Shure SRH840 monitoring headphones. 44 Ohm 102dB/mW. So your 2X gain can be loud on them. They would appreciate the high bias mode also if played very loud. Can be found at around 120 Euro if you will search enough. If you could consider semi open I would have recommended AKG K240 Studio. More comfortable, cheaper, classic. 55 Ohm 104dB/V.I think closed one's are best, considering our rather small livingroom
Salas.
Are the Max input important, when chosing headphones ?
This are the specs. of them :
Transducer Type: Dynamisk, Neodym-Magnet
Driver størrelse: 40 mm
Følsomhed: 102 dB SPL/mW
Impedans: 44 & ohm;
Max. input effekt: 1000 mW
Frekvensområde: 5 Hz - 25 kHz
Netto vægt (uden kabel): 318 g
Kabel længde: 3 m
Kabeltype: Aftagelig, coiled
Plug: Forgyldt 3,5 mm stereo ministik
1Vac (1.41Vpk) is equivalent to >115dB (>118dB SPLpeak) into 44ohms 102dB/mW headphones.
The 1000mW limit is equivalent to 6.6Vac into 44ohms and would be 132dB !!!!
A headphone amplifier limited to 1Vac maximum output will sound very loud with these headphones.
The 55ohms 104dB mentioned above are ~1dB louder for the same 1Vac.
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Well, no longer cheap... prices nearly doubled. Wonder why?
Siberia, If I were in your shoes, I'll keep precious Nch and Pch JFet for other projects.
Thanks, Jasper and Massimo.
Yes... I have been looking at those too
They are on sale here in DK for 79Eur incl. shipping!
-Just gonna wait a little until next month i think
I was thinking of how i handle the connection for headphone. Do you guy's just turn off the poweramp.?
i have a Jack 6.35mm chassis connector, which opens connection between leg's on left and right side, when jack is inserted.
-Anyway i was thinking of placing a flipswitch at front, where i select between headamp. / Poweramp; when selecting headamp. the poweramp. is automatically powered down. I allways place both inlet and outlet sockets for main's on back of preamp. anyway, for the purpose of controlling the sequence. (first on / first off etc...)
Jesper.
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Some closed headphones I have tried at that level are:
Akg 272hd, has that back hall akg feel. Very wide stage, low bass impact but it goes deep. Sounds like closed k701 with less bass and smaller soundstage. Probably more "speaker-like" than most closed phones.
Akg 545, more upfront and bass than 272, sounds more like an non akg phone. But good.
Beyer 770, more bass, recessed mids. Smaller soundstage. Vocals are pinpoint but at the expense of mids. Sounds more like "headphones", less like speakers.
AT a900x, these are my current closed backs. Big sound. More bass and smaller stage than akg but it's a good compromise. Seem to do everything well...more speaker-like than beyer 770 but not as thin and back-hall positioned as akg.
But really I think most open phones are better. I use mine at work so no choice.
If you can, I'd try akg k701, grado, senn 600/650 and a hifiman. Headphones are really personal, this will give you an idea of how much they can vary.
Good guides.
Best AKG I tried is K712 Pro as I had reported in a much earlier post. Most balanced in virtues. Excluding the discontinued 1000 which is an expensive collector's item by now.
Morning.
Il'l proberly go crazy about it, and create a hole circuit for this to be automatic
I think, family will forget unplugging headphones otherwise.
-Anyway i got one of those nice red NEC relays for this.
-Had to do something, while waiting for my transformers
Jesper.
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Both L-R, Gnd-L, Gnd-R, are shorted for a splitsec. when plugging/unplugging the Jack.
Donno if this preamp. can stand this?
Jesper.
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Theoretically yes. When there is no big offset or no big signal. I think I did it at a point with the lab supply where I could protect with a current limit. But I did not risk it with the normal supplies. It should blow the fuses otherwise. There are non shorting jacks to choose when you don't need them have secondary functions though.
www.neutrik.com/zoolu-website/media/download/2804/Jack+Circuits
www.neutrik.com/zoolu-website/media/download/2804/Jack+Circuits
Hi.
I tried some small 3.5 jacks + female, here at job.
They also momentary for a splitsecond make shorts between L/R - Gnd
Only happens, when inserting and unplugging.
Strange... Maybee they all do ??
Jesper.
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shorting depends on the shape of the contact in the socket and on the depth/width of the depression between the conductors of the plug.
If the hard plastic (non conductor) between the conductors was made at the same diameter as the ¼" conductors, then a narrow curved contact inside the socket would not short across the plastic insulators.
If the hard plastic (non conductor) between the conductors was made at the same diameter as the ¼" conductors, then a narrow curved contact inside the socket would not short across the plastic insulators.
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There's a whole world of various 'plug & sockets'- 4 and 5 pin miniature plugs avoid all this potential shorting of the amp plus offer the possible advantage of the 4 wire connection - replacing the typical 1/4" jack plug is pretty straightforward and doesn't need to be the large 'clunky' cannon plug style - the Swisstac (?) 4 pin isn't so common but the 5 pin version is used as a video connector and readily available - many companies make these ...