I'm not risking it with the caps to be honest, the large computer grade types may be able to handle it but I've seen the effects when the smaller ones are pushed to their limit
I was also going to ask what are Lima caps😀
I was also going to ask what are Lima caps😀
Re: cap ratings
Ric,
I too have run caps close to their voltage rating, using regulated supplies of course and have no problems. (60 volts on 63volt caps) But I never get close to exceeding the ripple rating or temperature rating as these will definitely shorten the caps life. I would recommend caps of higher temp and ripple current rating to the point they become too large to fit.
Roger
Ric Schultz said:
Ric,
I too have run caps close to their voltage rating, using regulated supplies of course and have no problems. (60 volts on 63volt caps) But I never get close to exceeding the ripple rating or temperature rating as these will definitely shorten the caps life. I would recommend caps of higher temp and ripple current rating to the point they become too large to fit.
Roger
I have found a source for the 63v 1500uF Rubycon ZL caps that I was considering for my UCD power supply, but was pretty much convinced by Eva & others that a very low impedence supply for a class D amp is perhaps not a great idea.
Problem is the purchase minimum is 120 @ $3.70 USD ea. so maybe a group buy is in order as I have had lots of interested parties email me about purchasing. However being in Australia is not the best place to organise a world wide group purchase (due to postage costs) so maybe someone else in the US or the UK is interested in organising?
Regards,
Dean
Problem is the purchase minimum is 120 @ $3.70 USD ea. so maybe a group buy is in order as I have had lots of interested parties email me about purchasing. However being in Australia is not the best place to organise a world wide group purchase (due to postage costs) so maybe someone else in the US or the UK is interested in organising?
Regards,
Dean
Deanbob:
I'm with you 🙂 but what values are we talking about?
Will that be 470uF/100V for the modules' PS caps?
(since you seem to be abandoning the idea of using for main PS caps)
If that is the case I'll be very interested as my taxes refund check will soon arrive 😀
Regards
I'm with you 🙂 but what values are we talking about?
Will that be 470uF/100V for the modules' PS caps?
(since you seem to be abandoning the idea of using for main PS caps)
If that is the case I'll be very interested as my taxes refund check will soon arrive 😀
Regards
No, its the main PSU caps, 63v 1500uF. I may be able to ask for a certain order of 470uF 100v caps.
I have checked the datasheets, the problem may be that the Rubycons will be taller than the heatsink where the current caps are the same height. My UCD400 module has 85 degree caps 100v which is an interesting choice as the they are right next to the heatsink with no circulation, and when I was testing the amp for a short while with a small heatsink the caps got very hot. IMO a 63v 105 degree cap would be a better choice for heat and form factor (although the 100v 470uF caps have better ripple & impedence as expected in the larger form factor).
The datasheet for the caps are here:
http://www.rubycon.co.jp/en/catalog/e_pdfs/aluminum/e_ZL.pdf
Regards,
Dean
I have checked the datasheets, the problem may be that the Rubycons will be taller than the heatsink where the current caps are the same height. My UCD400 module has 85 degree caps 100v which is an interesting choice as the they are right next to the heatsink with no circulation, and when I was testing the amp for a short while with a small heatsink the caps got very hot. IMO a 63v 105 degree cap would be a better choice for heat and form factor (although the 100v 470uF caps have better ripple & impedence as expected in the larger form factor).
The datasheet for the caps are here:
http://www.rubycon.co.jp/en/catalog/e_pdfs/aluminum/e_ZL.pdf
Regards,
Dean
Hi Dean 🙂
That woud be very nice!
I hope some other member is interested as I can't buy 120 😉
I have plenty of room and my modules are put in vertical position appart the fact that I use a...(sorry J-K) ...copper foil...ahemm...for heatsinking the caps 😀 (radiation + convection)
There are 105ºC anyway.
Thanks for your interest.
Mauricio
That woud be very nice!
I hope some other member is interested as I can't buy 120 😉
I have plenty of room and my modules are put in vertical position appart the fact that I use a...(sorry J-K) ...copper foil...ahemm...for heatsinking the caps 😀 (radiation + convection)
There are 105ºC anyway.
