Dave
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Post by Dave on Jun 16, 2014 19:51:47 GMT
Hi guys, Just a rushed couple of pics of my assembled and fully functioning Kameleon. Javier did the difficult bit and I put everything in a case. Might post further pics after my return from holiday. The case was originally black but I spray painted it and added the lettering, just so I don't forget what it is  .  "  " Cheers, Dave. PS. the source is my Blackberry 64GB Playbook and, if you look closely at the second pic, you will see that it is advising that it is playing 24/192 files which is what it should be doing - I have mainly HiRes files loaded into the library. [links edited] |
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Rabbit
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Post by Rabbit on Jun 16, 2014 20:17:15 GMT
Glad that you got it for the holiday Dave. Have a good time. I know it's pretty soon as well isn't it. Nothing nicer than being in a lovely place with a good headphone.  |
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Rabbit
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Post by Rabbit on Jun 16, 2014 20:22:36 GMT
Richard, that black enclosure looks really nice, a very nice build. I will be building another (silver) one and plan to make lots of pictures and assembly tips. I haven't touched any of my other amps any more and use this amp exclusively. Love it with the HD650, T50RP, DT1350 (currently fitted with the EDT1350NL pads, the EDT1350-SL pads are mounted on the Beyer T50P. My other headphones do not get much time at this moment. I fitted the big pads to the DT1350s and finished the filter too. I'll give it all a good listening at work tomorrow - but wow the pads are sooo comfy!
I built the HD681 filter but I'm not sure I like it - it seems a bit lifeless to me - but it was only a quick listen. I give it some time when I'm back off my hols.
When they're quite flat, they can sound a bit uneventful imo. After all, if they sound realistic, then they sound the same as 'normal' I guess, and we are all used to headphones that most definitely aren't flat. Good recordings can sound breathtaking while awful recordings seem to sound quite nasty!! The 'bloom ' in many headphones can cover up recording flaws and also compensate or 'help' equipment flaws as well. First time I heard the t40, I felt the sound was very controlled...... You soon adjust and then realise when you go to something else just how coloured so many headphones are. |
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dicky
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Posts: 230
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Post by dicky on Jun 16, 2014 21:06:38 GMT
Initially, I found the T50s quite odd, but tuned into them quite quickly. However, I much prefer the modded EVOs unfiltered. Perhaps I should find some better recordings!
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solderdude
Administrator
measureutternutter
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Post by solderdude on Jun 17, 2014 5:21:36 GMT
If you can pinpoint what you don't like about the filtered EVO the filter can be adjusted accordingly.
The filter is designed for an EVO with the felt discs removed.
otherwise too much brightness is removed.
If you are using the EVO with the felt still on, it simply remove the inductor.
If you want less bass removed it is just a matter of increasing the value of R4 to a value you prefer.
The T50RPs cannot be corrected as well as on the filter boards but at least it is much closer to 'flat'.
Even though the kameleon cannot get it perfectly flat it sounds good within a minute or so when coming from an amp with the filter board.
On the Kameleon is has a tad less upper mids but this can even be beneficial on lesser (shoutier) recordings.
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juke
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Post by juke on Jun 18, 2014 21:50:23 GMT
The Vapex batteries arrived today and sure enough they are the orangey/red and silver ones. First one is on a trickle charge so I'll be all set for the new arrival  Syd |
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juke
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Post by juke on Jun 25, 2014 14:34:36 GMT
A note aside. Those looking for capacitors for the filters and having a hard time finding certain values in the correct sizes can also use 1206 sized SMD capacitors and solder those onto the pads. NP0 or C0G is preferred but X7R can also be used.
I'm ordering some parts for a K701 filter which I was too late to add to my Javier build.
I've spent hours searching Farnell, as usual. I'm going to use SMD 1206 capacitors as suggested but I'm not sure of the voltage 25v, 35v? Can't find C0G or NP0 in the values I need so I'll get X7R.
I'm also going to have a go at the desk-top version but I'm not sure what LED to order for the un-catalogued one, pref. blue but not too fussed.
Do you recall what case it was that you used Frans?
Thanks, Syd
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solderdude
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measureutternutter
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Post by solderdude on Jun 25, 2014 16:53:32 GMT
The desktop version isn't as easy to build as it would appear from the photos.
It has a buffer circuit entirely built in SMD on the bottom of the PCB (which is needed but not visible) and had to tinker a lot with the power supply to get it to work correctly as I make use of the internal resistance of the batteries which has to be emulated on the dual power supply + some changes in the power management.
Most likely a desktop version will see the daylight one day which would be easier to build.
No problem using 1206 type capacitors, X7R is good enough (at least it is for me)
The K701 filter is experimental and may still need some tinkering. I don't own one any more so cannot check the filter.
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Javier
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Digital bytes
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Post by Javier on Jun 25, 2014 19:19:14 GMT
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juke
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Post by juke on Jun 26, 2014 12:32:28 GMT
Thanks Frans, Javier. Order duly sorted.
The desk amp will be a nice project if/when it comes to fruition.
Syd
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solderdude
Administrator
measureutternutter
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Post by solderdude on Jun 28, 2014 17:55:51 GMT
I had measured the (modified) T50RP on the Kameleon. It shows it cannot correct the T50RP perfectly but still offers a much better extension to both ends of the spectrum well below 20Hz and above 20kHz ! Only in the 3kHz area it drops about 5dB lower than ideal. The dip at 70Hz is a measurement artefact and not really there, at least in a much lesser extend.  For comparison the stock (modified) T50RP and via the Kameleon (L channel only).  Lower bass extension is improved and so is the dip at 4kHz (by a decent 5dB) and extension above 10kHz. |
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Post by deireleire on Jul 3, 2014 7:18:14 GMT
Had a head to head with my brand new kameleon / modded T50RP's last night and listened to a wide range of genres. My conclusion: this amp with corrected filter turned the ugly T50RP's into a beautiful swan (in appearance it stays ugly). Now I understand why you would design an amp with a built-in correction filter, it's not to show off It's a pity this will never be commercially available, ex when buy some HP's the manufacturer gives you a universal plug-in module with it to correct the major flaws (Frans get your patent asap). I'm just glad to be one of the privileged to own such a wonderful combo. Can't wait to hear the combination with the HD650 tonight! |
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solderdude
Administrator
measureutternutter
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Post by solderdude on Jul 3, 2014 13:06:47 GMT
Going to build me another one in a few weeks or so.
I want one amp permanently 'HD650-fied' and another one permanently 'T50RP-ified'.
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Rabbit
Administrator
Posts: 7,091
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Post by Rabbit on Jul 3, 2014 16:11:42 GMT
Going to build me another one in a few weeks or so. I want one amp permanently 'HD650-fied' and another one permanently 'T50RP-ified'. Or perhaps a bigger box with a switch in order to go between filters? One filter for a closed headphone and one for an open? Trouble is though that something like that would need a redesign I guess. |
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juke
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Post by juke on Jul 5, 2014 22:32:32 GMT
I've been trying my Javier-built Kameleon over a few days now and I can confirm that I'm still delighted with it. I have been using the HE-6 filter
and as Frans assured me, it handles these 'phones really well. It requires the volume control up to around 75% or so but that leaves a good reserve
for those lower-output recordings.
I'm so pleased with it I have actually ordered a bigger battey and 120Gb SSD for my iRiver.
It works well with my iPhone as well, actually a bit better volume output with it, but since the last iTunes 'update', iTunes no longer 'sees' my phone so I haven't got much music on it.
Followed all the advice on the Apple web site but still nothing...
So another great Frans design in my collection!
Syd
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