SDA SRS 1.2TL Sonicap Upgrade
DarqueKnight
Posts: 6,765
Introduction
I replaced the stock electrolytic and mylar capacitors and the ceramic metallic resistors immediately after acquiring my SDA SRS 1.2TL loudspeakers in December of 2001. I chose AudioCap PPMF series polypropylene resistors and Mills MRA-12 resistors for the upgrades. Sonicaps (the house brand at Sonic Craft) were not on the market at that time.
After Sonicaps became available, I noticed that some speaker modders who initially chose AudioCaps switched to them. Sonicaps were said to provide more overall resolution and more bass impact, although no one mentioned a "night and day" difference between the two. I sent an email to Jeff at Sonic Craft and asked his opinion on switching from AudioCaps to Sonicaps. I included a 1.2TL schematic. His advice was that replacing the AudioCaps with Gen I Sonicaps would not be "worth the money" and that better results would be gained by doing the following:
1. Replacing the 0.25uF cap with a 0.22uF/200V Sonicap Gen 2.
2. Bypassing the three 12uF AudioCaps with a 0.1uF Sonicap Platinum.
This upgrade supposedly would yield an across the board improvement from the middle midrange up. I wasn't adventurous enough to deviate that far from the original crossover design. I hope that a few of the brave souls reading this will try the recommendations shown in 1 and 2 on their SDA's. Please be gracious enough to provide us with a detailed report of your results.
A long time ago, I was advised by a Polk engineer to remove the silver mica bypass capacitors and the polyswitches. The bypass capacitors were used to improve the transient response of the stock mylar and electrolytic capacitors. In SDA's, bypass capacitors are not needed with faster film capacitors. Furthermore, they can introduce an artificial "airiness" and other artifacts that are not present in the recording. However, some people may find these effects sonically pleasing. Do what you like. The polyswitch is there to protect the tweeters. It is not needed if you have a quality high current amplifier and are not prone to overdriving it.
Based on prior knowledgeable advice and my own listening and modding experience with SDA's, I chose to decline the high frequency bypass option and go with replacing the AudioCaps with Gen I Sonicaps.
I requested pairs of Sonicaps matched as closely as possible to each other and to the nominal schematic values. The stock capacitors were 10% tolerance parts. Elliot at Sonic Craft called a couple of hours later and said that he was having trouble getting close to the 0.25 uF value and that if I wanted that value closely matched, it might delay my order. Elliot is the man who usually answers the phone when you call to order parts. He said that he had some 0.22 uF caps that were close to each other and asked if those would work. I agreed to take the 0.22 uF caps. My order was placed on Tuesday and I received my caps on Thursday.:)
Figure 1. An early birthday present for my SDA SRS 1.2TL's.
The measured values of the Sonicaps were as follows:
Installation Procedure
Carefully pinch the expansion tips of the standoffs and ease them out of the large inductor coil flange. The plastic expansion tips can become brittle with age, so care must be taken not to break them. Ask me how I know. If you do break one of your standoff tips to the point that it is not usable, don't get overly concerned. Although the original standoffs are no longer available, you can make a suitable replacement. One such replacement is a plastic bolt and plastic nuts.
The Sonicaps and the AudioCaps are about the same size, so there was no drama involved with orienting parts this time. There is more that one way of orienting the larger replacement parts on the circuit board. Use whatever orientation you find to be most stable for your circuit board. I say this because someone else's 1.2TL circuit boards may be different in size and shape from mine. Even if your board is the same as mine, you still may find another parts orientation advantageous.
The time to complete the first crossover from removal to re-installation, excluding the time to take pictures, was 1 hour 37 minutes. The second crossover took 1 hour 13 minutes.
Figure 2. Completed recapped crossover. Don't try this at home.:p
The completed recapped crossover for the left channel is shown in figure 2. The 13.5 uF cap is under the 27 uF cap. The lead lengths of the Sonicaps were more than adequate with the exception of one lead for the 27 uF cap. A 4 inch extension wire was required. The extension wire is the red wire at the bottom of figure 2.
The capacitor leads were covered with an appropriately sized piece of shrink wrap tubing prior to soldering. The tubing was shrunk with a 1600 watt hand held hair dryer.