Thanks for your interest.
Mauricio
Re: Re: Re: layout
Calvin,
I think we agree although the layout need not always be low inductance, for example, when its in series with an inductor.
In high frequency layout, which I've consulted for some years, parasitics are very important and exteemly usueful. One needs to use then to your advantage whenever you can.
Thanks for the schemaitc.
I can't speak for the other UcD's, but as of late the UcD400 use ferrites on board to isolate the main bypass caps from the input power filter. Thus... they have a pi filter with the main supply cap.
And, if you've put a scope on the board, its obvious these do an excellent job to passing audio range currents and stopping switching range currents.
Adding another one starts to sound like designing a filter, which was my point. Its a filter. Mind the passband and stop bands.
To low a bandwidth, and that current spike (where all the energy comes from btw, can't pass in full force.) Make it two wide a bandwidth, and you've got ton's of ripply.
I think the traditional method is to overkill the supply caps and let the transformer saturate, not good. If an inductor is going to help that, it needs to be about the size of the power transformer.
Mike
Hey Gertjan,
Me to on the SMPS. I've also been pondering the linear more and agree with your concusion on just using a cap multiplier.
It also is a elegant way not to blow up the transistor at power on 🙂
I spent some time trying to figure out if I could find a synchronous buck regulator up to the task and came up empty. Oh yeah, I think LTC has a 100V sync buck, forgot to check.
Off line seems like it would be a real pain given you need to sink current too. (ideally)
I'll tell you what I've been pondering.
Ideally, a synchonous buck would be good, since it could regulate the suppy for both sourcing and sinking.
Problem is there are not many out there that can handle ~75V input. (I pick that number, becuase with maximum duty cycles and decently high switching frequencies, I think you want at least that much headroom.)
Then I though, well, what if a guy did say a 50V traditional rail and put another rail stacked on top ( or bottom for that matter) with a buck reg on that rail.
I hope your getting my drift, becuase its wordy, but in affect, have a compliance range of say 10V on the buck reg and its output would be a cap accross the 50V rail.
Again, hope it makes sense.
I know, have seen, have played with several 30A buck regs that can run off 12 to 18V rails. Gotta check LTC though, I think they have a part if I recall.
Then I started thinking about just doing an A/B amp on a say 12V rail again in series with the main supply rail so it could regulate the final output cap voltage, and source and sink.
All these are complicated though, besides a good HV buck reg, which would be easiest by far.
Another thought is this. Use another UcD as a buck regulator!
Stick a huge cap on the output, maybe decoupled with 100mohms.
That for sure seems like the fast way to regulated supplies. A bit expensive, but if your times worth much, likely a bargin.
Mike
Found the beast:
http://www.linear.com/pc/downloadDocument.do?navId=H0,C1,C1003,C1042,C1032,C1082,P2427,D3366
Calvin said:Hi,
@Mike
"1) You want to pass 120Hz current spike to get power to the amp.
2) You want to attenuate HF stuff that the transformer is coupling or is created by the rectifiers.
3) You want to present the lowest possible impedance to the amp in relation to its PS inputs."
1) No, You don´t want any spike to get to the amp. 100/120Hz Spikes are hum, i.e. noise. Just simple and clean DC...nothing else is our wish
2) high-frequent noise generated by the rectifier should be treated right there...at the pins of the rectifier, using a RC-snubber, or at least some C-snubber.
3) Yes and thats the reason to use a low ohmic and inductive layout. The circuit likes to be powered by a voltage source -->ideally 0Ohms, 0mH output impedance. The Pi-Filter has the advantage that the relatively small first cap and the inductance filter spikes much better than just a cap. The stress on the rectifier and therefore the generated noise is lower because of lower loading currents. The cap at the PS-output serves as the power reservoire and the low impedance drive point for the circuit, therefore it can be built with big low ESR caps. Of course the PCB layout has to be a low ohmic and low inductive one.
