Topic: HD800s out of a speaker amp (Read 2775 times)

Elysian · « **on:** June 30, 2012, 10:09:17 AM »

I have a question I probably know the answer to already, but wanted to confirm with the experts

I've been reading how it's popular to drive some orthos directly from the taps of a modest speaker amp (e.g., 10W to 25W at 8ohms), and I was wondering what to expect if I hooked up an HD800 directly to a low noise speaker amp like a First Watt JFET Class A design.

I've noticed on some amps like certain Woos, if you turn the volume pot way up with no music playing, you'll hear static on a lot of Sennheisers. Interestingly enough, the Hifimans don't have that noise. From what I've read, speaker amps are much noisier than headphone amps at low power, so would something like the HD800 be unbearable even on a well-designed JFET Class A speaker amp? This takes into assumption that the speaker amp will be carefully controlled by a preamp, to keep the volume low enough not to blow out the headphones.

Thanks for any thoughts, whether it's from direct experience or hypotheses. I'm curious enough to build a termination plug for some Sennheisers to see how they'd perform, if it might be an interesting experiment.

RexAeterna · « **Reply #1 on:** June 30, 2012, 10:16:48 AM »

i use nothing but my power amps to drive headphones. it works out so perfect with lot of headphones. wpc of the amp itself is not an issue. it just means more ''headroom''. i driven headphones on power amps that can drive over 300w into a 2ohm nominal load and no issues.

i say using speaker amps is probably the best thing i ever done in the past. it's only an issue if you have very high sensitive, low impedance headphone if your power amp does not have input levels for left and right channel cause might run into noise issues and will have like zero headroom on the gain/volume knob.

for the hd800 300ohm nominal i say you be more then fine with noise on most amps. noise is only an issue if the amp has crappy s/n ratio and/or the headphone is very high sensitivity(above 100 db/1v). you be more then fine.

spritzer · « **Reply #2 on:** June 30, 2012, 12:51:19 PM »

The hiss you hear is the residual noise of the amp, source, cables being amplified so how much you hear depends on the sensitivity of the transducer. Most companies are obsessed with gain these days (MOAR LOUD!!!) which only compounds the issue. Pass isn't one of these though and the LCD-2's sound just fine off the F5.

One thing about the HD800 that requires some investigation is the output impedance of the amp. They may have been designed for the 120ohm standard and that's why they sound so crappy off the 1ohm or less amps.

RexAeterna · « **Reply #3 on:** June 30, 2012, 01:04:09 PM »

i didn't know that. i would think anything less then 1ohm be perfect and will allow you to hear what headphone driver really performs like. i think cause 120ohm and above loosens the bass a bit to calm the treble issues through masking? i never used an hd800 personally so this is just an ignorant guess here on my part. the output impedance is another reason why i love using power amps instead as well cause it seems to make a cleaner sound/signal even if the headphone itself might sound on it's own.

Anaxilus. · « **Reply #4 on:** June 30, 2012, 03:03:34 PM »

We have a thread here on the IEC spec and the HD800. I actually have a 100ohm breakout box for my Sansui.

Elysian · « **Reply #5 on:** June 30, 2012, 05:20:11 PM »

Very interesting! I thought that there would've been some sort of electronics issue why this would be a poor idea, but the experimentation people have been putting the HE-6 through has gotten me around to thinking, especially now that Justin mentioned to consider a quality low-noise speaker amp design like a Nelson Pass.

Rex: Do you drive your headphones directly from the taps? A friend helped me make a pair of XLR->taps cables for the HE-6 I'll be receiving in the next week or two, and I'm really curious to try a HD600/650/800 after deciding on an amp.

spritzer: Yeah, lately I've been hearing a lot more amps that have very noticeable hiss once you turn the volume knob beyond 12 o'clock. I've never had that issue with the GS-1 or GES, but it's been really bad with a lot of headphone amps I've run across the last several months.

Anax: Thanks for mentioning the thread for the HD800 and IEC spec. I hadn't read it yet until now, lots of interesting stuff there. Linking it here for other people:
http://www.changstar.com/index.php/topic,90.msg695.html

Re the other thread and peoples' comments, does that means anything with less than 1 output ohm (like the 0.4 for the First Watt J2) would pair very poorly with the HD800? Does that mean the HD800 will probably sound thin and shrill on it, and I'll need to build a breakout box for the HD800 if I get a J2 instead of an F1? Specs here: http://firstwatt.com/prod.html

Thanks for walking me through this. Aside from the BA, I'm pretty dispirited about the general dynamic headphone amp arena.

maverickronin · « **Reply #6 on:** June 30, 2012, 05:53:57 PM »

In my somewhat limited experience I think the HD800 does better with lower output impedance. Tighter bass but a hair sharper treble.

RexAeterna · « **Reply #7 on:** June 30, 2012, 05:54:27 PM »

@Elysian

yes. directly at the outputs. all my headphones are balanced for this very reason. i have a 1/4'' trs to speaker out box i made while ago for testing loaner pairs off of speaker outs and so forth but personal pairs always directly off of taps. i have 4-pin xlr to bare wire adapter i made for my df's and sextetts and the sa5000 i have uses 3-pin xlr to bare wire adapters too. i made 4-pin xlr to trs and have dual 3-pin xlr to 1/4'' but i only use that with my guitar amp for now.

i have no issues either with them.

Elysian · « **Reply #8 on:** June 30, 2012, 06:04:22 PM »

maverick: Thanks for the feedback! I'm less worried about matching the Sennheiser with the amp now.

Rex: Perfect! I already have a pair of XLR to speaker taps made for the HE-6, and will figure out how to do that for the HE800. The HE-6 was pretty straightforward for obvious reasons. I wonder if the HD800 and other good dynamics will be any more complicated, as I'd rather just order the parts separately from Redco.

I actually just pulled the trigger on a used First Watt J2 and got a fantastic deal on it with a full 3 year warranty, so I should have it by next Tuesday. I will report back on how some high-end headphones sound on the J2.

I was reading up on the Dark Star, but it seems like a speaker amp that happens to have a volume pot and headphone jacks. I wasn't that pleased reading about the components that went into it, and my hunch is that a First Watt will be able to get just as loud (for headphone listening) but will have much better resolution and detail. Seems like it's better just to go for a top-flight lower-power speaker amp like a J2 or F5 given the recent SS dynamic amp design trends.

maverickronin · « **Reply #9 on:** June 30, 2012, 06:16:25 PM »

Quote from: Elysian on June 30, 2012, 06:04:22 PM

maverick: Thanks for the feedback! I'm less worried about matching the Sennheiser with the amp now.

I might be in the minority around here on that point though.

Author Topic: HD800s out of a speaker amp (Read 2775 times)

Elysian

HD800s out of a speaker amp

RexAeterna

Re: HD800s out of a speaker amp

spritzer

Re: HD800s out of a speaker amp

RexAeterna

Re: HD800s out of a speaker amp

Anaxilus.

Re: HD800s out of a speaker amp

Elysian

Re: HD800s out of a speaker amp

maverickronin

Re: HD800s out of a speaker amp

RexAeterna

Re: HD800s out of a speaker amp

Elysian

Re: HD800s out of a speaker amp

maverickronin

Re: HD800s out of a speaker amp

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Author Topic: HD800s out of a speaker amp (Read 2775 times)

spritzer