Poll

I would like...

Stand-alone amp
14 (42.4%)
DAC and Amp
6 (18.2%)
The whole bang shoot, USB, crossfeed etc
6 (18.2%)
A mistress for christmas
7 (21.2%)

Total Members Voted: 33

Author Topic: Forum DIY Headphone amp kit  (Read 39762 times)

Offline Cure

  • Trade Count: (0)
  • AVForums Member
  • **
  • Posts: 82
Re: Forum DIY Headphone amp kit
« Reply #15 on: August 20, 2010, 01:23:46 PM »
Okay, I'm going for the fully built as well. Gert and Ludo should just team up and come up with a nice head amp for mass production. Customs' taxes are way too high with imported amps. 

@rodney
You selling your hd 650? Pm me

Offline Prince

  • Forum Moderator
  • Trade Count: (+8)
  • *****
  • Posts: 2,674
Re: Forum DIY Headphone amp kit
« Reply #16 on: August 20, 2010, 01:34:29 PM »
I'm in. Whichever option gets decided on.
"F5 Amp Power + Pedal Power = F5 Pedal Power"

Offline GearSlave

  • Peacekeeper Extraordinaire
  • Trade Count: (+3)
  • AVForums Veteran
  • *****
  • Posts: 8,796
  • Ohm's Law has no business in Audio
    • Studio B
Re: Forum DIY Headphone amp kit
« Reply #17 on: August 20, 2010, 04:43:53 PM »
Alright, so things are as clear as mud...

I think it's a given that there's enough interest, now we need to beg the question, which design to use? If I'm reading this right, it's between the TPA 6120 and Ludo's brew. I think it's going to be a little unfair to put it up to a vote, but in the interests of keeping costs down it does make sense to stick with one design. If we do go the TPA route, we will need to get double sided PCBs professionally made as the TPA chip has specific heatsinking requirements. If we go Ludo's route, it's up to him if he'd have PCBs made or if he wants to do it himself.

Point is, I'm not too sure where to go from here. I'm not phased which way it goes, I've got many HP amps here and planning on doing a Valve Hybrid in any case. But seeing as we have almost 18 interested parties, I'm sure we can do something very nice.

We also need to consider the following:
- Use of Boutique parts (Like fancy volume pot and funky caps for example)
- What features you want (USB input, SPDif input, Crossfeed [urgh], etc)
- I'd still like to get some concensus on the kind of money people are prepared to spend on this.
- What are we doing for casework. I quite like the AP enclosures for this. They quite cheap and look decent for something that costs around R150.

So ja, not really much closer to a final design. At least we know there's enough interest to warrant going further.
Resistance is not futile; it is voltage divided by current (R=V/I)

Offline BWS

  • Administrator
  • Trade Count: (+1)
  • *****
  • Posts: 15,476
Re: Forum DIY Headphone amp kit
« Reply #18 on: August 20, 2010, 04:45:23 PM »
onward and upward ;D
Whoever originally coined the word 'Lisp' and put an 'S' in it's spelling, is a Douchebag !!

Offline chipwelder

  • Trade Count: (+1)
  • AVForums Veteran
  • *****
  • Posts: 5,045
Re: Forum DIY Headphone amp kit
« Reply #19 on: August 20, 2010, 05:28:19 PM »
I'm not in the market, but wouldn't it make sense to have Ludo's headamp end talk to Gert's USB DAC... it seems significant thought went into Ludo's design already, I guess it won't fit on the same board... so you prolly will have two boards - I'm guessing that won't matter as you could just get a case that'll fit both... I don't know if you'd have to split PSU's? prolly only if you not interested in the budget side.
OK! I've had it! I don't give anymore Kharma. Kharma should work in mysterious ways...

Offline xumbug

  • Trade Count: (+5)
  • AVForums Veteran
  • *****
  • Posts: 1,469
Re: Forum DIY Headphone amp kit
« Reply #20 on: August 20, 2010, 05:29:36 PM »
I'm in for a fully built version, I think i said that somewhere else.
SDA Acoustics loudspeakers, Audio Research Ref 3 Pre amp and Ref 210 power amps, Bel Canto VB3.5 Dac, Pathos Endorphin cd player, squeeze box touch.

Offline Cure

  • Trade Count: (0)
  • AVForums Member
  • **
  • Posts: 82
Re: Forum DIY Headphone amp kit
« Reply #21 on: August 20, 2010, 07:05:57 PM »
I suggest we redo the poll.

1. Are we up for an standalone amp/ dac, or combo?
2. USB connection, Crossfeed, spdif would be nice but that would depend on majority's budget.
3. knobs, cases, psu etc would be dependent on the budget as well.

