Legato 3 - Look ma! No caps!

[Spev]

What 2n2 filter caps are you using there staccatiss?

 

[BrianDonegan]

How can I be sure the power amp can handle the DC from legato 3 ?
Is there any test procedure ?

I dont know if it is relevant but I had a problem when direct coupling Ventus with my power amp.
There was a hum. The problem solved when I used a tin foil capacitor.
But I prefer the sound without the capacitor

Just do not connect ground between legato and your power amp. Without ground, there is no DC, and no problems.

 

[staccatiss]

They were originally intended for a loudspeaker crossover, and are of course not needed for a low cutoff.


/S

ok
but why 15µF? that shouldn´t be necessary to reach a low cutoff?
best
Leif

 

[leif christensen]

aren´t these capacitor designs different for speaker lvl x/O and line lvl use?
should sound even better in a smaller value imo
best
Leif

 

[BrianDonegan]

You need to know the input impedance of the next stage to calculate the correct cap value.

 

[leif christensen]

I know and that´s why I react on this extremely high value
It´s effectively a high-pass filter, right?
best
Leif

 

[Theodosis O.]

Just do not connect ground between legato and your power amp. Without ground, there is no DC, and no problems.

Thanks Brian,

You mean to connect only the + and - pin of an xlr jack and not gnt pin

I will try.

 

[staccatiss]

I used film and foil 1n0 polystyrenes from RIFA type PFE210.
For space reasons they are both on the underside and on the upper side.


/S

What 2n2 filter caps are you using there staccatiss?

 

[staccatiss]

Yep, it is a RC HP-filter of the 1st order with a cut-off at (2*pi*15u * 10k)^-1 = 0.94 Hz (-3dB). I could even use a 1uF cap but they are a bit costly and as I had three different pairs of VSF caps in the range 8u2 - 15u in my drawer, I just put the 15uF in and listened.

I have also tried the red-brown russian PIO // russian Teflon caps but the VSF is better, IMO.

/S

I know and that´s why I react on this extremely high value
It´s effectively a high-pass filter, right?
best
Leif

 

[Spev]

Thanks. I've just put some rifa pfr 2n2s in last night, but I'm not convinced. Sounds a bit flat and lifeless. Will have to try the pfes. I'm trying to resist ordering relcaps as I just can't justify the cost, but the niggle to try will never go away...

 

[BrianDonegan]

The best cap is no cap

 

[leif christensen]

buy the russion tefloncaps you often find on ebay...they sound great
only downside is size

Russian Teflon Capacitor K72P-6 2200pF 500V 1ps.or more | eBay

best
Leif

 

[staccatiss]

Interesting!
I sometimes use PFR:s as power supply bypass caps (10nF) but have not tried them as coupling caps.

Are the RelCaps available in 2n2?


/S

Thanks. I've just put some rifa pfr 2n2s in last night, but I'm not convinced. Sounds a bit flat and lifeless. Will have to try the pfes. I'm trying to resist ordering relcaps as I just can't justify the cost, but the niggle to try will never go away...

 

[staccatiss]

Well,
yes, and no, IMO.

We all have caps in the PS (except when using batteries).

Sometimes one can tune the sound with coupling caps.

And of course loudspeaker cross overs are full of mediocre caps....



/S

The best cap is no cap

 

[Spev]

Blimey, they're beasts. Anyone heard any difference between different types of polystyrene caps? I've a bag a nos RS axial ones. Are fancy pants rifas, vishays or relcaps any better (entirely subjective I know...)

 

[Spev]

Interesting!
I sometimes use PFR:s as power supply bypass caps (10nF) but have not tried them as coupling caps.

Are the RelCaps available in 2n2?


/S

partsconnexion and michael percy both have relcap RTs in suitable values (2n and 2n2 respectively). MP is $2 cheaper per piece.

 

[leif christensen]

just to clearify:
the russian caps I mentioned/referred to, was intended for filter position, not output
best
Leif

 

[Spev]

Yes, likewise. I'm sure 2n2 on output would sound odd to say the least!

 

[leif christensen]

 

[staccatiss]

They are very magnetic, so I do not use them. Instead I have tried the FT-2/3 as they are non magnetic.

Some like´m some do not like´m...



/S

buy the russion tefloncaps you often find on ebay...they sound great
only downside is size

Russian Teflon Capacitor K72P-6 2200pF 500V 1ps.or more | eBay

best
Leif