Unfortunately, as Lehmanhill says, Duelund is quite mean about tech details - but their gear usually sounds very good.
That is what i can find:
Resistors – Duelund Coherent Audio
Duelund Standard Graphite Silver Resistors | Hifi Collective
Duelund CAST Graphite Silver Resistors | Hifi Collective
Not much, in facts...
About the bunch, they should work WELL below max. wattage here, and in very low values, so TCR should not be a big problem, IMHO.
But i didn't notice Jantzen and Duelund ones start from 0R47, that would lead to paralleling and they're BIG...
Mundorf res are very little inductive, but maybe this little defect could be largely balanced by good SQ, that some other less-inductive technologies may not have.
But Tx221z look really promising, i didn't know about them. I think they're the first to test, then!
I may give the Ohmites a try in my next build. I'm planning to populate another set of boards identical to my first set so I can do some direct comparisons at some point. I guess it would help if I fixed my first boards though. 
Haven't gotten around to that yet.
Jac, your R11 question is very intriguing.
Haven't gotten around to that yet.Jac, your R11 question is very intriguing.
Absolutely! The Quad gives you a bit better distortion, in theory, but that is picking nits. One thing with SMD resistors in a power role is that you need heat transfer away from the chips. They may say it's rated at 1W or 2W, but that is assuming you manage the temperatures to their spec. That will often take a heat sink.
Actually, this is true of axial power resistors too. When I first tried the Quads in a 15k version for another project, I compared the Quad to a Vishay CPF 3W. I soldered each of them to a proto board and put 1W rms across the resistor. The Quad 1W with a 15 x 30 mm board had a temp between 30 and 35 deg C. The axial CPF was running at 66 deg C with 1W input. There was no possible way for it to reach the specified 3W.
Jac
I don't know the theoretical details, but apparently distortion is strongly related to power across a resistor. And multiple resistors are not additive. So 4 resistors in series/parallel connection are each running at 1/4 the power of a single identical resistor or -12 dB distortion from a single resistor of the same value.
My assumption is that 3 resistors in parallel would be running at 1/3 the power, so -9 dB,but that may not be correct on second thought because each of the parallel resistors would be of a higher value and that might affect it.
If you are up for it, you can read more in the paper at this link. Look for the "passive components" section on page 23 of the pdf.
http://www.nanovolt.ch/resources/low_distortion_oscillators/pdf/low_distortion_oscillator_design.pdf
I have also read that you can show this distortion effect with a good spice model, assuming the resistor model covers distortion.
Of course, I can't say that I can measure the difference, nor that I can specifically hear the lower distortion. What I can say is that the measured data and theory suggest that Quad resistors should be an improvement in performance. Even more important to me is that it allows (as does your suggestion of 3 parallel resistors) the possibility in power resistors of getting away from resistance materials (metal-Ox and thick film) that perform less well than metal film and foil. I can also say that, in my experience, they sound cleaner whether that is distortion, noise, or something else.
By the way, you may find it challenging to buy 2W metal film/foil SMD resistors. It seems that 1W is available, but many times higher wattage is in the catalog, but not available.
I hope I answered your question.
Jac
Thanks Jac. My intuitive understanding is that a larger resister will dissipate more heat. I did some searching for different values, and 2watt 1ohm is available from Mouser. My main attraction to doing it this way is to work with a slightly larger part - I don't enjoy fiddling with tiny SMD stuff.
Dan
Dan
Dan,
In my opinion, you will get most of the advantage of the Quad resistor as long as you can use a nice thin film or foil. I think a lot of the difference is in getting away from thick film materials.
I'm not sure if these are the parts you were thinking of, but they might work out well. A variation on what Dario had suggested, Vishay Dale Power Metal Strip resistors, this time in the WSR series. They don't really say what material is used, but its likely an improvement on thick film.
WSR21R000FEA Vishay / Dale | Mouser
Pretty big though. Make sure you have a lot of heat transfer surface area to put the heat into the air.
In my opinion, you will get most of the advantage of the Quad resistor as long as you can use a nice thin film or foil. I think a lot of the difference is in getting away from thick film materials.
I'm not sure if these are the parts you were thinking of, but they might work out well. A variation on what Dario had suggested, Vishay Dale Power Metal Strip resistors, this time in the WSR series. They don't really say what material is used, but its likely an improvement on thick film.
WSR21R000FEA Vishay / Dale | Mouser
Pretty big though. Make sure you have a lot of heat transfer surface area to put the heat into the air.
I checked again on Mouser, and you are right, the 2watt version of the Susumu is out of stock, so the Quad 1watt it is. I'll probably imitate your layout for the copper clad board as well.
The improvement you describe reminds me of what I heard when replace RN55s with Z-foils, so excited to do this mod. It'll probably be a couple of weeks though.
The improvement you describe reminds me of what I heard when replace RN55s with Z-foils, so excited to do this mod. It'll probably be a couple of weeks though.
It is interesting though. After reading the diy article, I can't help but imagine somebody at Dueland listening to different hardness pencils to find out what works best. I am guessing that they chose the very hard 5H because it has less clay.
Given the explanation of pencil graphite in the diy article (below), the manufacturing process is very close to carbon composition resistors. I would guess that they sound something like the Allen Bradley comp resistors which are prized in certain valve circles.
GRAPHITE RESISTORS
Resistor Guides discussion of how carbon composition resistors are made.
Carbon composition resistor >> Resistor Guide
Jac
