Hi Russ / Brian,
While waiting for the new B II batch to appear “In stock” I read the whole Buffalo II thread here and came upon the Legato announcement.
Well, I was about to happily order the IVY III with BP Placid etc. but I am now hesitating between the two I/V stages.
I know it’s very subjective and down to a personal taste but could you please be so kind and help me to choose the right one for me?
My system is a modified pre Naim NAC 202 w/ local Superregs and NAP 250.2 power going to a pair of 15” Tannoy DMTs. I am mainly a rock music listener (unfortunately, with poor sound quality very often) and I am looking for fast bass with good grip, good dynamics and smooth mids and treble.
So, IVY or Legato will suit better my (rocking) needs, please?
Thank you,
Ivo
While waiting for the new B II batch to appear “In stock” I read the whole Buffalo II thread here and came upon the Legato announcement.
Well, I was about to happily order the IVY III with BP Placid etc. but I am now hesitating between the two I/V stages.
I know it’s very subjective and down to a personal taste but could you please be so kind and help me to choose the right one for me?
My system is a modified pre Naim NAC 202 w/ local Superregs and NAP 250.2 power going to a pair of 15” Tannoy DMTs. I am mainly a rock music listener (unfortunately, with poor sound quality very often) and I am looking for fast bass with good grip, good dynamics and smooth mids and treble.
So, IVY or Legato will suit better my (rocking) needs, please?
Thank you,
Ivo
Being in the same situation I was wondering if anyone could comment on the IVY vs. Counterpoint differences in sound, not that these are identical or something, I am just curious as these are different topologies created by the same team, hoping that this will correlate in the new battle of the output stages 
.
To be honest I am in the SET lovers team and the idea of Legato (Counterpoint) fits my plans better. I kind of feel that Russ and Brian are trying to offer something for people who do not care fanatically about measurements and numbers but more about the sound, could you guys please elaborate a little on what made you design the Legato? Possibly some subjeeeeective comments ? Again many thanks for everything.
And bring on the AC2!!!
. To be honest I am in the SET lovers team and the idea of Legato (Counterpoint) fits my plans better. I kind of feel that Russ and Brian are trying to offer something for people who do not care fanatically about measurements and numbers but more about the sound, could you guys please elaborate a little on what made you design the Legato? Possibly some subjeeeeective comments ?
Again many thanks for everything.And bring on the AC2!!!
Hi Guys,
It is very difficult for me to comment on such questions. Because you are asking me for a subjective opinion. Still, I will do my best.
These two circuits are so extremely different.
They approach the challenge of accomplishing excellent linearity and high dynamic range in two very different ways.
IVY-III is "technically" superior and sounds incredible. It uses the same fully symmetrical feedback scheme as Nelson Pass' excellent super symmetrical applications. I am never disappointed in listening to it. It is DC coupled, and it - like most of my modules - really shines when used with fully balanced gear, but it is by no means lacking when used single ended. It combines active I/V with passive filtering in a way the leaves the audio signal both clean and crisp. The two stages of IVY-III work in concert to excellent effect.
The Legato and the IVY-III have this in common, an opamp based BAL/SE stage. Here is why, there simply is no better active solution I have found (yet). The wonderful thing is, there is no harm if you decide not to use it. You can use a transformer or other mechanism to get single ended output from the balanced signals. It is up to you. In the meantime you can use it as is and simply enjoy it.
The legato uses no opamps and no global feedback *at all* to achieve its excellent linearity. It instead uses a bit of local feedback which is called a CFP (complimentary feedback pair) which is a way to achieve extremely high trans-conductance and linearity from one logical transistor which is actually made up of one PNP and NPN pair. Much higher trans-conductance than could be achieved with any single FET or BJT is accomplished using the CFP. Legato as a system is quite simple. A classic common base amplifier with a CCS fed buffer. Very clean, very quiet, very musical, and impossible to forget.
So in the end. I can only recommend this: Try them both and decide which you like best for yourself. I have yet to be able to decide which I like best. I use both. The bottom line is you are not going to be disappointed with either of them.
Cheers!
Russ
It is very difficult for me to comment on such questions. Because you are asking me for a subjective opinion. Still, I will do my best.
These two circuits are so extremely different.
They approach the challenge of accomplishing excellent linearity and high dynamic range in two very different ways.
IVY-III is "technically" superior and sounds incredible. It uses the same fully symmetrical feedback scheme as Nelson Pass' excellent super symmetrical applications. I am never disappointed in listening to it. It is DC coupled, and it - like most of my modules - really shines when used with fully balanced gear, but it is by no means lacking when used single ended. It combines active I/V with passive filtering in a way the leaves the audio signal both clean and crisp. The two stages of IVY-III work in concert to excellent effect.
The Legato and the IVY-III have this in common, an opamp based BAL/SE stage. Here is why, there simply is no better active solution I have found (yet). The wonderful thing is, there is no harm if you decide not to use it. You can use a transformer or other mechanism to get single ended output from the balanced signals. It is up to you. In the meantime you can use it as is and simply enjoy it.
The legato uses no opamps and no global feedback *at all* to achieve its excellent linearity. It instead uses a bit of local feedback which is called a CFP (complimentary feedback pair) which is a way to achieve extremely high trans-conductance and linearity from one logical transistor which is actually made up of one PNP and NPN pair. Much higher trans-conductance than could be achieved with any single FET or BJT is accomplished using the CFP. Legato as a system is quite simple. A classic common base amplifier with a CCS fed buffer. Very clean, very quiet, very musical, and impossible to forget.
So in the end. I can only recommend this: Try them both and decide which you like best for yourself.
I have yet to be able to decide which I like best. I use both. The bottom line is you are not going to be disappointed with either of them. Cheers!
