Deang Posted March 31, 2014 Author Share Posted March 31, 2014 Mark (and others). Please be aware that this is NOT the implementation that I've been using. Quote Link to comment Share on other sites More sharing options...
Deang Posted March 31, 2014 Author Share Posted March 31, 2014 Yes. Quote Link to comment Share on other sites More sharing options...
Thaddeus Smith Posted March 31, 2014 Share Posted March 31, 2014 I'd once again like to extol the virtues of my "platinum level" battery upgrade to Duracell lithium 9v's. I personally believe they have extended the performance by 287%. Quote Link to comment Share on other sites More sharing options...
Deang Posted March 31, 2014 Author Share Posted March 31, 2014 Nope. Dennis (DJK) is playing around with it. I want to provide something proven, well known, and accepted. It also needs to be practical and affordable. The bridged method doesn't meet any of those requirements. Quote Link to comment Share on other sites More sharing options...
Guest David H Posted March 31, 2014 Share Posted March 31, 2014 I'd once again like to extol the virtues of my "platinum level" battery upgrade to Duracell lithium 9v's. I personally believe they have extended the performance by 287%. Yeah, but you are Biased... Quote Link to comment Share on other sites More sharing options...
Johnny's Jill Posted March 31, 2014 Share Posted March 31, 2014 When I worked for ESS in the 80's both battery bias implementations were tested. It was determined at that time it was too expensive and test results were inconclusive. My design preference was the bridged method, however either way the improvements were subtle. With the price and quality of capacitors these days, either method should be fairly inexpensive to implement. I just looked at parts express. Building a pair of type B's with Dayton capacitors standard configuration is $11 Building in bridge configuration would run $14 for the cap, and an extra $3 for the additional battery. Dave just built a pair of Heresy with bridge bias, sounded great. Craig 73 1 Quote Link to comment Share on other sites More sharing options...
Deang Posted March 31, 2014 Author Share Posted March 31, 2014 Before I reveal the measurement I just took, does everyone agree that I have this wired as the schematic indicates. Quote Link to comment Share on other sites More sharing options...
Deang Posted March 31, 2014 Author Share Posted March 31, 2014 Actually, you can't bias any of the capacitors with that circuit. I get zero volts at all points. It's like I said a few pages back, I doubted that it would even work because there's no connection back to common. Quote Link to comment Share on other sites More sharing options...
Deang Posted March 31, 2014 Author Share Posted March 31, 2014 (edited) If I provide a path with my test lead, I can charge two of the series capacitors, while the other two remain uncharged (because they aren't part of the biasing circuit). It's an easy fix, but there is no point to it. Look folks, the capacitors are either charged or they aren't, and in this case they clearly aren't. So unless the schematic is wrong, or I incorrectly wired the circuit, I think we can lay this one to rest. As for comments indicating a subtle difference, I didn't think that at all. It may not be like changing out an amplifier, but it was enough of an improvement that I didn't have to strain to hear it. If it is defined as "subtle" by the standard of others, please consider that all of the subtleties add up - and you end up with some truly great sound. Edited March 31, 2014 by DeanG Quote Link to comment Share on other sites More sharing options...
Axz Hout Posted April 1, 2014 Share Posted April 1, 2014 x Quote Link to comment Share on other sites More sharing options...
Guest David H Posted April 1, 2014 Share Posted April 1, 2014 (edited) Dean, I think the idea is to charge the capacitors, not the circuit. I just ran several tests regarding both of these circuits, what I found using typical charging, is the Capacitance changes significantly with the circuit charged. I will try again with a drive in the circuit and retest. I don't know what you are looking at, I have had no issues charging either circuit. Dave Edited April 1, 2014 by GotHover Quote Link to comment Share on other sites More sharing options...
Deang Posted April 1, 2014 Author Share Posted April 1, 2014 (edited) I posted pictures of both the schematic and the circuit. I asked that people compare them to make sure I wired it correctly (as the schematic shows). I received an email that confirmed what my measurements had already told me: "Hi Dean, Well, I can tell you one thing, it won't bias the caps to 9V. It's a weird phantom circuit. I'd say it does nothing. If you draw it out and connect the foils of each of the four caps, you will discover this: 8 foils become 4 pairs. The battery only connects 2 pairs! And even then, the battery is not referenced to ground. So, 2 foils have 9V between them with self reference, and 2 foils are floating with no reference." So, it either doesn't work or the schematic is wrong. Please tell me your kidding about me not understanding what this is supposed to do? Edited April 1, 2014 by DeanG Quote Link to comment Share on other sites More sharing options...
