We were in the lucky position that we didn't have to buy any since Brian's donation to this group buy contained enough of them. Brian's BOM listed them as Mouser 280-PRM7-0.47. That's all I know.Bengali said:
Peter
AndrewT said:
National's datasheet for LM3886 suggests use Elcos to prevent oscillation and small bypasses (0,1 uF) in addition to "prevent any high frequency feedback through the PS lines" but I trust in Mauro's design and his expertise.
He did deep analysis and measurements of its circuit and if they were necessary for sure Mauro would have included them. 😉
Regarding LM318N on datasheet I can't find nothing about PS decoupling.
ClaveFremen said:
These ceramics must be at least X7R type, C0G/NP0 would have been better but it's hard to find them in such values. 🙄
Their detrimental effect is low in C17/C18 positions (where National's datasheet suggests their use), not so low in C19/C20 positions.
I chose to trust Mauro and my ears, no PS bypasses in my MyRef 😀
Exactly. Expressions are mixed up often, and I use to stick to the one that is actually used in the thread, because that helps poeple to follow things better.madisonears said:
Ceramics have the advantage of very low impedance and are therefore one of the best choices for power supply decoupling.
Avoid them in the signal path, if you can, because they have the piezo effect. If you connect a ceramic to an oscilloscope and knock on it, you can see spikes as a result of that effect. So they would introduce unwanted noise into the signal path, if excited in some way, e. g. through vibrations.
Everyone does not rave about them. The ones, who do, why do they rave about them?madisonears said:
Many of them, because they heard other people rave about them.
Many others, because they are paid for it. Mundorf spends a lot of money on advertising, and magazines live off that. So what else shoud they do but rave.
Some rave, because they paid an indecent amount of money on those caps and cannot admit that they are not worth it. And can they be bad with those specs? The tan(delta) is publshed with 0,0002 for all of them except the so called Tube Caps. Impressive! But, hold it. What is tan(delta) in the first place and how does it affect the sonic quality?
Then there are the lucky ones, who rave, because those caps just happened to harmonize with their equipment and their listening taste at a certain point in time.
If you skip the marketing rap, all those oil capacitors are metal-paper capacitors. MP capacitors have such bad properties that they were only used as motor starter capacitors in the past.
One of the flaws is that the paper is compressed, when the electrodes attract each other as soon as current flows. Thus the distance between the electrodes changes and consequently the capacity and some other properties. That is probably, why they are constantly changing their "sound" and why it takes extremely long to "burn them in". In some cases you have to burn them in again and again, because that effect is reversible, and it depends on the current that flows, i. e. on the music that is played and the signal strength. So, while they sound fantastic one day, they may sound terrible the next day and mediocre the day after, but return to great sound one week later.
Regarding Mundorf caps, I am going to ignore that cynical speculation and proceed with my own unbiased experiment. I will report the results after a fair period of evaluation. I am not being paid by Mundorf, and I have no reason to promote their products.
Perhaps you have a motive for being so critical? I can't believe that all the carefully controlled listening tests of caps were all influenced the way you describe.
Do you actually have this amplifier, or are you just another internet "expert" on everything? Please tell us about your direct experience with the MyRef, and then I'll give your criticism some credibility.
Peace,
Tom E
Perhaps you have a motive for being so critical? I can't believe that all the carefully controlled listening tests of caps were all influenced the way you describe.
Do you actually have this amplifier, or are you just another internet "expert" on everything? Please tell us about your direct experience with the MyRef, and then I'll give your criticism some credibility.
Peace,
Tom E
I agree to some extent. I think that Mundorfs are crazy priced but there are people I respect who think they are great caps. Gordon at Wavelength for instance.
