classd4sure said:
I meant to say 47nF + 100R and maybe // to 22nF.
I skipped the 22nF.
Could be imagination but I've played a several rather complex pieces (Telarc/Hans Zimmer junk) along with a few old favorites so far, and who knows how long it'll take the new caps to break in... but it's more dynamic than ever. Micro-detail seems to have gotten a finely honed edge, to the point that each and every instrument in full orchestral pieces have a clearly defined voice and distinct presence.
Then there's the unexpected.
On top of that it seems everything else that was good before got even better, with a whole new sense of power and dynamic range... could that be? I wish I could measure it and see what happened, but this can't have been a bad thing, seems I lucked out with this "what I had kicking around" combo!
BTW I installed them right at the rectifiers as close to the pins as possible. The caps are Digikey # 495-1614-ND
47nF 275Vac X2 rated EMI suppression cap... (might not need a resistor??)
The resistor is a standard ceramic 100R .5 watt.
Anyway,
!!!!!!!!!
Chris,
Glad it worked so well.
Just a couple of comments. Going blind, no scope, I'd avoid using a parallel cap unless you plan to spend alot more on the snubber. The reason is that you lower the resonance of the ring, and thus need a much larger cap in the RC part. Like 10 to 50uF. The resistor will also need to get smaller, and thus higher power. It gets painful fast.
A note to all you snubber types out there. there is no penalty for making the cap larger. Make it a 1 or 2 uF's if you like. It reaches a point of diminishing return. You could also just do a resistor.
Chris, if you care to do anything, you might want to go to 47 ohms and try it.
As for what good are sims for this. There as perfect as the model
One thing I noted while doing the sim and taking some measurements of leakage on a transformer is in the real world, you don' t know what that inductance really is. You might know the leakage inductance to 1%, but the line inductance figures in too.
So, you could put a X cap on the primary. Thought of that. Then you know the leakage inductance quite well. This will have some affect on the optimal snubber though.
I bought some 1uF X caps but haven't tried them yet.
Bottom line. Use an Xcap on the primary. Use a big cap in the RC because to small can cause issues and too big only becomes a problem for resistor power dissipation. I'd go at least 470nF.
Then the resistor should likely fall in the range of 33R to 200R I'd estimate.
If you just have a cap, what you get is a ring that just goes on the whole cycle. I wouldn't do that, but hey, maybe it will sound good
By the way, I wired up a chassis with dual bridges and IE core transformers and two UcD's running out of phase. Like you have (only a toriod). The bridges are nothing fancy, 50A plane old recovery types. Not a stitch of humm out of the box!
Sounds better. Much better low end. More of a difference than bypass caps make for sure. No downside. I hate to admit that I sealed it up before snubbing the bridges, which likely really could use it too.
Mike
Hi Mike,
I agree with you and I've no plans at all to mess with this snubber any further without doing it right... envolving a scope that I don't have.
As a blind value guess I'm indeed exctatic with the results... near magical.
I'd actually go as low as 10 ohms on the resistors, but these little carbon ones are a half watt.. what I have, seems to work.
I do have a 470nF reserved for the primary ... as an X cap. I'm not sure about the size of it but it's just for HF.
No plans to install it yet though, can wait until I have a soft start circuit ready to go in.
Glad to hear of the success with the dual bridge method, do you give credit for the improved bass to the dual bridges or the out of phase wiring? Really I found little difference from a normal stereo setup to out of phase, was no downside to going out of phase either, and you know it's reinforcing the bass, maybe not audibly though. I left it like that
Best regards,
Chris
I agree with you and I've no plans at all to mess with this snubber any further without doing it right... envolving a scope that I don't have.
As a blind value guess I'm indeed exctatic with the results... near magical.
I'd actually go as low as 10 ohms on the resistors, but these little carbon ones are a half watt.. what I have, seems to work.
I do have a 470nF reserved for the primary ... as an X cap. I'm not sure about the size of it but it's just for HF.
No plans to install it yet though, can wait until I have a soft start circuit ready to go in.
