hiwi3 said:
Hi Bill,
No need for embarassment, it happens, sorry for your luck though.
I'm surprised they had the CRD's on em already, must have grabbed your modules' from the wrong batch? I doubt the commercial gods would have allowed us this top secret tweak they came up with :bs:
I agree with you about leaving the mains earth out. My "chassis" if you will, is still earthed. What you do is leave the supply float from chassis/earth by not connecting the PSU's common to it directly... it still gets earthed indirectly through the module via the signal shield, which assures the output is correctly referenced to the input this way, which I think is the main issue, as a bonus it cleans up the signal ground.
If you do leave it float, I highly recommend the case be earthed for safety reasons. The only part of my PSU that connects to the chassis - earth is the static shield wire, which would be very good to have also for safety purposes with a floating supply.
The XLR shields' connection point is usually recommended to be as close to the connector as possible, keeps the loop area small making it more immune to noise pick up. Since you also need mains earth connected to the chassis at its point of entry, the shields end up connecting to it through the case, which is fine.
You can use the "non black" Neutrick's which connect to chassis internally, or the black ones which have a tab on them, that will let you wire the shields together on the case, as close to the connectors as possible, and then connect the modules' signal grounds to that point.
If a ground loop forms and you hear noise it's through your source and you can try any number of options to cure it.
Recommend you wire a 100W bulb in series with your power cord while you test this stuff out.
Take your time with it too. It's a good idea to take a little break from it before you do your final check and add power, I know it's hard to pull yourself away at that point but it pays off in that you'll spot things instantly which you'd otherwise remain blind to. The best break is a nights worth of sleep too.
Regards,
Chris
Gentlemen, you are too fast for me 😀
Mmm...please don't quote the entire previous reply. My fingers are fatigued
I am convinced that we can achieve R or C-core's magic (or better) if we use an AC mains filter that includes a big isolation transformer. I will post the schematics in my (sadly unfrequented) thread for my humble filter.
Let me tell you a little story: I received as a gift a BIG EI transformer from an old hemodyalisis machine, 220VAC to 120VAC. I was saving it to power a cheap SACD player that I want to import from USA. Yesterday I remembered that my cheap Sony transport can use 110 to 240VAC. So I connected it and ...wow! magic 😀
It totally transformed the sonic presentation of the system to a liquid, detailed and relaxed presentation. The amplitude of the soundstage increased and, I don't know how to explain this, the"fluidity" of music's flow in the room got more natural. Bass is stronger and articulated and midrange more human. As a whole the sound became coherent. I am very exited with this and I am searching for Tx dealers.
Sorry, I got lost Do the bias tweak refer to biasing the opamp into class A? Never done.
Good luck to all.
Mauricio
Mmm...please don't quote the entire previous reply. My fingers are fatigued
I am convinced that we can achieve R or C-core's magic (or better) if we use an AC mains filter that includes a big isolation transformer. I will post the schematics in my (sadly unfrequented) thread for my humble filter.
Let me tell you a little story: I received as a gift a BIG EI transformer from an old hemodyalisis machine, 220VAC to 120VAC. I was saving it to power a cheap SACD player that I want to import from USA. Yesterday I remembered that my cheap Sony transport can use 110 to 240VAC. So I connected it and ...wow! magic 😀
It totally transformed the sonic presentation of the system to a liquid, detailed and relaxed presentation. The amplitude of the soundstage increased and, I don't know how to explain this, the"fluidity" of music's flow in the room got more natural. Bass is stronger and articulated and midrange more human. As a whole the sound became coherent. I am very exited with this and I am searching for Tx dealers.
Sorry, I got lost
Do the bias tweak refer to biasing the opamp into class A? Never done.Good luck to all.
Mauricio
Chris-
I dunno... I'm (obviously) no whiz, but there is some kind of 3-lead SMT device that looks to be in the right spot for a biasing CRD. It's hand-soldered, and there isn't a blank spot. If not a CRD, then I suppose ignorance is bliss. I could try to post a photo, if JP wouldn't object.
I like your grounding approach. I'm using the tab on a black Neutrik to connect about an inch away from the connector. I'll remove the connection from the PSU common and replace it with one from mains earth.
