Thanks Brian,
Can you guide me on the Legato2 resistor values? Input sensitivity on the Intega DHC 80.2 is 200mv so trying to knock down the I/V voltage on output to something that would make sense. I know I have to change out R1 - R4 but is Legato2 the same as what is instructed in the manual ... ie must I change R21 - R24 as well an multiply my R1-R4 value by 2.2?
Can you guide me on the Legato2 resistor values? Input sensitivity on the Intega DHC 80.2 is 200mv so trying to knock down the I/V voltage on output to something that would make sense. I know I have to change out R1 - R4 but is Legato2 the same as what is instructed in the manual ... ie must I change R21 - R24 as well an multiply my R1-R4 value by 2.2?
I'm guessing that unlike the Legato 1 (R21-24) you swap R9-16. Now these resistors are in series? So what I currently have is 339ohm resistors for R9-16. To take a guess if using 68ohm R1-4 would I then replace R9-16 with 150ohm or would I use 75ohm resistors to make a total of 150ohm as they are in series?
I have not been able to find a clear answer for this unfortunately as most folks on here seem to post about Legato 1 and not Legato 2.
Last I'd like to ask again what folks think about replacing the BP caps with some Mundorf .1uF silver oils? I have them and would like to use them. I know there are a lot of folks on this thread who prefer to remove the caps all together and that is what was done in Legato 3...
Anyway any help is greatly appreciated. I've been sitting on this project forever and would like to finish it up just need some knowledgeable guidance.
Best Regards,
TJ
I have not been able to find a clear answer for this unfortunately as most folks on here seem to post about Legato 1 and not Legato 2.
Last I'd like to ask again what folks think about replacing the BP caps with some Mundorf .1uF silver oils? I have them and would like to use them. I know there are a lot of folks on this thread who prefer to remove the caps all together and that is what was done in Legato 3...
Anyway any help is greatly appreciated. I've been sitting on this project forever and would like to finish it up just need some knowledgeable guidance.
Best Regards,
TJ
TJ...
You are asking about the output caps? .1 uF is way too small a value to use here, these caps are for AC coupling. As an example, I am using the Legato 2 from the balanced outputs only. I jump the positions on the board for stock electrolytic caps, and then use Mundorf Supremes mounted off board connected directly to the XLR outputs. I use 3.9 uF Supremes, and this gives a corner frequency of 3.7 Hz (into my amps 11K impedance per phase). If I put 0.1 uF caps here the result woudl be a corner frequency of 144.8 Hz, and all bass frequencies would be cut off.
Russ recommends at least 4.7 uF here, but the actual needed value will depend on the input impedance of the following stage.
If you leave the caps off you will pass DC on to the next stage, with, perhaps disasterous results for your speakers (like burned woofer voice coils).
You are asking about the output caps? .1 uF is way too small a value to use here, these caps are for AC coupling. As an example, I am using the Legato 2 from the balanced outputs only. I jump the positions on the board for stock electrolytic caps, and then use Mundorf Supremes mounted off board connected directly to the XLR outputs. I use 3.9 uF Supremes, and this gives a corner frequency of 3.7 Hz (into my amps 11K impedance per phase). If I put 0.1 uF caps here the result woudl be a corner frequency of 144.8 Hz, and all bass frequencies would be cut off.
Russ recommends at least 4.7 uF here, but the actual needed value will depend on the input impedance of the following stage.
If you leave the caps off you will pass DC on to the next stage, with, perhaps disasterous results for your speakers (like burned woofer voice coils).
barrows,
Thanks very much for your reply I think I understand this a bit better now. So really .1uF caps wouldn't really have an application in the Legato2. Thanks for saving me the trouble.
My Integra PrePro has the following specs: Input Sensitivity and Impedance: 200 mV/47 k-ohms (Line).
Given this what in your opinion would be some good values to use. Also you say you jumpered something to allow for the use of standard electrolytic caps...can you share what was jumpered? Is it the square pad in the middle of where the bipolar caps connect?
Can you shed some light on my previous resistor question?
Best Regards,
Theo
Thanks very much for your reply I think I understand this a bit better now. So really .1uF caps wouldn't really have an application in the Legato2. Thanks for saving me the trouble.
My Integra PrePro has the following specs: Input Sensitivity and Impedance: 200 mV/47 k-ohms (Line).
