Re: Re: Re: Re: Re: Re: Re: Re: Snubber circuit for free!
I think I'll just stick with it hardwired and not bother with a pcb, I was hoping to get idea's from people off here for a decent psu which I could draw out, convert it to pdf and post the files on the forum so anybody could etch their own
BWRX said:
I think I'll just stick with it hardwired and not bother with a pcb, I was hoping to get idea's from people off here for a decent psu which I could draw out, convert it to pdf and post the files on the forum so anybody could etch their own
Re: Re: Re: Re: Re: Re: Re: Snubber circuit for free!
Ray,
Sorry to say, I haven't done it yet. Got LM6172's though. Playing with the bias current issues. Got side tracked on another amp build too. I also have to get my amps back to more or less stock.
I've also been playing around with a very simple discrete diff amp that only uses 5 transistors and simulates very good distortion. That might take the front seat over the 6172, but perhaps I should do this first since its pretty easy.
It should be easy enough to do but I've accepted the fact, that at least in my system were the preamp has offset (simple npn follower) its going to need AC coupling of both inputs. Haven't got the AC coupling caps yet.
t,
You got it!. 🙂 Make the triangle cut come down right to the cap pad, so it needs to move a bit to the left, and get deeper. Hope you can use at least 3 oz copper on this!
In regards to the other kind comment, yes, it adds inductance, but it is a way to use parasitics to your advantage, much in the same way a 4 pole Cap works.
Mike
ray bronk said:
t. said:
Ray,
Sorry to say, I haven't done it yet. Got LM6172's though. Playing with the bias current issues. Got side tracked on another amp build too. I also have to get my amps back to more or less stock.
I've also been playing around with a very simple discrete diff amp that only uses 5 transistors and simulates very good distortion. That might take the front seat over the 6172, but perhaps I should do this first since its pretty easy.
It should be easy enough to do but I've accepted the fact, that at least in my system were the preamp has offset (simple npn follower) its going to need AC coupling of both inputs. Haven't got the AC coupling caps yet.
t,
You got it!. 🙂 Make the triangle cut come down right to the cap pad, so it needs to move a bit to the left, and get deeper. Hope you can use at least 3 oz copper on this!
In regards to the other kind comment, yes, it adds inductance, but it is a way to use parasitics to your advantage, much in the same way a 4 pole Cap works.
Mike
Supply cap recommendations
Hi all,
Taking Chris's advice and making a ground up open chassis for R&E (research and enjoyment) 🙂
I thought I'd outright ask what people are happy with for main supply caps for a monoblock UcD400.
Any "how they sound compared to.... would be great.
Also, how much cap you used, blah blah.... want as much data as I can get.
I'm not cost constraining myself to much on this.
On my list are:
Jensen 4 poles
BNC T caps
Elna Cerifine, which I read bruno thought were okay.
Massive bank of small caps, maybe Panasonic M series.
Any recommendations for smallish 470~2000uF and not necessarily just low ESR,good sounding 63~80V caps would be great.
Any others?
I'm in the US, so would really like to keep it N. America, but I"m open to anything.
Also, as long as I"m at it, What transformers are there that are deem'd good IYO. I"m thinking 400~700VA range.
My list includes:
Toriods:
Piltron (Should I get the shield?)
Avel
Antek (The guy on ebay that has some ones that look nice and very under rated)
Any good source for IE cores.
Any good sources for R cores.
THanks in advance
Mike
p.s. If you have any sonic comparisons, I'd be quite interested.
Hi all,
Taking Chris's advice and making a ground up open chassis for R&E (research and enjoyment) 🙂
I thought I'd outright ask what people are happy with for main supply caps for a monoblock UcD400.
Any "how they sound compared to.... would be great.
Also, how much cap you used, blah blah.... want as much data as I can get.
I'm not cost constraining myself to much on this.
On my list are:
Jensen 4 poles
BNC T caps
Elna Cerifine, which I read bruno thought were okay.
Massive bank of small caps, maybe Panasonic M series.
