Superlux HD-681 modifications

[Deleted]

I have used the skytronics pads on the HD681 and found the sound to alter slightly.
a bit less bass can't hurt the HD681, it has too much of it.
Personally I like the amount of deep bass as it is not over the top and doesn't 'polute' the overall sound.

Pads DO make (sometimes big) sonic differences.
I found the velours AKG pads to work best on the HD681 but the sonic signature is somewhat different from the original sweaty pads and do prefer the signature of the velours AKG pads.
Once I put Beyer pads on them.. just for the fun of it to try ... sounded horrible !

[rainman]

Dec 10, 2009 11:13:54 GMT PinkFloyd said:

Dec 9, 2009 23:14:25 GMT @clausdk said:

Does it make a difference if one makes the filter in an extensioncord or something ?
Does it have to be so close to the drivers ?

No Difference at all Claus.... Frans says:

"the first 2 filters were built in an extension cord.
There is no audible difference between a built-in filter and a filter in an extension cord.
if you want even less treble replace the 39 Ohm resistor with a 56 Ohm resistor.
The 'character' of the headphone will still be preserved.
Bass and mid presentation will not be altered by the filter.
Only the exaggerated details and 'Sss' will be balanced to normal representation.
Call me stupid but I prefer the HD681 with filter above my HD650 and DT770 and DT880.
If you do not like sweaty ears... order the velours pads."

Hi Guys

Mike or Frans (or anyone else who can)- would you build an extension cord for the hd681 to sell??

[Deleted]

Rainman:

PM me
I might be able to whip up one more filterbox in the coming few weeks.
Together with the 2 outstanding requests fro filter boxes I have reached the end of my stock.
Some parts have to be ordered in the coming weeks.

> edit:

I have 2 new HD681's left in stock.
1 filter modded and 1 unmodded (in unopened package)
Also there are 2 filterboxes are still available.
These will be the last I will make (out of parts)

pricing: see New HD681 for Sale (1 unmodded, 1 filter modded) add in the 'for sale' section

[rainman]

I have recently become the lucky owner a a "Frans Filter Box". The following is an extract of the email I sent him:


I was expecting the filter to make the HD681 behave better, but instead it made them behave badly. After only five minutes or so of casual listening with the filter and my Neco V2 portable AD8610 at the top of the staircase, the 681 walked off to find my Senn HD555, grabbed them and slapped them across the face. Naturally, the HD555 feels rather offended and a bit embarrassed.

Seriously, they sounded good before, but with a tiring flaw; though still worth every penny of £20 inc postage. They sounded like much more expensive phones.

They come close to my HD650! Whilst I don't find that they can quite match the detail, soundstage, realism or comfort of the 650, they are NOT worlds apart. And were talking about world class Senns here that cost WAY, WAY more!!

I'm very impressed Frans! Your filter box makes a technically subtle, but effectively vast improvement. The bass hits harder and very tight. Tighter, maybe.. The mids have come forward, allowing vocals to be heard with much more realism. And the treble is much more calm. I haven't listened for long periods yet, so hope to give you an update in due course... But they way they are, I can't imagine the the highs becoming tiring..

The construction feels professional too mate!

Thanks Frans. Many thanks.

Best regards,

Omar

[UzminiNu]

Sounds very impressive!Can't wait for my "Frans FilterBox Kit"

[Deleted]

@ UzminiNu,

Omar has the '2nd edition filter' that drops the highs to 'normal' levels and thus more in the direction of the HD650 (which I own too)
You requested the 'first edition filter' which only takes off the sibilance but leaves the highs elevated compared to a flat respons and it holds it's character.
I included a few resistor values so you can change the filter in the direction you like.
Sennie fans will like the 2nd filter better.
AKG, Grado, ATH AD fans will like the first filter better.
a matter of personal taste/preference

Personally I prefer the '2nd filter' but initially didn't dare to post it as it alters the 'character' of the cans too much.
Most people seemed to like the sonic character but didn't like the sibilance so I made the filter so it only took off 'the edge'.

Should filter owners like their external filter altered to '2nd edition' and not being able to replace 2 resistors themselves, send it over and I'll modify it and ship it back for only the shipping costs (2 - 3 Euro)

[UzminiNu]

Amazing -now- this morning i recieved the post from Frans!

[rainman]

I think everyone who has a Frans Filter Box, should take off their hats to Frans! And if you're not wearing one, find one, put it on, then take it off! It really makes the already good 681 into extremely great phones. And that too to your own personal taste! I'm a Senn fan so mine is spot on for me. But it doesn't mimic the Senns 100%; it does undoubtedly retain much of the 681's character- but only the best of it's character. I can't comment on the 1st edition FFB, though Frans was good enough to throw in some resistors to adjust if necessary, but I think he's got it spot on for my taste. It's like a Senn, but with a livelier top end, but not TOO lively, at all. Just right.

I did mention that l to my ears, it even comes close to my Senn HD650! And that's a world class phone! But because if it's different character, it's really just a different listen, catering to the mood. The Senn HD650! How on Earth can that be done for a grand total of under £40!?!

