SRS upgrade questions
Comments
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Larry, I noticed that you have also used the XPA-2. I would really be interested in your impression of the XPA-2?
Yes I did,and no you don't:cool: For the price of the XPA-2 go for a Adcom 5802,Rotel,Parasound ect..
If you lived near by I would let you borrow my Adcom for a few days just so you could see how great of an amp it is. The XPA-2 was out of my house in a week.. -
Direct Current Resistance.
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Thats for capacitors that are connected in series.The voltage will be the same across paralleled capacitors.Personally I would never use paralleled caps in the seiries part of a hi pass or bandpass filter for a midrange.However I would have no quams about using paralleled capacitors in the shunt leg of a low pass filter if very large values were required.As always YMMV.
Exactly! Further, no one here could hear the difference in a 2 X 130uF and a 2 X 91uF + 75uF combo in the location it is going in. -
Quote:
Originally Posted by FTGV
Thats for capacitors that are connected in series.The voltage will be the same across paralleled capacitors.Personally I would never use paralleled caps in the seiries part of a hi pass or bandpass filter for a midrange.However I would have no quams about using paralleled capacitors in the shunt leg of a low pass filter if very large values were required.As always YMMV.
Exactly! Further, no one here could hear the difference in a 2 X 130uF and a 2 X 91uF + 75uF combo in the location it is going in.
I fully agree. I suspect others here vehemently disagree.cristo
NAD C 545BEE cd player, Philips AF877 turntable / Shure V15V-MR with JICO SAS stylus,
Tascam 122 mkIII cassette deck, Harman Kardon 3480 receiver, Terk FM-50 antenna in the attic,
Soundcraftsmen SE550 stereo equalizer, Polk Monitor 10a speakers
(with Sonicraft/Solen/Mills crossover rebuild) -
Larry, I noticed that you have also used the XPA-2. I've looked for a GFA -585 and these are not easy to come by. My other concern is in what shape I will find it, and how much $ to get it up to snuff. The XPA-2 would be new (all new caps, etc.) and comes with a good warranty. I would really be interested in your impression of the XPA-2?
Do not buy and Emo amp. Your SRS's deserve a little more refined amplifier. Just IMO, of course.
H9"Appreciation of audio is a completely subjective human experience. Measurements can provide a measure of insight, but are no substitute for human judgment. Why are we looking to reduce a subjective experience to objective criteria anyway? The subtleties of music and audio reproduction are for those who appreciate it. Differentiation by numbers is for those who do not".--Nelson Pass Pass Labs XA25 | EE Avant Pre | EE Mini Max Supreme DAC | MIT Shotgun S1 | Pangea AC14SE MKII | Legend L600 | BlueSound Node 3 - Tubes add soul! -
Do not buy and Emo amp. Your SRS's deserve a little more refined amplifier. Just IMO, of course.
H9
Thanks H9, I've gotten that from several people. It's off the list.SDA SRS modded: Xovrd, de-polyed, inductorized, interconnectorized, re-posted, dynamited, RDOd, spiked, gasketed, ringed (Larry's), and grill cloth blinged! Done this on my own? Not a chance. Thanks to Raife and all who forged easy to follow upgrades. At least a 100% improvement in sound and my personal listening pleasure! :cheesygrin:Pass XP-10 preamp, Parasound A21 amp, Pioneer Elite DV-58AV (Ric Shultz modded), Audioquest Sky IC's, No longer need my Sunfire sub after mods... -
I've started replacing the resistors on the XO'r with the Mills supplied by SonciCraft (very nice people to work with by the way). I'm wondering about the tolerances/specs. For example, I've got a stock 22.5ohm resistor that is being replaced by a Mills 22.0ohm. The stock measures spot on 22.5, the mills measures 22.1. Interestingly even though the stock resistors are just 10% tolerance, so far all of the them have been spot on spec. All of the Mills measure a tad high or low. I know from the specified 22.5 to the Mills 22.1 is less than 2% off, but I'd feel better if my stock resistors were all over the map. Would do you think?SDA SRS modded: Xovrd, de-polyed, inductorized, interconnectorized, re-posted, dynamited, RDOd, spiked, gasketed, ringed (Larry's), and grill cloth blinged! Done this on my own? Not a chance. Thanks to Raife and all who forged easy to follow upgrades. At least a 100% improvement in sound and my personal listening pleasure! :cheesygrin:Pass XP-10 preamp, Parasound A21 amp, Pioneer Elite DV-58AV (Ric Shultz modded), Audioquest Sky IC's, No longer need my Sunfire sub after mods...