"relitive to its ~1uH inductor on a UcD." Don´t know what You mean??? I´m not familiar with the actual implementation of the UcD (and sorry, no, having a low speed and quite costly internet connection I won´t read all 119 pages of just this thread to be updated)
So could You just explain which inductor You mean??? A circuit schemativ would be very helpful too. I´ve got this one, which is only showing the amp´s circuit (guess its the UcD180)
jauu
Calvin
Calvin,
I think we agree although the layout need not always be low inductance, for example, when its in series with an inductor.
In high frequency layout, which I've consulted for some years, parasitics are very important and exteemly usueful. One needs to use then to your advantage whenever you can.
Thanks for the schemaitc.
I can't speak for the other UcD's, but as of late the UcD400 use ferrites on board to isolate the main bypass caps from the input power filter. Thus... they have a pi filter with the main supply cap.
And, if you've put a scope on the board, its obvious these do an excellent job to passing audio range currents and stopping switching range currents.
Adding another one starts to sound like designing a filter, which was my point. Its a filter. Mind the passband and stop bands.
To low a bandwidth, and that current spike (where all the energy comes from btw, can't pass in full force.) Make it two wide a bandwidth, and you've got ton's of ripply.
I think the traditional method is to overkill the supply caps and let the transformer saturate, not good. If an inductor is going to help that, it needs to be about the size of the power transformer.
Mike
ghemink said:
Hey Gertjan,
Me to on the SMPS. I've also been pondering the linear more and agree with your concusion on just using a cap multiplier.
It also is a elegant way not to blow up the transistor at power on 🙂
I spent some time trying to figure out if I could find a synchronous buck regulator up to the task and came up empty. Oh yeah, I think LTC has a 100V sync buck, forgot to check.
Off line seems like it would be a real pain given you need to sink current too. (ideally)
I'll tell you what I've been pondering.
Ideally, a synchonous buck would be good, since it could regulate the suppy for both sourcing and sinking.
Problem is there are not many out there that can handle ~75V input. (I pick that number, becuase with maximum duty cycles and decently high switching frequencies, I think you want at least that much headroom.)
Then I though, well, what if a guy did say a 50V traditional rail and put another rail stacked on top ( or bottom for that matter) with a buck reg on that rail.
I hope your getting my drift, becuase its wordy, but in affect, have a compliance range of say 10V on the buck reg and its output would be a cap accross the 50V rail.
Again, hope it makes sense.
I know, have seen, have played with several 30A buck regs that can run off 12 to 18V rails. Gotta check LTC though, I think they have a part if I recall.
Then I started thinking about just doing an A/B amp on a say 12V rail again in series with the main supply rail so it could regulate the final output cap voltage, and source and sink.
All these are complicated though, besides a good HV buck reg, which would be easiest by far.
Another thought is this. Use another UcD as a buck regulator!
Stick a huge cap on the output, maybe decoupled with 100mohms.
That for sure seems like the fast way to regulated supplies. A bit expensive, but if your times worth much, likely a bargin.
Mike
Found the beast:
http://www.linear.com/pc/downloadDocument.do?navId=H0,C1,C1003,C1042,C1032,C1082,P2427,D3366
I too would be interested in obtaining the rubycon ZL 63V series, if you have a UCD400 you'd probably want the 100V version.
I've emailed rubycon and have not gotten a response.
I'd also be interested in trying the silmic 2 and purecap variety of elna caps.
Since we obviously stand no chance whatsoever at obtaining any of these caps at the desired sizes anywhere, unless maybe you're near or from Thailand, I'd like to propose a group buy so that we may all sample the above mentioned caps, and any others of great interest, and hopefully we can work something out to serve both the ucd180 and 400 owners.
I've emailed rubycon and have not gotten a response.
I'd also be interested in trying the silmic 2 and purecap variety of elna caps.
Since we obviously stand no chance whatsoever at obtaining any of these caps at the desired sizes anywhere, unless maybe you're near or from Thailand, I'd like to propose a group buy so that we may all sample the above mentioned caps, and any others of great interest, and hopefully we can work something out to serve both the ucd180 and 400 owners.