Glad to hear of the success with the dual bridge method, do you give credit for the improved bass to the dual bridges or the out of phase wiring? Really I found little difference from a normal stereo setup to out of phase, was no downside to going out of phase either, and you know it's reinforcing the bass, maybe not audibly though. I left it like that
Best regards,
Chris
classd4sure said:Hi Mike,
I agree with you and I've no plans at all to mess with this snubber any further without doing it right... envolving a scope that I don't have.
As a blind value guess I'm indeed exctatic with the results... near magical.
I'd actually go as low as 10 ohms on the resistors, but these little carbon ones are a half watt.. what I have, seems to work.
I do have a 470nF reserved for the primary ... as an X cap. I'm not sure about the size of it but it's just for HF.
No plans to install it yet though, can wait until I have a soft start circuit ready to go in.
Glad to hear of the success with the dual bridge method, do you give credit for the improved bass to the dual bridges or the out of phase wiring? Really I found little difference from a normal stereo setup to out of phase, was no downside to going out of phase either, and you know it's reinforcing the bass, maybe not audibly though. I left it like that
Best regards,
Chris
10 ohms is a bit low unless the resonance is quite low and won't damp much. I wouldn't waste my time there unless going to 47 and 22 was was showing improvement.
Not sure about what causes the bass improvement. I doubt its the out of phase thing. I only had 12000uF per rail, so I decided it would be a good idea since that's kind of at the edge of the recommended values.
I also wouldn't rule out that its the bridge diodes, AND the caps are different. The chassis is a Denon PMA2000 Mark IV. The caps are I suspect audio grade, whatever that means, as are the transformers.
the only bummer in it was I managed to much up the preamp in the integrated amp I put them in. Not enough time to fix it yet.
I didn't have an up to date schematic and was attempting to power the UcD's from a seperate regulated +/-12V.
Nothing that removing like 50 scews can't start to solve though
by the way, did you ever not have the xsys 68A bridges in your amps? Was it the only thing that changed or did you do the 4 poles at the same time.
Just trying to determine what things are for sure improvements. Its always so much easier to shot gun lots of changes at once even though it clouds what each element adds.
Mike
Hi Mike,
My setup has been through many variations as I started with what I thought would be "the worst" and kept moving on.
I didn't do it all scientifically though as many things have enough obvious reasons to be considered improvements there's simply no need to.
A good example of that would in fact be the power supply upgrades.
For instance I'd originally started with 10 000uF Cerafines with a single ordinary ~25A bridge rectifier that I ripped out of my old pioneer receiver.
From there I went to 10 000uF BHC T-networks caps with the dual IXYS 68 amp FRED bridges.
From there I jumped up to two 15 000uF Jensen 4 poles in // per rail.
Modules were wired bi-phase since the first rendition, at which time I'd tried that both common stereo and bi-phase back and forth a few times.
So I'm afraid I can't tell you what kind of difference to expect with better bridges, suffices to say the soft recovery properties will help, and two are better than one by far. "T" found a big improvement with using them.
I think the better bass you're getting is very likely from the dual rectifiers and also yes the types of caps make a gigantic night/day kind of difference.
If you really want a kick, give the 4 poles a try, either Jensen of BHC.. likely being better as they also have the slit foil technology. The sound is fast, detailed, holographic and musical with them.
Worth every penny!
My setup has been through many variations as I started with what I thought would be "the worst" and kept moving on.
I didn't do it all scientifically though as many things have enough obvious reasons to be considered improvements there's simply no need to.
A good example of that would in fact be the power supply upgrades.
For instance I'd originally started with 10 000uF Cerafines with a single ordinary ~25A bridge rectifier that I ripped out of my old pioneer receiver.
From there I went to 10 000uF BHC T-networks caps with the dual IXYS 68 amp FRED bridges.
From there I jumped up to two 15 000uF Jensen 4 poles in // per rail.
Modules were wired bi-phase since the first rendition, at which time I'd tried that both common stereo and bi-phase back and forth a few times.
So I'm afraid I can't tell you what kind of difference to expect with better bridges, suffices to say the soft recovery properties will help, and two are better than one by far. "T" found a big improvement with using them.