Any recommendations for smallish 470~2000uF and not necessarily just low ESR,good sounding 63~80V caps would be great.
Any others?
I'm in the US, so would really like to keep it N. America, but I"m open to anything.
Also, as long as I"m at it, What transformers are there that are deem'd good IYO. I"m thinking 400~700VA range.
My list includes:
Toriods:
Piltron (Should I get the shield?)
Avel
Antek (The guy on ebay that has some ones that look nice and very under rated)
Any good source for IE cores.
Any good sources for R cores.
THanks in advance
Mike
p.s. If you have any sonic comparisons, I'd be quite interested.
nasty?
Hi,
@t: no reason to send nasty smilies! Just gave You an answer to Your q.
I´d say to reduce the inductance place the hot traces and ground places very close to each other. Inductance is a function of circumfered area, so try to make the area small. Additionally I´d use several smaller traces connected in parallel instead of just one big trace.
Let the Trace point towards a solder point of a cap and not a small part of the trace just leaving the main trace perpendicular this
Another trick might be to etch capacitors into the board itself.
jauu
Calvin
Hi,
@t: no reason to send nasty smilies! Just gave You an answer to Your q.
I´d say to reduce the inductance place the hot traces and ground places very close to each other. Inductance is a function of circumfered area, so try to make the area small. Additionally I´d use several smaller traces connected in parallel instead of just one big trace.
Let the Trace point towards a solder point of a cap and not a small part of the trace just leaving the main trace perpendicular this
Another trick might be to etch capacitors into the board itself.
jauu
Calvin
Re: nasty?
Calvin,
You are correct in your technique, but your optimizing something that is arguably a negative thing. I don't think we want a wide band HF path thru/to the filter caps when your trying to filter out high frequencies?
How your tying into the cap pads is perfect! I think your layout would be fine too btw, just not really better. Thanks for showing another good way.
Board capacitance is very effective, but typically you need to do it with the parallel planes. I'd guess your cap traces are on the order of a few pF. That technique is used in IC layout, but the scale is much smaller.
Best Regards,
Mike 🙂
Calvin said:
Calvin,
You are correct in your technique, but your optimizing something that is arguably a negative thing. I don't think we want a wide band HF path thru/to the filter caps when your trying to filter out high frequencies?
How your tying into the cap pads is perfect! I think your layout would be fine too btw, just not really better. Thanks for showing another good way.
Board capacitance is very effective, but typically you need to do it with the parallel planes. I'd guess your cap traces are on the order of a few pF. That technique is used in IC layout, but the scale is much smaller.
Best Regards,
Mike 🙂
Re: Re: Re: Re: Re: Re: Re: Re: Snubber circuit for free!
Thank you Mike, I'll try and slightly alter the triangle cut, if theres anything else you can think of that would be great🙂
Just thought it would have been nice to post an easy to etch psu for anybody to try out
Portlandmike said:
Thank you Mike, I'll try and slightly alter the triangle cut, if theres anything else you can think of that would be great🙂
Just thought it would have been nice to post an easy to etch psu for anybody to try out
Re: nasty?
Hi Calvin,
I am sorry, I didn't mean to come across as being nasty🙂
We are all friends on here so any opinions are appreciated, it would have been nice to have seen something like what you would recommend is better though.
Thank you for your board layout
Calvin said:
Hi Calvin,
I am sorry, I didn't mean to come across as being nasty🙂
We are all friends on here so any opinions are appreciated, it would have been nice to have seen something like what you would recommend is better though.
Thank you for your board layout
Re: Supply cap recommendations
I'm of the belief that with some extra nursing even industrial type caps (of proper selection) will perform adequatly to say the least.
I haven't proven that concept in practice though, since I lack the equipment to do it right. What I opted instead to do was go for what I trust won't require the extra nursing, and that is 4 pole caps. I can swear by their effortless dynamics and punch, there's no going wrong with them, either BHC or Jensen.
Cerefines are certainly nice, but it's kind of like having FC decoupling caps, in that they lack the air, only are more neutral than FC by far.