A folded rectangular piece of 1/4" soft foam was placed under the caps. Once everything was soldered down, strips of Scotch 3850 packing tape were used to tightly bind the caps to each other to reduce vibration. Some people like to use hot glue. I prefer packing tape because it is easier to remove in the likely event that I desire future crossover upgrades.;)
Figure 3. The Mills MRA-12 resistors were placed on the bottom of the board.
Laying the caps lengthwise on the board left no room on top for the resistors. They were placed on the board bottom as shown in figure 3. The standoff near the upper left corner must be removed to properly solder a connection for a 12 uF capacitor. Notice that the solder hole for the capacitor butts against the standoff. You will need to take care to flatten the side of the solder bubble adjacent to the standoff so that it will fit securely back into the board.
Figure 4. Reassembled crossover assembly.
Figure 5. Who'd have thought that lurking behind this big, thick, and impressive
brushed aluminum plate was a little bitty circuit board?
Listening Evaluation
The only manufacturer's literature published for the Sonicaps is what is on the Sonic Craft website. There is no mention of the required break in time, but Elliot said that 100 hours was required for them to reach their full sonic potential.
The right channel crossover was done first, then reinstalled and the sound compared to the left channel with my preamp set to mono and the SDA interconnect removed. The balance control was repeatedly moved back and forth from right to left. I heard the following changes:
1. The recapped right side had more tactile and apparently louder bass. I could feel more vibrations coming through the floor and my seat cushions. The sound level meter registered the same volume on both sides.
2. The bass on the recapped side sounded slower and less defined and articulate.
3. The recapped right side had more upper midrange and high frequency detail. It did not sound brighter. I could just hear more decay, overtones, and details like a singer's inhaling and exhaling between phrases was clearer. I could also more clearly hear the subtle clicking sounds of saxophone players working the keys.
4. Some percussion instruments in the backround were heard more clearly. I also heard some percussion sounds that were previously unnoticed.
5. Sounds at both sides of the sound stage had more weight and detail.
I had previously replaced the stock caps in some of my other SDA's with Sonicaps, so items 1-5 came as no surprise. However, as expected, the degree of improvement was nowhere near as dramatic going from AudioCaps to Sonicaps as when I went from stock to Sonicaps.
When listening in stereo mode after both recapped crossovers were installed, I noted that the sound stage width and depth remained the same, but some vocals and solo instruments in the center were now projected 1/2 to 1 foot higher.
After 25 hours, bass speed was back up to pre-recap level and the bass definition and articulation had improved a lot, but it was still not back to pre-recap level.
After 80 hours, more high frequency and midrange detail was heard. Voices were clearer and heavier. Piano notes were more dynamic and had more weight.
After 102 hours, bass definition and detail had surpassed pre-recap levels.
After 106 hours, the bass was a little bit punchier and heavier. The apparent sound volume was louder, although the sound volume was not measurably louder. However, when the noise floor is lowered by continued break in, the sound reaching your ears consists of a higher percentage of the music signal, therefore, the music sounds louder.
The concept is the same as if you and another person were having a conversation in a room where other people are talking. If the other people in the room lower their voices or stop talking altogether, your voice, and the voice of the person you are talking to, will seem louder, although neither of you raised your voices.:)
Between 106 and 150 hours, I heard no further changes, so I assumed the Sonicaps were all grown up.
I replaced the stock electrolytic and mylar capacitors and the ceramic metallic resistors immediately after acquiring my SDA SRS 1.2TL loudspeakers in December of 2001. I chose AudioCap PPMF series polypropylene resistors and Mills MRA-12 resistors for the upgrades. Sonicaps (the house brand at Sonic Craft) were not on the market at that time.