I think the better bass you're getting is very likely from the dual rectifiers and also yes the types of caps make a gigantic night/day kind of difference.
If you really want a kick, give the 4 poles a try, either Jensen of BHC.. likely being better as they also have the slit foil technology. The sound is fast, detailed, holographic and musical with them.
Worth every penny!
classd4sure said:
Chris,
I've been pondering the 4 poles. Why did you switch from the BHC's? Just more cap?
I actually got a good value price for buying a case of the T caps.
I haven't pulled the trigger yet though.
I will eventually go to the fast soft bridges..... I think. I've heard that ordinary bridges aren't all that bad if snubbed correctly, but fast soft must be better.
I listened a lunch to my latest dual bridge amp. It is way way better at staging and more dynamic too. To many things to know what is the cause unfortunately.
I must say I think changing out bypass caps is a waste and even the wima dual 0.33uF's didn't make as big a difference as the new chassis. Go figure. Its got more of the dynamics I'm craving, but I haven't tried the most demanding music for that yet.
I plan to try the "charge coupled" filter cap concept I mentioned awhile back too. I've got some good caps for the purpose, just haven't gotten the time yet to try it.
Best Regards,
Mike
Well I went Jensen 4 poles because I could order them locally from partsconnexion, mainly on the gamble that it was the "4 pole" aspect that made the biggest difference in sound over the slit foil, and I wasn't dissapointed.
I needed the extra capacitance and decided to not mix caps.
I find dynamics incredible now but would still like more air on the high end. I know it's there, just need to bring it out a little more. Might shorten my speaker wires a little...... maybe.
I needed the extra capacitance and decided to not mix caps.
I find dynamics incredible now but would still like more air on the high end. I know it's there, just need to bring it out a little more. Might shorten my speaker wires a little...... maybe.
classd4sure said:
You should try some silver plated speaker wire. It adds what seems to be 3dB of mids and highs, and they are clearer and more detailed. The bass tightened too. That's my finding although I haven't bothered with anything but that wire for along time becuase the results were so stunning.
Carol makes a version that is not that expensive. I think its not even a buck a foot. If you need a link, I can dig one up.
Mike
How stupid can I be?
...don't answer!
Finally I had the time and guts to try the upgrade that Mike and Chris recommended: totally separate dual secondaries (dual-phase?) for my UCD 400 (see post #239), plus dubling capacitance from 20mF to 40mF per monoblock, Epcos Sikorel (100V). Also, I disconnected XLR's pin 1 from chassis. Everything is floating.
It is very congested inside: 2.5'' wide caps. I had to form a V with them. Anyway they prob. protect better from noise this way.
Appart that my balanced power filter is devoid of C and L to later test each component's effect.
The sound became more punchy, with better midbass, more flesh (or meat, as you say ) . There's more solidity to images. I should have done this long ago.
For now, I find that the sound is a little dirthy and lost some elegance. I will allow for more cap brake-in before I start to mod the power filter. Maybe I miss the enhanced clarity that the filter gives.
Dear Rha61:
Months ago you recommended CLC configuration as the best for Sikorel PS: can I abuse of your kindness and ask for specific L unit(s) that would fit?? Any link?
I remember you recommended something like 4mH (with 0R5). I am unable to pick the right item
(ethernal beginner)
Gratefully yours...
Mauricio
...don't answer!
Finally I had the time and guts to try the upgrade that Mike and Chris recommended: totally separate dual secondaries (dual-phase?) for my UCD 400 (see post #239), plus dubling capacitance from 20mF to 40mF per monoblock, Epcos Sikorel (100V). Also, I disconnected XLR's pin 1 from chassis. Everything is floating.
It is very congested inside: 2.5'' wide caps. I had to form a V with them. Anyway they prob. protect better from noise this way.
Appart that my balanced power filter is devoid of C and L to later test each component's effect.
The sound became more punchy, with better midbass, more flesh (or meat, as you say
) . There's more solidity to images. I should have done this long ago. For now, I find that the sound is a little dirthy and lost some elegance. I will allow for more cap brake-in before I start to mod the power filter. Maybe I miss the enhanced clarity that the filter gives.