Hi Ray,
What you're looking for is a Wima mkp2 cap... I guess your reading machine is interpreting a W as an L? Anyway, they're available from Mouser... http://www.mouser.com/index.cfm?&ha...*.33uf*+*mkp2*&Dk=1&Ns=SField&N=110&crc=false
What you're looking for is a Wima mkp2 cap... I guess your reading machine is interpreting a W as an L? Anyway, they're available from Mouser... http://www.mouser.com/index.cfm?&ha...*.33uf*+*mkp2*&Dk=1&Ns=SField&N=110&crc=false
Re: Re: Re: Re: layout
Hi Mike,
Thanks for all that info. I'm not really into designing my own dedicated SMPS. Just try to modify an existing one. Yes, using an UcD to supply UcDs could be a very decadent option. I do not know if they would be happy with 100mOhm load (with large caps after the 100mOhm). I guess an additional LC filter with a very large C and the L to make that large C "invisible" to the UcD module.
Still think that a capacitance multiplier could be a nice option (simpler and safer for DIY than an SMPS) in combination with a conventional tranny. In fact, I also have two whitenoise capacitance multiplier kits (built up) and working. However, want to mod them a bit before actually using them.
For my woofer amps I use a bridged setup, so not much pumping to fear, my woofer/midrange amps are not bridged, but only start from about 150Hz, so no pumping to fear.
Gertjan
Portlandmike said:
Hi Mike,
Thanks for all that info. I'm not really into designing my own dedicated SMPS. Just try to modify an existing one. Yes, using an UcD to supply UcDs could be a very decadent option. I do not know if they would be happy with 100mOhm load (with large caps after the 100mOhm). I guess an additional LC filter with a very large C and the L to make that large C "invisible" to the UcD module.
Still think that a capacitance multiplier could be a nice option (simpler and safer for DIY than an SMPS) in combination with a conventional tranny. In fact, I also have two whitenoise capacitance multiplier kits (built up) and working. However, want to mod them a bit before actually using them.
For my woofer amps I use a bridged setup, so not much pumping to fear, my woofer/midrange amps are not bridged, but only start from about 150Hz, so no pumping to fear.
Gertjan
deandob said:
Hi Dean,
Those 63V 1500uF caps also fit on the UcD400 board since they are 18x40mm, same as the Panasonic FC 100V 680uF. They do of course stick out but that is Ok for me as I mount the modules vertical as well.
I was actually thinking of the ZL 63V 1000uF 16x35.5mm, that cap has an impedance at 100kHz of only 21mOhm, lower than any of the 100V caps and significantly lower than the 36mOhm of the 100V 680uF FC cap. Of course 1000uF is more capacitance then the standard 470uF but that should not be much of an issue (DC protection issues due to more stored energy on the UcD board???). Then to go extreme, one could consider doing two of those caps in parallel (one on top and one on bottom of the PCB) to create a very low impedance of about 10mOhm. This would then give a total of 2000uF on board (or even 3000uF if you go for the 1500uF caps). Hope that in such an extreme case, the snubber caps are still effective to suppress ringing 🙂
Can you let me know your source?
Gertjan
correct caps brand and value
Hi MX-5,
Well, it does help to pay attention. The eloquence Voice Synthesizer built in to the JAWS program which is a Screen Access program to read to me what is on the screen, ... well, it did say the W in Wima. Now, my original question because this thread has gotten so big, would these Wima caps be used on that .068 output cap as well as the 2 filter caps on the board?Thanks.
Ray
Hi MX-5,
Well, it does help to pay attention. The eloquence Voice Synthesizer built in to the JAWS program which is a Screen Access program to read to me what is on the screen, ... well, it did say the W in Wima. Now, my original question because this thread has gotten so big, would these Wima caps be used on that .068 output cap as well as the 2 filter caps on the board?Thanks.
