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dementedchord
Psychotic State alumni ch
i didnt peruse the parts list but the basic ideas you stated make sense... good luck...
sweetbeats
Reel deep thoughts...
Ethan,
I don't know how, but I just now noticed your post from a couple weeks ago...
where have I been...
Sorry about that and thank you. I'll take a closer listen..
And furthermore...
I understand this now, though I'm struggling to grasp what this means in the real world...How different might my eq section be from channel to channel if I use a 20% cap vs. the 5% spec'ed by Tascam? I'd prefer to get the 5% fro sure but just can't seem to find it...
I don't know how, but I just now noticed your post from a couple weeks ago...
where have I been...Sorry about that and thank you. I'll take a closer listen..
And furthermore...
I understand this now, though I'm struggling to grasp what this means in the real world...How different might my eq section be from channel to channel if I use a 20% cap vs. the 5% spec'ed by Tascam? I'd prefer to get the 5% fro sure but just can't seem to find it...
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dementedchord
Psychotic State alumni ch
http://dkc3.digikey.com/PDF/T083/1668-1670.pdf
i've always used the panasonics... most of the B series and all of the V are 5%...
i've always used the panasonics... most of the B series and all of the V are 5%...
evm1024
New member
If the mfg wants 5% do it.
When making parts the mfg tests them then pulls out the 1% parts leaving the rest having at least a 1% error. Next out go the 2% then 5% then 10% leaving the rest with at least a 10% error. Lastly pull out the greater than 20% error parts and mark them unspecified.
So the 20% parts have between a 10 and 20 % error.....
This is a general way of doing it and I'm sure that some vendors do it some other way.
Closer to spec the better.
When making parts the mfg tests them then pulls out the 1% parts leaving the rest having at least a 1% error. Next out go the 2% then 5% then 10% leaving the rest with at least a 10% error. Lastly pull out the greater than 20% error parts and mark them unspecified.
So the 20% parts have between a 10 and 20 % error.....
This is a general way of doing it and I'm sure that some vendors do it some other way.
Closer to spec the better.
sweetbeats
Reel deep thoughts...
Okay...that's definitely my line of thinking.
Now the question is, the spec is for 5% electrolytic, Panasonic B series are polyester...
Now the question is, the spec is for 5% electrolytic, Panasonic B series are polyester...
sweetbeats
Reel deep thoughts...
I'm trolling for more responses...
Sorry Ethan and dementedchord...no disrespect meant to you. Your input has been priceless, I'm just pining for additional input from you two or hopefully others as well to specifically address my post a few back with the Excel charts of PS caps...below is another version of the charts with additional specifics as far as the make, series and value/voltage specs of the caps I'm thinking of getting for the two supplies in the 58 and the supply for the 520 (to save the hassle of anybody having to go to the Digikey site and cross-reference to help me out).
Maybe a normal person would just go for it at this point, but this is my very first foray into recapping and I want to get a firm handle on what I'm doing, so if anybody has a few minutes to look at the cap charts below and cross reference with the schematics (M-520 PSU schemo is included in this zip bundle, and a JPEG of the 58 PSU can be found herehttps://www.torridheatstudios.com/f...ascam 58/Tascam 58 Power Supply Schematic.jpg).
I may be over the top on my need for security in this, but that's just me I guess.
If you haven't figured that about me yet, its never too late! 
I'm looking for (after a closer look at the materials linked/attached to this post) either "looks good" or criticism/questioning of my selection(s) and hopefully suggestions.
Also still wondering about that 5% cap spec'ed for C12 on the M-520 input card (i.e. Tascam spec'ed a 5% electrolytic but I can't hardly find 10% electrolytic caps much less 5%...) Do I just go ahead/is it okay to use a poly cap when electrolytic is specified?
Thanks in advance guys...I think once I get past this first recap process I feel a bit more confident about selections...this is just uncharted territory for me.
Sorry Ethan and dementedchord...no disrespect meant to you. Your input has been priceless, I'm just pining for additional input from you two or hopefully others as well to specifically address my post a few back with the Excel charts of PS caps...below is another version of the charts with additional specifics as far as the make, series and value/voltage specs of the caps I'm thinking of getting for the two supplies in the 58 and the supply for the 520 (to save the hassle of anybody having to go to the Digikey site and cross-reference to help me out).
Maybe a normal person would just go for it at this point, but this is my very first foray into recapping and I want to get a firm handle on what I'm doing, so if anybody has a few minutes to look at the cap charts below and cross reference with the schematics (M-520 PSU schemo is included in this zip bundle, and a JPEG of the 58 PSU can be found herehttps://www.torridheatstudios.com/f...ascam 58/Tascam 58 Power Supply Schematic.jpg).
I may be over the top on my need for security in this, but that's just me I guess.
If you haven't figured that about me yet, its never too late! I'm looking for (after a closer look at the materials linked/attached to this post) either "looks good" or criticism/questioning of my selection(s) and hopefully suggestions.