Thanks for the great advice (just a bit too late) about taking a break... it would have saved me some frustration and $!
-Bill
I dunno... I'm (obviously) no whiz, but there is some kind of 3-lead SMT device that looks to be in the right spot for a biasing CRD. It's hand-soldered, and there isn't a blank spot. If not a CRD, then I suppose ignorance is bliss. I could try to post a photo, if JP wouldn't object.
I like your grounding approach. I'm using the tab on a black Neutrik to connect about an inch away from the connector. I'll remove the connection from the PSU common and replace it with one from mains earth.
Thanks for the great advice (just a bit too late) about taking a break... it would have saved me some frustration and $!
-Bill
classd4sure said:
Well you did help thanks🙂
I'll experiment with the grounds later and post my results
I found this post regarding the J511 http://www.diyaudio.com/forums/showthread.php?postid=490671#post490671 if Bruno likes it then its got to be worth a try before mucking about fitting external reulators
I'm making the most of the late nights until its back to the **** hole on the 3rd Jan
maxlorenz said:Gentlemen, you are too fast for me 😀
Mmm...please don't quote the entire previous reply. My fingers are fatigued
I am convinced that we can achieve R or C-core's magic (or better) if we use an AC mains filter that includes a big isolation transformer. I will post the schematics in my (sadly unfrequented) thread for my humble filter.
Let me tell you a little story: I received as a gift a BIG EI transformer from an old hemodyalisis machine, 220VAC to 120VAC. I was saving it to power a cheap SACD player that I want to import from USA. Yesterday I remembered that my cheap Sony transport can use 110 to 240VAC. So I connected it and ...wow! magic 😀
It totally transformed the sonic presentation of the system to a liquid, detailed and relaxed presentation. The amplitude of the soundstage increased and, I don't know how to explain this, the"fluidity" of music's flow in the room got more natural. Bass is stronger and articulated and midrange more human. As a whole the sound became coherent. I am very exited with this and I am searching for Tx dealers.
Sorry, I got lost
Good luck to all.
Mauricio
The AC mains filter using an isolating transformer sounds interesting, our mains is not exactly that good to be honest, the hi-fi always sounds better later at night which is ok but makes me limited to what volume I can listen to it
Only mains filters I've tried was those things using chokes,X rated caps etc and they always seemed to make the sound worse although the isolation transformer would probably be much better
If you look at the link in the above Bruno explains the reason for op-amp mod
Hi Mauricio,
Fatigued from rolling the wheel down? Click and drag 🙂
K so, I disagree, kinda. Not to say an isolation transformer isn't a good thing, but imagine if you had to buy one..
People have often reported very similar improvements with a simple "DC" mains filter as well, at the total cost of a very very small fraction of an isolation transformer. I think that's worth investigating, or was your filter such a beast, and have you compared the two? Why not try the isolation transformer with your amp?
Yeah, it is the "class A" tweak, really it doesn't work like that, but that is the one. Provisions are already on the modules you just have to slap a current regulating diode on there.
Hi Bill,
It sounds like you do have it there. Have you seen the insanely high res. photo of the UCD700?? I don't think you'd have to worry if you wanted to post a pic., couldn't be worse than that 🙂
Let us know if your replacement module has them as well.
I've the same connectors but have yet to implement them. So your case wasn't earthed before, and you'll earth it now? Cool. Earth it at point of entry as standard practice, if you try running another wire from there over to the XLR tab connection point on the case, you've created a loop. Just let them connect via the chassis, I think that should work fine. Will you be floating your PSU from the chassis too?
Let us know what happens/how it improves.
About the break thing,
I designed and built a robot back in school and I remember clearly working on it through the wee hours one night, as with most nights. Guess I was more burnt out than usual this time.
Every connection I made that night had to be redon probably before the solder even cooled because I was putting everything in the wrong place. Some were redone two /three times. It was very slow going but I figured I needed to push ahead with it, even though I knew I was wasting my time....
When I finished what I wanted to get done that night I was content with my work, it all looked good.