Dear Rha61:
Months ago you recommended CLC configuration as the best for Sikorel PS: can I abuse of your kindness and ask for specific L unit(s) that would fit?? Any link?
I remember you recommended something like 4mH (with 0R5). I am unable to pick the right item
(ethernal beginner)Gratefully yours...
Mauricio
Interesting reading and thanks for the info.
I do have a few questions in regard to placing a cap & resistor network across each of the two secondaries.
1. Are the best values to try .47uf cap & 47 ohm resistor?
2. When you say a .47uf cap + 47 ohm resistor across each secondary, are you saying insert the cap & resistor end to end as in series (not parallel)?
3. if 1 & 2 are correct above, I do want to try this. I have on hand several .22uf caps. would there be any harm if I parallel two of these .22uf caps together to make a total of .42uf?
Thanks in advance.
I do have a few questions in regard to placing a cap & resistor network across each of the two secondaries.
1. Are the best values to try .47uf cap & 47 ohm resistor?
2. When you say a .47uf cap + 47 ohm resistor across each secondary, are you saying insert the cap & resistor end to end as in series (not parallel)?
3. if 1 & 2 are correct above, I do want to try this. I have on hand several .22uf caps. would there be any harm if I parallel two of these .22uf caps together to make a total of .42uf?
Thanks in advance.
Stevenacnj said:
First off, 47ohm and .47u are values that seemed to work with a toriod I tested. From simulation results, there is no harm is overkilling the cap, Bigger, until the resistor starts to get hot.
47 ohms is a good median value. Less resistance may require a bigger cap to be optimal. More resistance can also be tried, but values much over 200 ohms I don't think will damp enough.
Bottom line, 0.47uF and 47 ohms is a good start.
Yes, in series, end to end.
I would NOT put any cap right accross the AC secondaries unless you have a scope to verify the results.
maxlorenz said:Need help from the BIG Brothers
As I said, I got everything on the UCD floating, SAFE... the ON-pin, wich is connected to chassis through a toggle switch.
Wouldn't it be better to connect the ON-pin to the module's own ground pin???
Thanks
Mauricio
Mauricio,
Not sure what you got. Connecting the /on pin to chassis ground when nothing else is connected seems not to be a good idea.
I'd tie it to your PS ground.
Also, in a recent excersice with great results, I put two UcD's in a single chassis sharing the ps rails. I used dual bridge split secondary type configuration.
The inputs were single ended, as my life is still religated to this.
I didn't bother to connect the input ground to anything.
inputs were wired out of phase on one channel as were the speaker outputs.
Ground of the power supply is tied to chassis. It works better than a total float in the other monoblocks I have, but.... there are lots of differnces.
I could not bring myself to connect the ground inputs to anything since the boards were already connected to something and this would make ground loops.
So, there may be other ways to do it with good results.
Amps are still dead quiet and have zero hum. Stage in this stereo amp is better than monoblocks floating using center tap transformers.
I doubt I answered your question
Best Regards,
Mike
Dear Mike:
On the contrary...
...that helped. I fear my chassis could be an antenna like it is now.
JP? Bruno?
That is interesting (I remember perhaps Chris did the same). A little drawing for us,
Did you get better bass or more depth???
Agree. And some more ways to do it bad also
A thousand thanks
M
On the contrary...
...that helped. I fear my chassis could be an antenna like it is now.
JP? Bruno?
That is interesting (I remember perhaps Chris did the same). A little drawing for us,
Did you get better bass or more depth???
Agree. And some more ways to do it bad also
A thousand thanks
M
maxlorenz said:Dear Mike:
On the contrary...
...that helped. I fear my chassis could be an antenna like it is now.
JP? Bruno?
That is interesting (I remember perhaps Chris did the same). A little drawing for us,
Did you get better bass or more depth???
Agree. And some more ways to do it bad also
A thousand thanks
M
classd4sure said:
Chris,
I am fan of yours for sure! You've been very helpful to me.
We just don't always agree on.... what might be worth trying.
I think that sums it up. I'm always up for a suprise!
Mauricio,
Pictures are hard.
an example would be as follows.
