Well you still have time to go balanced of course. Make sure your CDP has balanced out.
So I spoke with Fred from Silonex. He says "whats the lowest ohms you get" and I say I have only tested with 80k in series with 5V so still its about 900-1.2k but that I dont care to much if I get 40ohms or not. He asks what the max resistance I get is and I say that I only test to 80k in series so my answer is the same. He says if I turn it off (the LED) then what? I say that a few megohms. He says 'see its in spec'. What? To me thats not in spec. They have a curve on their datasheet that shows an expected response and he says that that would be a typical response but not a guaranteed response and I said that I have over 500 and not one of them follows that graph so how can this be typical? We go back and forth a lot. It comes down to him not wanting an unhappy customer and Allied freaking out a bit because they are concerned that the 3k or so they have of these could all be junkers. So he wants to work with me to find a good solution that may even produce better matching results. Fine, this is fine, lets work on it and see what we come up with.
This means that your matches may take longer. Nearly a guarantee. I will email you all that have placed orders and explain what is going on. It may take longer or it may not. Allied already sent my other bag supposedly so I will try those out to.
He is going to send me some samples of other LDRs. I am hoping to use the same resistive material or at least get the same quality of beautiful sound out of any new ones. I will not compromise the sound quality even if distortion figures are better that does not guarantee a better quality of sound in my opinion. These are extremely low anyway since we are using them at one of the lowest distortion voltages we can. If you need to know more about this its in the datasheet and on the website. Check it out.
I will keep you updated. He is supposed to email me today to start the ball rolling on my needs.
Uriah
So I spoke with Fred from Silonex. He says "whats the lowest ohms you get" and I say I have only tested with 80k in series with 5V so still its about 900-1.2k but that I dont care to much if I get 40ohms or not. He asks what the max resistance I get is and I say that I only test to 80k in series so my answer is the same. He says if I turn it off (the LED) then what? I say that a few megohms. He says 'see its in spec'. What? To me thats not in spec. They have a curve on their datasheet that shows an expected response and he says that that would be a typical response but not a guaranteed response and I said that I have over 500 and not one of them follows that graph so how can this be typical? We go back and forth a lot. It comes down to him not wanting an unhappy customer and Allied freaking out a bit because they are concerned that the 3k or so they have of these could all be junkers. So he wants to work with me to find a good solution that may even produce better matching results. Fine, this is fine, lets work on it and see what we come up with.
This means that your matches may take longer. Nearly a guarantee. I will email you all that have placed orders and explain what is going on. It may take longer or it may not. Allied already sent my other bag supposedly so I will try those out to.
He is going to send me some samples of other LDRs. I am hoping to use the same resistive material or at least get the same quality of beautiful sound out of any new ones. I will not compromise the sound quality even if distortion figures are better that does not guarantee a better quality of sound in my opinion. These are extremely low anyway since we are using them at one of the lowest distortion voltages we can. If you need to know more about this its in the datasheet and on the website. Check it out.
I will keep you updated. He is supposed to email me today to start the ball rolling on my needs.
Uriah
5V in series 80K is very close to full attenuation of a 100K pot. In fact, that is the exact case with my POS surplus 100K pot, it max out at 80K, way sooner than the specs. I don't recall seeing anything this low. Did you check how much current the LED draw?
I will check the lowest readings of those that I have measured so far when I get home. I will post the date code and reading for your reference.
I will check the lowest readings of those that I have measured so far when I get home. I will post the date code and reading for your reference.
Actually I have done some further testing. (Fred I forgot to recheck your numbers and will do so).
