Beyerdynamics DT990

[Pfenning]

My lovely wife purchased the DT990 250 ohm premium cans for me for fathers day, and I got a chance to try them last night. I was a bit disappointed in their performance. I currently have Sennheiser HD545 that are a bit low ohm (125 ohms I think) for my Crack amp (stock tubes, no mods, no speedball) . I was just expecting a bigger leap in sound quality. My question is about break in time. What will it take to get them broke in, and how much will the sound change during break in? I was surprised that my Senn's sounded better top to bottom, had more clarity and depth, and actually played a little louder that the 990's.

Pfenning 

[Laudanum]

They wont change much.  You might get used to them but I wouldnt expect them to change much.  Then again, I dont really subscribe to the headphone break-in thing.  Only cans I have that I noticed what I truly believe to be a burn in or break in was with my AKG 601's.  I never noticed anything I would consider signifigant change from either of my Beyers (880 or 990 pro).  Of course, YMMV.  I think Senn fans and Beyer fans are very different, Im not surprised that you are having a hard time listening to the Beyers coming from Senns.  I love the 990's but dont use them for everything.  They are great for bass light stuff or if you just want to thump.  I think the 880's are more balanced.  In fact, to my ear they definitely are.  Neither are what I would call mid-centric, especially the 990's.  They arent warm or romantic sounding phones, that's for sure.  But lacking clarity isnt how I would describe them.  Going from Beyers to Senns (atleast the ones Ive listened to) would make me understand the audio speak meaning of "vieled".  But of course it would be both a relative and a temporary effect.  If I switched to Beyers after spending time with the Senns, I would find the Beyers analytical or overly bright, again, atleast temporarily.  In the end, it comes down to what one ultimately prefers.  Ahh, but what do I know anyway ... just my 1/2 cents worth. 

[HF9]

I agree with much of what Laudanum stated (aside from break-in ); Sennheisers and Beyers tend to have different sound signatures each with their own following. The Beyer DT990 itsself is a very polarizing headphone, people either love it or hate it. The frequency extremes, both the low frequency bass and the high frequency treble are emphasized and the midrange doesn't stick out too much. When it comes to headphones, you have to get a feel for what you like and don't like, then read reviews (or preferably go to meets) and try and get a sense for the way the headphone presents something. The DT990 has what I would consider a colored and bassy sound, you might be looking for something more neutral like the DT880.

I personally enjoyed my DT990 600ohm with the Crack, I happen to be one of the few that like that headphone

[Pfenning]

Something weird is going on then, because I was expecting exactly what you guys described with the heavy bass and treble. They sound flat and almost distorted. The bass is flabby and to use an audiophile term, they sound like they are crapping out  . I had the volume between 1/2 and 3/4, and it wasn't anywhere near loud. I was listening to Nirvana unplugged on vinyl through my seduction with c4s and russian teflon caps, which I've listened to lot of times through my foreplay paramour Pi4 set up. Should I install the speedball and try them again? I bought them off amazon because of the easy return policy. There is no where near me to test out headphones.

Pfenning

[Grainger49]

I would give them some time to break in.  It works for capacitors and speakers; who knows what else!  Surely it works for headphones.

[Pfenning]

Something else I just thought of. When I push the headphone plug all the way in, I get no sound, but if I pull it out one detent, I have music in both ears. Maybe I have an issue with my jack wiring causing the poor sound quality. Also, with a 250 ohm headphone, how much volume should I expect from Crack. Should it be approaching painfully loud at full volume?

Pfenning

[Doc B.]

Something else I just thought of. When I push the headphone plug all the way in, I get no sound, but if I pull it out one detent, I have music in both ears. Maybe I have an issue with my jack wiring causing the poor sound quality.
Pfenning

Yes. Usually the deal is you get one channel with it all the way in and sound in both from that single channel when you pull it out partway. That usually means that the tip connection is bad. But in this case maybe connections are reversed or something like that. Anyway, carefully go over the connections on the headphone jack.

[grufti]

... .  Also, with a 250 ohm headphone, how much volume should I expect from Crack. Should it be approaching painfully loud at full volume?

Pfenning

Yes!

The outcome obviously depends on the source, but if that source makes other things go lound then your Crack should play LOUD.

[Pfenning]

OK, so I found my error, I had the wire connecting the input tube to 5u soldered to 2u. I corrected the mistake, and now I have sound in both channels. The only problem now, is the sound in the right channel is not as loud as the sound in the left channel. I tested both sets of headphones I have, 2 different sources, 2 different sets of rca cables, and it's the same with all combinations. The right channel is significantly quieter. Could I have damaged the input or output tube with my mistake? Could it be a problem with the power transformer wiring? I'm not sure where to start looking.

Pfenning

[Doc B.]

Try redoing the voltage measurements, and post anything that is off. Not likely that a tube was damaged, but possibly there is something still miswired or a cold joint on the side that is more quiet.

[Laudanum]

When you do square it away ...  I have the 250 ohm Pro's, not the Premiums.  Very similiar but a little different.   The bass is plentiful but not what one would call "tight".  It's relative of course but the bass isnt really loose, it just isnt tight and controlled compared to some phones.  Of course, sometimes tight, controlled bass in audiophile terms = there isnt any      They have plenty of low end (extending up into midbass) and plenty of treble with no lack of clarity.   Midrange can seem a bit recessed.    Think "smile" eq curve (but just for a visual, they arent completely sucked out in the midrange).   They also arent super efficient but they do play plenty loud.   With a 6AS7 as the output tube I would rarely go beyond 2'oclock on the pot with a 2 volt source.  With some vinyl - Seduction (w/c4s) directly into Crack - I had to crank it pretty good (4 mv cart).  Not all the way but getting close to 3/4.  But that was rare, just a couple LP's.   
My AKG 601's are less efficient by a good bit and my MB Quarts are more efficient.  I dont have a hi Z Senn in the house to compare but I think they spec different.  Beyer at db/mw and Senn at db/V.  You can do a conversion but that relies on the specs of each manufacturer being accurate.  (The 990 premiums [and pros I think] are spec'd at 96 db/mw @ 1Khz).  Im going to guess that your Senns probably are more efficient.