Within the first two seconds of looking at it the next day, after a few hours sleep, I'd noticed instantly everything I'd done had to come apart, it was all wrong, every, single, wire. I also fixed it all in 1/10 the time it took to screw it up.
As for the other nights working on it, usually how it went is when I'd start to work on it, I'd spend a little while fixing the last few connections I'd made the night before, then spend a little while getting a little further ahead on it, then spend a little while screwing up something else which I'd have to fix the next day when I started on it again.
A little break does wonders, and some rest even more, lessons learned the hard way. Still I often dismiss my own advice, I know it's a big risk and it's nerve racking but.. gotta hear it huh? If you can't wait the smoke surely tells you if you got it right or not.
Want another good tip I learned the hard way? Don't let anyone "help" you. If you need another set of hands rig something up, grab some clamps, use tape, glue, whatever. Trust me you'll be better off!~
Regards,
Chris
Fatigued from rolling the wheel down? Click and drag 🙂
K so, I disagree, kinda. Not to say an isolation transformer isn't a good thing, but imagine if you had to buy one..
People have often reported very similar improvements with a simple "DC" mains filter as well, at the total cost of a very very small fraction of an isolation transformer. I think that's worth investigating, or was your filter such a beast, and have you compared the two? Why not try the isolation transformer with your amp?
Yeah, it is the "class A" tweak, really it doesn't work like that, but that is the one. Provisions are already on the modules you just have to slap a current regulating diode on there.
Hi Bill,
It sounds like you do have it there. Have you seen the insanely high res. photo of the UCD700?? I don't think you'd have to worry if you wanted to post a pic., couldn't be worse than that 🙂
Let us know if your replacement module has them as well.
I've the same connectors but have yet to implement them. So your case wasn't earthed before, and you'll earth it now? Cool. Earth it at point of entry as standard practice, if you try running another wire from there over to the XLR tab connection point on the case, you've created a loop. Just let them connect via the chassis, I think that should work fine. Will you be floating your PSU from the chassis too?
Let us know what happens/how it improves.
About the break thing,
I designed and built a robot back in school and I remember clearly working on it through the wee hours one night, as with most nights. Guess I was more burnt out than usual this time.
Every connection I made that night had to be redon probably before the solder even cooled because I was putting everything in the wrong place. Some were redone two /three times. It was very slow going but I figured I needed to push ahead with it, even though I knew I was wasting my time....
When I finished what I wanted to get done that night I was content with my work, it all looked good.
Within the first two seconds of looking at it the next day, after a few hours sleep, I'd noticed instantly everything I'd done had to come apart, it was all wrong, every, single, wire. I also fixed it all in 1/10 the time it took to screw it up.
As for the other nights working on it, usually how it went is when I'd start to work on it, I'd spend a little while fixing the last few connections I'd made the night before, then spend a little while getting a little further ahead on it, then spend a little while screwing up something else which I'd have to fix the next day when I started on it again.
A little break does wonders, and some rest even more, lessons learned the hard way. Still I often dismiss my own advice, I know it's a big risk and it's nerve racking but.. gotta hear it huh? If you can't wait the smoke surely tells you if you got it right or not.
Want another good tip I learned the hard way? Don't let anyone "help" you. If you need another set of hands rig something up, grab some clamps, use tape, glue, whatever. Trust me you'll be better off!~
Regards,
Chris
classd4sure said:
what's wrong with buying things? 😉
I have two Iso transformers. Ebay is the place for stuff like this, especially if you buy locally and save the horrendous shipping charges on these heavy beasts. My 12 amp unit cost me less than the higher grade outlets and damping sheets I installed in it...
Peter
You're welcome again 🙂 I find it rather pointless until your amp is really rocking though, so I will be happy to hear of the results. Maybe I got it all wrong, who knows?
In particular it is the "DC filter" type that many seem to report as vastly improving the sonics in a similar fashion an isolation transformer does. Leads most to wonder if it's the removal of DC that also makes an isolation transformer sound so good, but haven't seen anyone do a direct comparison. I think it makes sense and is worth looking into.
In terms of space/cost I'd be far more interested in the DC filter were that true.
They can be coupled with a PI filter to help smooth the less than ideal sine wave out of them.