At this stage of the game, my advice would be to pick what looks good on paper for a supply and stick with it, working out all the grounding issues as I'm sure you'll be OK with, get it to sound as good as it can, and then move on from there.
Plitron... I haven't tried a transformer after transformer, too damned expensive a component to play with. I went with plitron not because said voodoo review swore by it, but because they're located closest to me and therefore have cheaper shipping.
Aside from that they're a total rip off with their prices.
I used their plain jane power supply grade transformer with the added options of a static screen and mu shielding.. do what you like. I don't feel it's a necessity with the UCD modules, but obviously, it wont' hurt. Though I dont' forget Eva's warning about the static screen, all I know is once you have it, you have no option but to ground it, and it works OK for me.
I'd avoid their audio line at all cost, given the prices and its' simply unecessary for a good sound.
Give yourself a healthy set of rectifiers for a change, it won't hurt.
Of all things I've tried, layout is what makes it musical and dynamic in the end, the parts will add to that, but won't make up for it.
Some changes even seem good at first but tiring in the long run, those are tricky, so it's worthwhile having this kind of test jig until you have it all sorted out.
OT:
To anyone with an open mind or a love of metal, the new tool album 10 000 days is a wicked one for testing.
Cheers,
Chris
Portlandmike said:
I'm of the belief that with some extra nursing even industrial type caps (of proper selection) will perform adequatly to say the least.
I haven't proven that concept in practice though, since I lack the equipment to do it right. What I opted instead to do was go for what I trust won't require the extra nursing, and that is 4 pole caps. I can swear by their effortless dynamics and punch, there's no going wrong with them, either BHC or Jensen.
Cerefines are certainly nice, but it's kind of like having FC decoupling caps, in that they lack the air, only are more neutral than FC by far.
At this stage of the game, my advice would be to pick what looks good on paper for a supply and stick with it, working out all the grounding issues as I'm sure you'll be OK with, get it to sound as good as it can, and then move on from there.
Plitron... I haven't tried a transformer after transformer, too damned expensive a component to play with. I went with plitron not because said voodoo review swore by it, but because they're located closest to me and therefore have cheaper shipping.
Aside from that they're a total rip off with their prices.
I used their plain jane power supply grade transformer with the added options of a static screen and mu shielding.. do what you like. I don't feel it's a necessity with the UCD modules, but obviously, it wont' hurt. Though I dont' forget Eva's warning about the static screen, all I know is once you have it, you have no option but to ground it, and it works OK for me.
I'd avoid their audio line at all cost, given the prices and its' simply unecessary for a good sound.
Give yourself a healthy set of rectifiers for a change, it won't hurt.
Of all things I've tried, layout is what makes it musical and dynamic in the end, the parts will add to that, but won't make up for it.
Some changes even seem good at first but tiring in the long run, those are tricky, so it's worthwhile having this kind of test jig until you have it all sorted out.
OT:
To anyone with an open mind or a love of metal, the new tool album 10 000 days is a wicked one for testing.
Cheers,
Chris
Re: Re: nasty?
What about making that PCB a double layer one with one side completely used as a ground plane and have the + and - rails at the other side? Would be a low resistance, low inductance path from terminals to caps. For people that want as low as possible series resistance and inductance, that should be the choice I think. In such case, it may also be good to use a large number of low series resistance caps in parallel, that would lower series resistance and inductance further. The rubycon ZL caps look nice for that (if you can get them). A bunch of Panasonic FCs maybe good as well although not that many people seem to be happy with them.
Gertjan
Portlandmike said:
What about making that PCB a double layer one with one side completely used as a ground plane and have the + and - rails at the other side? Would be a low resistance, low inductance path from terminals to caps. For people that want as low as possible series resistance and inductance, that should be the choice I think. In such case, it may also be good to use a large number of low series resistance caps in parallel, that would lower series resistance and inductance further. The rubycon ZL caps look nice for that (if you can get them). A bunch of Panasonic FCs maybe good as well although not that many people seem to be happy with them.
Gertjan
Re: Re: Re: nasty?
