Blue LED on iBasso D10

My very first Bling Bling Mod on the D10

Blue LED

How does it sound ? It is just bluer, and more Beautiful
Tested with Bluer than Blue by Livingston Taylor, Chesky Records

Some may think that changing to blue LED would require more power and hence less battery life.  But that may not be the case, Taking a textbook LED implementation on 5V a 330Ohm resistor is connected in series with the LED. The turn one voltage for red LED is 1.7V for Yellow is 1.9 for Green is 2.1 and blue 3.1Volts So the effective current for Red LED is 10mA, for yellow it is 9.3mA for Green is 8.7mA and Blue is 5.7mA. Just changing from Yellow LED to blue LED would almost save half the power. Most of which is loss to the resistor. But I am not that power conscious. I reduce the resistor value so that the power consumption is almost the same, The blue LED is too dark if you just change it, without changing the resistor.


The 1 sampling delay in PCM2906

Investigating as to why SPDIF is much better than USB interface on the D10. I started some additional investigation. Using a software waveform generator I generate square waves and measure it on the scope this is what I found.

This is a 1Khz Square wave using SPDIF. The left and right signal is place close together on a dual trace OSC-Scope

The wave form is mono and I adjusted the amplitiude on the OSC-Scope so that you could see the waveform side by side. The ringing (overshoot and undershoot) is normal.

Using USB and even trying with different computer this is what I get which is NOT normal.

As you could see highlighted by the 2 red arrow the signal is not in phase. It is about 4 degree out of phase, Or about one sample (sampling frequency) off. I could offset the phase in the signal generator so that is how I calculate the difference in Phase.
What this means is that one side of the sound is coming out slightly faster then the other. The Left and Right signal is suppose to be Mono or equivalent to Mono.

I will try to investigate more. Sorry for another troubling find.

Found an Errata from Texas Instrument.

An extract from the Errata

2.2 Inter-Channel Phase Difference
2.3 Exceeding Max-Packet Size
Problems, Restrictions, Workaround Analog, Embedded Processing, Semiconductor Company, Texas Instruments
The PCM290X has delay of 1 sample at each channels as follows:
· Up-stream data from ADC, S/PDIF in : Rch data delay (1 sample)
· Down-stream data to DAC, S/PDIF out : Lch data delay (1 sample)
Recording or playback of general audio or S/PDIF In/Out of Linear PCM, makes minimal difference to
the listener. However, the critical application for the inter-channel phase difference, data transfer
between USB and S/PDIF In/Out, can not be used.
If the inter-channel difference is not allowed, the user must solve this problem in the application
software. It is not possible to solve this problem by any modification of external circuit.
TI is considering corrections to solve the problem, and will notify the user when a solution is
Take care to note the problems listed in this document when considering the use of these products for
new projects.

There is an upgraded part 2906B
And according to the article, publish in Jan 2009 at

c. Fix of one-sample interchannel phase error in recording and playback.

If this is the case, Most of the existing product in the market would be affected as PCM290x is widely used.
EDIT: I wounder if the PCM270x are affected need to investigate

Using a USB to SPDIF is unlikely to solve the problem as the device is most likely using a PCM290x device. Unless it is using the upgraded version.

I need to catch some sleep.

I am really not expecting this.

Ibasso D10 First Mod

I just bought this amplifier 4 days ago upon discovering a bad resistor decided to OPEN this amp with the first soldering mod.

A am really force to modding this at a very early stage. Ideally I would have like a few more days or maybe week reading and understanding the circuit before any modification. I like to procrastinate and dream about every mod.

The following mod is what I would like to have done at this stage

1) Change the to Output bypass capacitor to MKP, But I do not have the required parts at home.

2) Change 2 of the resistors to Vishay-dale connecting Pin 2 and pin 6 of the LR Amplifier to ground.

The 2 feedback resistors are already using Vishay-Dale and I would like the input resistor to match that as well.

3) Change the 2 Input coupling capacitor to something else.  This would be hard to source as I could only place the cap on this side of the board and I only have about 3 or 4mm thickness to play with.

I end up only being able to have sufficient parts at home for the following mods

A) This 2 capacitors is to help the frequency response of the input DC coupling capacitors. I have wima at home but it just could not fit here.

B and D ) Power supply decoupling. This help reduce the RF interference and is quite effective especially for blocking mobile phone  signal.

C) what I could make do at home with the Output DC blocking capacitor

E) This is to match the other resistors so that we could have a balance output when Gain is set to High.

So far the main benefits I hear from the above mods are better RF interference – this is very obvious

Better clarity at the high end. I would not hear the whistle of Jennifer Warnes’s Lights of Louisianne which is not present before the mod. The mid is more mellow as well.

I am still using the original Op-Amp and have yet to roll, I have gather enough information for Op amp selection.

Using iBasso D10 as a Signal Generator

It is amazing how things have change over the years, I wounder if oscilloscope is going to be faced out of this world, as there are outboard probe connected to USB in the market. It certainly made my signal generator obsolete. I am currently using a software to generate different waveform to be fed. Maybe I need a more powerful amplifier. Well it seem my iBasso D10 would be able to fit the bill except that it have a capacitor at the output.  I like the ability to edit the waveform to any pattern I desire, this is something that a waveform generator will have difficulty following. Any electronic hobbies would seriously consider this as an alternatively  Signal Generator.  Just need to get a good software like Goldwave and you are ready to go.