I used to be a total cynic and frankly half a year ago I would have been reading Dario the riot act on his silly testing. But I have found that everytime I have a prejudice against a certain component or use of a component I can prove myself wrong or right given the right/wrong circumstance. For instance I think Silmics sound like crap in a chip amp, which might be why Dario winks every time he brings them up 😉, but I give him a lot of credit and thanks for going through this procedure to find the best sound for all of us to benefit from and I dont doubt that the Silmics could sound great given the right set of circumstances and those circumstances seem to be in the MyRef circuit. So, for Mundorfs to be run out on a rail with nothing to back it up is a bit of silliness. I for one happen to like the sound of a PIO cap which I believe was compared to the manufacturing process of the Mundorfs. So give it a chance and lets see if a hundred buck spent on caps gives a grand of sound back!
Tom I hope you get your investment back in sound. I have actually priced some Mundorfs and based on your experience and my DC offset on input I might consider buying the less expensive ones.
Uriah
I used to be a total cynic and frankly half a year ago I would have been reading Dario the riot act on his silly testing. But I have found that everytime I have a prejudice against a certain component or use of a component I can prove myself wrong or right given the right/wrong circumstance. For instance I think Silmics sound like crap in a chip amp, which might be why Dario winks every time he brings them up 😉, but I give him a lot of credit and thanks for going through this procedure to find the best sound for all of us to benefit from and I dont doubt that the Silmics could sound great given the right set of circumstances and those circumstances seem to be in the MyRef circuit. So, for Mundorfs to be run out on a rail with nothing to back it up is a bit of silliness. I for one happen to like the sound of a PIO cap which I believe was compared to the manufacturing process of the Mundorfs. So give it a chance and lets see if a hundred buck spent on caps gives a grand of sound back!
Tom I hope you get your investment back in sound. I have actually priced some Mundorfs and based on your experience and my DC offset on input I might consider buying the less expensive ones.
Uriah
Right on Uriah!
Careful testing can confirm what one believes to be true.
If the tests prove you wrong, then you learned something new.
Careful testing can confirm what one believes to be true.
If the tests prove you wrong, then you learned something new.
Bengali and quadtech:
Regarding the power resistor, I have also been curious what effect a Caddock or Vishay thick film would have in that position. The signal passes through that component, so it is certainly a factor in the sound of the amp. I have no direct experience with these thick film types, but they certainly enjoy a good reputation. They are expensive, though, and it would be a tight squeeze to get when on the board with its own heatsink. They cannot be used without a heatsink.
It is difficult to understand what Mauro meant in his post. I think he was warning against using thin film or oxide types because they aren't robust enough and might not have low inductance. These thick film power types have very low inductance and are designed to handle heavy loads: some are rated to 50 watts. Anybody wanna try one?
I don't think the difference in value (0.47 vs 0.5) would be a factor, as the 5% tolerance on the standard part can put it near 0.5 ohm anyway. There are 0.47 available, if it is critical, and the 0.5 can be obtained with tighter tolerance to keep it very near spec.
Peace,
Tom E
Regarding the power resistor, I have also been curious what effect a Caddock or Vishay thick film would have in that position. The signal passes through that component, so it is certainly a factor in the sound of the amp. I have no direct experience with these thick film types, but they certainly enjoy a good reputation. They are expensive, though, and it would be a tight squeeze to get when on the board with its own heatsink. They cannot be used without a heatsink.
It is difficult to understand what Mauro meant in his post. I think he was warning against using thin film or oxide types because they aren't robust enough and might not have low inductance. These thick film power types have very low inductance and are designed to handle heavy loads: some are rated to 50 watts. Anybody wanna try one?
I don't think the difference in value (0.47 vs 0.5) would be a factor, as the 5% tolerance on the standard part can put it near 0.5 ohm anyway. There are 0.47 available, if it is critical, and the 0.5 can be obtained with tighter tolerance to keep it very near spec.