Gertjan,
I think you are correct in that a two, or even 4 layer board will give much very good HF bypass. then again, the ucd has an inductor in series, so to what advantage I don't know.
Mike
ghemink said:
Gertjan,
I think you are correct in that a two, or even 4 layer board will give much very good HF bypass. then again, the ucd has an inductor in series, so to what advantage I don't know.
Mike
I've bypassed the FC's with "quality" film caps, on one module only.
It seems to be a very minute difference, only to serve to remove some of the coloration of the FC caps, the "air" hasn't returned in any significant way, however it seems the treated module seems to come out of the speaker more whereas the other is nailed to it.
This has only served to further my disgust. Must change the FC... must find a quality 63V cap ....
It seems to be a very minute difference, only to serve to remove some of the coloration of the FC caps, the "air" hasn't returned in any significant way, however it seems the treated module seems to come out of the speaker more whereas the other is nailed to it.
This has only served to further my disgust. Must change the FC... must find a quality 63V cap ....
Hi, Well, you could try the FN series of the Panasonic caps. I've been told they sound better than the FC, but the voltage rating only goes up to 50V.
Ray
Ray
You mean FM series?
There's also the BC136 I think? Also only 50V. I'd like at least a 63V cap that. Besides some day I'll rob someone for UCD400's so ... maybe I should just find a 100V cap now?
It seems alot of good would be caps are only offered to 50V though.
There's also the BC136 I think? Also only 50V. I'd like at least a 63V cap that. Besides some day I'll rob someone for UCD400's so ... maybe I should just find a 100V cap now?
It seems alot of good would be caps are only offered to 50V though.
Hi Mike:
Sorry for the very late reply,
I've been "kooking" something big.
I'll post pics when I'm done...just to prove it. I know many of you think that maxlorenz doesn't exist
...or hasn't built anything at all 😀
Rha's advice for PS was: 10K//100-> 4nH->10K.
That's what he wrote. He stated a 0R5 resistance for that inductor.
I will try it, eventually, when time allows. I see t. also is worried by this.
I've been lazy with UCD amps.
Tried the snubber 47nF/47R at each PS rail for my UCD400 monos. Contrary to my guess it did make a significant change:
Totally changed the tonal balance to midrange/midbass, making the amp sound more "powerfull" but missing HF extension, detail and transparency wich are good points of Sikorel caps. It sounded slow. The warm midrange was appealing, though...
Maybe something like 10nf with less R will be OK.
Now I reference the "ON-PIN" to the module's own PS ground and these amps never sounded cleaner. PS is totally floating now.
My HF are still a bit brutal...but cleaner.
Many things to try: snubber from various sizes; X cap on primaries; snubber on secondaries; playing with power filter...etc...before I could feel like I can go for the separate opamp suply 🙁
I wonder what ALW is doing with his modules
About PS caps, maybe the advice from Chris is the best as those caps seem to have good HF behaviour.
Plitron is good.
Cheers
Mauricio
Sorry for the very late reply,
I've been "kooking" something big.
I'll post pics when I'm done...just to prove it. I know many of you think that maxlorenz doesn't exist
...or hasn't built anything at all 😀 Rha's advice for PS was: 10K//100-> 4nH->10K.
That's what he wrote. He stated a 0R5 resistance for that inductor.
I will try it, eventually, when time allows. I see t. also is worried by this.
I've been lazy with UCD amps.
Tried the snubber 47nF/47R at each PS rail for my UCD400 monos. Contrary to my guess it did make a significant change:
Totally changed the tonal balance to midrange/midbass, making the amp sound more "powerfull" but missing HF extension, detail and transparency wich are good points of Sikorel caps. It sounded slow. The warm midrange was appealing, though...
Maybe something like 10nf with less R will be OK.
Now I reference the "ON-PIN" to the module's own PS ground and these amps never sounded cleaner. PS is totally floating now.
My HF are still a bit brutal...but cleaner.
Many things to try: snubber from various sizes; X cap on primaries; snubber on secondaries; playing with power filter...etc...before I could feel like I can go for the separate opamp suply 🙁
I wonder what ALW is doing with his modules
About PS caps, maybe the advice from Chris is the best as those caps seem to have good HF behaviour.
