advertisement


Connecting headphones to speaker amp terminals?

So, I have decided to buy the Can Opener, thanks Derek. Who knows whether this’ll blow up the Amptastic with its earth arrangement….?
 
Alex S said:
So, I have decided to buy the Can Opener, thanks Derek. Who knows whether this’ll blow up the Amptastic with its earth arrangement….?
Click to expand...

I'd be tempted to go for a directly wired solution myself but the floating ground situation makes me want to play it safe and take a feed via a sort of step-down box. So I'm gonna wait until somebody else goes first before I try it myself :D

Still, I think you're gonna be in for a treat as the Amptastic makes for a really enjoyable and really involving headphone amplifier. There's definitely some colouration going on, and you don't quite get every last nuance of detail, but what it gives you in return is pure sonic comfort and bliss. I've never heard a sound like it before. I listened to Mahler 9 last night and there are moments when some of the woodwind instruments normally sound a bit too sharp and piercing... but not through the Amptastic. Everything just sounded really sweet and really organic. I also listened to Desperado by the Eagles and it was the same. It's the best headphone amplifier I've ever had.
 
I really don’t want to blow up my Amptastic so I’ll await further advice and in the meantime try a Temple Bantam Gold, very close in character and easier for me to sacrifice if it comes to it.

I presume you’re just using the SMPS with your Amptastic?
 
Alex S said:
I really don’t want to blow up my Amptastic so I’ll await further advice and in the meantime try a Temple Bantam Gold, very close in character and easier for me to sacrifice if it comes to it.

I presume you’re just using the SMPS with your Amptastic?
Click to expand...

Yeah just using the supplied PS unit.
 
John Clayton/Temple got back to me and his amps no worky with a can opener and will likely go into protection mode. Amptastic I very much doubt also. No reflection on Derek whatsoever, happy to buy the thing at price paid but it’ll sit in a cupboard until I have a suitable amp.

I guess this is a heads up that if you’re thinking of the can opener as a solution you don’t want to be having a class T, D or valves probably.
 
Alex S said:
John Clayton/Temple got back to me and his amps no worky with a can opener and will likely go into protection mode. Amptastic I very much doubt also. No reflection on Derek whatsoever, happy to buy the thing at price paid but it’ll sit in a cupboard until I have a suitable amp.

I guess this is a heads up that if you’re thinking of the can opener as a solution you don’t want to be having a class T, D or valves probably.
Click to expand...

Oh, this sounds like something I should know about. I'm guessing the Temple amp is another Tripath amp? Everything has been working fine so far, although if using my Amptastic to feed my HD650s via the Demion Pro Gold switch box I bought is likely to kill the amp then I'll happily abort things. Dunno if the Demion unit and the Can Opener share the same basic arrangements inside but I defo don't want to blow up my Amptastic!

I've got a Rega IO and an old Marantz NR-1504 AVR at hand so I'll try them out; I can only borrow the IO as that's my bedroom system amp where it works perfectly. Regardless, I'll be disappointed if I really shouldn't use the Amptastic to drive headphones as it makes for a positively charming headphone amp.
 
Temple are chip amps, can’t remember which, but not Tripath. Same difference it seems. Tread carefully I reckon.

A trip to Aldi costs me x2 the cost of the can opener so I’m not bothered but think I’ll stick with my Sugden Headmaster.
 
The issue with a lot of class D Amps (extracting more power than you expect from the low-voltage wall wart supply) - is that they are effectively small bridged amps, per channel. So there is no '0v' side of the output signal that is common between channels.

Then, if you make an adapter such as for headphones that would normal bond both nominally 'speaker returns' together -deep unhappiness follows in short order.

Not really an artifact of class D so much as some of the ways some of such things, are made to work.

And, also - if your headphones have curious modern fashion for a 4-pin 'balanced' i.e. each earpiece has separated connection - (think: just like a mini pair of speakers) - curiously enough if you are careful these should work fine: because at no point are you creating a hard wire connection between each channel.


yet a simple can-opener approach - def not. unless the Class D amp has both output )v returns referenced to the same supply.

The easy way to check: take a digital voltmeter with resistance-test function, and with the amplifer un-powered, unplugged - try to simply measure the resistance between both black/'0v' speaker terminals. If it is damn nigh close to 0.1 ohm or less - a simple headphone adapter along the lines explored by others above - will work.

ETA:
(NB - with a simple hobbyist, rarely-used DVM, do it this way:

  • Measure the resistance with the probes shorted together , first:
  • Then measure the amp as above.
  • If the difference between these numbers is under, say 0.3-0.5 ohms - all should be OK.

