Which headphone amp?

Davesax1965 wrote: I'm vaguely considering building some valve based headphone amps for sale. Time's taken up building the modular, though !

Don't forget to sell them for £2,000 each so people know they are high end.

Hi Solan, I notice you're new to the forum.

I sort of "build the odd bit of electronics". 

Incidentally, the little blue box to the right of my shiny head (with the big light on it) is a valve preamp. Didn't build it. ;-) It's a Studio Art V3, uses a 12AU7 valve at low voltage levels. Theoretically not very good, then again, I'm not distorting it or expecting high gain so it does the job. 

With thousands of pounds of electronics there, that, going into a very old Lexicon audio interface is what I use for professional audio recording. The modular - all 13 oscillators - goes into a vintage 1990's Alesis Quadraverb effects unit. 

That's the level of technology I use and I've been around recording audio since the very early days. If you're trying to replicate a sound, then the absolute best reproduction you'll get out of it is dependent on the original quality of the recorded sound itself. (Admittedly, I fiddle around with EQ and post production effects a lot.) 

A lot of prog rock from the seventies was recorded on tin boxes and sounds crap. You won't get any more out of it by spending thousands on a headphone amp and expensive headphones. You may THINK you do and you may THINK you can hear a difference, it's just confirmation bias. "I've spent this much so it must sound good." Wrong. 

A non power amp is a very simple thing to produce nowadays, essentially using a jack, two resistors, one chip and a couple of capacitors - and an output jack. The rest of the amp can be made slightly more complicated to boost certain frequency ranges but essentially, it's very simple electronics. That one TL072 chip, which costs less than $1, contains more electronics of better quality than anything non solid state produced in the 1970's. You might think that old stuff, full of dodgy carbon resistors, leaky electrolytic capacitors and components with values all over the place, had "character" - what it had was "distortion" but if you're desperate, you could pay through the nose for old oil in film or tropical fish caps, knackered NOS capacitors and the like and produce something "vintage" - and charge a fortune for it, as a lot of amp makers do. It'd sound rubbish. 

But this is what happens. Rubbish sounding kit using "authentic" components is snapped up by people who then decide "it sounds great because I've spent a fortune on it." Example. The capacitors in Gibson guitars on the tone control go for hundreds of dollars for an original. 10, 22 or 47 microfarads, I can't remember which, now. Put any old 22uf cap in and it'll sound much the same, but purveyors of old caps will tell you it sounds "darker" or "vintage" whilst removing $200 from your wallet. 

Actually, the cap doesn't come into play unless you switch the tone off, but..... ;-) 

Headphone amps have become so ridiculous by this point. When we some 25 years ago were making amps with distortion numbers well below the threshold of human hearing...we funnily enough couldn’t discern a difference between that and another amp with similar performance....even when one was blue and the other black!
Nowadays we’ve bettered those numbers 10 fold or in some cases well above that...yet there are no brownie points for making the inaudible even more inaudible.
The fact of the matter remains, almost all amps sound the same if they’re matched with the right gear aka don’t hook up a 20 ohm dynamic driver headphone to an amp with an output impedance of say 10 ohm if you are looking for transparency. You’ll most likely experience an impedance hump in the bass plus some added distortions.
I also have a few tech interested friends who vehemently herald pricey components and special wires as being paramount for obtaining the best sound quality possible...yet when I hid their amps behind a big box and levelmatched the buggers they couldn’t discern any sort of difference between the insanely pricey Frankenstein they’d been working on and a cheap Magni 2.

Before anyone out there goes on to get him or herself a headphone amp, please do yourself a favour and read up on the important bits. Output impedance of the amp is personally where I’d start. Power is a long way down the list simply because most headphone amps on the market today will drive just about any headphone to perfection...unless you are getting an HE-6 or a Susvara.
Then again..a headphone amp is only really needed if you are missing volume.

Edited by Guldbamsen - December 20 2020 at 05:10

Any post which starts "I've not listened to a tube amp" can safely be ignored in a discussion about amps. ;-)

If crappy picture disk vinyl sounds the same as a CD to you and you somehow work a lava lamp into this, have you considered that your hat may be too tight ? ;-)

Or, Svein, is this just somewhat of a wind up ? ;-)))))))))

Edited by Davesax1965 - December 20 2020 at 10:01

Another one, just to make Davesax take me seriously even though I have never listened to a tube amp: https://www.scientificamerican.com/article/making-sense-world-sveral-senses-at-time/

Edited by Solan - December 20 2020 at 11:00

Now, back to that lava lamp. Put one on, and look at it while you listen to a Solid State amp. Doesn't it sound warmer?

Catcher10 wrote: For analog instrument amps, tubes are the way to go it seems, I don't recall seeing a guitar stack that was not tubes on stage..

Regarding noise floor. 

I switch on a Korg MS synth I had (used to have the original, now I have the reissue, which is SMD and not TTL, I can hear the difference) and because of the inherent filter design, I can hear noise. Or. I pick up one of my guitars with P90 pickups in it, there's noise as well. Inherent noise.

If you listen to a 70's recording, there's inherent noise in it. Valve amps, old pickups, bad electronics. 

So how, can I ask, can you tell "original recording noise" from "modern hi fi amp noise" ?

And why oh why oh why does it matter if you can or not ? Given the cost of reducing it. 

Holistics ... he he, yes, we can end up very late 60ies with that one, and if we truly work on it, we'll end up with profundities like that the "The best music is no music", with no music meant as some mystical something you can only understand when on LSD.

Edited by Solan - December 22 2020 at 10:42