solderdude
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Post by solderdude on Feb 18, 2015 19:58:22 GMT
You need a filter to get sound.
To measure the power supplies a filter isn't needed.
D3 voltages = O.K.
Z1 = O.K.
R16 = cO.K. The output of the opamp switches from low (on 2 batteries) to high on one battery.
When IC3 output is low the MOSFET should conduct, when IC3 output voltage is high (close to Ubatt) the MOSFET should switch off.
Cathode of D8 0: one batt 0 = O.K.
Jumper J1 (both pins WITHOUT the jumper)2.94 7.81 one batt 2.19 5.65 = O.K.
So far it seems the circuit around IC3 is working properly.
Where things start to go wrong is with the MOSFET.
It is supposed to connect the amplifier power pins to the battery and the gate 'recieves' the correct voltages for this.
The measurements on the power pins of the OPA's say that it doesn't recieve any power.
It seems the (soft) sound you are hearing is the players output signal leaking directly though the components.
The amplifier part isn't 'on' at all it doesn't appear to receive any voltage.
LED1 on the front panel (which is labelled incorrectly as 'batt low') should alkways be off in this case.
LED2 (incorrectly labelled as 'power') should light when operating on 1 battery and be off when operating on 2 batteries.
When the amp would function normally LED1 would would be on when the amp is switched on and the battery is full.
LED2 should be off when switched on and working on 2 batteries and be on when switched on and working on 2 batteries.
Now... to check for proper operation of the amp part (to see if the OPA's work correctly) the amp must not have a module and no HP connected.
On the top side, between the caps you can see a trace from MF1 pin to IC2.
You must mount a jumper wire from the power switch to the 'single pin' on MF1.
This 'bypasses' MF1.
IF the power LED comes on repeat the measurements on pin 7, 6 and 4 of the OPA's.
When pin 7 = +9V, pin4 = -9V and pin 6 = 0V then switch it off.
Mount the filter module and switch it on and check if it works as expected.
If it does, remove the jumper wire between the single pin of MF1 (the one connected to IC2) and replace MF1.
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juke
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Post by juke on Feb 19, 2015 0:11:27 GMT
Thanks for all this Frans. I follow it all OK .
Now it gets odd. I didn't have the two front LEDs installed so I did that before doing anything else.
I reconnected one battery as I just wanted to check something else. I worked a little more at the LEDs,
at that point I smelled heat and saw that the battery was smoking! I wrapped it and pulled the connectors off,
it's bulging and the label has peeled due to the heat. It's still hot to the touch and it's at least 10 mins
since I disconnected it.
I feel it must be a fault in the battery as I had done nothing but installed the LEDS (correctly!)
The board and components all look perfect and had no heat at all when I ran my fingers over them.
They are the same batteries, same supplier as I used last time and even the USB charger wasn't connected as it was recharging the other Kameleon.
I'll call the supplier tomorrow to see what they say, could have been nasty.
I think I'll transport this battery and it's less evil twin to the garage floor for the night......
Syd
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juke
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Post by juke on Feb 19, 2015 18:49:10 GMT
I contacted Vapex and they say that only a dead short or overcharging could cause what has happened. They are replacing the battery which is good anyway.
I checked all over the area as you described Frans and sure enough the 'middle pin' of MF1 was sitting 'dry' above the board. I had missed that component when building so added it with the big capacitors in place which was fiddly
and in retrospect,stupid. Removed two caps and 2 seconds with the iron and glorious sound!
Sorry to have given you this bother again Frans but your help is greatly appreciated.
I have since also tried the 701s filtered and they have changed character greatly, I need more listening time but they sound quite bass heavy on brief listening but nice in a sort of 'tube/valve' way. They will have their uses so won't be sold now I think.
I used two alkaline PP3s for re-testing the new amp, no heat nor any other problem. I'll use them later tonight again (and keep an eye on them!)
I'll PM you about another Kameleon board Frans, they're sort of addictive.