Given this what in your opinion would be some good values to use. Also you say you jumpered something to allow for the use of standard electrolytic caps...can you share what was jumpered? Is it the square pad in the middle of where the bipolar caps connect?
Can you shed some light on my previous resistor question?
Best Regards,
Theo
TJ...
First, are you going to use the balanced outputs directly? Or are you going to use the single ended outputs?
I only use the balanced outputs of the Legato 2, so I eliminate the onboard AC coupling caps, and jump their positions on the board (as they are in series with the signal). Then I mount the big 3.9 uF Supremes at the sides of the board and wire them directly to the outputs (XLR jacks). If you are using the single ended outputs then you will need another approach. Much of this has been discussed in the general Legato thread, or earlier in this thread.
Of course, the new Legato 3 is entirely different, and none of this would apply to it.
I did not quite understand your question regarding resistors.
First, are you going to use the balanced outputs directly? Or are you going to use the single ended outputs?
I only use the balanced outputs of the Legato 2, so I eliminate the onboard AC coupling caps, and jump their positions on the board (as they are in series with the signal). Then I mount the big 3.9 uF Supremes at the sides of the board and wire them directly to the outputs (XLR jacks). If you are using the single ended outputs then you will need another approach. Much of this has been discussed in the general Legato thread, or earlier in this thread.
Of course, the new Legato 3 is entirely different, and none of this would apply to it.
I did not quite understand your question regarding resistors.
Since you already have the Mundorf 0.1uF SIO Caps on hand, I suggest you can try to parallel them to the 100uF BP Caps to hear if there's any difference.
I have removed the stock BP Caps & replace them with Obbligato Premium Gold 4.7uF which results in much better clarity & separation but with the Mundorf 0.01uF SIO (which I already had) added in parallel, the highs are more extended & smooth.
This is my build. The Mundorf SIO Caps cannot be seen as they are mounted below the Obbligatos.
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Hi Barrows,
Yes I plan on using my XLR outputs from my Legato2 to an Integra Preamp processor. I guess I would be using some caps similar to your supremes...i'd like to go Mundorf SOI caps but the high capacitance values are just to much money for me right now. Though I do have some 4.7uF SonicCap GEN-1 I can use.
I'm not sure I understand how you jump the AC Coupling caps. I thought you said leaving them out would introduce the possibility of DC creeping into the signal and frying speaker voicecoils as a possibility?
Just to make it clear i'm talking about the Bipolar 100uf Caps in the Legato2....these are the AC coupling caps you refer to correct.
My question about the resistors is how to lower the overall output...since my Integra PrePro only has an input sensitivity of 200mv I don't want a 2V spike in signal clipping my preamp so I am aming to reduce the output volatage as much as possible without gettting to crazy. I have replaced R1-4 with 60ohm resistors...now I just need to know what other resistors I have to swap out on the legato2.
Best Regards,
Theo
Yes I plan on using my XLR outputs from my Legato2 to an Integra Preamp processor. I guess I would be using some caps similar to your supremes...i'd like to go Mundorf SOI caps but the high capacitance values are just to much money for me right now. Though I do have some 4.7uF SonicCap GEN-1 I can use.
I'm not sure I understand how you jump the AC Coupling caps. I thought you said leaving them out would introduce the possibility of DC creeping into the signal and frying speaker voicecoils as a possibility?
Just to make it clear i'm talking about the Bipolar 100uf Caps in the Legato2....these are the AC coupling caps you refer to correct.
My question about the resistors is how to lower the overall output...since my Integra PrePro only has an input sensitivity of 200mv I don't want a 2V spike in signal clipping my preamp so I am aming to reduce the output volatage as much as possible without gettting to crazy. I have replaced R1-4 with 60ohm resistors...now I just need to know what other resistors I have to swap out on the legato2.
Best Regards,
Theo
TJ...
OK. C5, 6, 7, and 8 are the AC coupling capacitors (aka DC blocking). The stock ones supplied are the 100 uF, green, Nichicon MUSE parts. Take a look at the schematic and you will see that these parts work in series with the outputs-make sure you understand the schematic.
To use larger, better sounding, film caps, you need to jump the spots on the board for these caps, otherwise there will be no signal at the output. Then you add the replacement caps directly between the balanced output of the board and the output jacks (assuming you are not using the SE section of the board at all).
