Touch hardware mods

[UV101]

?

Personally I've never had a problem with Fidelity Audio and have become friendly with the owner over the past 5 years. He's a good guy, extremely enthusiastic about what he does. When business is quiet, he'll spend more time explaining things than usual. Following his positive press in
Hifi world mag this month (feb 2012) he's a little more busy than usual!!

I sincerely hope that you are able to resolve any problem, as I say he's a good guy ad not just in it for your money!!!

[HumanMedia]

Roger that.

From the Audio Fidelity site:
1x Sanyo Oscon SEPC 470uF 6.3v decoupling capacitor (Oscillator_1 3.3V)
1x Sanyo Oscon SEPC 470uF 6.3v decoupling capacitor (Oscillator_2 3.3V)
1x Sanyo Oscon SEPC 470uF 6.3v decoupling capacitor (Clock 5V)
1x Sanyo Oscon SEPC 470uF 6.3v decoupling capacitor (USB psu)
1x Sanyo Oscon SEPC 470uF 6.3v decoupling capacitor (Digital 5V)

2 caps are definitely for each of the new clock oscillators

1 cap has been moved to the new clock board "Clock 5V"
But is it attached to the clock board or to the main pcb board?
Is it bypassing the 74LVCU04A chip at location U14 - and actually attached underneath the new clock board? Note that caad bypasses the 74LVCU04A with two caps in parallel - a 100nF U2J and a 100uF polymer cap. I wonder how the clock board fits in? does it fit into the sockets left by the old oscillators or piggy back or replace the 74LVCU04A chip?

1 cap is replacing the existing E cal 33uF cap found below L7and to the right of TP67 (is this the digital 5V?) Note that caad replaces this cap with a 100uF polymer SMD.

So where is the last cap on SBGKs board? Is it for the USB power supply?
SBGK if you can take some better photos of your board it would be very helpful.

Examining caads mods I see more bypass caps, most very small smd modules. Wow. He also bypasses C106, C135, U34 (SPDIF output buffer) and U15 and U33 (Clock switches)

Studying SBGK's pic 3 it looks like 3 of the SEPC caps are on the micro clock. One will be on the regulator and the other 2 are local decoupling for the individual oscillators. The final cap is on the main unit rail.

In the fidelity audio pic, there are only 2 on the clock. There is one on the main unit rail and 1 for local decoupling for both rails on the dac chip itself (left of the DAC chip) the final cap (right of the DAC chip) is post reg (cant rememeber if thats the 3.3v reg or the 5v reg).

Not sure what order things were done in but fidelity audio tend to do things in a "bespoke" manor. If SBGK's unit went to them with the I2s mod fitted or were advised it was going to be done, they wouldn't have fitted the 2 caps the the dac chip (as its not used) and tailored the package to suit.

[UV101]

?

[HumanMedia]

Caads Mods Summary (Part One)

Supplied pdf image from Caad: http://forums.slimdevices.com/attach...7&d=1312026081

Component located at U14 - 74LVCU04A hex inverter chip (14 pin chip)
Modification - Add 2 decoupling caps (100nF U2J SMD and a 100uF polymer cap) in parallel linking pin 14 (Vcc) and pin 7 (gnd) of the 74LVCU04A chip. Use copper tape to connect the pads.
Note - ONLY use SMD components for decoupling. Do NOT use leaded because 1mm of the lead will introduce around 1nH and this will increasee the ripple between the Pin 7 and Pin 14. It would Be a good idea to replace the U14 hex inverter with single inverter Gates (no buffered must Be used as the U14 already is. When using single gate inverter instead of a hex inverter have advantage of very short bonding wires and you will be able to place the 100nf very close between the supply pin and gnd pin.

Before image (from passiondiy.fr):


After image for only a single cap used (from passiondiy.fr):

[HumanMedia]

Caads Mods Summary (Part Two)

Component located at C106 and C135 - 10uF 0805 caps
Modification - Replace each cap with 47uF to 100uF good quality cap. (eg. Blackgate 47uF HQx)

Before image (from passiondiy.fr):

[HumanMedia]

Caads Mods Summary (Part Three)

Component at U15 and U33 - C97K Clock switches (6 pin chips)
Modification - Add 100nF in parallel with a 47uF polymer SMD or Blackgate HQx across middle pins of each switch chip (pins 2 and 5?)

Before image (from passiondiy.fr):


After image (from passiondiy.fr) - note that the second 47uF bypass cap seems to be missing from U15?):

[HumanMedia]

Caads Mods Summary (Part Four)

Component Below L7 and to the right of TP67 - Main Digital 5V rail with existing E cal 33uF cap
Modification - Replace the existing E cal 33uF cap with a 100uF polymer SMD

Before image (from passiondiy.fr):

[HumanMedia]

Caads Mods Summary (Part Five)

Component at U34 - SPDIF output buffer (5 pin chip)
Modification - Add 100nF U2J cap in parallel with a 100uF polymer SMD (or say Black gate 47uF HQx) from pin 1 to 5 of the chip
Note - ONLY use SMD components for decoupling. Do NOT use leaded because 1mm of the lead will introduce around 1nH and this will increasee the ripple.

Before image (from passiondiy.fr):


After image (from passiondiy.fr):

[UV101]

are those the pics from pssiondiy.fr?
I think they've been posted lots of times here unless there is anything new in those?

[HumanMedia]

are those the pics from pssiondiy.fr?
I think they've been posted lots of times here unless there is anything new in those?

Nothing new, but all the info is now grouped together (and not in French)
I found myself spending too much time re-referencing the same material from many locations. Now it's all in one spot and summarized.