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I've started replacing the resistors on the XO'r with the Mills supplied by SonciCraft (very nice people to work with by the way). I'm wondering about the tolerances/specs. For example, I've got a stock 22.5ohm resistor that is being replaced by a Mills 22.0ohm. The stock measures spot on 22.5, the mills measures 22.1. Interestingly even though the stock resistors are just 10% tolerance, so far all of the them have been spot on spec. All of the Mills measure a tad high or low. I know from the specified 22.5 to the Mills 22.1 is less than 2% off, but I'd feel better if my stock resistors were all over the map. Would do you think?
I noticed that on my SDA2's when I did the crossover. Besides one way out of whack cap, most of the originals were well within the 5% range. And the Sonicaps I used were further out. I haven't retested to see if they just needed some break in time though. -
You need a circuit simulator to test caps, just putting them on a DVM won't tell you anything about their performance, life or spec.
H9"Appreciation of audio is a completely subjective human experience. Measurements can provide a measure of insight, but are no substitute for human judgment. Why are we looking to reduce a subjective experience to objective criteria anyway? The subtleties of music and audio reproduction are for those who appreciate it. Differentiation by numbers is for those who do not".--Nelson Pass Pass Labs XA25 | EE Avant Pre | EE Mini Max Supreme DAC | MIT Shotgun S1 | Pangea AC14SE MKII | Legend L600 | BlueSound Node 3 - Tubes add soul! -
You need a circuit simulator to test caps, just putting them on a DVM won't tell you anything about their performance, life or spec.
H9
H9, I agree with you on the caps, but what I'm concerned about are the Mills resistors.SDA SRS modded: Xovrd, de-polyed, inductorized, interconnectorized, re-posted, dynamited, RDOd, spiked, gasketed, ringed (Larry's), and grill cloth blinged! Done this on my own? Not a chance. Thanks to Raife and all who forged easy to follow upgrades. At least a 100% improvement in sound and my personal listening pleasure! :cheesygrin:Pass XP-10 preamp, Parasound A21 amp, Pioneer Elite DV-58AV (Ric Shultz modded), Audioquest Sky IC's, No longer need my Sunfire sub after mods... -
H9, I agree with you on the caps, but what I'm concerned about are the Mills resistors.
I wouldn't worry a bit. Hooking them to a meter is not the same as using them in a real world application.
H9"Appreciation of audio is a completely subjective human experience. Measurements can provide a measure of insight, but are no substitute for human judgment. Why are we looking to reduce a subjective experience to objective criteria anyway? The subtleties of music and audio reproduction are for those who appreciate it. Differentiation by numbers is for those who do not".--Nelson Pass Pass Labs XA25 | EE Avant Pre | EE Mini Max Supreme DAC | MIT Shotgun S1 | Pangea AC14SE MKII | Legend L600 | BlueSound Node 3 - Tubes add soul! -
preface: I know very little in regards to the properties of electronic circuits.
question: Does error compound when running capacitors in parallel? For example: say you have a 260uf cap you decide to split with 2 130uf caps with 5% tolerances in parallel, is the tolerance still 5% because it is 5% over 260uf or does it compound to 10% error? Logic as I know it says it stays 5%, but again, I've never taken an eletronics course of ANY level, and am kind of learning as I go.design is where science and art break even. -
I've started replacing the resistors on the XO'r with the Mills supplied by SonciCraft (very nice people to work with by the way). I'm wondering about the tolerances/specs. For example, I've got a stock 22.5ohm resistor that is being replaced by a Mills 22.0ohm. The stock measures spot on 22.5, the mills measures 22.1. Interestingly even though the stock resistors are just 10% tolerance, so far all of the them have been spot on spec. All of the Mills measure a tad high or low. I know from the specified 22.5 to the Mills 22.1 is less than 2% off, but I'd feel better if my stock resistors were all over the map. Would do you think?