Skinny, make another poll for this.
Now we know we have the numbers to make this (ie Gert) work hehehe

   

Offline GearSlave

  • Peacekeeper Extraordinaire
  • Trade Count: (+3)
  • AVForums Veteran
  • *****
  • Posts: 8,796
  • Ohm's Law has no business in Audio
    • Studio B
Re: Forum DIY Headphone amp kit
« Reply #22 on: August 20, 2010, 07:40:47 PM »
Well, if I had to kick this off with my thoughts...

1. Rather just do the amp. You can get a million DACs for cheap that'll perform much better than anything I can come up for little money. As I've said many times before, get yourself a Musiland Monitor 01US for R650 if you want USB/DAC/SPDif. That can then feed the HP amp and is literally the best value for money out there.
2. See 1 above. I wouldn't suggest crossfeed though. Let's keep it clean. You can use the crossfeed plugin on Foobar if you want that feature.
3. Knobs are an issue, unless we can get Ian or Hugo to make us a couple. The case is easy and the PSU is a PCB mounted transformer. Nice and neat.

That's my take on the features for now.
Resistance is not futile; it is voltage divided by current (R=V/I)

Offline Cure

  • Trade Count: (0)
  • AVForums Member
  • **
  • Posts: 82
Re: Forum DIY Headphone amp kit
« Reply #23 on: August 20, 2010, 07:56:45 PM »
alright guys, we heard the master speak. It's up to us to let him know what we want.

I myself prefer a standalone HP amp. I think everyone here's on the sam as i am.

Gert, why don't you give us idea what would be the amp like, aside from the overt 6120. We could throw some ideas later on after hearing what's on your mind.

@all
Budget? Let's talk about budget.

Offline GearSlave

  • Peacekeeper Extraordinaire
  • Trade Count: (+3)
  • AVForums Veteran
  • *****
  • Posts: 8,796
  • Ohm's Law has no business in Audio
    • Studio B
Re: Forum DIY Headphone amp kit
« Reply #24 on: August 20, 2010, 08:21:02 PM »
Attached is the schematic of the unit, except for the PSU. I leached this somewhere off the web, can't remember where to be honest. What is interesting about the design is that the TPA6120 is run in inverting mode. According to the datasheet, this configuration offers the best distortion performance. There's a catch though, it needs to be driven by a low impedance source. Because it's not possible to guarantee a low impedance source will be provided, you have to have a buffer stage before the TPA. I generally use OPA2134's here, but many other Duals can be used.

Oh, and I've got nothing to hide by not showing component values. I was just too lazy to put them in, as it was for my own use. I'll do that in due course.
Resistance is not futile; it is voltage divided by current (R=V/I)

Offline Cure

  • Trade Count: (0)
  • AVForums Member
  • **
  • Posts: 82
Re: Forum DIY Headphone amp kit
« Reply #25 on: August 20, 2010, 08:39:30 PM »
Thanks Gert.
Will wait for the others to chime in.

Oh, and please give us a ballpark on the whole she-bang.

Offline Prince

  • Forum Moderator
  • Trade Count: (+8)
  • *****
  • Posts: 2,674
Re: Forum DIY Headphone amp kit
« Reply #26 on: August 20, 2010, 08:43:05 PM »
@Gert - Thanx for the suggestions.

I agree, standalone headphone amp is fine by me. The most cost effective and neatest/cleanest looking design we can get.

:)


"F5 Amp Power + Pedal Power = F5 Pedal Power"

Offline xumbug

  • Trade Count: (+5)
  • AVForums Veteran
  • *****
  • Posts: 1,469
Re: Forum DIY Headphone amp kit
« Reply #27 on: August 20, 2010, 08:55:48 PM »
Knobs are not a problem, Mantech have got some beautiful classy black anodised ones in 4 different sizes, I have an acc with them and know Manny very well, he will always help.
SDA Acoustics loudspeakers, Audio Research Ref 3 Pre amp and Ref 210 power amps, Bel Canto VB3.5 Dac, Pathos Endorphin cd player, squeeze box touch.

Offline Cure

  • Trade Count: (0)
  • AVForums Member
  • **
  • Posts: 82
Re: Forum DIY Headphone amp kit
« Reply #28 on: August 20, 2010, 09:33:40 PM »
lets keep the ball rolling. It'll help if we include the prices as well. At least we'll know our budget (either to trim it down or increase it to maximum levels.....nah just kidding!)

1. design module by master Gert
2. knobs by mantech - R??
3. enclosure - ???? this has to be Gert's decision.
4. what else??

Offline Blues

  • Trade Count: (0)
  • AVForums Veteran
  • *****
  • Posts: 1,061
  • when in doubt, knock'em out
Re: Forum DIY Headphone amp kit
« Reply #29 on: August 20, 2010, 09:54:54 PM »
I'm also interested in a headphone-amp, especially if gert has his fingers in it  ;)
I had the blues, so bad one time,
It put my face in a permanent frown
Now I'm feelin' so much better,
I could cakewalk into town