Syd
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Rabbit
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Post by Rabbit on Feb 19, 2015 19:27:39 GMT
That's very dangerous Syd. I once had a battery set light to itself in an rc heli. It burst violently into flames.
Put it into a hole for the time being? Stick a nail through it and run. Then it's spent.
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solderdude
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Post by solderdude on Feb 19, 2015 21:45:43 GMT
Hi Syd,
It couldn't have been overcharging as the batteries are trickle charged.
That's why it takes so long before the batteries are charged.
This is done via a 1W DCDC converter so high charging currents aren't possible.
I hope you didn't connect the battery across the clip you shorted for the tests .... That would certainly let out the smoke.
I don't have any boards left but Javier does as I sent most of them to him.
The K701 filter is 'experimental'
If you find it has too much bass I can recalculate the filter and perahps only address the 3kHz peak, that one seems to be the most offensive.
Glad you found an open circuit. It was either that or a defective MOSFET.
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juke
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Post by juke on Feb 19, 2015 23:16:15 GMT
I actually pre-charged the batteries on a good quality trickle charger. It took around 17-20 hours to charge each battery and the charger switches off automatically, the charger only takes one at a time in that size) They then sat about a day or more
before being used. They were then linked up to the amp for about 2-3 hours before taking them off briefly. Both batteries were removed while I soldered in the LEDs. I then did your tests a second time, then disconnected both batteries.
The link for one battery was done by plugging the + and - connectors into each other as each is a separate lead for it's polarity. I then disengaged that link and added one battery, I looked away at some other part of the amp and turned my head back again to see a liitle smoke and a distorted battery.
So I then wrapped the battery and pulled the leads off it, the other pair of connectors were sitting disconnected from anything. I had done nothing between times to cause any possibility of a short and when I moved the jumper and used alkalines they worked fine with no heat or any other issue.
Has to be a rogue battery, no other possibilty.
I haven't had a long listen to the 701s yet Frans but the brief session I had, I liked them though I accept they're not flat. May be good for my older recordings that don't benefit from revealing phones. I'll certainly be bothering you if I change my mind!
One final question, I used the second version of the 'new' 650 filter, is it designed to work with the foam removed? I haven't done that yet.
Syd
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juke
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Post by juke on Feb 19, 2015 23:27:09 GMT
That's very dangerous Syd. I once had a battery set light to itself in an rc heli. It burst violently into flames. Put it into a hole for the time being? Stick a nail through it and run. Then it's spent. I remember that Ian, seems a long while ago now but some things don't get forgotten! Mine will certainly be disposed of carefully, I don't know about a stake through it's heart but maybe to be on the safe side...... Syd |
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z3d
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Post by z3d on Feb 21, 2015 13:03:31 GMT
Hello You are running some very solid and interesting projects there! Thank you for all the work and passion you put in what you are creating for us Frans, Javier, Rabbit (sorry I don't know your name) and Jeremy (which I met via email of Garage1217) and also for all the technical-thing you are sharing here and on the main website, that's enlightening! I'm auditioning a Philips Fidelio X2 and Sennheiser HD600 right now at my house and I'm deciding which one to keep and which one to send back to amazon. My source is an Asus Essence STX soundcard with it's former headphone amplifier TPA6120A2 chip through which I'm running a bit-perfect foobar2000 asio build with good results (in my opinion, of course). In the same chain there are also a pair of studio monitor speakers (m-audio bx8 d2) and their subwoofer (sbx10). I'm interested in the passive filter project and I'd like to know if someone compared HD600 to HD650 (already measured by Frans) pre and after the filter-mod. Thank you and I wish you a peaceful weekend  |
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Rabbit
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Post by Rabbit on Feb 21, 2015 14:18:27 GMT
Hello, and welcome to DIYAH. It's nice to see new members actively posting rather than just reading. My name is Ian or 'Rabbit' on here.