Doug,
You were actually sent 22.1 Ohm (face value) resistors. I'm pretty sure your invoice reflects that. However, I could be wrong. The slight variance in value actually has less to do with the sonic result, than the actual construction/materials used to make the part. I have seen several 20 year old electrolytic caps that were very close to face value, but they had an ESR greater than 0.4 Ohms.... Would perfectly matched parts be good? Sure, but we would be assuming that the XO design was 100%. I kind of doubt that. Further, send the drivers from each speaker off to be tested. You would be shocked how far off from one to the other that they are. None of this takes into account, speaker placement, room response, or personal taste. This is a very deep subject. I'm trying to keep from getting deep into it
Jeff -
I noticed that on my SDA2's when I did the crossover. Besides one way out of whack cap, most of the originals were well within the 5% range. And the Sonicaps I used were further out. I haven't retested to see if they just needed some break in time though.
When the Sonicap G1 first came out, we offered a 10% tol. They have been better than 5% for at least the past 8 years. If you have, or ever receive, a Sonicap outside 5%, feel free to return it. Many Polk owners over the years have taken advantage of the free matching on Sonicaps. Matched pairs are generally matched Left to Right better than 1%. Since distribution has moved back here to Texas, I try to match pairs better than 0.1%. In many cases 0.01%.
However, all good things come to a end. Sometime in 2011, we will start charging for Sonicap matching:frown: -
preface: I know very little in regards to the properties of electronic circuits.
question: Does error compound when running capacitors in parallel? For example: say you have a 260uf cap you decide to split with 2 130uf caps with 5% tolerances in parallel, is the tolerance still 5% because it is 5% over 260uf or does it compound to 10% error? Logic as I know it says it stays 5%, but again, I've never taken an eletronics course of ANY level, and am kind of learning as I go.
No, it will stay the same, or actually improve. Say we have two 130uF %5 tol caps. Cap "a" measures 123.5uF, and cap "b" measures 136.5uF. Paralleled, they would sum to 260.0uF. Now, let us pick two caps on one extreme of the tol. Cap "A" measures 123.5uF, and cap "B" measures 123.5uF. Paralleled, they sum to 247uF. The difference from target (260uF) is 13uF. Still 5%. -
I believe checking values of received component parts is always a good idea as sometimes a mistake can be made, or items damaged in shipping as was documented earlier this year by and OP who received damaged Dueland Resistors.
The concern I would have with using a lot of at home equipment is that the quality of the meter may be lacking for precise measurements, and few private parties pay for calibration of their meters which is usually required at least on an annual basis for industry use.
My belief is that the best approach is to contact the vendor by phone if there is a concern on accuracy of components to discuss what is found. I know the OP with the damaged resistors promptly received a replacement and the vendor was investigating better packaging methods.
Have a happy New Year. -
No, it will stay the same, or actually improve. Say we have two 130uF %5 tol caps. Cap "a" measures 123.5uF, and cap "b" measures 136.5uF. Paralleled, they would sum to 260.0uF. Now, let us pick two caps on one extreme of the tol. Cap "A" measures 123.5uF, and cap "B" measures 123.5uF. Paralleled, they sum to 247uF. The difference from target (260uF) is 13uF. Still 5%.
Thanks! I had figured the math (statistic probabilty) similarly, I just didn't know if there was something else going on, possibly some interaction, etc. I appreciate your help!design is where science and art break even. -
But would the trend not be like resistors in that the tolerance is usually on the low side as this will amount to big savings in raw materials over large batch production?No, it will stay the same, or actually improve. Say we have two 130uF %5 tol caps. Cap "a" measures 123.5uF, and cap "b" measures 136.5uF. Paralleled, they would sum to 260.0uF. Now, let us pick two caps on one extreme of the tol. Cap "A" measures 123.5uF, and cap "B" measures 123.5uF. Paralleled, they sum to 247uF. The difference from target (260uF) is 13uF. Still 5%.
Regardless they will likely be far tighter tolerance than were the original (typically 10-20% tolerance) lytics unless Polk went to the effort to actually test them.