Wire the right amp like this:
RAmp +in to Right +in (XLR),
RAmp -in to Right -in,
Amp output+ to +out (binding post to speakers)
Amp output GND to -out
for the left:
LAmp +in to Left -in,
LAmp -in to Left -in,
Amp output+ to -out
Amp output GND to +out
Thus, the two amps, when driven by the typical mostly mono bass music signal, are out of phase, each drawing and pumping from different supplies.
I think it can help more than it can hurt, but don't know if its anything major. I suspect my benifits are the other stuff rather than this in my latest chassis, but if you don't have big bypass caps, which I didn't, then it does help in sub 120Hz input pumping issues.
I think Chris said it was not a big difference, but couldn't hurt.
Since you seem to have lots of time to try stuff, and this doesn't require any break in, give it a listen by itself and see what you get. I'd like to hear your comments on sound.
I didn't bother trying it the other way, "in phase" as this is an ancient trick for power amps. NAD, to name one, was doing this almost from the beginning. They had to invert an input to accomplish it. Since the UcD is a true diff amp front end, we don't need that potential penalty. Seems like a good thing.
As for your floating chassis. Do you ground your chassis to earth ground?
None of my equipement has an earth ground, thus you really do want to tie the chassis to something by my thinking. My house doesn't have grounded recepticles in most places!
I noticed no difference at all having my supply grounded to the chassis or totally floating (lacking an earth ground).
I think if you have earth grounded equipement, it opens up potential problems by providing a second path for ground currents to flow. If its floating from earth, I don't imagine problems unless you've got lots of stray magnetic fields, and can imagine some shielding issues as you mentioned.
Bruno also commented somewhere that grounding the XLR ground directly to the chassis was a good thing, right at the connector entrance. This makes good sense from a shielding standpoint.
Hope this helps.
Mike
Dear Mike:
He, he are you kidding!!
I see now. I was mistaken as I thought it involved somehow the PS rails also
Currently my stereo amps run on an active system, so a pair of UCD180 with 44mF, BHC cans, for PS, feed the sensitive pro woofers (and my new 15'' coaxials, wich are are even more sensitive, are almost here ) . Maybe this trick won't help here 
If I decide to return to passive CX, I will surelly try it.
I even bought "american type" AC receptacles. Local units s***s!
Best regards
M
He, he
are you kidding!!I see now. I was mistaken as I thought it involved somehow the PS rails also
Currently my stereo amps run on an active system, so a pair of UCD180 with 44mF, BHC cans, for PS, feed the sensitive pro woofers (and my new 15'' coaxials, wich are are even more sensitive, are almost here
) . Maybe this trick won't help here If I decide to return to passive CX, I will surelly try it.
Yes. I fear an accident without it.
I even bought "american type" AC receptacles. Local units s***s!
I think this depends on your whole setup. The last time I lifted this connection I heard less noise.
Best regards
M
maxlorenz said:Dear Mike:
I even bought "american type" AC receptacles. Local units s***s!
Best regards
M
Yeah, I recently moved from a 100 year old victorian mansion that I had rewired totally. Had a few home runs for audio.
Now, in my 60's construction home, I get 200ft douglas firs to look at, but the wiring is totally wacked.
One of these days, my big audio tweak home wire related.
I've been looking for a line conditioner, like a sola CVS or MCR.
The MCR's look to be better for noise reduction and still provide 3% regulation. That, and perhaps a isolated earth ground out to the garden. (Earth ground really gets wacked with typical home loads)
The issue I have with the line conditioners is that "K factor" spec.
For a "electronic load" its 20 X the VA rating of the device.
Still thinking about your technically balanced thing too. Don't have my brain around that yet. I'd also like to find some big high voltage bipolars for a line conditioner. I do have a 100uF 160V one, but don't know the make or model to buy more
Easy enough to do, and I have some transformers that are almost right. So much to try, so little time.
Also been trying to get a big 500VA+ R core, but I've found no off the shelf units.
And I still don't have my JBL4343 grills done for child proofing.
I'll likely be talking about all this a year from now as "things to do".
Mike
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