[docentore]

This thread has it's beginning in C&C appreciation thread by H20Fidelity
 
I have decided to open separate modding thread to avoid the appreciation thread being cluttered.
 
There are few reasons why I wanted to mod the C&C.

• Learning new things is always good thing.
• I’ve read that the amp has problems with power section, it is underpowered.
• The soldering in my amp was very poor.
• Few of the components looked like burned / damaged (tantalum caps)
•  

I could not get this from my head and the amp SQ started to deteriorate (it's all in my head )
 
Ok, lets cut the crap and get things done.
 
Some technical details (according to manufacturer):
- Maximum output power: 300mW +300 mW;
- Headphone adapter Impedance: 8-300ohm;
- THD + N: <0.001%; Long life time: about 80 hours;
- Pocket size, Size: 76 * 57 * 13mm (aluminum housing);
- Weight (including batteries): 100g;
- Charging Power Interface: 5V0.5A DC, Universal miniUSB interface.
- Signal noise ratio :110dB
 
Known parts list (no need for obvious parts like jacks or DTDP switches). And no, there are no red WIMA couplins caps
- 3x 1000uF electrolityc capacitors 6.3V 8x11.5mm
- 2x 0.22uF (220nF) film caps
- 2x 0.15uF (150nF) film caps
- 2x 0.18uF (180nF) film caps
- 2x 0.12uF (120nF) film caps
- 2x 0.015uF (15nF) film caps (all film caps need to be 7.2x6.5x2.5mm or smaller)
- 4x 100uF tantalum caps (probably size A or B).
- 2x TPS60403 inverting charge pump outputting aproximately -/+4V and 169mA on battery and 250mA on USB power (confirmed by Tai/CieOS)
- 3.7V Lithium-Ion battery compatible with Nokia 5M (need to be confirmed)
- 10K A double taper logarithmic potentiometer with switch (made by Alpha)
 
Most of the IC's are sanded down but I was lucky enough to get the charge pumps deciphered. Maybe someone will be lucky with the rest of the parts.
 
So I've recapped half of the film caps, all electrolitycs, 3 out of four tantalum capacitors. Quite happy with results.
To do: change charge pumps for ones outputing more current (original ones have 60mA of output). I have couple of LM2662 and LM2663 - 200mA of current output.
 
I'm also thinking of changing the enclosure for a little bit bigger. Best size for me would be a 5mm higher one, which would give some extra space for caps and power section, but I can't find one anywhere. I think I will stick it into nice 2.5" hdd enclosure.
 

Any thoughts?

 

[docentore]

Few pictures of the internals with original parts and modified:

 
 

 

[Ari33]

Thanks for starting this thread.. subb'd
 
It would be very handy to know the exact dimensions of the circuit board and also how much/little could be removed from its sides safely. 

 

[docentore]

Quote:

Thanks for starting this thread.. subb'd
 
It would be very handy to know the exact dimensions of the circuit board and also how much/little could be removed from its sides safely. 

 
52mm x 72mm - this is approximately size of pcb. There are cutouts in corners 2mm wide - I would say that you could remove those 2mm from each side, only one between layer connection would be lost, the positive power polar. Easy to be transferred using alternative ways.

 

[Ari33]

Thanks, that wee casket I was looking at might just be big enough then.. I'll get some pics up if/when I do it.

 

[docentore]

no worries. I'm looking at 2.5" enclosures as we speak on dx. I'm thinking of sawing off a bit of the hdd casing, the whole amp would be more square size, but would give some space for extra parts

 

[Ari33]

I also want to remove the plastic slider switches at the back and replace them with some nice S/S micro toggle switches for a bit of bling. I just need to find out what type of switch to go for and how many pins the switch would need to have.

 

[docentore]

Quote:

I also want to remove the plastic slider switches at the back and replace them with some nice S/S micro toggle switches for a bit of bling. I just need to find out what type of switch to go for and how many pins the switch would need to have.

Those are DPDT switches (On-On), 6 pins, I'll get the raster measured later.

 

[docentore]

I have bigger case ordered, received some samples from TI, but I cannot do anything more as my solder iron decided to die. I will continue when my new solder wand arrives.

 

[docentore]

I've received few parts this week so I decided to borrow solder iron and do some more modding. I wanted to test the LM2662's with BH2. Also received some AVX OxiCap's - they were to replace tantalum caps. What can I say, everything went well, the BH2 is getting more current (the new charge pumps give 3 times more if needed). I need to find unmodded BH2 around Dublin to compare.
Some pictures:
 
 
LM2662's charge pumps installed on Brown Dog adapters:

 
 
First test with BH2 - passed without any problems!

 
 
 
 
All ready, just waiting for the case.

 
 
This case is very tight! Took me over half an hour to install it back in the case without anything shorting, disconnecting etc. A 2mm taller case would be blessing.

 

[Ari33]

Great work Doc, Kudos to you, that's great news. Thanks for being the guinea pig!

 

[docentore]

No worries. I used the schematics from the datasheet:

 
I desoldered 2 original IC's and capacitors (original were ceramic 1uF as fly caps and 10uF as coupling caps) and used some nice tantalums from broken iPod board (47uF KO Kemet) - 2x fly caps + 1 coupling cap. I've left the ferrite beads there and just connected everything on the other side, there is some space there plus its easy to solder to ground, input +V and output -V.
 
EDIT: Day of testing and my ear drums feel like punching bag It definitely helped with bass, I prefer to have the LF off now. Also feel like the clarity improved and the amp is a bit faster. 

 

[Kamakahah]

I love the work, but man is it time consuming. GJ.

 

[docentore]

Small update here. This is a picture of op-amp rollable C&C BH2. Just finished it. 
 
I can't say how does it sound now with different op-amps - I'm too tired now. During all the mods I broke the SF fiunction, when it is on ot only affects right channel, can't find the fault.
After listening 2-3 favourite tracks with 3 dfferent op-amp I'm not sure if I like the amp anymore, or maybe it is X3 sitting in my pocket and sating those words through me