Deang Posted April 1, 2014 Author Share Posted April 1, 2014 Original schematic. Fritz's comments from the original thread are below: "...the one battery method is the method used by most of the production implementations of battery biasing. I think the one battery method is great if you are going to maintain the zero ground reference. My thoughts were to move away from using a zero ground reference and use a floating ground reference. Only difference is in a floating ground reference each side of the cap is driven to a different potential , which only makes sense in an AC circut. The zero ground reference approach is cheaper to do, but only drives one side of the caps while at the same time, tying the different L/C circuits together." Nothing in that post makes any sense, and neither do any of his other comments in this thread. Quote Link to comment Share on other sites More sharing options...
Axz Hout Posted April 1, 2014 Share Posted April 1, 2014 x Quote Link to comment Share on other sites More sharing options...
Deang Posted April 1, 2014 Author Share Posted April 1, 2014 It's easier on the eyes because it's right. Okay, let's try it again. One picture is the bridged circuit and the other is the JBL method. The larger meter is showing the capacitance. I have two .10uF capacitors connected in series. The capacitors are charged, and capacitance is stable. 1 Quote Link to comment Share on other sites More sharing options...
Guest David H Posted April 1, 2014 Share Posted April 1, 2014 The larger meter is showing the capacitance. I have two .10uF capacitors connected in series. The capacitors are charged, and capacitance is stable Yes, I re-did my test and the capacitance is stable. Must have had a poor connection. Dave Quote Link to comment Share on other sites More sharing options...
Guest " " Posted April 1, 2014 Share Posted April 1, 2014 Dean, I think the idea is to charge the capacitors, not the circuit. I just ran several tests regarding both of these circuits, what I found using typical charging, is the Capacitance changes significantly with the circuit charged. I will try again with a drive in the circuit and retest. I don't know what you are looking at, I have had no issues charging either circuit. Dave I guess we need a standard that can be agreed upon as to how these things should be tested...of course...I would welcome that....keep in mind that you are talking to someone who got yelled at and publicly humiliated for putting a k-69/510 mid and a k-70-g/k-701 tweet on top of a lascala back in 2009....now everyone is doing it and all is well.....so I am used to getting stoned in the town square. Quote Link to comment Share on other sites More sharing options...
Deang Posted April 1, 2014 Author Share Posted April 1, 2014 (edited) You got yelled at because you were running that combination of drivers and horns with an AK-4 network. Hey, I just wired them up and put the meters to the caps. One way results in numbers that make sense and the other results in zeros. If you're getting any numbers at all with the bridged method, then 1) the caps had previously been charged with an AC signal (in which case you will see the numbers drop as the capacitor slowly discharges), or 2) you are testing in such a way where you are using your common test lead to complete the circuit. Using new capacitors, and following the schematic, I get nothing. Edited April 1, 2014 by DeanG Quote Link to comment Share on other sites More sharing options...
Guest " " Posted April 1, 2014 Share Posted April 1, 2014 I love this place...used to be capacitor replacement would make the natives restless, then speaker wire got them riled up, then tube swapping , then the which horn is better, then there was the ss vs tube vs t-amp, now we have the battery bias wind it to the left or wind it to the right discussion. Please don't get upset. I am just a humble 9th grade drop out, everything I learned about electricity I learned by sticking a fork in an electrical outlet during the 3rd grade. Quote Link to comment Share on other sites More sharing options...
Guest David H Posted April 1, 2014 Share Posted April 1, 2014 Two terms are being used. First is biasing the cap, and second is charging the circuit. They do not mean the same thing. Biasing the cap must create a voltage across the dielectric as measyred from foil to foil. This is true for one cap or four. This voltage must appear internal to the cap. Charging the circuit is a different and imprecise notion. The battery in the bridge circuit is creating a voltage between two internal foils, but not within the same cap. That will not have the same effect as biasing the cap. If you draw the arrangement showing the two foils for each cap the lack of bias becomes obvious. Are you saying a pair of caps connected in series can not be biased? Dave Quote Link to comment Share on other sites More sharing options...
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