SO I tested at 18k and at 200k. Very promising. We may have to use 250k or higher like even 500k dual audio pots to control them, but this MAY be the BEST batch ever. When I got 1k at 80k I was crestfallen. Very upset that they were so terrible. However they were all within 300 ohms of each other. If I was going for 1k pots it would be heaven. So I went and tested at 200k. Almost all of them were at 3-3.4k. Very good news so far. Fred from Silonex had said they get really unpredictable at super low amps. I am at microamps and they seem promising. At 18k they were all around 260-300R. So maybe they proceed linearly. I need to check this with some massive trimmers. Then I need to make a prototype with a 250k - 500k somewhere around there dual log pot and see if we have a winner. If so I will be buying more and revising my recommendation for a circuit. That would only be that we should use a higher value than 100k. SO this is simply due to the inconsistencies in their manufacturing process, but hopefully it will work to our advantage today.
I will keep you all updated, you know that
Uriah
SO I tested at 18k and at 200k. Very promising. We may have to use 250k or higher like even 500k dual audio pots to control them, but this MAY be the BEST batch ever. When I got 1k at 80k I was crestfallen. Very upset that they were so terrible. However they were all within 300 ohms of each other. If I was going for 1k pots it would be heaven. So I went and tested at 200k. Almost all of them were at 3-3.4k. Very good news so far. Fred from Silonex had said they get really unpredictable at super low amps. I am at microamps and they seem promising. At 18k they were all around 260-300R. So maybe they proceed linearly. I need to check this with some massive trimmers. Then I need to make a prototype with a 250k - 500k somewhere around there dual log pot and see if we have a winner. If so I will be buying more and revising my recommendation for a circuit. That would only be that we should use a higher value than 100k. SO this is simply due to the inconsistencies in their manufacturing process, but hopefully it will work to our advantage today.
I will keep you all updated, you know that
Uriah
Yesterday I ordered 50 25turn trimmers at 500k and 50 more at 1MOhm. This is very strange as normally I would be only testing up to 40k. However I LIKE this change of events for matching. So far anyway. We will see how testing turns out. This is costing a lot of money but hopefully it will be worth it and if it is hopefully Silonex got their act together and started getting these manufactured with higher quality control. Maybe its just a weird quirk.
Bought a few 250 and 500k dual log pots so I can build up prototype LSAs and test out the new LDRs after I find a few matches. THEN I will test out of this batch for you guys as long as things are looking good. Otherwise I will continue with the return and exchange with Allied.
Will keep you in the loop.
Uriah
Bought a few 250 and 500k dual log pots so I can build up prototype LSAs and test out the new LDRs after I find a few matches. THEN I will test out of this batch for you guys as long as things are looking good. Otherwise I will continue with the return and exchange with Allied.
Will keep you in the loop.
Uriah
Alan,
You have LDRs from an earlier matching that I think you are referring to. I think its best to use 100k with them. This new batch is acting completely different than any other batch I have ever matched. It might allow 500k pots. I have to get testing once I get my trimpots in. They are on order with Mouser.
So for you Alan, I would use a 100k pot as you will get greater range with the matched sets you have now.
For your recent order I dont know yet. I suspect 250k or 500k, not sure yet.
Uriah
You have LDRs from an earlier matching that I think you are referring to. I think its best to use 100k with them. This new batch is acting completely different than any other batch I have ever matched. It might allow 500k pots. I have to get testing once I get my trimpots in. They are on order with Mouser.
So for you Alan, I would use a 100k pot as you will get greater range with the matched sets you have now.
For your recent order I dont know yet. I suspect 250k or 500k, not sure yet.
Uriah
First Round Results
I have tested 549 LDRs at 200k in series with 5.039VDC
Results are great and average resistance is 4296R at 200k in series with voltage. Min was 2.5k max was 6k.
This particular batch of LDRs is frankly weird. Maybe it will become the norm. Maybe they changed the manufacturing process. I dont know but their datasheet has not changed and these do not fit the datasheet. Nevertheless, they will work for our purposes.
