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Post by Imagemaker18 on Mar 18, 2013 17:08:40 GMT
Hi, Mick & Chris
I just tweaked the T40/50 active filter by changing some component values, at Frans' suggestion, for even lower signal to noise ratio. I must say, the result is astounding! In effect, the improvement really is academic, because even before the tweaking, at normal, even extreme listening levels there was no audible noise! Tested it with source connected, but without signal!
Now, after the tweaking, I would have to turn up the level to maximum, which would cause ear damage, in order to hear some slight noise! I never cease to be amazed at Frans' constant striving for perfection, while being extremely modest about his accomplishments!
Mick, the HE-6 active filter is exactly the same as the one I built, and as I said, turns a great pair of phones into a phenomenal one! It corrects the 10kHz dip and even improves the already great mid and sub bass! I am certain that you will be very pleased!
Cheers! Israel
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Post by Deleted on Mar 19, 2013 7:55:14 GMT
Hi Israel, Looking forward to receiving it, hopefully by the weekend, he has also made me a +12-12v (dcdc) inverter for it, which i didn`t expect, what can i say. . Mick.
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Post by Imagemaker18 on Mar 19, 2013 16:22:07 GMT
Hi Israel, Looking forward to receiving it, hopefully by the weekend, he has also made me a +12-12v (dcdc) inverter for it, which i didn`t expect, what can i say. . Mick. Hi, Mick You may recall that initially my HE-500 active filter I built used two 9V batteries, but I noticed that their lifespan was rather short, so I modified it to use a DCDC +12V/-12V output converter to enable me to use a walwart transformer type AC adapter. I built the T40/T50 filter with a DCDC +12V/-12V output converter as well. Below are some photos of the interior of the final results: Active Filter for the HE-500 Active Filter for the T40/T50 Cheers! Israel
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Post by Deleted on Mar 19, 2013 19:07:34 GMT
That's a really neat shoe-horning job Israel I have just completed my filter, with the later add on, but had to spend some time troubleshooting. Its fairly well sorted now and transforms the whole presentation of the sound, to my ears, not just the 'affected' frequencies. I need a bigger case now, as you say battery power isn't really an option, they don't last long. I'll have to make the wallwart mods. Syd
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Post by PinkFloyd on Mar 19, 2013 19:36:09 GMT
Nice workmanship Israel
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Post by Deleted on Mar 19, 2013 19:46:12 GMT
X2,
I expect mine will look very similar internally as yours Israel.
Well done.
Mick.
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Post by PinkFloyd on Mar 19, 2013 21:03:46 GMT
Where can we buy one of these filters? Who is selling them?
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Post by Rabbit on Mar 19, 2013 21:09:22 GMT
Mine was really cheap.
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Post by PinkFloyd on Mar 19, 2013 21:27:59 GMT
Did you get yours from HappyMonkey.com or monkeywithtitshappyplace.com? ARGOS are out of them at the moment
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Post by Rabbit on Mar 19, 2013 21:33:50 GMT
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Post by Imagemaker18 on Mar 19, 2013 22:58:37 GMT
Nice workmanship Israel Thanks for the kind words, Mike, Mick & Syd! I am pleased with what they do to the SQ of the HE-500 and the T40/50! I owe all of it, and my hat is off to the genius, who designed it, and patiently guided me through the process! Cheers! Israel
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Post by Imagemaker18 on Mar 19, 2013 23:03:32 GMT
Where can we buy one of these filters? Who is selling them? Mike, Something tells me, you can whip-up one or two of these in a flash! Cheers! Israel
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pagan
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Post by pagan on Mar 20, 2013 9:00:26 GMT
With an opamp there
Pinky or JLH the psu
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Post by Deleted on Mar 24, 2013 15:01:55 GMT
Ian,
Am i right in assuming you prefer the T40`s over the T50`s!!!.
If so, what are the reasons for your preference.
Thanks.
Mick.
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Post by Rabbit on Mar 24, 2013 15:59:15 GMT
Ian, Am i right in assuming you prefer the T40`s over the T50`s!!!. If so, what are the reasons for your preference. Thanks. Mick. I prefer the T40 because they're modified, Mick. My T50 has no dampening and has just the 940 pads. They're overly warm as a result but good with the filter. In effect, they give a bit more boom tizz than the T40 because they're not treated inside. The T40 is just well balanced because Frans has done the full works on it and measured the cups' responses until they were flat. He did find that each cup was slightly different as well so he changed the amounts slightly to compensate. So in effect, he's matched the cups making my T40 into one helluva headphone. It's the one that I feel most at home with now. For any music as well. The T50 is standard except for pads. (Like yours?) The T50 is the exact same as the T40 as far as the drivers go. The vents are open though so it's a semi-closed headphone. Frans thinks that the only difference may be in the matching of the drivers. The T50's are better matched. I'm not certain, but he may have taken one of the drivers in my T40 out and replaced it with something that was a closer match to the other side. You shouldn't have that problem with a T50. Funnily enough, I like the T50 with standard pads for monitoring since they're so mids focused. Once you get the filter in line Mick, the headphone will lift dramatically in the top end and will have more 'air'. It's not subtle either!!
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Post by Deleted on Mar 24, 2013 16:13:27 GMT
Thanks Ian, Sounds like you have a nice bespoke pr of T40`s there. Enjoy. Mick.
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Post by Rabbit on Mar 24, 2013 16:19:10 GMT
T50 will be the same, Mick. Have you padded them out yet or are they still standard? They also need an amp with loads of current available.