Regards,
Chris
Well I've got my pieces of cable so when I've had lunch I'll give it a go🙂
I've not used the mains filter with the UCD amp, I've around several other amps I did try it with and to be honest it just killed the music IMHO.
It was one of those tweaks which seemed to improve things at first but after longer listening I just prefered the sound without it
I've not used the mains filter with the UCD amp, I've around several other amps I did try it with and to be honest it just killed the music IMHO.
It was one of those tweaks which seemed to improve things at first but after longer listening I just prefered the sound without it
This is the mains filter incase anybody is interested
http://www.triode-systems.com/modules/wfsection/article.php?articleid=3
http://www.triode-systems.com/modules/wfsection/article.php?articleid=3
pburke said:
Nothing if you have money to burn. I pretty well have to sell my amp now as a bunch of parts in a box.
Your iso's will make a nice set of paper weights when we get to the truth of this.
Not to mention the filter can be built into the amp and sold with the unit. 😉
I still haven't come to trust ebay. When I want something I want it now, so I don't like the auction aspect at all, and the "Buy Now" prices are often rediculous, then you have to rely on some BS'd rating system to know if the seller is a worm or not? Not all that appealing to me, I guess if I could afford the risk it'd be different.
t. said:
So that's not a DC filter.
Time for some King Kong UCD style.
Regards,
Chris
Yes, I meant that exactly.
Or half that, even. In my case grounds are dirty and connect to neutral at the panel so I'd probably try the whole thing and blast not putting any circuitry in the neutral line, just build a good level of redundancy into it.
Or half that, even. In my case grounds are dirty and connect to neutral at the panel so I'd probably try the whole thing and blast not putting any circuitry in the neutral line, just build a good level of redundancy into it.
Classd4sure,
The CRDs which you refer to;are these T25/T26 on the 400AD module?These are unpopulated on the 2 modules I purchased in Feb but the 4 modules I purchased in Oct have components designated L1VND in place. I presume these must be CRDs?
Would welcome your comments please.
Regards,
Bob Lewis
The CRDs which you refer to;are these T25/T26 on the 400AD module?These are unpopulated on the 2 modules I purchased in Feb but the 4 modules I purchased in Oct have components designated L1VND in place. I presume these must be CRDs?
Would welcome your comments please.
Regards,
Bob Lewis
BOB LEWIS said:
Hi,
If memory serves that's their designation, was stated in another thread. I'd presume the same, nothing else they could be. Guess they're now included.... a bit late, but
Oh, about that DC filter, I'd do away with the MOV and use a TVS, MOV's degrade with each use.
Greets,
Chris
Bruno used fully discrete input buffers in his reference amp (see Hypex site under applications).
So i think it can be good mod. I have some time ago, when i made preamp using DACT stepped attenuator, thoughts to replace UCD input buffer by DACT CT101 preamp module.
http://www.dact.com/html/line_stages.html
I do not know if this will work well or not.
About separate supply.
Could this LC Audio low noise regulator be good enough to be used separate supply for UCD input buffer?
http://www.lcaudio.com/index.php?page=69
So i think it can be good mod. I have some time ago, when i made preamp using DACT stepped attenuator, thoughts to replace UCD input buffer by DACT CT101 preamp module.
http://www.dact.com/html/line_stages.html
I do not know if this will work well or not.
About separate supply.
Could this LC Audio low noise regulator be good enough to be used separate supply for UCD input buffer?
http://www.lcaudio.com/index.php?page=69
Pasi P said:
Hi Pasi,
The CT101 looks promising, provided that bandwidth is nicely flat.... maybe it looks too good considering there's no graphs or anything. Also it seems a lllllittle too pricy for my taste, when it looks like there's 5$ worth of components on it.
The LCaudio regulator looks interesting I'd think it's worth a try, supposedly that price includes a transformer, very reasonable I think.