Ray
Re: correct caps brand and value
Ray,
A Wima cap could be put in parallel with the output filter but this would change the filter value, not a good thing. A .1uf cap has an impedance of 4.5 ohms at 350 kHz so probably wouldn’t have much effect anyway. If a smaller value cap is used, like .01uf this would have 45 ohms Z and be of even less use. When we talk of power supply bypassing it is another story as we are dealing with artifacts up into the mHz range and these small caps can be of real value. I would like to try putting a surface mount part of .01 uf directly on the 470 uf parts pads. This .01 should be cog or npo @ 100 or 200 volt rating and should be considerably more effective than the Wima.
Roger
ray bronk said:
Ray,
A Wima cap could be put in parallel with the output filter but this would change the filter value, not a good thing. A .1uf cap has an impedance of 4.5 ohms at 350 kHz so probably wouldn’t have much effect anyway. If a smaller value cap is used, like .01uf this would have 45 ohms Z and be of even less use. When we talk of power supply bypassing it is another story as we are dealing with artifacts up into the mHz range and these small caps can be of real value. I would like to try putting a surface mount part of .01 uf directly on the 470 uf parts pads. This .01 should be cog or npo @ 100 or 200 volt rating and should be considerably more effective than the Wima.
Roger
Hi all,
Well, so no one has found a cap to suitably replace thow 2 caps on the board, for those 470 mf caps. Don't want the FC caps. and no one has had any luck with the .068 cap either? I'm more than likely showing my ignorance here, but on those filter caps, couldn't you put a bypass cap (cap in parallel) on each of the 2 caps?
Seems like changing out resistors and stuff, would be a real pain, especially if they are surface mounts. The transformer can I guess be debated all day long. I just figure I need to know what are the basic stuff to do to tweak out the amps.
Ray
Well, so no one has found a cap to suitably replace thow 2 caps on the board, for those 470 mf caps. Don't want the FC caps. and no one has had any luck with the .068 cap either? I'm more than likely showing my ignorance here, but on those filter caps, couldn't you put a bypass cap (cap in parallel) on each of the 2 caps?
Seems like changing out resistors and stuff, would be a real pain, especially if they are surface mounts. The transformer can I guess be debated all day long. I just figure I need to know what are the basic stuff to do to tweak out the amps.
Ray
ray bronk said:
Ray,
From above!
I would like to try putting a surface mount part of .01 uf directly on the 470 uf parts pads. This .01 should be cog or npo @ 100 or 200 volt rating and should be considerably more effective than the Wima.
Roger
Hi Roger,
I have tried the film caps you sent me to bypass them across the pins, extremely short leads and value 220nF.
Results already mentioned here, seems to help somewhat with the coloration of the FC in mid and upper frequency range, does not, may have a very small effect with 3D imagery, but the fact is it just is no where near as good as the stock United Chemicon KMG cap in either case, coloration or "air".
I think more caps would have been best by factory as it's a bit of a bottleneck in stock format.
Anyway, I do hear a bit more roughness on the bypassed module, read that as HF ringing. Rather than NPO or COG I'd therefor recommend you try an X7R so that it acts as more of a snubber with the higher ESR, it should offer a cleaner sound.
Ray there is no .068 cap on the module, it is 680nF, or .68uF.
People have had luck with the caps, I'm happy with the filter cap I selected and others are happy with the Wima caps.
Some have stated that the amp may lack dynamics and I feel you've eaten that right up, but those same people also found better performance by plugging them into a commercial amplifier with the commercial power supply over their full monoblock implementation..... that signifies their layout is sub optimal more so than the amp module itself.
You can change resistors, op amps, caps, to your hearts content until the sound is tuned just so, odds are that "properly wired" and a "good layout" and "ground scheme" you will be tickled by even the stock module, and given a few very simple cap changes after that, namely the AC electrolytic coupling caps, you'll most likely be at a point where you aren't willing to mess with it any further.
As per the rest of this thread, you need to read it more carefully, but retain an objective view. You should really give the modules a try before ever worrying about modifying them anyway.
Regards,
Chris
I have tried the film caps you sent me to bypass them across the pins, extremely short leads and value 220nF.
