solderdude
Administrator
measureutternutter
Posts: 4,886
|
Post by solderdude on Dec 10, 2015 6:00:14 GMT
Would there be an interest in a crossfeed module so the Kameleon can also do crossfeed as a side grade to the 'flat' module ?
Almost finishing the manual for the portable version.
Then of to building 2 different enclosure desktop versions.
Will be selling them around Feb 2016.
|
|
|
|
Post by deireleire on Dec 10, 2015 8:24:48 GMT
That's one small step for man, one giant leap for mankind. It's my birthday in februari, I know now what to get  |
|
solderdude
Administrator
measureutternutter
Posts: 4,886
|
Post by solderdude on Jun 3, 2017 15:22:45 GMT
For those that have built the portable Kameleon amplifier there is a small (easy to do) modification for the battery management section. This has no influence on the audio quality. When batteries are brand new or getting older after many many hours of usage the internal resistance of the battery is a bit higher than under optimal conditions. This causes weird behaviour on start-up. Mostly when batteries are in need of recharging. During the development a variable power supply was used and this one, of course, did not show this poor behaviour. It only happens with real batteries. The modification consists of adding a small electrolytic capacitor (10uF) with a voltage rating of 16V or higher. HOW to do this is decribed in the latest manual on the last page, but the modification guide alone can also be downloaded HERE. Do note that this applies to the portable version only so NOT the desktop version nor the inline-Kameleon as these do not run on batteries and thus do not have that circuit. The same applies to the early portable Kameleon 2 amplifiers (the ones with the volume control). But as this one has the parts mounted differently another instruction is needed. The modification guide for the portable Kameleon 2 can be found HERE |
|
Crispy
very active
Madrigal music is playing - Voices can faintly be heard, "Please leave this patient undisturbed."
Posts: 779 
|
Post by Crispy on Jun 3, 2017 19:24:19 GMT
For those that have built the portable Kameleon amplifier there is a small (easy to do) modification for the battery management section. This has no influence on the audio quality. When batteries are brand new or getting older after many many hours of usage the internal resistance of the battery is a bit higher than under optimal conditions. This causes weird behaviour on start-up. Mostly when batteries are in need of recharging. During the development a variable power supply was used and this one, of course, did not show this poor behaviour. It only happens with real batteries. The modification consists of adding a small electrolytic capacitor (10uF) with a voltage rating of 16V or higher. HOW to do this is decribed in the latest manual on the last page, but the modification guide alone can also be downloaded HERE. Do note that this applies to the portable version only so NOT the desktop version nor the inline-Kameleon as these do not run on batteries and thus do not have that circuit. The same applies to the early portable Kameleon 2 amplifiers (the ones with the volume control). But as this one has the parts mounted differently another instruction is needed. The modification guide for the portable Kameleon 2 can be found HEREThanks Frans, will be doing this mod as soon as time permits. Just had a look at my surplus caps and I have a spare 10uf 50V cap so no need to buy nothing |
|
Crispy
very active
Madrigal music is playing - Voices can faintly be heard, "Please leave this patient undisturbed."
Posts: 779
|
Post by Crispy on Jun 5, 2017 11:00:45 GMT
Frans, I wasnt quite sure from the update picture exactly where to solder the 10uf cap  Is this correct?  Battery Management |
|
solderdude
Administrator
measureutternutter
Posts: 4,886
|
Post by solderdude on Jun 5, 2017 11:34:52 GMT
The - is correct (on the - of the battery) the + of the capacitor needs to go on the right side of R12 (the one with 2703 on it) like this:  |
|
Crispy
very active
Madrigal music is playing - Voices can faintly be heard, "Please leave this patient undisturbed."
Posts: 779
|
Post by Crispy on Jun 5, 2017 11:45:21 GMT
The - is correct (on the - of the battery) the + of the capacitor needs to go on the right side of R12 (the one with 2703 on it) like this:  Thanks Frans, it says in the update to put the + to R13 thats why I drew it out as before but it did not look right? I can now see how it is in Parallel to Z1. Got a bit of spare time this afternoon so will do the mod then  Thanks again |
|
Crispy
very active
Madrigal music is playing - Voices can faintly be heard, "Please leave this patient undisturbed."