The HD600 has a lighter touch than the HD650 as sold. Another difference I've noticed is that the treble on the HD650 is sightly smoother sounding than the HD600. The HD650 also has a lift in the bass area, so it's quite a weighty sounding headphone.
With a Kameleon filter, the HD650 really lifts into another league. The bass hump is reduced and the bass extends further down. What this actually does is to provide a rich deep bass that no longer overpowers or 'bleeds' into the upper bass, which means that the HD650 treble, which actually does extend a long way up becomes more apparent as a result.
The HD650 with a Kameleon amp, whichin reality is a filtered amp is one of the best headphone sounds that I've heard.
I'm quite curious about te X2 which is supposed to be a very good headphone and also quite close to the HD600 in terms of quality. HD600 is a lovely headphone as well, ith nothing too emphasised.
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solderdude
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Post by solderdude on Feb 22, 2015 18:45:21 GMT
Hello I'm auditioning a Philips Fidelio X2 and Sennheiser HD600 right now at my house and I'm deciding which one to keep and which one to send back to amazon. My source is an Asus Essence STX soundcard with it's former headphone amplifier TPA6120A2 chip through which I'm running a bit-perfect foobar2000 asio build with good results (in my opinion, of course). In the same chain there are also a pair of studio monitor speakers (m-audio bx8 d2) and their subwoofer (sbx10). I'm interested in the passive filter project and I'd like to know if someone compared HD600 to HD650 (already measured by Frans) pre and after the filter-mod. I just auditioned the X2 and it is better than the X1, no doubt also it has replaceable earpads. It's more fun and engaging than HD600. The HD600 is 'closer to the truth' perhaps, not necesarilly better sounding. On a good source and amp the HD600 sounds great though. IMO the HD650 is better but also warmer (in stock form) The HD600 and HD650 have slightly different drivers. The HD600 has a slightly lower 'hump' in the lows and drops off fractionally sooner down below. The HD650 doesn't have a small 'hump' in the 3kHz range and is slightly less refined in the treble. Thinking of altering the filter for HD600 somewhat to lower that peak. When both HD600 and HD650 are 'corrected' it may be hard to tell them apart I think. Love the HD650 once corrected... it (and the equipment used) seems to 'disappear'. It's the only headphone I have experienced it with but many orthos can do a similar disappearing act. |
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z3d
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Post by z3d on Feb 23, 2015 21:33:06 GMT
Hello, and welcome to DIYAH. It's nice to see new members actively posting rather than just reading. My name is Ian or 'Rabbit' on here. The HD600 has a lighter touch than the HD650 as sold. Another difference I've noticed is that the treble on the HD650 is sightly smoother sounding than the HD600. The HD650 also has a lift in the bass area, so it's quite a weighty sounding headphone. With a Kameleon filter, the HD650 really lifts into another league. The bass hump is reduced and the bass extends further down. What this actually does is to provide a rich deep bass that no longer overpowers or 'bleeds' into the upper bass, which means that the HD650 treble, which actually does extend a long way up becomes more apparent as a result. The HD650 with a Kameleon amp, whichin reality is a filtered amp is one of the best headphone sounds that I've heard. I'm quite curious about te X2 which is supposed to be a very good headphone and also quite close to the HD600 in terms of quality. HD600 is a lovely headphone as well, ith nothing too emphasised. Hi Ian, please to meet you! Well I have to decide which one to keep but I have still some days left to compare both.. At now HD600 has a slight edge over X2, but I want to listen more in order to give an objective opinion, then I will share with you my findings with Honestly I think none are at 100% of their potential because of the way through which I'm driving them, sure an Ember could make easier to judge! |
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z3d
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Post by z3d on Feb 23, 2015 21:40:51 GMT