After Sonicaps became available, I noticed that some speaker modders who initially chose AudioCaps switched to them. Sonicaps were said to provide more overall resolution and more bass impact, although no one mentioned a "night and day" difference between the two. I sent an email to Jeff at Sonic Craft and asked his opinion on switching from AudioCaps to Sonicaps. I included a 1.2TL schematic. His advice was that replacing the AudioCaps with Gen I Sonicaps would not be "worth the money" and that better results would be gained by doing the following:
1. Replacing the 0.25uF cap with a 0.22uF/200V Sonicap Gen 2.
2. Bypassing the three 12uF AudioCaps with a 0.1uF Sonicap Platinum.
This upgrade supposedly would yield an across the board improvement from the middle midrange up. I wasn't adventurous enough to deviate that far from the original crossover design. I hope that a few of the brave souls reading this will try the recommendations shown in 1 and 2 on their SDA's. Please be gracious enough to provide us with a detailed report of your results.
A long time ago, I was advised by a Polk engineer to remove the silver mica bypass capacitors and the polyswitches. The bypass capacitors were used to improve the transient response of the stock mylar and electrolytic capacitors. In SDA's, bypass capacitors are not needed with faster film capacitors. Furthermore, they can introduce an artificial "airiness" and other artifacts that are not present in the recording. However, some people may find these effects sonically pleasing. Do what you like. The polyswitch is there to protect the tweeters. It is not needed if you have a quality high current amplifier and are not prone to overdriving it.
Based on prior knowledgeable advice and my own listening and modding experience with SDA's, I chose to decline the high frequency bypass option and go with replacing the AudioCaps with Gen I Sonicaps.
I requested pairs of Sonicaps matched as closely as possible to each other and to the nominal schematic values. The stock capacitors were 10% tolerance parts. Elliot at Sonic Craft called a couple of hours later and said that he was having trouble getting close to the 0.25 uF value and that if I wanted that value closely matched, it might delay my order. Elliot is the man who usually answers the phone when you call to order parts. He said that he had some 0.22 uF caps that were close to each other and asked if those would work. I agreed to take the 0.22 uF caps. My order was placed on Tuesday and I received my caps on Thursday.:)
Figure 1. An early birthday present for my SDA SRS 1.2TL's.
The measured values of the Sonicaps were as follows:
Table 1. Measured values of Sonicap Gen I Capacitors.
Installation Procedure
Carefully pinch the expansion tips of the standoffs and ease them out of the large inductor coil flange. The plastic expansion tips can become brittle with age, so care must be taken not to break them. Ask me how I know. If you do break one of your standoff tips to the point that it is not usable, don't get overly concerned. Although the original standoffs are no longer available, you can make a suitable replacement. One such replacement is a plastic bolt and plastic nuts.
The Sonicaps and the AudioCaps are about the same size, so there was no drama involved with orienting parts this time. There is more that one way of orienting the larger replacement parts on the circuit board. Use whatever orientation you find to be most stable for your circuit board. I say this because someone else's 1.2TL circuit boards may be different in size and shape from mine. Even if your board is the same as mine, you still may find another parts orientation advantageous.
The time to complete the first crossover from removal to re-installation, excluding the time to take pictures, was 1 hour 37 minutes. The second crossover took 1 hour 13 minutes.
Figure 2. Completed recapped crossover. Don't try this at home.:p
The completed recapped crossover for the left channel is shown in figure 2. The 13.5 uF cap is under the 27 uF cap. The lead lengths of the Sonicaps were more than adequate with the exception of one lead for the 27 uF cap. A 4 inch extension wire was required. The extension wire is the red wire at the bottom of figure 2.
The capacitor leads were covered with an appropriately sized piece of shrink wrap tubing prior to soldering. The tubing was shrunk with a 1600 watt hand held hair dryer.
A folded rectangular piece of 1/4" soft foam was placed under the caps. Once everything was soldered down, strips of Scotch 3850 packing tape were used to tightly bind the caps to each other to reduce vibration. Some people like to use hot glue. I prefer packing tape because it is easier to remove in the likely event that I desire future crossover upgrades.;)
Figure 3. The Mills MRA-12 resistors were placed on the bottom of the board.
Laying the caps lengthwise on the board left no room on top for the resistors. They were placed on the board bottom as shown in figure 3. The standoff near the upper left corner must be removed to properly solder a connection for a 12 uF capacitor. Notice that the solder hole for the capacitor butts against the standoff. You will need to take care to flatten the side of the solder bubble adjacent to the standoff so that it will fit securely back into the board.
