"The Wire" Ultra-High Performance Headphone Amplifier - PCB's

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A

AndrewT

R.I.P.
Joined 2004
Er, that should have been 5 Watts into the Sennheisers.
Remind me not to read my notes and graphs too early on a Saturday morning.
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No.

2.3Vac as measured by the Pano Test is the predictor to maximum power for an 8r0 load.
i.e. one measures 2.3Vac
Then the maximum power that the amplifier would ever need to deliver into a 8r0 test load would be 2.3² = 5.29W into 8r0.

But your headphone is 600ohms, not 8r0.
The maximum power delivered to the 600r dummy load is (4*2.3)² / 600 / 2 = 70.5mW (+18.5dBmW)

i.e. if your headphones are 90dB/mW, the maximum with a 0dBfs signal would be 90+18.5 = 108.5dB
 
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H

hochopeper

Member
Joined 2009
opc said:
Given that you have a 50VA transformer, and you live in Australia, the land famous for its very high mains voltage, I'd bet money that you're well over 15.5VDC before the regs.

It's still worth checking, but I'd be surprised if it was an issue.

If it is a problem, let me know and I can send you some resistors for the cost of lettermail, which should only be a dollar or two.

Cheers,
Owen
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Owen you're very generous! I'll sort aive out for resistors, I'm ordering some box enclosures from e14 this week and I'm probably going to see him next weekend.

Regarding high mains voltages .... well only at times ... I've seen some distribution transformers with voltages that fluctuate 230V - 250V over the course of a day with everything in the network as 'normal'. There might be a km or so of LV circuit off the end of that.

aive said:
Haha thanks Owen that'd be awesome.
Click to expand...

You only need 2 resistors ... check the BOM. Owen's done the math for you so you only change the resistors R30, 55. My spreadsheet says 13V output and ~500mA load is okay for anything from 220V (230V - 4%).

Anyways, yeah ... sent you an SMS about next weekend.

Chris
 
tribbs

tribbs

Member
Joined 2011
Bal-Bal Potentiometer

Another novice balanced inquiry, please...

I will be using a 10K Quad stepped attenuator for the Bal-Bal Wire.
(I didn't find a discussion here specific to a Bal-Bal pot implementation.)

What R values should be used for R21, R22 & R23, R24?

Do I short (0R) R22 & R23 and change R21 & R24 from 1K to 100K? (10 x 10K?)

Where exactly do I connect the pot's input and output? :eek:
 
R

rondr

Member
Joined 2011
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R

rondr

Member
Joined 2011
tribbs said:
Good to know.
You're also using an attenuator in the Bal-Se?
I have the Bal-Se to build in the wings...
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Yes. I used another 10k Gold Point attenuator in place of R3, 4 and R9, 10 on the Bal-Se board from 3 or so years back. Somewhere in one of The Wire threads is discussion about omitting the input resistors on the Bal-Se when using a pot or attenuator but not so sure where to find it. These threads are getting so long and hard to find info them. Here is the build I did on the Bal-Se at post #191. http://www.diyaudio.com/forums/head...hread-impressions-gallery-20.html#post3118326
 
D

dfreemansc

Member
Joined 2004
Thanks Owen, much appreciated.
I'll give local people a bit of time to respond, then get back to you.
BTW - I know its been said before, but the boards are amazingly good!

In fact, stuff it - I still get excited when I get an envelope from abroad, can I take you up on your offer please?
Let me know postage cost & I'll Paypal across to you.
Have you still got my address from the board order?
Thanks again
Dave
 
A

aive

Member
Joined 2013
So I've built a couple of The Wire's, one SE for my dad, and one BAL-BAL for myself.

I am amazed at how good the amp sounds (particularly the BAL-BAL since that's the one I've spent the most time with) - awesome job Owen :)

I was initially concerned with "only" having a gain of 1, but it is PLENTY for my LCD-3Fs. Note, I am driving the amp from balanced output of Audio-GD M7 DAC. I was also concerned with the stigma associated with "eew op-amps, chip audio, etc" but I think the audio quality from The Wire is just as good if not better than my other discrete amps.

In comparison to my Headamp GS-X Mk2 (Kevin Gilmore based design) and Kevin Gilmore Dynahi (DIY amp I built last year with ABM sigma-22 PSUs), The Wire sounds just as good if not better - The bass slams just as hard, and I also think it has more resolution throughout the full range bass to mids to highs (airier, crisper, more resolving), but that could be just my poor audio memory and "ooh shiny new toy" thinking.

I actually wish I found and built your amp much earlier and saved my pennies instead of buying the GS-X...

Plus, The Wire is TINY!! Still can't get over how compact it is. I did curse your name a few times though Owen while soldering the interconnects, sorry :eek: Man I wish there were headers/connectors for those for noobs like me :D

Plus, plus, I also learnt how to solder SMD by building your amps, and it's actually quite enjoyable.

All round, a great experience, and again, awesome product :) Thanks for your contribution to the DIY community.

Going forward, I got a couple of cases coming from modushop for the amps and I've gotta tweak the PSU resistors for 12 VDC output (hochopeper is hooking me up with those).

Hochopeper also keeps talking up your upcoming DAC, so I'm going to have to get that too when it's available. I'm currently wary of delta-sigma DACs (prefer R2R), but I've learnt that negative pre-conceptions don't really apply to your designs :p I'm still planning to get a Schiit Yggdrasil when it comes out, so I'm keen to hear how it sounds via your amp - the hype re the bit-depth and accuracy of its DAC chips + secret sauce filter has got me hooked.

Ok I think I've gushed enough. I'll post some piccies up of my build when I get some time (maybe I'll wait till I get them in a case) :) Thanks again Owen :cheers:
 
M

mcluxun

Member
Joined 2010
mine is coming along.
jd4CWOo.jpg

BAL/BAL with diyinhk PSU,
Bud industries 2U case
 
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