Posts: 779
|
Post by Crispy on Jun 5, 2017 12:35:17 GMT
Mod done  I am really annoyed with myself for catching the battery with the soldering iron GRRRRRRR  Do you think it may have damaged the battery?  |
|
solderdude
Administrator
measureutternutter
Posts: 4,886
|
Post by solderdude on Jun 5, 2017 17:39:49 GMT
I had knicked my battery too if it is of any consolation.
Don't worry, it's just a plastic wrapper and plastic enclosure.
And yes, you can also use the right side of R13 (as you can see they are connected) but you covered R13 so showed you how to connect to R12 instead.
The mod is done correctly.
The amp should show better on/off behavior when the battery is nearing the voltage where they need to be charged.
|
|
Crispy
very active
Madrigal music is playing - Voices can faintly be heard, "Please leave this patient undisturbed."
Posts: 779
|
Post by Crispy on Jun 6, 2017 7:37:56 GMT
I had knicked my battery too if it is of any consolation. Don't worry, it's just a plastic wrapper and plastic enclosure. Yeh thats some consolation, I just thought to myself you ham fisted jerk  the real problem at 61 is my eyesight is not as good as it used to be  The amp should show better on/off behavior when the battery is nearing the voltage where they need to be charged So if I am reading this correctly, then the amp should not just switch off without any warning when it gets near the point where the batteries need charging? Will the Red light come on but give me time to finish listening to maybe 1 - 2 more tracks? |
|
solderdude
Administrator
measureutternutter
Posts: 4,886
|
Post by solderdude on Jun 6, 2017 17:46:11 GMT
The improvement is in the following areas.
When a low impedance headphone is connected and the amp is switched on when the battery already had a few hours of playing time the amp would switch on and off and on and off and sometimes stay on.
With the mod it simply switches on.
When the batteries are near depletion and the amp was switched on it would not switch on any more while there still was juice in there.
With the mod it will switch on even when the batteries need recharging.
After about 10 seconds it will look at the actual battery state and when there is enough juice left it will play.
When it really needs to be recharged it will switch itself off (red LED on, no music playing)
|
|
juke
very active
Posts: 396
|
Post by juke on Jun 20, 2017 23:13:42 GMT
Frans
I got the Purple Heart 'phones out tonight for the first time in a while.
On the Mk 1 Kameleon without R1 as required, I have the slider on an old iPhone 4s (using iPeng app to control modded Touch 2) at 25% for comfortable listening. It also feels 'high geared'.
Is it possible to alter the PH module to spread the volume range?
|
|
solderdude
Administrator
measureutternutter
Posts: 4,886
|
Post by solderdude on Jun 21, 2017 4:52:31 GMT
So you want a lower gain for the mk1 Kameleon ?
Those Fostex phones are quite efficient.
Will have a look, should be possible.
|
|
solderdude
Administrator
measureutternutter
Posts: 4,886
|
Post by solderdude on Jun 21, 2017 16:21:23 GMT
In this case (for the Kameleon-1) you can lower the gain by 3 dB so the overall gain ends up at +4dB instead of +7dB.
This is pretty easy to do:
change R5 from 10k to 6.8k
change R7 from 3k to 2.7k
You can make these changes without desoldering the already existing parts by simply soldering another resistor on top of the ones already in there.
In this case:
On top of R5 solder a 22k
On top of R7 solder a 27k
You will have slightly more subbass with this filter which isn't a bad thing.
|
|
juke
very active
Posts: 396
|
Post by juke on Jun 22, 2017 22:13:46 GMT
I got the mod done Frans.
I replaced the R7s as I had the right value but not the value to lay on top of the existing part.
R5 I did the other way, the board survived both methods.
The difference in the sound is incredible, the bass has changed and the treble is quite a bit clearer, this mod has really changed these 'phones far more than I could have thought.
I had hardly used them after an initial few hours, they were quite tiring to listen to but have come together beautifully now.
They're probably not accurate as there is a warmth there but treble doesn't suffer, I'm really glad I have them now.
Thanks yet again.
|
|
the real problem at 61 is my eyesight is not as good as it used to be 