Also still wondering about that 5% cap spec'ed for C12 on the M-520 input card (i.e. Tascam spec'ed a 5% electrolytic but I can't hardly find 10% electrolytic caps much less 5%...
) Do I just go ahead/is it okay to use a poly cap when electrolytic is specified? Thanks in advance guys...I think once I get past this first recap process I feel a bit more confident about selections...this is just uncharted territory for me.
Attachments
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dementedchord
Psychotic State alumni ch
as to C12... we've got things spread out in several threads and didnt find the schemo quickly... but did see where ethan said it was a coupling cap to the fader i believe... the reason they might spec a tighter tolerance here is these caps can have a significant effect on the frq response of the circuit... so tighter tolerence means channels will match better... in fact this is one point where i might have suggested useing a larger value... often the bottom end opens up some... polys dont come in large enough values for the most part to sub here... you could always buy 2-3X's as many as you need and test them yourself???
sweetbeats
Reel deep thoughts...
demented, good food for thought...it generates more questions in my mind though from which I will presently refrain...I still don't know where to find electrolytic 5% caps so until I can resolve that its a moot point.
Can anybody comment on my cap selections in my last post?
Can anybody comment on my cap selections in my last post?
sweetbeats
Reel deep thoughts...
Are audio grade caps just hype?
So I'm getting ready to recap so boards in my Tascam M-___ (i.e. mystery) mixer...this thread: https://homerecording.com/bbs/showthread.php?t=270992...anyway, I have no schematics, so at my knowledge level it would be difficult at best to know which caps are in the audio path and which ones are not. I'd like to use audio grade caps for those that are in the audio path, but does it really matter? Am I buying into some kind of hype by thinking there will be some difference using audio grade caps, and if it is worthwhile, then is there any harm in using audio grade caps in circuit pathways that are non-audio?? :???: (since I don't know which caps are non-audio path and it is worth using audio grade caps for audio circuits, then I'd just use all audio grade caps...)
So I'm getting ready to recap so boards in my Tascam M-___ (i.e. mystery) mixer...this thread: https://homerecording.com/bbs/showthread.php?t=270992...anyway, I have no schematics, so at my knowledge level it would be difficult at best to know which caps are in the audio path and which ones are not. I'd like to use audio grade caps for those that are in the audio path, but does it really matter? Am I buying into some kind of hype by thinking there will be some difference using audio grade caps, and if it is worthwhile, then is there any harm in using audio grade caps in circuit pathways that are non-audio?? :???: (since I don't know which caps are non-audio path and it is worth using audio grade caps for audio circuits, then I'd just use all audio grade caps...)
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dementedchord
Psychotic State alumni ch
have to admit i think audiograde could be dubious distinction... sure some are better than others and can "not detract" from the sound as much... does that constitute an improvement??? ie. the whole reason that caps became an issue in audio is that they introduce some phasing all of them no exceptions... but different dialectrics induce different amounts... and i'm not sure there's a good spec for discerning which... imo it's best to use a good general cap for all uses... i generaly use a polypropalene or polyystyrene or pollyunsaturated or poloy....
sweetbeats
Reel deep thoughts...
so...wait...you replace electrolytics with poly-whatevers where possible? :???:
D
dementedchord
Psychotic State alumni ch
sorry for the confusion... usually an electrolytic is used because of the value needed... if ya can find a poly that has the same value sure you can use it... but a polypropelene that would work in the supply would be the size of a football... what i was saying was more along the lines that i'm not sure wondercaps are worth the extra dough...
sweetbeats
Reel deep thoughts...
Wondercaps maybe not worth it...got it...
PS poly cap = football...got it.
Cool. thanks for the info.
PS poly cap = football...got it.
Cool. thanks for the info.
Somnium7
Noise Criminal
Yet more considerations
On my console I bypassed electrolytic stage coupling caps with poly caps. So each of the hundreds of 22uF caps that pass audio signals have a 1uF poly in parallel with them. Obviously this makes for alot of extra work. This isn't necessary by any means it is more of a modification. It's one you should decide on before you start the recapping because it's best done at that time. IMO it does result in cleaner highs than with electrolytics alone.
Next, glued caps. Before attempting to desolder your old caps it is a good idea to use an exacto knife to cut this gunk around the base of the cap. The reason is because if you leave it on it requires you to use a great deal of force to remove the cap. So if the cap isn't completely desoldered you will wind up tearing the pad and traces on the bottom of the PCB because you'll think it is only the glue holding the cap when in fact there is still some solder keeping it connected.
Also, I have found that this glue can become acidic and corrode the leads of components over time. I saw this in my Toa quite a bit and adopted the practice of scraping as much of this crap off as possible.
In the power supply I recommend you change out the snubber caps for the rectifiers if you have them. Large, high current linear supplies frequently have snubber caps which are usually very high voltage rating ceramic discs placed right next to each side of the bridge rectifiers. Snubber caps take the most abuse of all the caps in any power supply which degrades them significantly over time. I'm sure I mentioned this in my postings about my RX-7 but there was a serious reduction in noise after replacing the snubber caps.