Reason for this edit: the DVM probe lead resistance is significant when you are trying to measure very small resistance - the round trip you measure in step 1 can easily approach 1ohm for cheap meters!)
 
Does anyone remember the Rega Ear? (At least, I think it was called the Ear, before they started using the name for their headphone amps?)

Couple of pairs of leads to connect to the speaker outputs, with a heatsink-esque styled box at the end containing the headphone socket - presumably, something similar inside to The Can Opener?

I've used it with various Verker era Naim amps (140, 250, 135s), albeit very occasionally - nothing blew up, so OK with these era Naim amps for more regular use?
(This thread is making me paranoid, not to mention the short cable runs on the Ear... :eek:)
 
Cut 'n paste from the Audio room if missed or of interest:

"I just spoke with John Clayton/Temple and he is going to dig out his father's circuit diagram and hopefully post it here, in the DIY section I would think.

He was fairly certain that his amps would not be damaged using the Can Opener or similar (and by extension the Amptastic but the Temples have inbuilt protection, the Mini-1 may not so I'd not use it) but that it was essentially a waste of time."
 
It just occurred to me that I don't have to connect my Amptastic to the tape out of my amplifier to get a headphone out via that Demion speaker switch. I can simply insert the Demion unit between my amp and speakers and take a headphone feed from that. Sure, it means giving up on the idea of using my Amptastic as a headphone amplifier, but equally, it means it should work without any faff and it also means I won't need to buy a dedicated headphone amplifier, what with the Amptastic needing all four connections to be live, so to speak, and the issues that follow.

It would mean boxing up the Amptastic and going back to the drawing board to try and figure out how to make use of it another way. But it would be the simplest way of adding a headphone option to my main system as my Teddy Pardo amp doesn't have a headphone socket.

I'm off tomorrow so I think I'll try it out then.

EDIT: I just realised I can't do that because as soon as I turn up the volume for headphone listening, the speakers will activate accordingly. Doh!
 
Last edited:
Caledon1297 said:
Does anyone remember the Rega Ear? (At least, I think it was called the Ear, before they started using the name for their headphone amps?)

Couple of pairs of leads to connect to the speaker outputs, with a heatsink-esque styled box at the end containing the headphone socket - presumably, something similar inside to The Can Opener?

I've used it with various Verker era Naim amps (140, 250, 135s), albeit very occasionally - nothing blew up, so OK with these era Naim amps for more regular use?
(This thread is making me paranoid, not to mention the short cable runs on the Ear... :eek:)
Click to expand...

Finally managed to find a photo of it.

(Credit to OP for photo)
ci5qcGc
 
I've used tripath amps with Hifiman headphones to good effect.

The easiest way to drive the HD650s is to buy one of those reasonably priced litz cables off eBay to the length you want remember they go round the back of the amp so add 0.5m on to be sure. Make sure from the photos they don't meet and merge at the yoke but remain separate (but wound together) to the jack plug.

They should have 4 (or 8) wires direct to the headphone jack. Cut the cable at the jack so you have 4 (or 8) bare cables. With a multimeter work out which ones go to the L/R +/- pins on the headphone plugs and attach banana plugs in a way you will remember which is which.

Next recheck every banana plug against every terminal to make sure the only connection is to the intended pin.

Plug the banana plugs in and you're ready to go.
 
lawrence001 said:
I've used tripath amps with Hifiman headphones to good effect.

The easiest way to drive the HD650s is to buy one of those reasonably priced litz cables off eBay to the length you want remember they go round the back of the amp so add 0.5m on to be sure. Make sure from the photos they don't meet and merge at the yoke but remain separate (but wound together) to the jack plug.

They should have 4 (or 8) wires direct to the headphone jack. Cut the cable at the jack so you have 4 (or 8) bare cables. With a multimeter work out which ones go to the L/R +/- pins on the headphone plugs and attach banana plugs in a way you will remember which is which.

Next recheck every banana plug against every terminal to make sure the only connection is to the intended pin.

Plug the banana plugs in and you're ready to go.
Click to expand...

That's really helpful and really intuitive when you put it like that it. Four connections to four connections? That's got t solve the ground issue for sure. I'll have a look and as you say, it might be easiest to ask for a balanced HD650 cable to come with 4 banana plugs :)
 
For an amp that has low enough distortion to drive the most sensitive IEM's and also ample power to run stuff like Susvara, Expanse/Stealth and HE-6 I'd be looking at the Topping LA90 using a female 4-pin XLR to 4 spades/banana adapter cable.
 
You must log in or register to reply here.


advertisement


Back
Top