Hello I'm auditioning a Philips Fidelio X2 and Sennheiser HD600 right now at my house and I'm deciding which one to keep and which one to send back to amazon. My source is an Asus Essence STX soundcard with it's former headphone amplifier TPA6120A2 chip through which I'm running a bit-perfect foobar2000 asio build with good results (in my opinion, of course). In the same chain there are also a pair of studio monitor speakers (m-audio bx8 d2) and their subwoofer (sbx10). I'm interested in the passive filter project and I'd like to know if someone compared HD600 to HD650 (already measured by Frans) pre and after the filter-mod. I just auditioned the X2 and it is better than the X1, no doubt also it has replaceable earpads. It's more fun and engaging than HD600. The HD600 is 'closer to the truth' perhaps, not necesarilly better sounding. On a good source and amp the HD600 sounds great though. IMO the HD650 is better but also warmer (in stock form) The HD600 and HD650 have slightly different drivers. The HD600 has a slightly lower 'hump' in the lows and drops off fractionally sooner down below. The HD650 doesn't have a small 'hump' in the 3kHz range and is slightly less refined in the treble. Thinking of altering the filter for HD600 somewhat to lower that peak. When both HD600 and HD650 are 'corrected' it may be hard to tell them apart I think. Love the HD650 once corrected... it (and the equipment used) seems to 'disappear'. It's the only headphone I have experienced it with but many orthos can do a similar disappearing act. Hi Frans. HD600 and HD650 have different drivers or share the same one with just different tuning? Talking about filtering an headphone: in addition of the different FR we want to achieve, it will affect even the separation between instruments, the detail retrieval and the sounstage depth/width? If yes, which are the causes? A consequent different group decay could be one of the reasons? |
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Rabbit
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Post by Rabbit on Feb 23, 2015 21:49:36 GMT
Hello, and welcome to DIYAH. It's nice to see new members actively posting rather than just reading. My name is Ian or 'Rabbit' on here. The HD600 has a lighter touch than the HD650 as sold. Another difference I've noticed is that the treble on the HD650 is sightly smoother sounding than the HD600. The HD650 also has a lift in the bass area, so it's quite a weighty sounding headphone. With a Kameleon filter, the HD650 really lifts into another league. The bass hump is reduced and the bass extends further down. What this actually does is to provide a rich deep bass that no longer overpowers or 'bleeds' into the upper bass, which means that the HD650 treble, which actually does extend a long way up becomes more apparent as a result. The HD650 with a Kameleon amp, whichin reality is a filtered amp is one of the best headphone sounds that I've heard. I'm quite curious about te X2 which is supposed to be a very good headphone and also quite close to the HD600 in terms of quality. HD600 is a lovely headphone as well, ith nothing too emphasised. Hi Ian, please to meet you! Well I have to decide which one to keep but I have still some days left to compare both.. At now HD600 has a slight edge over X2, but I want to listen more in order to give an objective opinion, then I will share with you my findings with Honestly I think none are at 100% of their potential because of the way through which I'm driving them, sure an Ember could make easier to judge! Hi, It's really good to see new members get in and start posting. I'm very interested in what you find between the two. I've heard a lot of good things about the X2 and how it is an 'entertaining' listen. I like the HD600 a lot but I do prefer the HD650 tbh. With a filter, it's amazingly good. X2 is one I'd like to try though. |
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z3d
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Post by z3d on Feb 25, 2015 6:55:40 GMT
Hi Ian, please to meet you! Well I have to decide which one to keep but I have still some days left to compare both.. At now HD600 has a slight edge over X2, but I want to listen more in order to give an objective opinion, then I will share with you my findings with Honestly I think none are at 100% of their potential because of the way through which I'm driving them, sure an Ember could make easier to judge! Hi, It's really good to see new members get in and start posting. I'm very interested in what you find between the two. I've heard a lot of good things about the X2 and how it is an 'entertaining' listen. I like the HD600 a lot but I do prefer the HD650 tbh. With a filter, it's amazingly good. X2 is one I'd like to try though. Hi Ian At the moment it's a tie: yesterday evening I listened to a CD switching both headphones for all the songs and I have even more doubts than before :> Today I will listening to two CDs and switch again the headphones and than I will have to decide. If I was deciding right now it will be hard but I think I will keep HD600, not for a abvious edge over X2 because honestly the latter is more enjoying but only because I think it will benefit more from amping (ember). It's even hard to make a proper comparison for me because with Ember the setup will change quite a bit; right now I'm using the headphone out from my soundcard which got 2x 49860 OP amps (the ones I prefer after some listening) and the TI TPA6120A2 headphone chip which could add some sound signature to the chain; when amping I will use the 2x RCA out from the same soundcard which got 2x 49860 op amps and a dual mono 49710 HA to99 (metal) op amp as buffer. In top of that I really haven't any clues about how much the improvement will be big with ember and the right rube, so I'm quite lost at the moment....ough! |