Given this strange situation I didnt know what 4 points I would match at since normally my max resistance in series with 5VDC would be 40k and would result in numbers similar to those achieved with 200k. You can see where these LDRs present a bit of an unknown and are acting 'weird'. I want to provide you guys with LDRs that I know will function similar to the average Lightspeed in terms of overall output impedance. I will consider what to do next. I am considering testing half of them for use with a 250k pot and the other half for use with a 500k pot. The half that are measuring 5k-6k would be used with a 250k pot and the half that are measuring lower would be used with a 500k pot. I think its best if I measure that lower half next at about 400k and see how that works out. If they are getting to erattic because of the miniscule power they are getting then I will abort that plan and go for a 250k pot for all of them which would mean my next measuring would be at 150k, 75k, 37k or thereabouts. We will see what works best.
Uriah
I have tested 549 LDRs at 200k in series with 5.039VDC
Results are great and average resistance is 4296R at 200k in series with voltage. Min was 2.5k max was 6k.
This particular batch of LDRs is frankly weird. Maybe it will become the norm. Maybe they changed the manufacturing process. I dont know but their datasheet has not changed and these do not fit the datasheet. Nevertheless, they will work for our purposes.
Given this strange situation I didnt know what 4 points I would match at since normally my max resistance in series with 5VDC would be 40k and would result in numbers similar to those achieved with 200k. You can see where these LDRs present a bit of an unknown and are acting 'weird'. I want to provide you guys with LDRs that I know will function similar to the average Lightspeed in terms of overall output impedance. I will consider what to do next. I am considering testing half of them for use with a 250k pot and the other half for use with a 500k pot. The half that are measuring 5k-6k would be used with a 250k pot and the half that are measuring lower would be used with a 500k pot. I think its best if I measure that lower half next at about 400k and see how that works out. If they are getting to erattic because of the miniscule power they are getting then I will abort that plan and go for a 250k pot for all of them which would mean my next measuring would be at 150k, 75k, 37k or thereabouts. We will see what works best.
Uriah
I pick the measuring points based on the pots that will be used.
For example, I measure the resistance at 9, 12, 3 o'clock positions of
a 100K pot and a 250K pot. If it is not too much trouble, pick 5 points, the lowest and the highest plus 3 points in between. I use all 6 due to my small batch
This kind of works for me very well because this allows me to sort out
which are good for 100K, and which are for 250K, and which are good for both!! In your case, you may want to use measure points for 250K and 500K instead.
For those who plan to build per George's design without any extra work in the power supply, another factor that affects the usable range is the number of LDR's per pot being used. I found that the ranges of resistance from 9 o'clock to 3 o'clock positions are quite different between 1 pot for 4 LDR's and 1 pot for 2 LDR's (dual mono).
By manipulating the above 2 factors, you can really improve the yield of good matches. Of course, that also means more labor of love .....
For example, I measure the resistance at 9, 12, 3 o'clock positions of
a 100K pot and a 250K pot. If it is not too much trouble, pick 5 points, the lowest and the highest plus 3 points in between. I use all 6 due to my small batch
This kind of works for me very well because this allows me to sort out
which are good for 100K, and which are for 250K, and which are good for both!! In your case, you may want to use measure points for 250K and 500K instead.
For those who plan to build per George's design without any extra work in the power supply, another factor that affects the usable range is the number of LDR's per pot being used. I found that the ranges of resistance from 9 o'clock to 3 o'clock positions are quite different between 1 pot for 4 LDR's and 1 pot for 2 LDR's (dual mono).
By manipulating the above 2 factors, you can really improve the yield of good matches. Of course, that also means more labor of love .....
udailey,
When George first brought this phenomenon to the forum it took quite a bit of wrangling to eventually get the Siliconex item on the table. There were other manufacturers batted around as a source for the attenuator until this information was published.
With the numbers being so completely unreliable at times. when doing the matching, would it not be a good idea to at least try some of the units from say Elmer, et al. or has this been tried.
I bought 30 ldr's from Allied about 6 months ago, after Nelson published his buffer schematic, and became so discouraged with the matching I gave up on this project.
With so much interest in this great design, and potential buying power, could not a more stable item be found. I really like this technology, kudos to George, but the matching is as you said a bi---.