Figure 4. Reassembled crossover assembly.
Figure 5. Who'd have thought that lurking behind this big, thick, and impressive
brushed aluminum plate was a little bitty circuit board?
Listening Evaluation
The only manufacturer's literature published for the Sonicaps is what is on the Sonic Craft website. There is no mention of the required break in time, but Elliot said that 100 hours was required for them to reach their full sonic potential.
The right channel crossover was done first, then reinstalled and the sound compared to the left channel with my preamp set to mono and the SDA interconnect removed. The balance control was repeatedly moved back and forth from right to left. I heard the following changes:
1. The recapped right side had more tactile and apparently louder bass. I could feel more vibrations coming through the floor and my seat cushions. The sound level meter registered the same volume on both sides.
2. The bass on the recapped side sounded slower and less defined and articulate.
3. The recapped right side had more upper midrange and high frequency detail. It did not sound brighter. I could just hear more decay, overtones, and details like a singer's inhaling and exhaling between phrases was clearer. I could also more clearly hear the subtle clicking sounds of saxophone players working the keys.
4. Some percussion instruments in the backround were heard more clearly. I also heard some percussion sounds that were previously unnoticed.
5. Sounds at both sides of the sound stage had more weight and detail.
I had previously replaced the stock caps in some of my other SDA's with Sonicaps, so items 1-5 came as no surprise. However, as expected, the degree of improvement was nowhere near as dramatic going from AudioCaps to Sonicaps as when I went from stock to Sonicaps.
When listening in stereo mode after both recapped crossovers were installed, I noted that the sound stage width and depth remained the same, but some vocals and solo instruments in the center were now projected 1/2 to 1 foot higher.
After 25 hours, bass speed was back up to pre-recap level and the bass definition and articulation had improved a lot, but it was still not back to pre-recap level.
After 80 hours, more high frequency and midrange detail was heard. Voices were clearer and heavier. Piano notes were more dynamic and had more weight.
After 102 hours, bass definition and detail had surpassed pre-recap levels.
After 106 hours, the bass was a little bit punchier and heavier. The apparent sound volume was louder, although the sound volume was not measurably louder. However, when the noise floor is lowered by continued break in, the sound reaching your ears consists of a higher percentage of the music signal, therefore, the music sounds louder.
The concept is the same as if you and another person were having a conversation in a room where other people are talking. If the other people in the room lower their voices or stop talking altogether, your voice, and the voice of the person you are talking to, will seem louder, although neither of you raised your voices.:)
Between 106 and 150 hours, I heard no further changes, so I assumed the Sonicaps were all grown up.
Proud and loyal citizen of the Digital Domain and Solid State Country!
Post edited by DarqueKnight on
Comments
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Economic Analysis
For me, just the improvements in bass slam, detail and articulation were well worth the $245 cost of the parts. Although the difference between the AudioCap sound and the Sonicap sound was not night and day, it was substantial and easily heard. The parts cost of the AudioCaps was $181.84 in 2001. This equates to $218.88 in 2008 dollars. Therefore, the Sonicaps cost 12% more...but they provided at least a 25% improvement...so no diminising returns this time. I am quantifying the 25% improvement solely on the amount of additional bass hitting my body.:)
During the course of my research for replacement film capacitors, I became aware that many audiophiles consider the Mundorf caps to be "the best". Well, "the best" is often relative to a particular application. Even people who are enamored of the Mundorfs admit that their very high cost provides a brutally punishing price to performance ratio.
How brutal and how punishing? Let's see. The third best Mundorf series is the Silver and Oil. Reviewers have stated that the performance differences between the S&O and the top two series are small and sometimes non-existant in certain applications. The largest value of the Mundorf's is 10 uF. That means that I would have to do a lot of parallel combinations to get the 12 uF, 13.5 uF, and 27 uF values needed for a SDA SRS 1.2TL crossover mod.
To get 12 uF, I could combine 10 uF ($166.15) and 2.2 uF ($71.90), for a total of $238.05. I would need six of the 12.2 uF combinations for a total of $1,428.30. Shall we continue or have you had enough?
