My 3 yr old only wants to turn the volume down .
post #346 of 1144
2/6/10 at 4:17am
I succesfully fulfilled the 74HC04 mod tonight. The Chameleon works great but I can't test if the USB input works. Michael confirmed the USB input worked fine there.
You can perform this mod at your OWN RISK!
Make sure you don't set the temperature of your soldering iron too high. I set it to 275 degrees celcius.
How difficult is this mod? Well, this one is easy compared to the DIR9001 mod of the Valab. I could even do this mod without using a magnifying glass. If you've fulfilled the DIR9001 mod succesfully, this one is certainly doable as long as you work precise. :-)
So here's the deal:
STEP 1: Read this post first
STEP 2: Remove the 74HC04. Just cut every leg of the chip carefully with a sharp knive, one at a time. Once you've cutted them all the chip will come loose. After that, heat every solderpad shortly (watch your pcb traces!) to remove all cutted legs from the 74HC04.
STEP 3: Either remove the 3 SMD resistors (right from the 74HC04 in the picture down here) or bypass them with a piece of small solid wire
STEP 4: Look at this picture first:
1/2/3: I decided to remove the resistors so I needed to reconnect the solderpads again.
4/5: Connect pin 3&4 and 10&11 together.
EDIT: How does it sound?
The Chameleon has now been on for 45 minutes and I noticed the bass got tighter and the highs less grainy which results in more transparency and better seperation of individual instruments. The effect of this mod is less noticable when the ASRC board is inserted but I can still hear the difference.
EDIT 2: It's 4 hours after the mod and have been listening carefully. This mod is a 'keeper' for sure. It is all just more accurate: Less speaker, more music! As X-Files fan I say: The Truth is (now) in here in stead of out there. :-)
Who dares to follow me?
p.s. Although there's no way back once cutted, the 74HC04 is really cheap so if you wanna go back, no problem as long as you keep your pcb traces alive.
Ripped out those Oscon sp from the digital board, and while I was at it the .1uf SMD as well. Kept blaming the over boated bass and soft attack on the BG decoupling caps as they continue their difficult childhood.
Replaced them with BG NX Hiq, and bypassed them with Wima 0.1uf, then replaced the rest of the SMD as well.
Its like this lizard just had a laxative and cleared out all the bloat.
50 wimas for the price of a beer, sprinkled liberaly in this dac works wonders.
Any one know how to safely hookup the transformer for output sans the output caps?[/COLOR][/B]
Bill, thinking about this out loud, wouldn't the topology be similar to the input pulse xfrmr section? That is 180R (iv) across the primary of the Ciniemag and 47KR across the secondary of the Cinemag? And all inductors, capacitors are gone from the circuit....