Now the DC is taken care of by the nice film caps we put on the output (in series with the signal). With your input impedance of 47K, you will have 23K per phase, and should use a really good film cap of 2.7 uF or higher. There is of course great debate on what film caps will sound best, I chose Mundorf Supremes and my build does sound great.
Personally, I do not believe in bypassing caps in the signal path (as the poster above has done), as this adds an additional path with a different time constant, and could possibly smear the signal in time, but some people like to do this.
As for the resistor values you need to match the output level with your input sensitivity, you will need Russ or Brian to give you the appropriate vaues. Are you sure your input sensitivity is that low? It seems that this component would not be compatible with traditional sources with such a low sensitivity, really weird?
EDIT: OK, I see you are using 60 ohm for R1, 2, 3, and 4. Then you would Russ' advice for the lower half resistors: R1*2.2=132 ohms, but on the Legato 2 these values use 2 resistors in parallel to better handle the load/heat, so you would double the value, hence 132*2=264. So you need 8 pieces of close to 264 ohms in value to best match your 60 ohm resistors you are using on the top half of the circuit.
I believe with these lower values the resistors are going to be dissapating quite a bit more heat, so this may be a problem-I would still request advice from Russ on this regarding the heat-the values I gave are accurate, but I am not sure about what power value (watts) of resistors you will need to keep them from failing.
OK. C5, 6, 7, and 8 are the AC coupling capacitors (aka DC blocking). The stock ones supplied are the 100 uF, green, Nichicon MUSE parts. Take a look at the schematic and you will see that these parts work in series with the outputs-make sure you understand the schematic.
To use larger, better sounding, film caps, you need to jump the spots on the board for these caps, otherwise there will be no signal at the output. Then you add the replacement caps directly between the balanced output of the board and the output jacks (assuming you are not using the SE section of the board at all).
Now the DC is taken care of by the nice film caps we put on the output (in series with the signal). With your input impedance of 47K, you will have 23K per phase, and should use a really good film cap of 2.7 uF or higher. There is of course great debate on what film caps will sound best, I chose Mundorf Supremes and my build does sound great.
Personally, I do not believe in bypassing caps in the signal path (as the poster above has done), as this adds an additional path with a different time constant, and could possibly smear the signal in time, but some people like to do this.
As for the resistor values you need to match the output level with your input sensitivity, you will need Russ or Brian to give you the appropriate vaues. Are you sure your input sensitivity is that low? It seems that this component would not be compatible with traditional sources with such a low sensitivity, really weird?
EDIT: OK, I see you are using 60 ohm for R1, 2, 3, and 4. Then you would Russ' advice for the lower half resistors: R1*2.2=132 ohms, but on the Legato 2 these values use 2 resistors in parallel to better handle the load/heat, so you would double the value, hence 132*2=264. So you need 8 pieces of close to 264 ohms in value to best match your 60 ohm resistors you are using on the top half of the circuit.
I believe with these lower values the resistors are going to be dissapating quite a bit more heat, so this may be a problem-I would still request advice from Russ on this regarding the heat-the values I gave are accurate, but I am not sure about what power value (watts) of resistors you will need to keep them from failing.
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Awesome,
Thanks barrows very much for your help. I will jumper the +/- pads intended for the muse caps and use my 4.7uF sonicraft caps for the XLR +/-...question though. What is the middle pad used for between the +/- for C5-8?
As for the resistors I'm using a 68ohm resistor. I saw 75ohm resistors discussed in the dual buff single legato thread and due to my input sensitivity thought I'd lower it even more. i will try a 1watt resistor and see what happens and report back.
Regards,
TJ
Thanks barrows very much for your help. I will jumper the +/- pads intended for the muse caps and use my 4.7uF sonicraft caps for the XLR +/-...question though. What is the middle pad used for between the +/- for C5-8?
As for the resistors I'm using a 68ohm resistor. I saw 75ohm resistors discussed in the dual buff single legato thread and due to my input sensitivity thought I'd lower it even more. i will try a 1watt resistor and see what happens and report back.
Regards,
TJ
To allow for caps with different pin spacing. The inner-most pad is tied to one of the outer pads.
Brain,
Can you or Russ speak to the resistor values? If I'm using 68ohm resistor for R1-4 would a 300ohm resistor be correct for R9-16 in Legato2?