Peace,
Tom E
How many carefully controlled listening tests of caps have you seen? I have seen about a dozen, where one Mundorf cap or other was in. Only one of them was carefully controlled. In that test the caps were used in passive speaker cross-overs, so the result is not even meaningful for DC blocking in an amplifier.madisonears said:
My comments were on MP capacitors, not on the amplifier. You said, yours are horrible.madisonears said:
udailey said:
Wow! Then I must consider myself a lucky guy 😉
Regarding silliness I'm in good company, also Peter Daniels uses sockets to test different components 😉 (thanks Peter for the great idea!
)If only I'd used sockets how many solder pads wouldn't be screwed up with soldering/desoldering! 😀
udailey said:
Thanks for the credit 🙂
ClaveFremen said:
Silmics used in your tests were burned-in? In which role (signal coupling/PS decoupling/etc.) ?
For instance some years ago I though that Silmics were bad on PS decoupling and I substituded all Simics used by Sony in my SACD player for PS decoupling with Rubycon ZLs:, wow!, sound opened up, like a veil removed, more highs too.
Two monts ago I've built my first Gainclone and had problems with harshness and lack of basses... well, part of the problem resided in the player! I've restored Silmics in PS and... miracle! Basses was there and harshness is gone! 😉 (no darkness too, but only after burn-in... 😎 )
So what we can learn from all this testing and swapping parts in circuits is that each piece of equipment will respond differently in each different system. That's pretty much the mantra of DIY and audio in general: not only must you account for different personal tastes when it comes to how something should sound, but you must also consider all the other elements of a system. Oh great!
What to believe? To be certain, you can only learn for yourself. However, if there is a general consensus among many different tests, then you must put some creedence in that conclusion. I have seen five reviews for reference, all of which seem to be conducted objectively, and there is definitely agreement among all of them regarding the upper level of performance.
http://www.ecp.cc/cap-notes.html
http://www.tempoelectric.com/caps.htm
http://www.humblehomemadehifi.com/Cap.html
http://www.vhaudio.com/21capacitorshootout.pdf
http://www.enjoythemusic.com/diy/0708/capacitor1.htm
I cannot explain the burn in phenomenon as well as Pacificblue, but I know it's real, and it's happening right now to the Mundorfs, and they're sounding really good. I'm still not convinced they're worth the cost, but I will give them more time. The AudioCap Theta's took about 10-15 hours to sound their best, and that was really good. The Silmic's and Wima's also took some hours to settle down. You can't make a quick judgment about this kind of stuff.
Peace,
Tom E
What to believe? To be certain, you can only learn for yourself. However, if there is a general consensus among many different tests, then you must put some creedence in that conclusion. I have seen five reviews for reference, all of which seem to be conducted objectively, and there is definitely agreement among all of them regarding the upper level of performance.
http://www.ecp.cc/cap-notes.html
http://www.tempoelectric.com/caps.htm
http://www.humblehomemadehifi.com/Cap.html
http://www.vhaudio.com/21capacitorshootout.pdf
http://www.enjoythemusic.com/diy/0708/capacitor1.htm
I cannot explain the burn in phenomenon as well as Pacificblue, but I know it's real, and it's happening right now to the Mundorfs, and they're sounding really good. I'm still not convinced they're worth the cost, but I will give them more time. The AudioCap Theta's took about 10-15 hours to sound their best, and that was really good. The Silmic's and Wima's also took some hours to settle down. You can't make a quick judgment about this kind of stuff.
Peace,
Tom E
Yeah my Silmics ran for a few weeks til somehow I fried my amp. The sound of the Silmics made the music feel thick and made the room almost claustraphobic. It really had me ticked off. I rebuilt that amp with FC's and that was a great difference.
Uriah
Uriah
udailey said:
Mmh, interesting your use of the words thick and claustrophobic... what do you mean exactly?
Silmics, in my SACD player, gave more 'body', the bass is tighter and 'bigger' and soundstage is very large and deep with little or no harshness.
From a different point of view I suppose we could use also the word thick. 🙄
They were used in PS decoupling, right? Bypassed? Which value?
FCs for sure have a very different sound, very fast and snappy but also a bit harsh and no much bass, in my Gainclone.