Results already mentioned here, seems to help somewhat with the coloration of the FC in mid and upper frequency range, does not, may have a very small effect with 3D imagery, but the fact is it just is no where near as good as the stock United Chemicon KMG cap in either case, coloration or "air".
I think more caps would have been best by factory as it's a bit of a bottleneck in stock format.
Anyway, I do hear a bit more roughness on the bypassed module, read that as HF ringing. Rather than NPO or COG I'd therefor recommend you try an X7R so that it acts as more of a snubber with the higher ESR, it should offer a cleaner sound.
Ray there is no .068 cap on the module, it is 680nF, or .68uF.
People have had luck with the caps, I'm happy with the filter cap I selected and others are happy with the Wima caps.
Some have stated that the amp may lack dynamics and I feel you've eaten that right up, but those same people also found better performance by plugging them into a commercial amplifier with the commercial power supply over their full monoblock implementation..... that signifies their layout is sub optimal more so than the amp module itself.
You can change resistors, op amps, caps, to your hearts content until the sound is tuned just so, odds are that "properly wired" and a "good layout" and "ground scheme" you will be tickled by even the stock module, and given a few very simple cap changes after that, namely the AC electrolytic coupling caps, you'll most likely be at a point where you aren't willing to mess with it any further.
As per the rest of this thread, you need to read it more carefully, but retain an objective view. You should really give the modules a try before ever worrying about modifying them anyway.
Regards,
Chris
Hi Chris,
Well, as far as dynamics goes, I was also going by the word of someone who is well respected in this field, and is too playing with the UCD modules. He told me that the IC frontend doesn't allow for good dynamics. He's probably going for a discrete frontend.
As far as mods go, I wish I could see, I'd probably be in there doing them anyhow. A couple of places that could be obvious is the cables for the frontend and the wiring used for the speaker out. Another place albeit small, for mods, I Wwould think getting rid of the pins and soldering the wires directly to the board.
I'll probably get the standard power supply. I think the only place I might readily do an upgrade is the main power supply caps. Spend the bucks, and get the 4 pole Jensens. Also, the type of solder seems to have an influence here. Which chip the 2134, or the AD chip. An Ad825 chip should I use? is supposed to be good too.
Just some thoughts. If you have any other ideas, let me know. I'm interested.
Ray
Well, as far as dynamics goes, I was also going by the word of someone who is well respected in this field, and is too playing with the UCD modules. He told me that the IC frontend doesn't allow for good dynamics. He's probably going for a discrete frontend.
As far as mods go, I wish I could see, I'd probably be in there doing them anyhow. A couple of places that could be obvious is the cables for the frontend and the wiring used for the speaker out. Another place albeit small, for mods, I Wwould think getting rid of the pins and soldering the wires directly to the board.
I'll probably get the standard power supply. I think the only place I might readily do an upgrade is the main power supply caps. Spend the bucks, and get the 4 pole Jensens. Also, the type of solder seems to have an influence here. Which chip the 2134, or the AD chip. An Ad825 chip should I use? is supposed to be good too.
Just some thoughts. If you have any other ideas, let me know. I'm interested.
Ray
classd4sure said:
Just to add a bit info for Ray. There is indeed a 680nF cap close to the speaker connection pins. This is the output filter cap. It can be replaced by two WIMA MKP2 caps of 330nF in parallel. One can be mounted in the position of the original 680nF cap while the other one can be mounted at the bottom side of the PCB. Those WIMA MKP2 cap are very small for polypropyleen caps, so wiring is short and thus RFI/EMI should not be much of an issue with those caps. Other polypropyleen caps maybe quite big and difficult to wire them with short wires. I have done some measurements, with the WIMA caps, HF residues in the 10-20Mhz range were suppressed better than with the original caps.
I would be against bypassing the 470uF caps with a film cap as it will give ringing. At least I can say that a 680uF panasonic FC bypassed with a 330nF WIMA MKP2 gives ringing which I consider undesired.
