jazzwave
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So, which you prefer to change for 1st mod; LO or HO caps? I have 32 Ohm and 300 Ohm cans
~ron~
~ron~
Wow babs, this is some bad-ass testing! You made me curious about those POSCAP`s now.
And I`m glad I`m not hearing "wrong" things. Your tests are much more "scientific & hi-tech" than my simple breadboard-fast-switch listening tests but You also rate FC caps on top - thanks for confirmation
In DX50 FW thread I was talking about oxicaps - I was talking about HO amps decoupling caps which I still wish to change for those (Yes I know room can be problem but I think I can fit them ): http://www2.mouser.com/ProductDetail/AVX/NOJD107M010RWB/?qs=%2fha2pyFadugxym376v1PCTxYMG83g6bUcOX5cpt8tb5fh%2fu5IBzi%2fA%3d%3d
You are still running 3x47uF 10V oxicaps there?
Also thinking about changing HO output amplifiers or DAC differential amp but I need Your advice - which way should I go with my gear (12-36 Ohm IEM`s and Fidelio X1) and FC caps (atm probably going to leave them in place, I like them)? Is changing only HO output amps enough SQ improvement or is differential a "must have"? Or should I go for both mods?
I am already changed the HO decoupling cap; the 3x47uF oxicaps are gone and I put one 330uF 10V POSCAP (#10TPE330M)
This cap fit nicely to the original pads
Bass seem tighter, and go definitively lower
But the ADA4841-2YRZ seem equivalent and have the good package (SOIC-8)
I am already changed the HO decoupling cap; the 3x47uF oxicaps are gone and I put one 330uF 10V POSCAP (#10TPE330M)
This cap fit nicely to the original pads
Bass seem tighter, and go definitively lower
Another worthwhile modification, in the same circuit, is the replacement of the differential opamp decoupling Cap (see picture, yellow rectangle), placed just over the Amplifier I just changed.
The original capacitor is a standard 100uF 6.3V tantalum in a 3528 case
I replace it with a 22uF 6.3V Oxicap (AVX #NOSB226M006R0600)
For differential opamp decoupling cap I ordered POSCAP in both cases D2E (# 6TPE100MI ) and B2 (# 6TPE100MPB).
Will try to fit D2E in that position because it has very good specs: ESR 18, ripple current 2800.
Anyway, I ordered #10TPE220MIL and will report back after installing.
The original HO decoupling capacitor is a standard 220uF 10V tantalum in a 7343 case
The original DAC differential opamp decoupling capacitor is a standard 100uF 6.3V tantalum in a 3528 case
I replace it with a 22uF 6.3V Oxicap (AVX #NOSB226M006R0600)
Any particular reason why You went with 330uF 10V POSCAP (#10TPE330M) instead 220uF 10V (stock caps spec) POSCAP (#10TPE220MIL) ?
330uF vs. 220uF poscap:
ESR - 25 mOhms vs. 18 mOhms
Leakage current - 330uA vs. 220uA
Ripple current - 3000mA vs. 2800mA
http://www.mouser.com/ds/2/315/TPE_OS-262406.pdf
Anyway, I ordered #10TPE220MIL and will report back after installing.
Are You still using oxicap there or also replaced it with POSCAP?
Regarding change of Dual Differential Amplifier I think this might be a worthy upgrade:
JRC: MUSES8820E
http://uk.mouser.com/ProductDetail/NJR/MUSES8820E/?qs=sGAEpiMZZMtxdzBvM0rKcdcB8W9ucxBQ8hRkSqFfJ7c%3d
maybe it is not suitable though to be positioned in the circuit straight after the DAC? Babs any thoughts.....?
2 x HO single amps will probably still be:
ADA4897-1ARZ
Like you Coil I am going to do the HO decoupling cap next and then tackle the main amp section.
Cheers
I decide to try to change the decoupling caps of the DAC analog power supply; same case, same voltage
There is 3 analog power supply pins on the DAC: AVDD (pin 15), AVDDR (pin 9) and AVDDL(pin 20)
These caps are located at left on the photo:
The LO decoupling cap is just above the differential amplifier
The 3 DAC decoupling caps are vertically aligned on the left of the picture
No possible error; these 4 black caps have an big (+) on it
I didn't expect lot,but I am surprised; there is a clear improvement: less noise and better separation of instruments
I keep it!
LOL, every time we are dealing with "old" capacitors change, You already have new mods ;D
Since You used 6TPE220MAZB for LO differential amp decoupling cap then I assume leakage current isn`t problem
because the one You used has it 138.6 uA which is over double higher than the one I`m going to use (# 6TPE100MI or 6TPE100MPB).
Now I have to order some more Poscaps for decoupling caps of the DAC analog power supply
The original HO decoupling capacitor is a standard 220uF 10V tantalum in a 7343 case
The original DAC differential opamp decoupling capacitor is a standard 100uF 6.3V tantalum in a 3528 case
The original DAC analog power supply decoupling caps are standard 100uF 6.3V tantalum in a 3528 case