CS4397 dac

[JDMz]

It bypasses the chip. Leo thinks the DAC sounds better without. I removed the chip completely as a last resort. If you do add a blob of solder to those points make sure you lightly scratch the surface so you get a good solder joint. I didn’t and ended up burning off the pad!

So I can try it bypassed and not bypassed? Is this bypassing the OPAMP or just that chip? Cus i bought a nice opamp.. lol

[Naqua]

JDmz.

It's just bypassing the chip. It normally mutes the output signal when there's no lock at the pll or when powering on.

Opamp stays in place

[Tripmaster]

So I can try it bypassed and not bypassed? Is this bypassing the OPAMP or just that chip? Cus i bought a nice opamp.. lol

Yes, just bypassing the chip.

[JDMz]

Hi, I messed up the trace of C54 on the side of the right output. Do you know where I can find this? I just see a bare board... got it from using a desoldering braid

pic


also,did you remove r28 and r29? mine has resistors there with 104 written on it
thank you


EDIT:
I used resistance checker and the RED's have 0. So I assume I can connect the YELLOW's?
It is weird.. I always thought current moves from - to +, why is it reversed?

[FireFly]

C54 is connected to R output

[JDMz]

are you sure? Doesnt it go negative to positive? so the left side of C54 goes to R output?

EDIT: I fixed it by doing what I described in the picture.. why is the capacitor connected backwards? + on +

[FireFly]

negative side of C54 is connected to R output. Positive side of C54 is connected to op-amp output.
If you bypass pads with wire, both positive and negative pads are connected to R output.

Don't understand about capacitor connected + on + or backwards

Signal is always traveling from higher level to lower lever. At op-amp output is higher level (source of the signal), at RCA is lower level. Capacitor is between, positive side goes to higher level, negative goes to lower level, where is problem?

Anyway, using lytic or tantalum for coupling is bad idea , but it is cheap

[FireFly]

Hi-res shematic

[Naqua]

Mod update:

Mod6:
c19 pana 470uf
c21 oscon 100 uf
c3 10 uf gpo
c18 100 uf oscon
c20 470uf pana
c25 10uf pana
c16 100 uf oscon
c17 100 uf pana

Muddy bass - "air" ok "beeing there" not ok
Less detail, less dynamics

MOD7
c19 pana 470uf
c21 pana 150 uf
c3 10 uf general purpose
c18 100 uf oscon
c20 oscon 100uf
c25 10uf pana FC
c16 100 uf oscon
c17 100 uf pana FC

round bass, power dynamics, Detail and highs-ok

also tried opa21047AP was to heavy on the bass, less depth didn;t like it.

Next round -> elna SILMICII instead of Pana FC

[FireFly]

tried all 3 types (Oscon, Panasonic FC, Elna Silmic II) during several days listening marathon
No big difference at all (the same values for all 3 types). Panasonic FC is the worst (less bass), Elna Silmic II and Oscon is equal, maybe is Oscon more stable in bass & mid region, but less details & less dynamic than Elna. Or just my imagination playing with me

Naqua:
Difference between your MOD6 and MOD7 is value for C20. Bigger value will "slow down" music, cause less details & muddy bass.

I increased C19 from 470μF to 1000μF. Changed C20 from 470μF to 220μF OSCON and changed C17 from 470μF OSCON to 100μF Elna Silmic II.