Legato or IVY III outputs for Buffalo II?

[Jeffrey Davison]

Thanks Russ,

Lagato 2 is not in hand yet as are the transformers, so nothing to make computations with yet.

It will (when built) be fed into a self built "Lo-Mu" tube pre-amp (w/ 100k pt and a WE421a / 5998).

JD

I don't know enough about your application to answer that. You may not need to adjust anything at all. I don't really like to use transformers.

All you really need to do is figure out how the about 150R output impedance will effect your transformer. That's all.

 

[Rosendorfer]

if you are using the BAL/SE stage you definitely do not need the buffer for Legato 1.

Honestly the only reason I added the buffer was to potentially drive highish impedance balanced wired headphones. But really, that is not the best use for this I/V stage.
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Cheers!
Russ

Hi Russ

Actually I would like to ask about this specific usage of buffer at Legato.

I'm using legato as my HeadAMP with HD 650 300OHM recabled for balanced use and it sounds realy nice, as for me, with plenty of power with my duall mono setup.
Actualy I'm bit worried that buffer transistors could be "bit too small" for this aplication and have been thinking about possibility/need of changing buffer transistors for bit higher power ones.
But I'm curious why this could be not "the best use."...?
Could You tell bit more...

Best Regards
Rosendorfer

 

[Russ White]

Hi Russ

Actually I would like to ask about this specific usage of buffer at Legato.

I'm using legato as my HeadAMP with HD 650 300OHM recabled for balanced use and it sounds realy nice, as for me, with plenty of power with my duall mono setup.
Actualy I'm bit worried that buffer transistors could be "bit too small" for this aplication and have been thinking about possibility/need of changing buffer transistors for bit higher power ones.
But I'm curious why this could be not "the best use."...?
Could You tell bit more...

Best Regards
Rosendorfer

No the transistors are not too small. Their dissipation is limited by the class A operation. Only if you wanted to significantly increase the idle current would you need to make a change.

The only reason I maid the statement was that a low impedance load is not ideal for AC coupled amplifiers. I too think it sounds great! But I prefer the IVY-III for balanced headphone use.

Cheers!
Russ

 

[fred_com]

All you would need to do is solder three FETs in parallel were you would normally use one. You don't need the two Rs in parallel at the CCS, but you could also do the same thing there. Just use two 680R where you would normally use one 320 or 340R.

Hi Russ, are those parallelled 680Rs just to dissipate heat more evenly? I mean, is there any other reason to replace 332R with two 680Rs in existing Legato circuit?

Thanks,
Fedor

 

[Russ White]

Hi Russ, are those parallelled 680Rs just to dissipate heat more evenly? I mean, is there any other reason to replace 332R with two 680Rs in existing Legato circuit?

Thanks,
Fedor

Yes, that is the only reason. It just keeps the thing running a little more comfortably at 15V rails.

 

[fred_com]

Got it, thank you.

 

[AR2]

I just ordered last weekend Buffalo II and Legato 2. Cannot wait to receive it.
I have California Audio Labs Sigma II DAC. Long time ago I did updates to it with extensive use of Black Gate caps throughout. That DAC is 16 / 44.1 and it is the time to retire it. I have been using it at work in my office with small tube amp. This DAC has tube output stage.

Now since CAL did really great work at the time, they provided me with lots of real estate. That makes this DAC perfect to be used for Buffalo. I could use complete PS as is, input switching between coax S/PDIF and Toslink and tube analog output. I could easily make connections to Buffalo II through plug in modules, just like the one used for CS8412. As you could see they made perfect grounding on board clearly divided for analog and digital ground. I am right now taking schematic down so that I could use traces for input and output.

I also would like to use Legato for balanced output and for fun, so that I could switch between tube and solid state Brian, do you have any suggestion for some slick switching between output stages, something that could easily swap between these output stages? I am obviously thinking something like relay that could be easily implemented. Also is there any portion of Legato I/V that has to stay and that you would suggest to keep when used with this tube output?

See included pictures

Thank you

 

[AR2]

I will also try this - Lundahl jFet buffer board that I dedicated for my DCX2496 output, but as I see I could use it here as well, ether with trafo or just buffer out if I want. As I see it it will be pop non stop, hehehe.

 

[pellesmil]

IVY iii ver 1,0,1 installaton Q. how should the sw1 be turned?
is the dot on the pcb illustrating the oval black point on the relay?, (lover left corner)
so when installed the text on the relay and the pcb aligns?

Thanx

P.

 

[BrianDonegan]

The dot is to be matched to the black bar, yes.

 

[natzev_i]

Hi All,
With Legato / IVY and Volumite do I need any kind of active pre-amp/1:1 buffer/linestage before connecting the DAC to the power amp, please?
What is the output impedance of the Legato/IVY stages, can they handle longer IC cable runs?
If I don't need the analogue volume pot and source selector any more is skipping the pre-amp a good idea or the active linestage will bring some more body to the music - what do you prefer?
Thanks!

EDIT: Also, can I drive two power amps for passive bi-amping, please?

 

[BrianDonegan]

Hi All,
With Legato / IVY and Volumite do I need any kind of active pre-amp/1:1 buffer/linestage before connecting the DAC to the power amp, please?
What is the output impedance of the Legato/IVY stages, can they handle longer IC cable runs?
If I don't need the analogue volume pot and source selector any more is skipping the pre-amp a good idea or the active linestage will bring some more body to the music - what do you prefer?
Thanks!

EDIT: Also, can I drive two power amps for passive bi-amping, please?

No
Yes
Yes
No
Yes

 

[natzev_i]

Five "Thank you"s, Brian!

 

[Rainbow62]

The reason is because Russ cannot possibly predict which preamp/amp you are going to use your Legato with to drive. Input impedances on amps/preamps can vary depending on manufacturer and design. I've seen some as low as 1000 ohms and as high as 200,0000 ohms.
So with a 100uf capacitor, he gets a corner frequency of 0.2Hz, with an input impedance of 10,000 ohms. If it is an input impedance of 1,000 ohms the same capacitor value, gives a corner frequency of 1.6Hz.

But you can change it to the value you think is appropriate in your system.

Anand.

Hi everyone,
Can someone explain what it's mean corner frequency 1.6 Hz, every frequency below are cutted off maybe?
What is the apropreate value to succeed?
I am running B II with legato 2 at single ended conversion by the supplyed op amp, and i am trying to find which is the best decoupling capacitors value.