I'm using silmic II's in my aleph P1.7. have not played long hours on it. I'm not too sure about capacitor burn in, if it's for real or not. is it really the caps burning in or our ears burning in, adapting, getting comfortable with the sound? 😀
back to the silmics II's, mine sounds very normal, absolutely nothing to get excited about. I'm considering bypassing them all with PIO's.
back to the silmics II's, mine sounds very normal, absolutely nothing to get excited about. I'm considering bypassing them all with PIO's.
Bengali said:
I've had those same thoughts, but when I first put together my first amp, it sounded like crap. Then, for about the first 2 days, it got noticeably better. In the first 30 minutes, the sound change was noticeable while I was listening.
Dumbass question of the day: what is required to use the LED outputs? Okay, LED'S. Got a couple of these:
http://www.parts-express.com/pe/showdetl.cfm?Partnumber=070-025
Anything else? Dropping resistors? All I want is an on/off indicator.
Mundorfs continue to improve. In response to wondering about cap burn-in, I testify that it is very real, no question about it. Over the course of 40 hours, these caps have gone from constricted and flat to edgy and bright, back to mellow but spacious, and now to a level of amazing inner detail and spatial layering. I listened last night to a symphonic recording I've heard hundreds of times, and new layers of instrumental detail were revealed with no harshness. I'm starting to like these, but I'm still not totally convinced. Sometimes the highs seem disconnected from the rest of the music, almost like a badly designed speaker.
My ears are not adjusting, as I don't sit in the room and listen all the while music is playing. I sit down to really listen for a little while in the afternoon, then again listen more attentively for an extended period in the evening. My ears are always "cold" for these sessions, so I can recognize changes that have transpired since my last session. I also still use another amp for reference. Anyone who disputes at least some amount of cap burn-in is an absolute fool.
Peace,
Tom E
http://www.parts-express.com/pe/showdetl.cfm?Partnumber=070-025
Anything else? Dropping resistors? All I want is an on/off indicator.
Mundorfs continue to improve. In response to wondering about cap burn-in, I testify that it is very real, no question about it. Over the course of 40 hours, these caps have gone from constricted and flat to edgy and bright, back to mellow but spacious, and now to a level of amazing inner detail and spatial layering. I listened last night to a symphonic recording I've heard hundreds of times, and new layers of instrumental detail were revealed with no harshness. I'm starting to like these, but I'm still not totally convinced. Sometimes the highs seem disconnected from the rest of the music, almost like a badly designed speaker.
My ears are not adjusting, as I don't sit in the room and listen all the while music is playing. I sit down to really listen for a little while in the afternoon, then again listen more attentively for an extended period in the evening. My ears are always "cold" for these sessions, so I can recognize changes that have transpired since my last session. I also still use another amp for reference. Anyone who disputes at least some amount of cap burn-in is an absolute fool.
Peace,
Tom E
madisonears said:
The board takes care of the LED voltage/current- just hook them up to the connector on the board. No dropping resistor needed.
I've got to substitute a dimmer LED for the one I used in my amp- it's like a blue headlight coming at you when you are sitting and listening.
John
Capacitor "Running in machine"
Has nobody ever invented a capacitor "running in circuit" so you can run in a few capacitors at a time "off-line"?
Has nobody ever invented a capacitor "running in circuit" so you can run in a few capacitors at a time "off-line"?
if cap burn in is for real, I was thinking of a cheap mp3 player running whatever time you desire, with the coupling caps through a load resistor.
I would think it would be the same if you did it through your preamp/amp.
those screw terminal blocks might work to firmly clamp down on the capacitor leads.
would be interesting to hear any difference if caps you burned in for a length of time and tried those vs. fresh caps.
😀
I would think it would be the same if you did it through your preamp/amp.
those screw terminal blocks might work to firmly clamp down on the capacitor leads.
would be interesting to hear any difference if caps you burned in for a length of time and tried those vs. fresh caps.
😀