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

[qusp]

ahh my mistake, you were talking about the psu. probably only 2 layer, but then i defer to the above. the blind blackgate love for any position confuses and frustrates the hell out of me

[opc]

Nope, even the PSU is 3 layers on a 4 layer process!

Cheers,
Owen

[idjoel2000]

Originally Posted by opc

idjoel2000:

The price was dropped down to $35 after I noticed an error on my price list.

There is no transformer included with the supply.

A lot of the cost is tied up in the fact that very good quality parts are used on the board. If you look at the price list, it's a collection of parts all hovering around the $1 mark, and it all adds up. The heatsinks cost a few dollars, the solid polymer caps on the output and the expensive Panasonic caps on the input. I could have brought the cost in at $20 if I cheaped out on absolutely everything, but it wouldn't have worked as well, and that's not the point of these builds. If that is what you want, then you're best off getting just the PCB's and buying low cost parts to build the rest. You can even omit most of the parts on the PCB to keep costs low. Just looking off-hand, you could probably build one up for $20 including the cost of the PCB if you were frugal.

A big part of what I've been trying to do with these builds is bring some engineering common sense to the parts selection. The parts I've selected for these builds are expensive compared to run-of-the-mill parts that might be used in mass production, but they're comparably cheap when you put them next to "audiophile" parts. Just a pair of Blackgate capacitors for the two input caps would cost you as much as the entire supply costs, and from a technical standpoint, they would be worse than the Panasonics and I can prove that to you with a ripple measurement. The same applies to the resistors I'm using. They have extremely tight tolerance and extremely low TCR which means they perform very well, especially in balanced applications where the tolerance really does matter. As a result, they cost about 47 times more than a comparable thick film 5% part would (47 cents vs. 1 cent) but they cost 40 times less than some of the boutique resistors I've seen around ($20).

It's all about getting the most for your money, and picking the best parts for the locations you need them. It's also about understanding exactly what makes a part "good" and not just going by the reputation it has.

And as always, if you completely disagree with the above, you're free to just buy the PCB and chose to populate it with $600 worth of parts, or $5 worth of parts. All three options will provide you with a good regulated power supply, and at the end of the day, that's really what matters most in terms of performance.

Cheers,
Owen

thank you for your explanation, owen. you put my mind at ease

[qusp]

3 layer coolness!! helps keep it nice and small too

I don't know that i would call foils boutique if thats what you are talking about, utter overkill for the application? perhaps, but in this balanced build i will be for sure using just a few, they are actually 8-12 each for the smd version custom specced to exactly the value you want and the comment above you mention about tcr and matching goes double for these parts as they are the very top of vishays development in this regard, totally non inductive, lower distortion even before the tighter matching is brought into it and stable across frequency and temperature. i bet you could measure the difference even vs the very nice parts you have chosen already.

they are the only exception i'm making to your mom apart from the bulk decoupling caps on the board, which will be replaced with lower voltage SMD panasonic polymers simply because they are low profile.

speaking of which opc, did you do any testing at lower voltages?

i'll have +/- 6-7vdc available. they'll be driving a pretty low impedance load and I've read of them getting a bit squirrelly under those low load impedance, low supply conditions. so that they become quite imbalanced on the positive and negative swing. any chance you could dial that in for me when you are doing your testing? the sort of imbalance i've seen reported (although at lower voltage than what i'll have) resulted in 1-1.5v difference which could make for enough offset to kill my jh13

[dggs]

Hi Owen,

Please "add" the following to my existing order:
BAL-BAL PCB x 2
BAL-BAL KIT x 1
PSU KIT x 2

Thanks,

[igor0203]

If you have any boards left, please add me for:

SE-SE Stereo Kit x1
PSU PCB and all parts x1

Regards,
Igor

[sek]

Hey Owen,

Originally Posted by opc

I'm going to re-open the GB until the extra boards have all sold.

In that case I'd like to upgrade my order to two sets of PCBs total:

2x PCB: BAL-BAL
2x PCB: PSU

As of my understanding this leaves me with boards for two PSUs and four balanced amplifier channels (i.e. two headphone amps). Right?

Cheers,
Sebastian.

[qusp]

yes, but ideally you should use 2 x psu for a single balanced build i would think, although i remember opc saying the difference wasn't as great as he thought it would be

[jdkJake]

Owen,

Please bump my order by another PSU kit.

This brings my order to:

2 SE-SE kits
1 BAL-BAL kit
4 PSU kits

Thanks Owen! Looking forward to the build.

[Bill Wilson]

Hi Owen: Sent a PM but have not hear from you. Need your paypal address to send funds or other method of payment.

One amp. Kit & One PSU

<eandwsvcs@embarqmail.com>

Thanks
Bill Wilson