Coupling Cap 220µF - the best is...

[Alfetta87]

Hi,

I was just tweaking the Audio Board of my DVD 2900: just after the output OpAmps (replaced by Dual AD825 devices), there is a 220µF/50V polarized (Elna Silmic II) as a DC blocking cap, in parallel to this a set of polarized - inverted connected (+ to +) Silimic (not II) of 2.2µF/ 50V.
I'd like to experience to get a better sound. Actually, to player is bright without going too far, but there is a lack of presence in the low midrange which takes some natural from the music. Compared to a Copland CDA288, the player sounds thin, even there is bass.
Haven't changed anything yet in the PSU, would start to change the 220µF to another, and replace the 2.2 against a single Auricap 1.0µF.
What would be the best Electrolytic Ersatz for the 220µF?

Thanks,
Dan

[analog_sa]

The Silmics are excellent. BG will be marginally better but don't expect a transformation. Why on earth do they use such gigantic values anyway?

[Alfetta87]

No Idea, why such high value. Will try lower values though.

Have also a pair of Balck Gates X, non polarized, maybe they worth it?

Dan

[fmak]

Originally posted by Alfetta87
Hi,

I was just tweaking the Audio Board of my DVD 2900: just after the output OpAmps (replaced by Dual AD825 devices), there is a 220µF/50V polarized (Elna Silmic II) as a DC blocking cap, in parallel to this a set of polarized - inverted connected (+ to +) Silimic (not II) of 2.2µF/ 50V.
I'd like to experience to get a better sound. Actually, to player is bright without going too far, but there is a lack of presence in the low midrange which takes some natural from the music. Compared to a Copland CDA288, the player sounds thin, even there is bass.
Haven't changed anything yet in the PSU, would start to change the 220µF to another, and replace the 2.2 against a single Auricap 1.0µF.
What would be the best Electrolytic Ersatz for the 220µF?

Thanks,
Dan

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You should try the BG FKs without bypass initially. You must burn in for a couple of weeks. The 825s are smoother with two FET current biasing to 3 mA or so.

The BGs are way better than Silmics; but you must use FKs or Cs if you thinkl FKs are too expensive.

[Peter Daniel]

One of the mods performed by Partsconnexion to Shanling player is instaling in output coupling position two BG STD 220u caps (back to back) with 2.2u Auricap in parallel to that. It sounds pretty good this way.

I also don't know why those capacitances are so high.

[fmak]

[QUOTE]Originally posted by Peter Daniel
[B]One of the mods performed by Partsconnexion to Shanling player is instaling in output coupling position two BG STD 220u caps (back to back) with 2.2u Auricap in parallel to that. It sounds pretty good this way.

I also don't know why those capacitances are so high.
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I have never liked back to back connections for caps; you ens up with signal going thru' 2 caps whatever the alleged theoretical benefits are.

You also probably don't need 220u. 100u or even 47u will do. For 47u, there is the BGNs.

[Peter Daniel]

They would probably get away with 4.7u as well.

And BG N are pretty good for coupling.

Regarding the previous way of connecting caps, I wouldn't do it that way either, nevertherless, I was surprised it still sounded decent.

[Alfetta87]

The DVD 2900 is supposed to be a High Quality player (when not High End), maybe for this purpose high value of 220µF is considered to be usefull in any situation (regarding the frequency response towards the LF) - whatever the connecting impedance would be. But the situation is that a preamp after the Denon could have a coupling cap as well - as it is the case with my BP 25 from Bryston, which has 100µF Roederstein ElCaps in the signal (before the electronics). My other, SRPP home made tubeamp (5687) has no input cap, so there is a need of a cap in the Denon, otherwise any cap would stay outside.

Will try smaller values and see how it works.

Dan

[Extreme_Boky]

Hi Alfetta87,

I have used AURI capacitors instead of various combinations of electrolytic capacitors with by-pass caps. In my opinion, a single capacitor in signal path is mandatory for a good sound! Try 4.7uF/200V AURI caps. Try to connect them from the output pin of your AD825's straight to the RCA connectors - AVOID pcb tracks! Be careful to preserve muting functions, as well as a proper RC loading of your output OP amps.

I must say that I have used Black Gate capacitors as well. I tried C type for signal coupling, N and NX in both stand-alone and super E cap configs, FK types... To me, 10uF/50V type C Black Gate sounded the best, but not as good as AURI caps. I love Black Gates in power supply filtering applications, as well as IC power supply rails high frequency decoupling applications where 0.1uF/50V NX type is absolutely fantastic. However, for the sound coupling, AURI caps are better. There are other high quality (and high price!!!) film foil capacitors around - but I haven't tried them. AURI caps are reasonably priced and sound open and natural.

Regards,
Extreme_Boky