Anyway my oscilloscope have been laying around for more than 8-10 years unused and it took me more than 30 minutes just to clean and remove all the accumulated dirt. I am surprise that it is still working.  I am force to used this to debug a faulty resistor on the Amplifier.

I wounder if there are any crazy animal other than me in this world who still have an oscilloscope at home.

3 Generation of Seagate 5400 rpm 2.5 Notebook Drive

Today I shall write a short intro to the 3 different generation drives from Seagate

They are all mainstream drive 5400 RPM 2.5″ Notebook drive they have a max capacity of 160G, 250G and 320G respectively.

Attached are the benchmark result of the 3 drives, first is the 5400.3

5400.3 Result

5400.3 Result

Following is the 5400.4 250G drive

5400.4 Result

5400.4 Result

And finally the latest 5400.5 320G drive

5400.5 result

5400.5 result

As we see from the result the improvement in speed is great

Added to the mix is a 7200 drive from Hitachi 7200 200G. Note that this drive is launch at around the same time as 5400.3 drives which is the oldest drive in the test

7200RPM 200G Hitachi

7200RPM 200G Hitachi

As could be seen from the graph great achievement have made since from the 3 to the 4 generation drive.  While the 5th generation drive is able to surpass the top of the line 7200 drive from Hitachi in term of media reading speed. But in term of access time 7200 still wins. It have to be said that the 7200 RPM drive being compared belong to the 5400.3 era. Point to note is the slow access speed of the 5400.5 drive after 40% mark of the drive.  It is really great to see and experience faster drive especially in the face of SSD.

From a usage perspective I would say that you could feel the speed difference moving from a .3 to a .4 drive, but moving from a .4 to a .5 drive is not that significant.

From the spec is the power saving of the latest 5400.5 drive that consume a max of 1.3W from the usual 2-2.2W, but in real life usage I do not experience a longer battery drive. likely because it is not always that the drive is operating at the maximum power.

Currently the latest 7200 RPM drive is not available for testing. Both Seagate and Hitachi have a newer generation of drive which according to spec if about 25% faster than the 5400 equivalent. 7200.3 drive from Seagate is already available for sale. and Hitachi have announce their equivalent.

The newer generation of drive does have the advantage of being faster. so if you want to buy a drive make sure it is oh the latest generation. As I last check all 3 generation is on sale at the shop at the time of writing.

I feel the harddisk company is definitely worried of the challenges that SSD would bring, It is if users would want to store HD movies on their Hard drives. As with the current capacities of Harddisk, the main reason to want a bigger drive is to store movies in High resolution. As fast SSD drive of 128G and above start appearing, there are less and less reason why users would want a hard drive apart from the price consideration. There isn’t so much data a user would need to bring on the road. If you do not believe me, try filling up a modern harddisk WITHOUT movies. The reason for getting a newer drive is for the speed not the capacity. With SSD the speed issue is solved.

Note that if you have a  320G drive, to fill it up with data using a 100BT Ethernet connection at max speed is 7 hours plus. In reality even 20 hours is insufficient. Worst if you use Vista.

Harddisk 7200RPM vs 5400RPM

Upgrading the harddisk on a laptop is the single most effective way to improve functionally and speed on a laptop, it is the single most important component.

Not only is a new harddisk faster, it is larger so you could store more files, and not to forget the assumption that a new harddisk would last longer than an old one.

Here I compare the existing king of the hill 2nd generation 7200 RPM  drive from Hitachi which is the 7k200. The upcoming 7k320 should be coming in a few months time. And the forth generation 5400 seagate drive the 5400.4 250G.

First are the benchmarks numbers



As you could see the forth generation drive from Seagate is pretty close to the 2nd generation 7200RPM drives. The reported numbers for temperature I assume is wrong as I felt the 5400 drive to be cooler to the touch compare to the 7200 drive. Maybe it is the way the position of the temperature sensor is taken .

I must say that the 5400.4 is very much faster than the 5400.3

In Windows experience index the 7200 drive is reporting 5.4 while the 5400 drive is reporting 5.3, previous generation 5400 drive are in the region of 4.7 to 4.9.

Conclusion if you are looking at an harddisk upgrade I would recommend the 5400.4 drives over the 2nd generation drive as the performance is pretty close at about half the cost not to forget the 50G of extra capacity and a cooler running drive.

Until the 3rd Generation 7200 drive is available.

T9500 Penryn Stepping difference Q4GG vs Q9WW

These are Engineering Sample stepping and would not usually be purchase.

Q4GG is stepping 4

Q9WW is stepping 6 same stepping as the retail version.

On the net the Stepping 4 T9500 is much cheaper than the stepping 6. Q9WW. What is the difference.?

Having tested both stepping this is what I found.

The stepping 4 have a fault temperature sensor, and most software like CPUID could not detect.

But this alone would not justified the price difference of the processor. It is actually the CPU working voltage

Mhz/step Q4GG Q9WW

800Mhz 1V 0.925V

1.2Ghz 1.05V 1V

1.6Ghz 1.075V 1.05V

2.0Ghz 1.15V 1.1V

As you can see from the table at the same frequency the stepping 4 CPU is consuming more power that the stepping 6. It is consuming more power then a menron CPU. and hense you could expect the laptop to be running hotter as well.

Instruction wise there is hardly and difference between the 2 CPU so all your application would still run fine, just a bit hotter.