Tad
When George first brought this phenomenon to the forum it took quite a bit of wrangling to eventually get the Siliconex item on the table. There were other manufacturers batted around as a source for the attenuator until this information was published.
With the numbers being so completely unreliable at times. when doing the matching, would it not be a good idea to at least try some of the units from say Elmer, et al. or has this been tried.
I bought 30 ldr's from Allied about 6 months ago, after Nelson published his buffer schematic, and became so discouraged with the matching I gave up on this project.
With so much interest in this great design, and potential buying power, could not a more stable item be found. I really like this technology, kudos to George, but the matching is as you said a bi---.
Tad
Tad,
I am talking with Silonex about trying a few others from them. I might try Vactrol as well, but really the options are pretty limited as most are not good just by their datasheets for our purposes. Plus, for the most part Silonex work, they are a pain but they work and sound wonderful. It costs a significant amount of cash to buy Vactrol compared to Silonex so trying them out has been something I have not been real interested in yet.
Most people use these things in musical instuments and in pots for instruments. They use a set resistor (film or such) and then one LDR so they could care less about matching and while it doesnt sound as good as a Lightspeed it still sounds good so its good enough for them and there is no reason for the manufacturers to try harder. Thats my guess anyway.
Uriah
I am talking with Silonex about trying a few others from them. I might try Vactrol as well, but really the options are pretty limited as most are not good just by their datasheets for our purposes. Plus, for the most part Silonex work, they are a pain but they work and sound wonderful. It costs a significant amount of cash to buy Vactrol compared to Silonex so trying them out has been something I have not been real interested in yet.
Most people use these things in musical instuments and in pots for instruments. They use a set resistor (film or such) and then one LDR so they could care less about matching and while it doesnt sound as good as a Lightspeed it still sounds good so its good enough for them and there is no reason for the manufacturers to try harder. Thats my guess anyway.
Uriah
Uriah,
Georges first introduction of this technology was using a separate led source a tube and a photo resistor. Would going back to this approach, in your opinion, possible yeild a matched pair earlier. We have to match the diode discrepency and the resistor error with the Siliconex units as they are. If we use just one led as the photo source for the 4 resistors would that not be easier to match. Just a thought. I really never could get anything approaching a useful set from the 30 SORTED units I bought from Allied. I also found that full volume, or thereabouts, was hard to achieve. Any thoughts on this.
I guess with your suggestion that the sorted units are not worth the extra expense I shall order 50 more nonsorted and give a match a go. Too many people applaud this technology not to give it another try.
A little note. The new issue of Future magazine has an article on the new series of infrared chip sensors. Maybe reading temperature instead of brightness could yield something useful.
Tad
Georges first introduction of this technology was using a separate led source a tube and a photo resistor. Would going back to this approach, in your opinion, possible yeild a matched pair earlier. We have to match the diode discrepency and the resistor error with the Siliconex units as they are. If we use just one led as the photo source for the 4 resistors would that not be easier to match. Just a thought. I really never could get anything approaching a useful set from the 30 SORTED units I bought from Allied. I also found that full volume, or thereabouts, was hard to achieve. Any thoughts on this.
I guess with your suggestion that the sorted units are not worth the extra expense I shall order 50 more nonsorted and give a match a go. Too many people applaud this technology not to give it another try.
A little note. The new issue of Future magazine has an article on the new series of infrared chip sensors. Maybe reading temperature instead of brightness could yield something useful.
Tad
In the spirit of learning and DIY I would try the single LED and 2 resistors and then another LED and 2 resistors. Not one with 4.
That would be neat however, I am convinced that its the resistive material Silonex uses in this particular LED that is so audiomagical. So while that idea will work most likely it will not sound as good. Still, it might be really nice. However you will possibly still deal with a resistive element that varies from resistor to resistor. Maybe its the resistive element and not the LED that is goofy. I dont know. But trying it could be fun
Dont buy sorted its a waste.
I will be buying more LDRs in July if you are willing to wait you maybe be able to buy any number from me for about 1.67USD each. Up to you.