Plitron is good.
Cheers
Mauricio
Hi Class for Sure, Yep, it's the FM Series. They're faster than the FC caps so I am told. Bummer, they only go up to 50V.
Ray
Ray
Re: Re: Re: Re: nasty?
Hi Mike,
Yes, the UcD has inductors in series, and thus only a very small amount of HF is coming out (and in) and indeed the speed with which current can be drawn from the main supply caps may actually be limited by those inductors. In that case, the 470uF caps on the UcD module itself are likely the most important caps to deal with for tweaking, although the experience of many people on this board suggests that the main power supply caps are very important as well.
Gertjan
Portlandmike said:
Hi Mike,
Yes, the UcD has inductors in series, and thus only a very small amount of HF is coming out (and in) and indeed the speed with which current can be drawn from the main supply caps may actually be limited by those inductors. In that case, the 470uF caps on the UcD module itself are likely the most important caps to deal with for tweaking, although the experience of many people on this board suggests that the main power supply caps are very important as well.
Gertjan
layout
Hi,
@Portlandmike: there is only one point in power supply filter where we would like to have some inductance. Thats in a pi-style filter with a relatively small capacitor followed by a series inductor and a second bigger capacitor (see attachement). But here we use a discrete component with low ohmic value (losses!) and high current capability.
The circuit itself should always see low impedances over its full working range at the supply lines -not only over the frequency range its output presents! Thats a quite often made mistake. Even though output bandwidth may be restricted to less than 100kHz, the supplies should best be blocked up into the MHz-range. The PowerSupplyRejectionRatio decreases to higher freqs, so the supply itself has to be clean, otherwise You´ll get interference and modulations.
So after the last capacitor in the main supply, there should be only very low ohmic and inductive values which means to hold the tracks/cables as short as possible and the associated inductance as small as possible. Thats the reason that every IC-manufacturer regards small decoupling caps as close to the IC as possible. You can even see that more and more ICs place their supply pins close to each other (DIP8, 5 and 6 e.g), while older models had them as far apart as possible (on a DIP8, Pins 4 and 7).
There is no need to use costly low ESR caps, when this is countered by a highly inductive layout or long supply cabling!
Using a double sided layout You can use one side for the hot supply lines and the other for ground. If these lines are placed over each other they form a capacitor, which is positive, because You may even need no additional discrete devices like film-Cs --which beside having some positive effect add size, weight, cost, complexity, and negative parasitic effects.
Regard the PCB rather as a component that interacts with the devices mounted on it and the circuits connected to it. Its not just a connection between devices A, B and C, but a device itself! Don´t throw money after best components when You counter their benefits with one bad component..the PCB
jauu
Calvin
Hi,
@Portlandmike: there is only one point in power supply filter where we would like to have some inductance. Thats in a pi-style filter with a relatively small capacitor followed by a series inductor and a second bigger capacitor (see attachement). But here we use a discrete component with low ohmic value (losses!) and high current capability.
The circuit itself should always see low impedances over its full working range at the supply lines -not only over the frequency range its output presents! Thats a quite often made mistake. Even though output bandwidth may be restricted to less than 100kHz, the supplies should best be blocked up into the MHz-range. The PowerSupplyRejectionRatio decreases to higher freqs, so the supply itself has to be clean, otherwise You´ll get interference and modulations.
So after the last capacitor in the main supply, there should be only very low ohmic and inductive values which means to hold the tracks/cables as short as possible and the associated inductance as small as possible. Thats the reason that every IC-manufacturer regards small decoupling caps as close to the IC as possible. You can even see that more and more ICs place their supply pins close to each other (DIP8, 5 and 6 e.g), while older models had them as far apart as possible (on a DIP8, Pins 4 and 7).
There is no need to use costly low ESR caps, when this is countered by a highly inductive layout or long supply cabling!
