Crispy
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Madrigal music is playing - Voices can faintly be heard, "Please leave this patient undisturbed."
Posts: 776
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Post by Crispy on Sept 4, 2017 12:24:16 GMT
Need to get my life going again. Have to repair an HE6 (done) and have a lot of headphones to measure yet as well as evaluate. Need to see if the HD250 and D600 can be modified easily. Need to open up a Philips to see how to access the swivel part. Need to put some Pinna's on the test rig and evaluate its impact. Have lots of Kameleon filters to calculate and test. A K501 will be visiting me soon for measurements etc. Need to tidy up 'my room' as I can't even walk in it any more. Busy at work etc. Need to get working on my ear issue (at this moment I have it well under control with the Kameleon and daily listening sessions) Ah well I won't be bored for quite some time I reckon. And I thought my life was busy A couple of questions Frans: 1. I noticed on the garage 1217 website that Jeremy has 3 different modules for the DT770 pro. The filter I made for my kameleon was for the 250ohm version but my headphones are the 80 ohm version. The differences are: DT770-Pro 80 (adds subbass lowers the bass slightly and removes the treble peak) DT770-Pro 250 (lowers the bass somewhat and removes the treble peak) What components would I need to change on the filter to make it suit my ohm version? This is the filter: 2. I just started listening to my Kameleon last night when it just switched off - forgot to charge it (again) even with the battery mod it just cut out. Would it be possible to mod the Kameleon to be able to play it while it is charging? Thanks
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solderdude
Administrator
measureutternutter
Posts: 4,882
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Post by solderdude on Sept 4, 2017 13:55:43 GMT
The Kameleon can play while charging it. There is a jumper on the back of the PCB that has to be in the open position for that. It is either marked 'charge' or 'CH-off' depending on the age of the board.
Will have a look at the differences in the filter. It's not just the filter characteristic but also the overall gain that is different.
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Crispy
very active
Madrigal music is playing - Voices can faintly be heard, "Please leave this patient undisturbed."
Posts: 776
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Post by Crispy on Sept 4, 2017 17:33:00 GMT
The Kameleon can play while charging it. There is a jumper on the back of the PCB that has to be in the open position for that. It is either marked 'charge' or 'CH-off' depending on the age of the board. Will have a look at the differences in the filter. It's not just the filter characteristic but also the overall gain that is different. Thanks Frans, just had a look and you were correct the jumper was in the charge off position: Jumped it over to the on position and yes it does still play while charging: That one little mod will save me a lot of aggravation, because I am so forgetful to charge the damn thing (same with my phone) at least now if I forget I can still have a good listen Thanks again
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solderdude
Administrator
measureutternutter
Posts: 4,882
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Post by solderdude on Sept 4, 2017 17:46:06 GMT
You can even power the amp without any batteries in it in that jumper setting.
To change the filter to 80 Ohm version all components need to change (due to the different gain). There isn't much difference in the filter action though. The treble peak is slightly different and the bass is lowered a tad less. When you want a bit more lows you can change C4 to 330nF.
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