The purpose of these snubber caps is to reduce the on/off switching noise of the diodes inside the rectifier. And that switching noise is considerable.
Finally, I found some really expensive audio quality caps and put them into a few modules while others had regular quality caps. If there was a difference it escapes me.
Perhaps I don't hear so good. After all I make music with heavily distorted digital synthesizers
With this I say go for the best bang for the buck. Changing the cap will cost you X number of $ and will be found to be an immediate and worthwhile improvement. For a few more $ you can bypass electrolytic caps in the audio path and get a little more improvement. And for yet a few more $ you can get audiophile caps and hopefully, maybe be able to hear the improvement.
On my console I bypassed electrolytic stage coupling caps with poly caps. So each of the hundreds of 22uF caps that pass audio signals have a 1uF poly in parallel with them. Obviously this makes for alot of extra work. This isn't necessary by any means it is more of a modification. It's one you should decide on before you start the recapping because it's best done at that time. IMO it does result in cleaner highs than with electrolytics alone.
Next, glued caps. Before attempting to desolder your old caps it is a good idea to use an exacto knife to cut this gunk around the base of the cap. The reason is because if you leave it on it requires you to use a great deal of force to remove the cap. So if the cap isn't completely desoldered you will wind up tearing the pad and traces on the bottom of the PCB because you'll think it is only the glue holding the cap when in fact there is still some solder keeping it connected.
Also, I have found that this glue can become acidic and corrode the leads of components over time. I saw this in my Toa quite a bit and adopted the practice of scraping as much of this crap off as possible.
In the power supply I recommend you change out the snubber caps for the rectifiers if you have them. Large, high current linear supplies frequently have snubber caps which are usually very high voltage rating ceramic discs placed right next to each side of the bridge rectifiers. Snubber caps take the most abuse of all the caps in any power supply which degrades them significantly over time. I'm sure I mentioned this in my postings about my RX-7 but there was a serious reduction in noise after replacing the snubber caps.
The purpose of these snubber caps is to reduce the on/off switching noise of the diodes inside the rectifier. And that switching noise is considerable.
Finally, I found some really expensive audio quality caps and put them into a few modules while others had regular quality caps. If there was a difference it escapes me.
Perhaps I don't hear so good. After all I make music with heavily distorted digital synthesizers
With this I say go for the best bang for the buck. Changing the cap will cost you X number of $ and will be found to be an immediate and worthwhile improvement. For a few more $ you can bypass electrolytic caps in the audio path and get a little more improvement. And for yet a few more $ you can get audiophile caps and hopefully, maybe be able to hear the improvement.
D
dementedchord
Psychotic State alumni ch
somnium good to see ya around.... everything copaceatic???
sweetbeats
Reel deep thoughts...
Hey Somnium...thanks for the post! How are ya??
Hm...I like this idea, but I struggle identify what is, and what is not audio. I can do it, I think, with careful study of the schematics...
So the poly cap leads just get stuffed in the same holes as the electrolytic cap and the pairs of leads just get soldered to the same respective pad? What voltage rating do you use for the poly cap? Same as the electrolytic? If I put up a sample schemo of something audio, and named all the electrolytic caps that are in the audio path, would you confirm for me that I got it? Then I could apply that confirmation to other PCB's knowing that I've got the right idea...
Cool...okay. Thanks. I've dealt with this on three caps so far and I think I did something similar to what you are saying, but your advice will help the next time I run into it.
Huh! Okay. So, here is a jpg of the power supply for the M-520. U001 and U002 are the 15V regulators, and U004 and U005 are the 18V regulators. Based on their location I would think C6 and C7 to be snubber caps...they are 0.01uF 50V caps...not very high voltage...Same with C26 and C27 proximal to U004 and U005. They are also 0.01uF 50V ceramics...BUT, then there are 0.01uF 500V caps...C14 and C16. Thems it?
This is extremely valuable real-world info. Thanks!
Hm...I like this idea, but I struggle identify what is, and what is not audio. I can do it, I think, with careful study of the schematics...
So the poly cap leads just get stuffed in the same holes as the electrolytic cap and the pairs of leads just get soldered to the same respective pad? What voltage rating do you use for the poly cap? Same as the electrolytic? If I put up a sample schemo of something audio, and named all the electrolytic caps that are in the audio path, would you confirm for me that I got it? Then I could apply that confirmation to other PCB's knowing that I've got the right idea...
Cool...okay. Thanks. I've dealt with this on three caps so far and I think I did something similar to what you are saying, but your advice will help the next time I run into it.
Huh! Okay. So, here is a jpg of the power supply for the M-520. U001 and U002 are the 15V regulators, and U004 and U005 are the 18V regulators. Based on their location I would think C6 and C7 to be snubber caps...they are 0.01uF 50V caps...not very high voltage...Same with C26 and C27 proximal to U004 and U005. They are also 0.01uF 50V ceramics...BUT, then there are 0.01uF 500V caps...C14 and C16. Thems it?
This is extremely valuable real-world info. Thanks!