I have no hunches on the temp except to say that a one degree swing in your measuring room will make a difference. Large difference. Just hook one up to measure then blow on it for a few seconds. Watch the DMM Fun fun.
My rear hurts along with my back. Been matching since 11am. Its now 3 and I have a ways to go.
I think it will take me 4 more intense days of work if my numbers from today come out satisfactorily. If they do not then these go back to Allied. We will see after I evaluate the results.
Uriah
That would be neat however, I am convinced that its the resistive material Silonex uses in this particular LED that is so audiomagical. So while that idea will work most likely it will not sound as good. Still, it might be really nice. However you will possibly still deal with a resistive element that varies from resistor to resistor. Maybe its the resistive element and not the LED that is goofy. I dont know. But trying it could be fun
Dont buy sorted its a waste.
I will be buying more LDRs in July if you are willing to wait you maybe be able to buy any number from me for about 1.67USD each. Up to you.
I have no hunches on the temp except to say that a one degree swing in your measuring room will make a difference. Large difference. Just hook one up to measure then blow on it for a few seconds. Watch the DMM
Fun fun. My rear hurts along with my back. Been matching since 11am. Its now 3 and I have a ways to go.
I think it will take me 4 more intense days of work if my numbers from today come out satisfactorily. If they do not then these go back to Allied. We will see after I evaluate the results.
Uriah
Have now measured 549 LDR at 200k and 400k in series with 5.0396VDC
Had to throw away about 20 LDR so far cuz they will obviously never match anything. Thats very good. Other than that it is obvious that the more LDRs you measure the better the matching gets. Thats just a given anyway but the spreadsheet is looking great right now. I will measure at a low level resistance next. Probably 100k then based on that one I will decide between 300k and 50k as the final measurement. I am thinking right now that probably I will measure at 100k and 300k so we will have 100k, 200k, 300k, 400k as the measurements. Figuring most people will not listen to extreme low volume or extreme high volume so testing for the most used points on a 500k pot makes most sense. If things start to look weird at 100k then I will go with 50k to get the best matching but if they are showing a real good linear relationship with each other at 100k as they have so far at 200k and 400k then I will go with 300k.
Real interesting stuff huh?
I am heading to Colorado tomorrow morning for a 2 week vacation and will finish up measuring/matching when I get home.
Of course I am still taking orders and will continue to do so right up to the point I ship and past that if I have extras.
Uriah
Had to throw away about 20 LDR so far cuz they will obviously never match anything. Thats very good. Other than that it is obvious that the more LDRs you measure the better the matching gets. Thats just a given anyway but the spreadsheet is looking great right now. I will measure at a low level resistance next. Probably 100k then based on that one I will decide between 300k and 50k as the final measurement. I am thinking right now that probably I will measure at 100k and 300k so we will have 100k, 200k, 300k, 400k as the measurements. Figuring most people will not listen to extreme low volume or extreme high volume so testing for the most used points on a 500k pot makes most sense. If things start to look weird at 100k then I will go with 50k to get the best matching but if they are showing a real good linear relationship with each other at 100k as they have so far at 200k and 400k then I will go with 300k.
Real interesting stuff huh?
I am heading to Colorado tomorrow morning for a 2 week vacation and will finish up measuring/matching when I get home.
Of course I am still taking orders and will continue to do so right up to the point I ship and past that if I have extras.
Uriah
uriah,
At a buck sixty seven I will surely buy about 40 units. Just email me when you want the money.
Magic in the resistiive element. Now that is pretty sweet. That would be a nice logo for George's commercial offering.
If you use one led for all four photo resistors and tweek with small passive pots channel tracking should be exceptional. Ummm!!!!
Thanks Tad
At a buck sixty seven I will surely buy about 40 units. Just email me when you want the money.
Magic in the resistiive element. Now that is pretty sweet. That would be a nice logo for George's commercial offering.
If you use one led for all four photo resistors and tweek with small passive pots channel tracking should be exceptional. Ummm!!!!
Thanks Tad
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