Russ
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Hi Russ,
I do not see Legato on the Twisted Pear website. Is it still in development, or are you nearly ready to go? How about price?
Also, I am not too familiar with transformers. How does the sound compare to the SE output? Would it be possible to just use a SE output off of the differential Legato instead?
Thanks.
I do not see Legato on the Twisted Pear website. Is it still in development, or are you nearly ready to go? How about price?
Also, I am not too familiar with transformers. How does the sound compare to the SE output? Would it be possible to just use a SE output off of the differential Legato instead?
Thanks.
Hi Russ, is this different from the way the IVY part on the Buffalo 32s is implemented? If yes, could you comment on the way it differs? Thanks for your response.
Kurt
Legato is working, but I had some things I wanted to change about the PCB. The new PCBs will be here early next week (Monday). Once they are verified I will send them off to Brian and we will offer them for sale. the cost will be similar top the IVY-III.
It is possible to take just one end of the Legato to get single ended signal, but I would not recommend it. You may get some transient on turn on and turn off that way. Still some may want to try it.
Cheers!
Russ
IVY-III is slightly different form the BUF32S output stage(IVY-II). But not a lot. The major differences are that it is floating (VOCM at 0V) referenced instead of 1.65V. This is because with super symmetrical feedback there is no advantage to the 1.65V reference. IVY-II and IVY-III are equivalent in terms of performance.
Cheers!
Russ
Russ, whats the current output of the Legato? Is it similar to the IVY (150ma)? Will it be able to power headphones directly? Is there any point running the output of the Legato (without its buffer stage) through a class A buffer then in to headphones? I am asking because I have a few unused JISBOS sitting around? Thanks
Hi Russ
I'm eagerly awaiting Legato, but....
It's not easy to adjust the regulators I'm using to +\- 12V to suite Legato. Possible, but involved, and certainly not suited to an easy comparison of Legato and IVY II.
Would Legato tolerate a 15V supply, and would there be any downside?
Thanks
Paul
I was impressed that you've tried to develop an op amp-free BAL to SE converter for Legato. Any progress? The op amp bothers me. Having heard IVY III I'd have to confess that this is irrational, but I just can't help it
I'm eagerly awaiting Legato, but....
It's not easy to adjust the regulators I'm using to +\- 12V to suite Legato. Possible, but involved, and certainly not suited to an easy comparison of Legato and IVY II.
Would Legato tolerate a 15V supply, and would there be any downside?
Thanks
Paul
I was impressed that you've tried to develop an op amp-free BAL to SE converter for Legato. Any progress? The op amp bothers me. Having heard IVY III I'd have to confess that this is irrational, but I just can't help it
Just waiting for the production boards to arrive.
I have been listening to the prototypes for weeks now, and tweaking and testing and getting things just the way I want. I hope you find it worth the wait, but that wait won't be much longer now
The board is very flexible.
You can even use small signal FETs if you like. I have had great luck with BS170/250.
Also the boar clearly shows where to jump and which parts to omit to skip the optional class A buffer. I would not do that. I have found it works best with the buffer.
Here is a pic of the coming board.
I have been listening to the prototypes for weeks now, and tweaking and testing and getting things just the way I want. I hope you find it worth the wait, but that wait won't be much longer now
The board is very flexible.
You can even use small signal FETs if you like. I have had great luck with BS170/250.
Also the boar clearly shows where to jump and which parts to omit to skip the optional class A buffer. I would not do that. I have found it works best with the buffer.
Here is a pic of the coming board.
Attachments
Hi Spartacus,
The best I can do is tell you how it simulates and sounds right now. The THD is amazingly low for having no feedback.
Here is the simulated FFT at 20khz it only gets better as the frequency gets lower.
I have many hours listening to it now. The noise floor is surprisingly low for a discrete cct. When I put my ear to the cone of a full range driver with the DAC directly coupled to a balanced power amp with about 20db gain I can't detect any noise at all.
The sound is really really awesome. It is so awesome that I am torn between it and IVY-III. I never expected this.
The output impedance is well under 1ohm. And the drive capability is about 20ma. I have used it driving 600ohm headphones with ease. But I am not sure I would drive a load less than that. It could be done with some tweaking.
Cheers!
Russ
The best I can do is tell you how it simulates and sounds right now. The THD is amazingly low for having no feedback.
Here is the simulated FFT at 20khz it only gets better as the frequency gets lower.
I have many hours listening to it now. The noise floor is surprisingly low for a discrete cct. When I put my ear to the cone of a full range driver with the DAC directly coupled to a balanced power amp with about 20db gain I can't detect any noise at all.
The sound is really really awesome. It is so awesome that I am torn between it and IVY-III. I never expected this.
The output impedance is well under 1ohm. And the drive capability is about 20ma. I have used it driving 600ohm headphones with ease. But I am not sure I would drive a load less than that. It could be done with some tweaking.
Cheers!
Russ
Attachments
The output impedance I mentioned is at the balanced outputs. As well as the FFT I posted is measured (in simulation) there.
I can tell you that it definitely sounds like the simulation is not at all far off.
The output at the BAL/SE converter is 21 ohms if you decide to use the indicated output resistors. But it can be much lower if you like. Just jumper at those spots. The resistors are there to help the opamp drive capacitive loads with stability if they exist. I honestly don't use the BAL/SE section much. Almost all my gear is balanced.
I can tell you that it definitely sounds like the simulation is not at all far off.
The output at the BAL/SE converter is 21 ohms if you decide to use the indicated output resistors. But it can be much lower if you like. Just jumper at those spots. The resistors are there to help the opamp drive capacitive loads with stability if they exist. I honestly don't use the BAL/SE section much. Almost all my gear is balanced.