To get 13.5 uF, I could combine two 6.8 uF ($121.10) for a total of $242.20. I would need two of the 13.6 uF combinations for a total of $484.40. Want more? OK.
To get 27 uF, I could combine two 10 uF (2 x $166.15) and one 6.8 uF ($121.10) for a total of $453.4. I would need two of the 26.8 uF combinations for a total of $906.80.
The grand total for a Mundorf Silver and Oil cap upgrade for a pair of SDA SRS 1.2TL's would be $2,890.54:eek:. This is over 10X the cost of the Sonicaps...and more than what I paid for the 1.2TL's.
For higher levels of "sticker shock", please go to the partsconnexion.com website and review the prices of the Mundorf Silver and Gold series and Silver/Gold and Oil series.
It is a verified true fact that properly modified big SDA's are...
Internal Wiring
In the far reaches of my imagination lurks the idea of changing out the internal wiring of my 1.2TL's for some of the current whizz bang stuff. I'd be more encouraged if I knew of at least one person who replaced the internal wiring of any kind of SDA loudspeaker and heard an improvement.
I spent a miserable day some years ago replacing the stock wiring in one speaker of my SDA 1B's, first with Monster Cable 12 AWG oxygen free copper then with "premium" 16 AWG Teflon jacketed oxygen free copper hookup wire. With either types of replacement wire, I heard no difference whatsoever from the speaker with stock wire. One of Polk's engineers told me changing internal wire was a waste of time, but I had to be sure.;)
In case any of you are curious about replacing the wire inside your SDA's, the wire in my 1.2TL's (and all my other current SDA's) was made by Atlas Wire Corporation in Schiller Park, IL. It is ordinary 16 AWG style 1015 stranded tinned copper wire with PVC insulation and rated for 600 volts and 105 degrees C.
I snipped off one of the spade driver connectors and looked at the stripped end of the wire under an 8X magnifying glass. The copper cross section and tinned outer coating were still bright, shiny and corrosion free. My 1.2TL's were manufactured in October of 1989.
I think I'll hold off on the internal wire upgrade a little while longer.
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Last Words
The Monoliths are mad because they really wanted Mundorf's.
Amazing how they still produce Such Good Sound while angry.Proud and loyal citizen of the Digital Domain and Solid State Country! -
Great write up.
I too would love to get my hands on S&O's for my mains, maybe one day."He who fights with monsters should look to it that he himself does not become a monster. And when you gaze long into an abyss the abyss also gazes into you." Friedrich Nietzsche -
Very cool write up AGAIN.
One of my observations of the break in period of the Sonicaps, in my case was after my guess of @ 400 hours I noticed even further improvement. My SDA's had a ( for a lack of a better term) shouty mid range that bothered me and it disapeared after @ the 400 hour mark. I am very pleased with mine, but this is your thread.
Excellent. Enjoy.
ScottI like speakers that are bigger than a small refrigerator but smaller than a big refrigerator:D -
I recall that Hearingimpared mentioned it took about 400 hours for the Sonicaps in his 1.2TL's to break in.Proud and loyal citizen of the Digital Domain and Solid State Country!
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My experience, break in was under 200 hours with Sonic Caps in my Tannoy HPD's."He who fights with monsters should look to it that he himself does not become a monster. And when you gaze long into an abyss the abyss also gazes into you." Friedrich Nietzsche
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Last month I made the opposite decision from that made by DarqueKnight, electing to use Jentens in the low pass of my second set of SDA 2Bs based on comments I presumed to be informed.
I found the Jentzens to be lacking. The Sonicaps are a huge bang for the buck and I intend to stick with them in the future, or at least until something better comes along.
Anyone considering using caps downmarket from the Sonicaps who are still on the fence after reading the subject post here should read the 9th post in this thread:The world is full of answers, some are right and some are wrong. - Neil Young -
Soooooo.....are you guys using a stop watch of some kind to "time" the break in period?
Richard? Who's your favorite Little Rascal? Alfalfa? Or is it........................Spanky?.................................Sinner. -
Nah. I keep a log.Proud and loyal citizen of the Digital Domain and Solid State Country!
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1. Replacing the 0.25uF cap with a 0.22uF/200V Sonicap Gen 2.
