Face said:
Nice but something's missing. It needs bigger caps.
dejanm said:
when I said "stacked " I meant on first ( preceding) LM317 on shoulders of second (succeeding) LM317 ;
I know there is some better term for that ( maybe even schematic in 317 datasheet ) , but I can't remember .....
look at Shiny sch , and you'll see what I mean .
somewhere in "another NS10 & Shiny " thread you'll find my ( as usual)
by J. Weissmuller written/by Chita influenced explanation of said reg ...
@Zen
Thanks a lot ... I will do my homework now ...
@Maxlorenz
You are certainly right. The reason for asking this (dumm ?) question was to try to narrow the number of reasonable options that should be explored. In that way I wanted to save some time, because some of the shunt regulators are not so simple to build.
Thanks a lot ... I will do my homework now ...
@Maxlorenz
You are certainly right. The reason for asking this (dumm ?) question was to try to narrow the number of reasonable options that should be explored. In that way I wanted to save some time, because some of the shunt regulators are not so simple to build.
installing two sets of outputs on B1
This is my first post here on DIY Audio.
I'm sorry if I missed this if it has been covered previously (this is getting to be a long thread)along the way.
Is there anything special I should do or take into consideration when installing two sets of outputs on my B1? One set of RCA's will be to drive my main amp and the second set will be used to drive the RCA inputs of a sub woofer plate amp. Is it fine to just parallel two sets of outputs or is something more that should be done?
Thanks
Keith
This is my first post here on DIY Audio.
I'm sorry if I missed this if it has been covered previously (this is getting to be a long thread)along the way.
Is there anything special I should do or take into consideration when installing two sets of outputs on my B1? One set of RCA's will be to drive my main amp and the second set will be used to drive the RCA inputs of a sub woofer plate amp. Is it fine to just parallel two sets of outputs or is something more that should be done?
Thanks
Keith
b-1 and freq&impedance issues
OK already,
I'll take a stab at this with apologies to those who actually understand this stuff better than I do-
The question that I raised about 200 posts ago about adding a second output to my B-! was answered,more or less by Andrew T (thank you again for the education and you efforts) and it looks something like this-
circuits have input and output impedances- that is to say they pass certain frequencies and block others based on resistance and reactance(look up the differences between the two and you will begin to get some answers if you don't understand it now, it is important to this discussion) Capacitors and resistors help setup these characteristic impedances (and also block dc from passing from one stage to another). Energy moving from one circuit to the next have ideal "power transfer" characteristics that relate to this discussion. Most of us have heard about "low output impedance into high input impedance for ideal voltage transfer" is one of the points of a "buffer stage". This is easier to think of in strictly resistance terms- low output resistance into high input resistance makes for happy electron flow(low demand for current).
The reactance part of this equation looks something like this; Reactance is the resistance to the flow of elelctrons based on their frequency(you did look this up before-right?) With capactors as the frequency descends so it sees more resistance from the cap. The bigger the cap the easier it is for low frequencies to pass through it. There is a formula(that you can look up under RC time constant(resistor/capacitor time constant) that will tell you the knee at which frequencies will begin to be resisted in a circuit based on that circuits characteristic impedance and its series capacitance ie its R/C time constant(again thank you AndrewT).
A more easy concept involves why you can't just split an output-one into two. One consideration has to do with the inputs of the amps seeing each other through a simple spit-this is not a good thing for the source or the amps. You need isolation from one amp input to another and that is what is accomplished by inserting resistors in the split "legs". What the simple resistor doesn't address is the reactive, R/C time constant issue and the low frequency roll off that would occur from simply spliting the signal between the two input impedances( the two amps).
These are important considerations and point to the difference between designing a circuit and building a circuit. I can Build but I don't have a good enough grasp of the engineering to Design
This is the point of some of the responses that I see that seem a tad retiscent or even pissy. The amateurs out her(and I am one) assume all there is to this hobby (and obsession) is the building, and those who know(dare I refer to the Philosopher Kings) that there is much more to understanding the habits of these little electrons feel as though our ignorant questions are an affront. Their knowledge is underappreciated.
Its a shame, no one goes home happy!.
I sincerly hope this helps on a number of levels.
I've had enough wine and have to get to finishing dinner and then off to listening to my newly built B-1.
r
OK already,
I'll take a stab at this with apologies to those who actually understand this stuff better than I do-
The question that I raised about 200 posts ago about adding a second output to my B-! was answered,more or less by Andrew T (thank you again for the education and you efforts) and it looks something like this-
circuits have input and output impedances- that is to say they pass certain frequencies and block others based on resistance and reactance(look up the differences between the two and you will begin to get some answers if you don't understand it now, it is important to this discussion) Capacitors and resistors help setup these characteristic impedances (and also block dc from passing from one stage to another). Energy moving from one circuit to the next have ideal "power transfer" characteristics that relate to this discussion. Most of us have heard about "low output impedance into high input impedance for ideal voltage transfer" is one of the points of a "buffer stage". This is easier to think of in strictly resistance terms- low output resistance into high input resistance makes for happy electron flow(low demand for current).
The reactance part of this equation looks something like this; Reactance is the resistance to the flow of elelctrons based on their frequency(you did look this up before-right?) With capactors as the frequency descends so it sees more resistance from the cap. The bigger the cap the easier it is for low frequencies to pass through it. There is a formula(that you can look up under RC time constant(resistor/capacitor time constant) that will tell you the knee at which frequencies will begin to be resisted in a circuit based on that circuits characteristic impedance and its series capacitance ie its R/C time constant(again thank you AndrewT).
A more easy concept involves why you can't just split an output-one into two. One consideration has to do with the inputs of the amps seeing each other through a simple spit-this is not a good thing for the source or the amps. You need isolation from one amp input to another and that is what is accomplished by inserting resistors in the split "legs". What the simple resistor doesn't address is the reactive, R/C time constant issue and the low frequency roll off that would occur from simply spliting the signal between the two input impedances( the two amps).
These are important considerations and point to the difference between designing a circuit and building a circuit. I can Build but I don't have a good enough grasp of the engineering to Design
This is the point of some of the responses that I see that seem a tad retiscent or even pissy. The amateurs out her(and I am one) assume all there is to this hobby (and obsession) is the building, and those who know(dare I refer to the Philosopher Kings) that there is much more to understanding the habits of these little electrons feel as though our ignorant questions are an affront. Their knowledge is underappreciated.
Its a shame, no one goes home happy!.
I sincerly hope this helps on a number of levels.
I've had enough wine and have to get to finishing dinner and then off to listening to my newly built B-1.
r
As simple as possible:
The in/output cap forms a low pass filter with the following resistance. You want the frequency of that low pass as low as possible (you want to hear low notes). Because you exactly know the input impedance of the B1, you can choose an input cap that is big enough to lead to a lox filter frequency and that is as small as reasonable, because of size and cost. For the output you don't know anything about the following stage, so chooseit as large as "possible" (by price, size and quality).
If you build the singe supply version (the original) of the B1 you can't because of the bias. If you would built the dual supply version (ZM) you would omit the input cap of the B1. As far as I see, you can't omit the output cap of the dddac because it has an output-offset of some volts and that will feed the pot of the B1 (which does no good).
Regards
Flo