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Post by Imagemaker18 on Mar 24, 2013 16:46:08 GMT
T50 will be the same, Mick. Have you padded them out yet or are they still standard? They also need an amp with loads of current available. Hi, Ian & Mick As you may recall, I have both the T40 and the T50. Both are modded in as precisely identical manner as I was able to - I used a precision scale (1/100 gram claimed accuracy) to weigh the damping materials. Right now the damping materials are .52gram of fiberglass in each cup and matched quantities of Dynamat on the business side of the drivers. They are both semi-open, i.e. vents are covered with some medium thickness felt. Yet, they don't sound identical! To my ears, the T40s are a little more clinical and dryer sounding, while the T50s have a wider sound stage, and are a little closer in SQ to my HE-500s. I am waiting for delivery of some sheep's wool, with which I plan to experiment. Most probably they will render different results - I hope better! I am planning to build a measuring rig, similar to the one Frans built, and perhaps after having that at hand will enable me to match them closer, and hopefully, achieve some of the HE-500 attributes for the T40/T50. Cheers! Israel
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Post by Rabbit on Mar 24, 2013 16:50:57 GMT
Hi Israel,
Persumably the drivers are the same colour? There are old drivers which are black I think and new ones which are white .... or the other way around.
Frans couldn't see any differences other than the enclosure being open on the vents.
Interesting if the T50 is better!! Better start plundering the local sheep....
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Post by Deleted on Mar 24, 2013 16:51:02 GMT
Yes Ian,
I have the 940 pads fitted, modeling clay in the inner cups and some cube foam pads 6x6x3mm (50)in each outer cup.
Happy with that, sounds good to me, just waiting for a filter now.
Not over impressed with the quality of fit by means of the 4 self tapping screws, that hold the inner and outer cups together.
The bosses that the screws screw into are very poor quality "plastic", and one of mine was showing signs of cracking after just one dismantle. I certainly would not want to dismantle too often, as stripped threads, and or broken bosses, is imminent even with VERY gentle torque applied to screws.
When i am satisfied that i wont be making entry anymore, i shall seal my two halves together probably using silicon sealant or such like, and just replace the screws for appearance value.
Mick
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Post by Rabbit on Mar 24, 2013 17:26:02 GMT
You know, reading your post - I instantly thought about sealing it when you think the sound is right. It'll probably improve the sound as well. I have heard that the screws are a bit touchy and to be very careful putting them back.
The padding should make it sound a bit more even after the pads have added the bass. They also add a slight mid bass hump so when you get the filter, that'll be diminished and the bass will go down to 10, the suck out in the treble will be restored and the headphone extends way further.
There's slightly more noise in the form of hiss, but you'd have to go way too loud to detect it. I can quite happily listen without filter (as I did for the week that Mike had mine) but having it switched in does clear it up enormously. It's nowhere like as closed in as yours probably sound at the moment.
I can't wait for you to get the filter in!!! If you like it as it is now, then it'll really grow on you when you hear the filter working.
Interestingly, the LFF mods get treble information info back via pads. He uses the Hifiman pads but I don't know how he attaches them. I asked Frans about it and he said that there had to be another way to fit them since the Hifiman pads have links on them. Actually, I have two Hifiman sets of pads here. (Pleather? Although they call them leather) I see what Frans is saying; plus the fact that they're round and not oval. I have a local friend who has an HE6.
I'm using the T40 as a reference now as well and comparing everything else with them to see which way they wander away from neutral!! Makes things a lot easier with a reference.
Recently been playing around with an AKG K450 which is a very sensitive portable headphone but darker than neutral and more like a Senn headphone which is surprising for an AKG.
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Post by Deleted on Mar 24, 2013 19:34:32 GMT
Yes Ian, I have the 940 pads fitted, modeling clay in the inner cups and some cube foam pads 6x6x3mm (50)in each outer cup. Happy with that, sounds good to me, just waiting for a filter now. Mick Mick Have a look through Frans' manual and I think Israel also did it, ie put felt over the back and front of the drivers in the 50s, removing the sticky bit first! I would try that before sealing up. Syd
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Post by Imagemaker18 on Mar 24, 2013 21:25:07 GMT
Hi Israel, Persumably the drivers are the same colour? There are old drivers which are black I think and new ones which are white .... or the other way around. Mine are the black ones on both the T40 and T/50. The black ones are the older ones, and according to Frans, slightly better quality as I recall. Instead of chasing sheep all over the countryside, I decided to pay for raw wool that has been washed, and free of foreign objects, and/or droppings , although the latter may have some hidden unknown acoustical beneficial effect?!?! But, I am not willing to go that far to find out! Cheers! Israel
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Post by Deleted on Mar 24, 2013 21:34:26 GMT
Hi Syd,
I have carried out what to my mind makes sense to improve these HP`s, more comfortable and better sealing ear pads, stiffening of the inner casing with clay, and some deadening of standing waves in the outer casing with foam pads.
This has given a positive increase in SQ to a small degree which i am very happy with, the filter option to my way of thinking will be the last upgrade and will probably give the best upgrade to the SQ.
I really can`t be bothered to constantly pull these apart and experiment, in the hope of finding utopia, as i am happy with the performance at the present level.
In fact i will now be sealing the two halves of the cups together, just in case someone discovers that adding a gram of fairy dust lifts the SQ to a whole new level, just in case i feel the urge to do the same.
For the price, these are a really nice sounding HP even without any modifications.
Mick.
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Post by Rabbit on Mar 24, 2013 21:40:28 GMT
For the price, these are a really nice sounding HP even without any modifications. Mick. That's exactly how I felt, Mick. I even liked the stock headphone with its incredible mids.
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