Regards,
TJ
Can you or Russ speak to the resistor values? If I'm using 68ohm resistor for R1-4 would a 300ohm resistor be correct for R9-16 in Legato2?
Regards,
TJ
Thanks for the response Russ,
But can you provide confirmation if I did change the value of R1-4 should R9-16 be 300ohms...ie double what 2.2*68 comes to as Barrows suggests. I'm not sure what the rule are for resistors in parallel ... in series double and in parallel half?
I'm using a dual mono Buff with 1 Legato2 so this doubles the voltage at output or that is what I've read...if the input sensitivity is 200mv for my preamp on the XLR inputs shouldn't I attempt to reduce the gain? If not wouldn't there be a possibility of clipping the input of my prepro?
I have not found a good resource which discusses input sensitivity and how best to match output of other equipment such as DACs to mate most optimally. I understand if you don't have time to do a whole lot of teaching on this thread but if you could point me to another resource anything would be useful.
Best Regards,
Theo
But can you provide confirmation if I did change the value of R1-4 should R9-16 be 300ohms...ie double what 2.2*68 comes to as Barrows suggests. I'm not sure what the rule are for resistors in parallel ... in series double and in parallel half?
I'm using a dual mono Buff with 1 Legato2 so this doubles the voltage at output or that is what I've read...if the input sensitivity is 200mv for my preamp on the XLR inputs shouldn't I attempt to reduce the gain? If not wouldn't there be a possibility of clipping the input of my prepro?
I have not found a good resource which discusses input sensitivity and how best to match output of other equipment such as DACs to mate most optimally. I understand if you don't have time to do a whole lot of teaching on this thread but if you could point me to another resource anything would be useful.
Best Regards,
Theo
Cross that bridge only if you need to. Build it stock for now, and see how it works out. You best bet will be to simply use an L pad after the Legato if your output is too high. But I seriously doubt it will be.
Hi Russ,
Thanks I will go stock values for now...ie 150ohm R1-4 and 681ohm R9-16. What is an L Pad?
Best Regards,
Theo
Thanks I will go stock values for now...ie 150ohm R1-4 and 681ohm R9-16. What is an L Pad?
Best Regards,
Theo
Hi Russ.
When I buy legato III with buffers, can I have a signal from op amp (to amplifier) and from buffer (to headphones) simultaneously?
Does the buffers makes any load to op amp and have influence on them? (I mean on their sound).
thanks
and regards
When I buy legato III with buffers, can I have a signal from op amp (to amplifier) and from buffer (to headphones) simultaneously?
Does the buffers makes any load to op amp and have influence on them? (I mean on their sound).
thanks
and regards
(Much) More Gain
Hi
I'm planning to build a Legato I/V stage to complement my Buffalo II. It will directly connect to the power amp which has a voltage gain of only 4.5. That means I need to at least double or triple the Legato balanced output voltage.
My question: What is the max gain that can be achieved by adjusting the I/V gain resistors (as described in the manual) and without too much performance degradation. Would it be wise to increase the power supply voltage? If yes, what else needs to be changed?
Thank's in advance, J.
Hi
I'm planning to build a Legato I/V stage to complement my Buffalo II. It will directly connect to the power amp which has a voltage gain of only 4.5. That means I need to at least double or triple the Legato balanced output voltage.
My question: What is the max gain that can be achieved by adjusting the I/V gain resistors (as described in the manual) and without too much performance degradation. Would it be wise to increase the power supply voltage? If yes, what else needs to be changed?
Thank's in advance, J.
hmmm
Hattori (nice!)
It may be too much of a compromise of the Legato's performance to double or triple the gain. I am sure Russ will have some insight into this. You may be better off with a different type of output stage if you need this much gain though.
Hattori (nice!)
It may be too much of a compromise of the Legato's performance to double or triple the gain. I am sure Russ will have some insight into this. You may be better off with a different type of output stage if you need this much gain though.
Barrows, thanks for the answer. Do you have anything in mind regarding a different type of output stage?
Still I think it should be somehow possible to upscale the Legato. Other (than the Sabre) DACs have much lower output current and therefore require more gain to the get the usual 2V at the output.
Still I think it should be somehow possible to upscale the Legato. Other (than the Sabre) DACs have much lower output current and therefore require more gain to the get the usual 2V at the output.
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