2. Bypassing the three 12uF AudioCaps with a 0.1uF Sonicap Platinum.
This upgrade supposedly would yield an across the board improvement from the middle midrange up. I wasn't adventurous enough to deviate that far from the original crossover design. I hope that a few of the brave souls reading this will try the recommendations shown in 1 and 2 on their SDA's.
I can't comment on the use of the Gen II cap in that position in that speaker, but I can comment on the use of the .1uF bypass caps. DON'T DO IT!!! It results in a artifacts (fake sound) in the high end. At first it sounds kind of neat, but in short order becomes annoying as hell. I couldn't get them out of there fast enough. Your mileage will not vary in SDA speakers.
Raife, your findings echo mine and reinforce what I stated, last week I think, that Sonicap's in the low pass make a noticeable and positive difference.Political Correctness'.........defined
"A doctrine fostered by a delusional, illogical minority and rabidly promoted by an unscrupulous mainstream media, which holds forth the proposition that it is entirely possible to pick up a t-u-r-d by the clean end."
President of Club Polk -
I can't comment on the use of the Gen II cap in that position in that speaker,
These comments from the Sonicraft website gave me pause about the Gen II:
"The Gen I is basically a fairly balanced capacitor. However, some find our "balanced" slightly thin and bright compared to the more lush "colored" capacitors which would include the Gen II. While the Gen II has a nice Midrange bloom,..."
I have never found the Gen I's to be thin and bright. I don't like lush or colored or a midrange bloom....I can comment on the use of the .1uF bypass caps. DON'T DO IT!!! It results in a artifacts (fake sound) in the high end. At first it sounds kind of neat, but in short order becomes annoying as hell. I couldn't get them out of there fast enough. Your mileage will not vary in SDA speakers.
I'm sure some people will like the added "ambiance".;)Raife, your findings echo mine and reinforce what I stated, last week I think, that Sonicap's in the low pass make a noticeable and positive difference.
Jesse, I have found that film caps, of any brand have always made a positive difference in the low pass sections of all my SDA's.
I know some people look at the schematics and see that the low frequency caps are not directly in the signal path and assume that those caps have no effect on the sound. However, those caps are in the crossover circuit and, like every other crossover component, including the printed wiring board, they are exerting some influence on the sound.Proud and loyal citizen of the Digital Domain and Solid State Country! -
Jesse, I have found that film caps, of any brand have always made a positive difference in the low pass sections of all my SDA's.
Agreed, but my point, the same as yours, is that Sonicap's do it better.
Here's the thread with my previous comments.
http://www.polkaudio.com/forums/showthread.php?t=68403Political Correctness'.........defined
"A doctrine fostered by a delusional, illogical minority and rabidly promoted by an unscrupulous mainstream media, which holds forth the proposition that it is entirely possible to pick up a t-u-r-d by the clean end."
President of Club Polk -
Raife,
Did Jeff happen to mention anything about using the Mundorf S/O's in the tweeter array, and using SONICAP's for the shunt caps in the mid/woof arrays? This is something that's been in the back of my mind for a future, all-out assault "gift" to my 2.3tl's. In one of my conversations with Jeff a few months back, discussing some of my Infinities, he had mentioned that the SONICAP turned out to be an excellent shunt capacitor, quite by accident.Polk SDA SRS 2
Polk RTA 15tl
Polk Monitor 7C
Polk Lsi9
Infinity RS-II (modded)
Infinity RS-IIIa (modded)
Infinity RS 2.5 x 2
Magnepan 1.6QR (modded)
System: http://forum.audiogon.com/cgi-bin/fr.pl?vevol&1290711373 -
There's absolutely no reason you can't do that and if you want the very best, do it with Duelund's.Political Correctness'.........defined
"A doctrine fostered by a delusional, illogical minority and rabidly promoted by an unscrupulous mainstream media, which holds forth the proposition that it is entirely possible to pick up a t-u-r-d by the clean end."
President of Club Polk -
There's absolutely no reason you can't do that and if you want the very best, do it with Duelund's.