The bass goes incredibly looowwww yet remains as well controlled as the frequency is deep. It's very natural in character but still really fun to listen too. Those mids are sooo real and warm. They were a bit cold before.. The highs are crystal and detailed, but NEVER too much.
If you really can't find a hat, then take off your phones!

Omar

[UzminiNu]

Omar you totally right!Frans is a really great guy!Whit his kind help and knowledge...
We are lucky...

[rainman]

~Yep. It's great to have the guy at Rock Grotto!

[djmattm]

Hi guys, i've just receiced my pair from Frans, the stock ones, and they're already burning in; ok here are my few and really non-audiophile thoughts:
1) The build quality is ok, nothing to complain about but neither to scream for a miracle
2) They are super comfy! Yes my other pair of hp are the akg k518dj, perhaps the most uncomfortable cans in the world but this is what i have so i compare to them....
3) I like the pads even if they are supersweaty
4) The sq is indeed very good, superior to my k518dj, i'm really enjoying them
5) I don't think they are too bass heavy, they are just right, obviously little bass shy in comparison to the akg but so many more details!
6) I don't think i'm going to modify them, maybe the cable but it's not so crappy
7) Thanks Frans for all, you're great!

[PinkFloyd]

I never take my hat off it's too cold but I will salute Frans

[Deleted]

I don't mind these kind of salute's.

[musicisum]

Hey guys,

I stumbled across this thread about a week ago and congratulations your enthusiasm has made me buy some 681's.
So now its time to mod em. do my first question is where can get some of Mick's (heliharris) aluminium rings from??
Im based in the UK if that effects this question?

Cheers guys.

[djmattm]

From what i understood they are not available anymore, that's a pity i know

[musicisum]

Ah... that is a shame. i will be ordering the materials to start the filter mod today so that should improve things.
Has anyone found anything similar to the aluminum rings that are available or should i except the red plastic?

[Deleted]

a lick of paint is all you can do to get rid of the red...
If you do this with the correct plastic paint or primer it could look well too.
You can try to pry them off carefully before painting them to get a nicer result.

[UzminiNu]

Sept 18, 2010 9:39:54 GMT PinkFloyd said:

I never take my hat off it's too cold but I will salute Frans

he he i was this weekend in nightlub with the name PURE

[Deleted]

Sept 18, 2010 14:44:18 GMT musicisum said:

Ah... that is a shame. i will be ordering the materials to start the filter mod today so that should improve things.
Has anyone found anything similar to the aluminum rings that are available or should i except the red plastic?

I have some of the the small Ali rings (4 required) and a set of the latest MK3 end caps and fittings left over musicisum, if you want them PM me your details.

Mick.

[sk971]

Hi Guys
New on here and not to late for the party I hope
Apologies for opening an old thread, but I have just got my HD681 and 50hrs burn later they are starting to sound good through my Arcam amp, but only on some tunes, on others they sound like wailing banshees!

I am planning to recable them probably in Canare starquad which is supposed to be warm sounding but this may not be enough to tame them.

I gather that Micks Aluminium rings are all gone, but may I ask If frans has any of his filters left .

Cheers Si

[sk971]

Well I will take that as a no. Looks like I will have to get my paws on a circuit board then.

In the mean time I have rewired them in some Hd650 cable which I had from a knackered pair of HD565s, also i put some blue tack on the back of the magnets and put some upholstery wadding back there too.

It sounded a bit flat like a pair of closed cans so I removed the wadding and it sounds good ,mids a bit more prominent and bass a bit punchier.The treble is still bitching though!

Anyway just wandering If anyone can tell me if strip circuit board is suitable for the filter?

Si

[Deleted]

Sorry I missed your posting.

All external filters have been sold.
I am out of PCB's.
Still can supply the needed parts (inductors, capacitors, resistors).
You can do 'free air' wiring or use a piece of cardboard with point to point wiring or a strip circuitboard or the stuff with just pads on it.
Doesn't matter how you make it.

the amount of highs will not go down with a recable.
You will need to loose about 7-8 dB in specific range of highs.
Only the filter can do that (or an equaliser).
If you like 'Sennheiser presentation' go for the '2nd' filter version.

You have to be carefull with wadding.
Only a tiny bit (equal amount L and R !!) is needed.
Too much and the bass is gone and sounds congested, ,which it is at that point as the movements of the diafragm are hinderd by the wadding.
Free (enough) airflow must exist behind the driver.

As far as I know all rings have been handed out and Mick is not making them anymore.

[sk971]

Thanks for the advice Solderdude.


If its ok I would greatly appreciate the parts to make a Mark 1 filter ,which I will use with strip board or cardboard.
Do you have a paypal account or some similar way i can pay you ?

I will play around with the wadding some more after I have made the filter, as its easily reversed.

Si

[Deleted]

Si,

You have PM

[rainman]

Solderdude really deserves a lot of credit for his filter! And his ever helpful advice!

Thanks again mate!

Omar