Using a double sided layout You can use one side for the hot supply lines and the other for ground. If these lines are placed over each other they form a capacitor, which is positive, because You may even need no additional discrete devices like film-Cs --which beside having some positive effect add size, weight, cost, complexity, and negative parasitic effects.
Regard the PCB rather as a component that interacts with the devices mounted on it and the circuits connected to it. Its not just a connection between devices A, B and C, but a device itself! Don´t throw money after best components when You counter their benefits with one bad component..the PCB
jauu
Calvin
Tweaking results
@All
Aside from all tweaking advice here, I got the best results
from:
1.) Grounding according to Hypex recommendations
(PSU floating)
2.) ON-Pin referenced to module ground
3.) CAT5 wire twisted, directly soldered to speaker terminal
4.) Shorter, heavier supply wires (twisted braided cable)
5.) Dual-mono, each module shielded in its own mini-enclosure
6.) Shielded signal cable (RG59)
7.) One module T-shape heatsink not connected to chassis
(decoupled) - I use a separate aluminium sheet
My PSU is on a double-sided PCB, +/- rails on one side,
back side is ground plane (like Gertjan's recommendation).
discrete HEXFREDS, 2x22.000uF SlitFoils per Rail.
So far this amp outperforms ANYTHING I've ever heard.
I also use Panasonic FCs to decouple PS inputs on UCD400
inputs. They initially seemed to have less resolution and treble but after
50-100 hours burn-in I start to like them better. But I actually
found that grounding and wiring has far greater
impact on the sound but your mileage may vary...
Next, I'll try WIMA's as filter caps.
Regards,
Mike
@All
Aside from all tweaking advice here, I got the best results
from:
1.) Grounding according to Hypex recommendations
(PSU floating)
2.) ON-Pin referenced to module ground
3.) CAT5 wire twisted, directly soldered to speaker terminal
4.) Shorter, heavier supply wires (twisted braided cable)
5.) Dual-mono, each module shielded in its own mini-enclosure
6.) Shielded signal cable (RG59)
7.) One module T-shape heatsink not connected to chassis
(decoupled) - I use a separate aluminium sheet
My PSU is on a double-sided PCB, +/- rails on one side,
back side is ground plane (like Gertjan's recommendation).
discrete HEXFREDS, 2x22.000uF SlitFoils per Rail.
So far this amp outperforms ANYTHING I've ever heard.
I also use Panasonic FCs to decouple PS inputs on UCD400
inputs. They initially seemed to have less resolution and treble but after
50-100 hours burn-in I start to like them better. But I actually
found that grounding and wiring has far greater
impact on the sound but your mileage may vary...
Next, I'll try WIMA's as filter caps.
Regards,
Mike
Mike,
What had you tried before having arrived at that particular combination? What improvements did you experience along the way?
By dual mono do you mean 2 xformers?
How did you connect your signal ground, I'm guessing you floated them, or there's little sense to #7, but even then I trust you drive them from the same source, so it fully decoupled and shielded front to back or what?
#7, can't see that being necessary, what extent did you go to to achieve isolation?
I submit to you that you simply got used to the FC, they do have less air and treble! Dramatically so. Also heavier coloration... depending on whatever your stock caps were, certainly was the case for me.
They took next to no time to burn in, few hours at most. Try your old caps back there and see if it's a burn in issue.
Wiring does have a huge impact, but it's a right or wrong thing, you know when you get it right.
Thanks for the info,
Chris
What had you tried before having arrived at that particular combination? What improvements did you experience along the way?
By dual mono do you mean 2 xformers?
How did you connect your signal ground, I'm guessing you floated them, or there's little sense to #7, but even then I trust you drive them from the same source, so it fully decoupled and shielded front to back or what?
#7, can't see that being necessary, what extent did you go to to achieve isolation?
I submit to you that you simply got used to the FC, they do have less air and treble! Dramatically so. Also heavier coloration... depending on whatever your stock caps were, certainly was the case for me.
They took next to no time to burn in, few hours at most. Try your old caps back there and see if it's a burn in issue.
Wiring does have a huge impact, but it's a right or wrong thing, you know when you get it right.
Thanks for the info,
Chris
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