more neutral.
The problem with parts connexion is their packaging of them.. less than ideal for what you'd consider to be gold, probably get them with a few scratches. Very careless of them. If you order clamps with them make sure you specify they don't throw them in the same bag with the caps at least. May as well have your expensive parts looking nice, rather than second hand junk out of someone's tool box.
Powersupply for this amp will support 5 channels of UCD modules in a single case.
Left & right channels are UCD400 modules with separate 300VA toriods with electrostatic shield. Dual bridges per channel with MBR10100 & 0.022uF bypass caps and the 10,000uf 63v T-Network (slit foil + 4 pole) caps per rail.
Centre & L / R surrounds are UCD180 modules powered by a single 300VA toriod+shield with a single PS, dual MBR10100 & bypass caps with 10,000uF slit foil (not 4 pole) per rail.
The amp will also include a balanced resistor ladder volume control, driven by a micro & connected to a PC via a USB connection. This aspect of the amp will be the most DIY and challenging however I have a schematic & prototyped the code in the micro so need to design the PCB board.
After the many hundreds of posts to this thread and related threads there seems to be no consistently agreed tweaks except for the following:
- Remove the coupling caps (if possible)
- Use a high quality power supply
- Ensure ground loops are minimised
Last weekend I rigged up the UCD ST400 modules after shorting the coupling caps and the sound was a significant improvement (soundstage & clarity) over an older DIY MOSFET amp I use, however I did think the dynamics were lacking slightly, possibly as I was tapping the PS from the MOSFET amp to power the UCDs.
Regards,
Dean
Left & right channels are UCD400 modules with separate 300VA toriods with electrostatic shield. Dual bridges per channel with MBR10100 & 0.022uF bypass caps and the 10,000uf 63v T-Network (slit foil + 4 pole) caps per rail.
Centre & L / R surrounds are UCD180 modules powered by a single 300VA toriod+shield with a single PS, dual MBR10100 & bypass caps with 10,000uF slit foil (not 4 pole) per rail.
The amp will also include a balanced resistor ladder volume control, driven by a micro & connected to a PC via a USB connection. This aspect of the amp will be the most DIY and challenging however I have a schematic & prototyped the code in the micro so need to design the PCB board.
After the many hundreds of posts to this thread and related threads there seems to be no consistently agreed tweaks except for the following:
- Remove the coupling caps (if possible)
- Use a high quality power supply
- Ensure ground loops are minimised
Last weekend I rigged up the UCD ST400 modules after shorting the coupling caps and the sound was a significant improvement (soundstage & clarity) over an older DIY MOSFET amp I use, however I did think the dynamics were lacking slightly, possibly as I was tapping the PS from the MOSFET amp to power the UCDs.
Regards,
Dean
I can fully recommend using tantalum bypass caps. As I predicted having both modules newly bypassed it is again holographic, the air has returned and has even more slam.
If you think for someone the module can't handle it, trace the circuit down and see for yourself. There's no reason not to add a bigger cap.
Main point here is whatever you want to do or use, just upgrade what's there. They're flat/thin and lifeless.
If you think for someone the module can't handle it, trace the circuit down and see for yourself. There's no reason not to add a bigger cap.
Main point here is whatever you want to do or use, just upgrade what's there. They're flat/thin and lifeless.
That's C6 & C7 the SMD bypass caps close to the supply pins. The OPA2134 (for the 400ST modules) requires at least 10nF ceramic caps.
The SMD cap on the UCD is unmarked, however assumings its in the vicinity of 10-100nF which pretty small and better slam would come from a larger cap, but it would also need to have excellent HF performance, so a tantalum with good ESR characteristics would do well.
You can purchase 20v 1uf low ESR tantalums from Mouser in a similar SMD form factor to the caps on the board. However watch polarity when soldering.
Regards,
Dean
The SMD cap on the UCD is unmarked, however assumings its in the vicinity of 10-100nF which pretty small and better slam would come from a larger cap, but it would also need to have excellent HF performance, so a tantalum with good ESR characteristics would do well.
You can purchase 20v 1uf low ESR tantalums from Mouser in a similar SMD form factor to the caps on the board. However watch polarity when soldering.
Regards,
Dean
deandob said:
Good stuff. There's a fairly wide variety of tantalums also, choose wisely. I'm getting away with a 15V tantalum right now. A larger margin would be very wise with them, but it would also be interesting to see how the voltage rating affects sonics.. not something I"ve been able to test yet.
1uF according to what I have tested is sub optimal, but better than stock. If you go too big, due to the current limitations of the regulator, it takes longer for the voltage to come up and it may introduce a small pop at turn on, but it is nothing too drastic, and, you can fix that easily enough just by recycling the stock ceramic SMT cap, if you wanted to.
The typical tear drop variety is also a perfect fit, just bend the leads up and solder it down.
This improves the sound across the entire range, gives the mids alot more body, it's by far one of the most significant mods I've done yet.
If you start to experiment with differenct sizes, you just might wish the stock module had provisions to really allow some play room here.
One other interesting thing to note is that while it really helps the FC bulk storage caps sound a hell of alot more lifelike, it will be worth trying different caps in their place yet again, perhaps even the stock ones.
Lastly, there is another very cheap ceramic cap, right at the input Fast-On's of the power rails, bypassing them to ground. This could be another very interesting improvement, like a proper RC snubber perhaps.
Cheers
I would probably try out the 'recommended' value by Dejan V. Veselinovic in his article 'Choosing an op amp', which is 10uF, 35V.deandob said:
Are there strong arguments against using a radial cap instead of an smd package if it is placed directly on the op amp pins? Or in the case when you place it on the pcb were the original component sits?
And what about the reliability of tantalum caps? Is simply choosing a higher voltage than the circuit suggests sufficient to prevent problems?
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