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solderdude
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Post by solderdude on Feb 25, 2015 10:08:01 GMT
HD600 and HD650 have different drivers or share the same one with just different tuning? different drivers, they also have different ordering numbers. HD580 and HD600 have the same drivers. The HD580, HD600 and HD650 have the exact same pads and the construction of the baffle also seems the same (but could still differ) and measure and sound (slightly) different. Talking about filtering an headphone: in addition of the different FR we want to achieve, it will affect even the separation between instruments, the detail retrieval and the sounstage depth/width? If yes, which are the causes? A consequent different group decay could be one of the reasons? The separation of instruments is something that happens in our brain. The electrical signal is always an addition of all sounds. The headphone doesn't separate them, it merely needs to 'follow' or reproduce that combined waveform. When the FR is natural (flat, in a flat recording) the brain has less problems figuring out which harmonics belong to which fundamentals and what instrument it is and where it seemingly comes from. When the FR is wonky some harmonics can be relatively too high and others too low. The brain gets confused as it differs and probably 'gives up' trying. As a result you don't hear things that well. Of course resonances (ringing) as seen in CSD's can also change the accuracy. Soundstage width (never heard depth with headphones) is a function of the same issue + channel separation + recording/mixing. With headphones that are already good performers by themselves (so no to very little ringing) and capable of reaching both sides of the frequency spectrum (20Hz to 20kHz) or beyond that have a wonky FR these headphones always show a sonic signature depending on FR. Imaging etc also is compromised. When these headphones are 'compensated' FR wise it becomes much easier for the brain to interpret what it is fed and can 'untangle' each instrument with ease. At least that is MY theory. I come to this conclusion because of the many experiments with many headphones and their compensations. These compensations are impossible to do by ear IMO (although you can get close) and a test rig that is 'calibrated' so equal SPL at all FR is shown as a straight line seems to produce the correct results. recordings that haven't been tampered with in a studio (mostly jazz and classical) and where the mics are just mixed and not EQ'ed or compressed or have received other 'operations' seem to sound extremely correct when fed to such a HP. Studio recordings MAY sound crap to decent, seldom excellent. This is logical as well... the recording is flat and the reproduction as well so no difficulties there. What's evident with the HD650 is that it needs only minimal 'correction' where as others may need very complex corrections. In case of the HD650 I noticed there is no 'equipment' nor 'headphone sound' present. It disappears and only real music remains. That's how I would describe it. The fact that I introduce phase distortions (inherent to analog filters) may frighten many but... when the HP + gear disappears and it sounds 'real' while phase (in certain parts of the band) has been altered I do not 'hear' this. This leads me to conclude that phase distortion isn't that problematic. Many people like tube amps (with output transformers etc) with limited bandwidth and considerable phase distortion so that too makes me believe it doesn't matter that much. So IF a headphone is already a good technical performer but is only off in FR and this can be compensated then the result is 'real sound'. When you FR correct a HP with 'bad performance' like ringing, too wonky FR, resonances etc. the results is a HP that may sound more tonally balanced BUT will not sound real. That's why only a few headphones qualify for this 'treatment' and it is rather pointless to put effort in polishing a turd. |
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