Well, if I decided to cross that cost boundary (or AudioNote's, or V-Cap Teflon's) I would certainly have to question my own "dedication" to this hobby.;)Polk SDA SRS 2
Polk RTA 15tl
Polk Monitor 7C
Polk Lsi9
Infinity RS-II (modded)
Infinity RS-IIIa (modded)
Infinity RS 2.5 x 2
Magnepan 1.6QR (modded)
System: http://forum.audiogon.com/cgi-bin/fr.pl?vevol&1290711373 -
Did Jeff happen to mention anything about using the Mundorf S/O's in the tweeter array, and using SONICAP's for the shunt caps in the mid/woof arrays?
No.This is something that's been in the back of my mind for a future, all-out assault "gift" to my 2.3tl's.
Go for it! My SDA's have always been very appreciative of gifts.:)Proud and loyal citizen of the Digital Domain and Solid State Country! -
Very nice work. One question - where did you get these parts? I cannot find the values you have on sites like handmade electronics, soniccraft.com, or parts express.
Thanks so much. I just got a pair of 1.2tl and want to upgrade the crossover.
Burson HA-160D > Adcom GFA-5802 > Polk SDA-SRS 1.2tl w/ Mye Sound Spikes, Mills/Sonicap XO, Larry's Rings, Dynamat Extreme, Cardas CCGR Binding Posts and Jumpers, Custom 10ga interconnect, Custom Gaskets, RDO-198 -
Very nice work. One question - where did you get these parts? I cannot find the values you have on sites like handmade electronics, soniccraft.com, or parts express.
Call Soniccraft, they are more than happy to make custom values for you, at no price penalty. If I recall correctly, they'll charge you the price of the next size up, as listed on their site.
JayJay
SDA 2BTL * Musical Fidelity A5cr amp * Oppo BDP-93 * Modded Adcom GDA-600 DAC * Rythmik F8 (x2)
Micro Seiki DQ-50 * Hagerman Cornet 2 Phono * A hodgepodge of cabling * Belkin PF60
Preamp rotation: Krell KSL (SCompRacer recapped) * Manley Shrimp * PS Audio 5.0 -
That sounds like a great manufacturer! I will get a hold of them. Thanks!
Burson HA-160D > Adcom GFA-5802 > Polk SDA-SRS 1.2tl w/ Mye Sound Spikes, Mills/Sonicap XO, Larry's Rings, Dynamat Extreme, Cardas CCGR Binding Posts and Jumpers, Custom 10ga interconnect, Custom Gaskets, RDO-198 -
One more question - you mention removing the silver mica bypass caps and the polyswitch. When you did this did you replace the polyswitch with a short run of wire?
I keep looking at this photo someone uploaded and it looks like you can remove one of the silver mica caps but the removing the other (the one below the 22.5 ohm resistor) looks like it might create an open circuit...
Lastly I see Sonicraft has 11 and 22 ohm mills resistors. Did you just use these because they were in the original tolerance of the stock 11.5 and 22.5 ohm resistors?
I am trying to build up my shopping list for the xover restorations. Thanks!
Burson HA-160D > Adcom GFA-5802 > Polk SDA-SRS 1.2tl w/ Mye Sound Spikes, Mills/Sonicap XO, Larry's Rings, Dynamat Extreme, Cardas CCGR Binding Posts and Jumpers, Custom 10ga interconnect, Custom Gaskets, RDO-198 -
I keep looking at this photo someone uploaded and it looks like you can remove one of the silver mica caps but the removing the other (the one below the 22.5 ohm resistor) looks like it might create an open circuit...
You have to run a jumper to close the circuit. -
I would suggest replacing the polyswitch with a 0.5 ohm resistor to keep the original resistance designed into the circuit as 0.5 ohms is audible.
Use a 10.5 and a 12 for the 22.5, etc.Political Correctness'.........defined
"A doctrine fostered by a delusional, illogical minority and rabidly promoted by an unscrupulous mainstream media, which holds forth the proposition that it is entirely possible to pick up a t-u-r-d by the clean end."
President of Club Polk -
Ahh I forgot about that.
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Got my new polyswitches from Polk today. Such great customer service! On a side note, Jeff from Sonicraft explicitly told me not to replace the polyswitches with a .5 ohm resistor. He said just to remove them. Maybe I should try both ways to see what sounds best?