Gertjan
Ray,
Whoever said person may be, can't substitute hearing for yourself. Secondly he could easily have a less than optimal setup to explain the lack of dynamics, what variations has he tried.. has the percieved problem actually been solved with a discrete front end.. or is it meant to be his claim to fame for his particular product release? Has he bypassed the front end and driven the comparator directly to know for sure? Maybe it's from the rail snubbers or particular supply setup, or the lack of an auxiliary supply to power the amps with, or a combination of the above.
An objective view and experimentation for yourself just can't be replaced, this thread serves as a loose guide only. I would not be at all quick to say the amp lacks dynamics, which is measured to be 110dB I believe, and is an area where it truly excels.
I do intend to try an AD8066 btw. Some of the specs are beyond overkill, but I've heard it has a good sound. I Also have some tantalum caps to bypass it with, and I may try that on the 8020 first too, right on the pins.
I'd also be willing to experiment with different SMT resistors if the given sort are of a poor variety, and still intend on making an aux supply for the front end happen, very very long term plans would also be a discrete front end, but that will be more as a design challenge than anything.
How do you intend on implementing 4 pole caps to the STD supply PCB? It needn't be Jensen caps either BTW, the BHC T-networks are excellent as well, possibly even more neutral.
I can also tell you it's very easy to get the amp to be fairly high end with respect to module mods, which of course implies you already have a good setup given everything else. You're just going for better precision and clarity, it is harder maintaining neutrality while doing it, which is something the stock amp was unbelievable at, that's what will take the most work.
Regards,
Chris
Whoever said person may be, can't substitute hearing for yourself. Secondly he could easily have a less than optimal setup to explain the lack of dynamics, what variations has he tried.. has the percieved problem actually been solved with a discrete front end.. or is it meant to be his claim to fame for his particular product release? Has he bypassed the front end and driven the comparator directly to know for sure? Maybe it's from the rail snubbers or particular supply setup, or the lack of an auxiliary supply to power the amps with, or a combination of the above.
An objective view and experimentation for yourself just can't be replaced, this thread serves as a loose guide only. I would not be at all quick to say the amp lacks dynamics, which is measured to be 110dB I believe, and is an area where it truly excels.
I do intend to try an AD8066 btw. Some of the specs are beyond overkill, but I've heard it has a good sound. I Also have some tantalum caps to bypass it with, and I may try that on the 8020 first too, right on the pins.
I'd also be willing to experiment with different SMT resistors if the given sort are of a poor variety, and still intend on making an aux supply for the front end happen, very very long term plans would also be a discrete front end, but that will be more as a design challenge than anything.
How do you intend on implementing 4 pole caps to the STD supply PCB? It needn't be Jensen caps either BTW, the BHC T-networks are excellent as well, possibly even more neutral.
I can also tell you it's very easy to get the amp to be fairly high end with respect to module mods, which of course implies you already have a good setup given everything else. You're just going for better precision and clarity, it is harder maintaining neutrality while doing it, which is something the stock amp was unbelievable at, that's what will take the most work.
Regards,
Chris
Hi Gerjan and Chris,
Gerdjan, so what was the sound difference between the 2 Wima caps, versus stock?
Hi Chris,
Well, as far as the supply goes, I admit ignorance here using these Jensens. Could these other caps you mentioned here, be implemented on that supply?
Now about the dynamics issue, I am only going by what I have read versus my friend's observations. I'll look for Mike's summary.I will probably have to ask someone to do the soldering for me. So once done, that's it.
Ray I don't want to do any mods unless I have some understanding that they do really improve sound.
Gerdjan, so what was the sound difference between the 2 Wima caps, versus stock?
Hi Chris,
Well, as far as the supply goes, I admit ignorance here using these Jensens. Could these other caps you mentioned here, be implemented on that supply?
Now about the dynamics issue, I am only going by what I have read versus my friend's observations. I'll look for Mike's summary.I will probably have to ask someone to do the soldering for me. So once done, that's it.
Ray I don't want to do any mods unless I have some understanding that they do really improve sound.
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