Regards,
Chris
So some of the UCD's come with the CRD's and some don't, if theres anybody who has a couple of modules with them and a couple without is there any chance you could compare them and let us know the sound difference😉
Farnell in the UK sells them but theres a minimum order charge
Farnell in the UK sells them but theres a minimum order charge
classd4sure said:
The common now join together at the psu boards and just a single ground wire from each of them goes to each of the UCD modules
Out of interest I did try to connect the now single common of each of the psu boards together but it was better when they was separate
I know I said it twice already but thanks 😀
I'll try the DC filter later, my transformers are dead silent, no buz etc which according to from what I've read means I don't have a DC problem with the torroidals but I'll try it anyway
Hi,
I'd imagine they all come with them now, no kidding, I'm bitting my words here, trying hard too! Um, anyway, there's a few other things different on the latest modules as well which would also affect the sound, like the change of filter caps, so a direct A/B with one wouldn't tell the full story on that mod in particular.
Digikey deals with the UK don't they? I know they have the CRD which JP recommended and I'd think it must be better than the formelly mentioned J511.
"The common now join together at the psu boards and just a single ground wire from each of them goes to each of the UCD modules
Out of interest I did try to connect the now single common of each of the psu boards together but it was better when they was separate
I know I said it twice already but thanks"
That's awesome, thank you. I'm a tad confused by that though, I guess you tried connecting the commons at the modules as well as at the PCU? The point is both to force them to share the same reference, for which I tap the common at a single point, like in the middle of that common link, otherwise it kills the soundstage, and also to not form any loops, or any big ones, which will modulate the reference and muddy things up.
That common reference point should also be as clean as possible. Even more importantly it should be at the input stage only.
Therefore, I'd think fully isolated from one another would be even better, as well as floating from the chassis/ earth, with the only common point they share being a single one formed where the shields earth to the chassis where you'd connect your signal grounds. If you try that you'd probably be
with a little
So, what kind of change did you perceive with just that little change at the cost of a wire or two? Was it a little one? Big one? Has it become musical? What happened to the soundstage?
That's the real question 🙂
"I'll try the DC filter later, my transformers are dead silent, no buz etc which according to from what I've read means I don't have a DC problem with the torroidals but I'll try it anyway"
Cool! You likely do have some DC on your line, having no buzz just means you've a good transformer or it's not high enough to affect it in an obvious manner. My transformer doesn't buz either but DC is rather high. It's got mu metal wrapping and an epoxy filled center. I've little doubt removing the DC would improve the sound though, looking forward to your results.
Regards,
Chris
I'd imagine they all come with them now, no kidding, I'm bitting my words here, trying hard too! Um, anyway, there's a few other things different on the latest modules as well which would also affect the sound, like the change of filter caps, so a direct A/B with one wouldn't tell the full story on that mod in particular.
Digikey deals with the UK don't they? I know they have the CRD which JP recommended and I'd think it must be better than the formelly mentioned J511.
"The common now join together at the psu boards and just a single ground wire from each of them goes to each of the UCD modules
Out of interest I did try to connect the now single common of each of the psu boards together but it was better when they was separate
I know I said it twice already but thanks"
That's awesome, thank you. I'm a tad confused by that though, I guess you tried connecting the commons at the modules as well as at the PCU? The point is both to force them to share the same reference, for which I tap the common at a single point, like in the middle of that common link, otherwise it kills the soundstage, and also to not form any loops, or any big ones, which will modulate the reference and muddy things up.
That common reference point should also be as clean as possible. Even more importantly it should be at the input stage only.
Therefore, I'd think fully isolated from one another would be even better, as well as floating from the chassis/ earth, with the only common point they share being a single one formed where the shields earth to the chassis where you'd connect your signal grounds. If you try that you'd probably be
with a little So, what kind of change did you perceive with just that little change at the cost of a wire or two? Was it a little one? Big one? Has it become musical? What happened to the soundstage?
That's the real question 🙂
"I'll try the DC filter later, my transformers are dead silent, no buz etc which according to from what I've read means I don't have a DC problem with the torroidals but I'll try it anyway"
Cool! You likely do have some DC on your line, having no buzz just means you've a good transformer or it's not high enough to affect it in an obvious manner. My transformer doesn't buz either but DC is rather high. It's got mu metal wrapping and an epoxy filled center. I've little doubt removing the DC would improve the sound though, looking forward to your results.
Regards,
Chris
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