Burson HA-160D > Adcom GFA-5802 > Polk SDA-SRS 1.2tl w/ Mye Sound Spikes, Mills/Sonicap XO, Larry's Rings, Dynamat Extreme, Cardas CCGR Binding Posts and Jumpers, Custom 10ga interconnect, Custom Gaskets, RDO-198 -
I respect Jeff and he is knowledgeable but he is not a Polk expert. If Jesse says to do it, do it and he's says to do it so do it.
Its my understanding that you want them to be as close to original spec's as possible. Polk did a tremendous amount of R&D to get them to a certain performance so you gotta trust that the values they use are in your best listening interest. -
Good enough for me - and I did order .5 ohm resistors so I will give them a whack. Three of the 5 new polyswitches I received measure .3 ohms and the other two measure .4 ohms so that sounds just about right! Thanks, my caps arrive tonight so hopefully all goes well and I have a fresh pair of speakers to talk about tomorrow (in my other thread as not to pollute this one any more).
Burson HA-160D > Adcom GFA-5802 > Polk SDA-SRS 1.2tl w/ Mye Sound Spikes, Mills/Sonicap XO, Larry's Rings, Dynamat Extreme, Cardas CCGR Binding Posts and Jumpers, Custom 10ga interconnect, Custom Gaskets, RDO-198 -
Make sure you have your tt ground secured tightly if you decide to tempt fate and remove those poly switches. My ground wire got knocked off during an equipment change and took out 4 tweeters that weren't protected. My new polk poly switches did their job and saved me from replacing another 6 tweeters. Good luck to you in which ever avenue you may choose and on your recap as well.
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As per Jeff @ Sonicraft I kept the .25uf, got rid of the silver micas (750pf). Also got rid of the polyswitchs. Right out of the gate it is a very impressive improvement. The HF is WAY better in every way and the image got bigger and increased in depth. No loss of bass as DK had. And they'll supposedly get better over time with break in. $250 well spent!
This is my first phase. I have binding posts on order. In phase two I am going to get rid of the recessed cup too. I plan to put on a painted piece of MDF in their place. It's hard to put on good spades with the stock cups. I also use a speaker filter (like Walkers; my DIY here: www.econotweaks.com) So having easier to access binding posts will make things handier and hopefully make a sound improvement as well. I will also mount the crossovers on a 11 X 5 board and point to point wire them.
ET
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System: MF Trivista SACD > Placette passive> CJ passive horizontal bi-amp> MF 2500A(LF) MF2100(HF) > 1.2TL's
Other: Speltz silver Eichmann IC's & speaker wire, Econotweaks Detail Magnifiers, PS Audio P-300(source), R. Gray 600, Al Sekala's AC R/C filters, R. Gray HT PC's, Oyaide R-1's,WPC-Z , M-1, Herbie's & DIY Isolation
Room: Qty 7 - 4' tall 18" diam. bass traps, Qty 4 - 4' X 2' X 4" panels. All DIY - man my wife is tolerant! -
I have owned some 1.2TL's for about 20 years. I love the speakers and can not find a speaker I would prefer. It is clear to me the sound quality has degraded so it is probably time to replace the crossoverrs The speakers still look like new. I do some light electronics but the directions above are a little over my head. Can someone either break it down a little for me, or suggest where you go to get this done. I can solder and follow directions but..... thanks very much in advance.
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I have owned some 1.2TL's for about 20 years. I love the speakers and can not find a speaker I would prefer. It is clear to me the sound quality has degraded so it is probably time to replace the crossoverrs The speakers still look like new. I do some light electronics but the directions above are a little over my head. Can someone either break it down a little for me, or suggest where you go to get this done. I can solder and follow directions but..... thanks very much in advance.
There are some step-by-step threads here. Do a search. If you still find it too scary (which I did at first, it was my first time in years) PM ben62670, he does crossovers for people all the time here and will do ya right by the price.
BTW welcome to Club Polk. -
howl
What hearingimpared says is true. Ben is a great guy and will do you right.
Welcome to Club Polk.
Hi Joe!!!
Go Saints!!!!
