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

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#781
Hi Guys,

I'm looking forward to getting the boards too! I haven't received a shipping confirmation yet, but hopefully I get one tomorrow. I was crossing my fingers that I'd get the boards in hand before the weekend, but if they ship late tomorrow, there's a good chance they won't make it here until Monday of next week 🙁

I've ordered single quantities of all the parts I need to build one of each board and test it, so I should be able to power through the construction and testing part of things in a few days. Once I'm done that, I'll start officially accepting payments.

Another piece of good news that I posted in the amp thread but neglected to post here is that I ordered more panels than I was expecting (due to a price break just above the number I was originally planning to order) so I now have 50 of each type of PCB.

For that reason, I'm going to re-open the GB until the extra boards have all sold. This includes kits or just PCB's. As usual, just make a post and let me know exactly what I should put you on the list for. Once the board count for any given type hits 50, that type will be sold out.

idjoel2000:

Everything you have on your list there will be perfectly fine. None of the resistors dissipate any appreciable power, and those caps in X7R will be perfectly fine.

Regards,
Owen
 
#784
Hi Bill,

No troubles, I'll keep track of it 🙂 If you want me to refund it in the mean time I can do that, but I figured I'd just let it sit until everything is ready to go.

Let me know what you prefer.

Regards,
Owen
 
#786
Owen needs no help to be prolific, he's probably got a bevy of interesting half done projects ready to go. I didn't have anything to do with this one other than pushing for a balanced build here and there given he and i use balanced sources. no it was the balanced input, lme49830 driver lateral mosfet power amp he needed a little kick in the ribs to do and its been crazy popular!! i had a lot of the parts for both of these builds already in my parts bin, so it was either beg the gerbers and get my own pcbs done, make them with my laser printer, or encourage a proper pcb run.
 
#790
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
 
#793
opc said:
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
Click to expand...

thank you for your explanation, owen. you put my mind at ease 🙂
 
#794
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
 
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