Discussion in 'General Audio Discussion' started by velvetx, Oct 29, 2015.
Give us all the build pics and parts list for sure!
If the price isn't listed, it probably means you can't afford it.
Will do - might be another week or so; waiting on some M6 hardware, but I'll put together a BOM + notes.
Are there any features in particular to look for in a good rack? Mass? Solid wood?
The one feature I want for sure is open on all four side for ventilation
dunno whether it is wrong but it looks fake. I prefer a well done rack to a fake one:
The Salamander Designs A2/M Archetype Series Stand has been great. Easy to put together, sturdy, highly adjustable.
You need strength for big heavy amps, stability/mass for turntables, open sides for ventilation, aesthetics for the sake of aesthetics...
Solid wood just happens to be a good fit for most of those, but frankly an IKEA rack or even a wire kitchen rack (with a couple cheap cutting boards as shelves) is perfectly fine as well.
It kinda depends on what mass/vibration scheme you subscribe to. There's kinda three different schools of thought:
Mass damp by way of coupling everything to something heavier
Couple everything to low mass vibration transmission devices/shelves/racks/stands to transfer everything into the floor (kinda the same as 1) but using lossless, low mass highly rigid shelfs/racks)
Decouple everything and create low mass vibration damping with constrained layer damping
so, depending on whats going on inside the component you're looking to isolate, for example, if it's got buzzy transformers, you might want to try to either isolate it with lossy footers, or mass damp it with spikes into a heavier mass.
Or, if it's something like a CD player/transport you might want to damp the vibrations from the unit by decoupling it from the rack.
Then, there's tube stuff, where the music signal played though the speakers might affect the output of the amp itself, i.e. feedback from the tube envelope.
it's really most dependent on the frequency of the noise you're looking to attenuate. Low frequency usually means either high mass and low Q, high frequency usually means low mass and high Q, or lower mass and medium Q.
Wow, that plate's got a hell of a rack on it!
Looks superb. Love the adjustability, and the lack of audiophool decorative components. I love this rack. I could just stare at it. Maybe sometimes touch it. I could <gasp> put my favourite equipment on it.
And whether or not one believes that cosmic vibration thing!
Oh yes, tube stuff. I always forget. One of the tiny number of solid-staters around here.
Turntables. Being able to play the music that a roomful of people are jumping around to. That's a challenge.
i use these myself, and completely agree. i bought one, and then i needed another, and then there was an empty level, which then had to be filled, and before you know it, they multiply.
Will be re-arranging my stuff soon. Does the Holo Spring 2 ever pick up noise from the Yggdrasil transformers? I am assuming the wood plank is just that and doesn't have any sort of electrically shielding or isolating material inside, etc.
On a different note, I don't like admitting this, and I do acknowledge that it could be indicative of possibly needing to refresh a component or two: I have two wood headphone cups made for the HE6se. I am not using them at the moment and placed them to the left and right of the input tube on the AF. And idk why, but the background became a little blacker. At first I thought it may be small vibrations in the case being damped or something similar, so I tried extra hockey pucks and other items in the same place - they too made a small difference, but not as much as these spare wood headphone cups. Tried this with different headphones on different days with different tubes and heard the same thing. Consequently, I'm going to screw around with different setups and "dampening" with spare materials since I need to rearrange things anyways.
EDIT: was just noise from the Yggdrasil that may have resulted in some kind of resonance or something - moved Yggdrasil much further away and the wood cups no longer make a difference.
Similarly, and this is more believable to me, but I tried extra sorbothane and "proper" vibration reduction materials under the AF. The pucks actually worked better for me in most cases.
I've yet to hear the Spring pick up noise from anything. The only noise I've heard in this system has been from wireless signals interfering with tubes when a phone is left in the room.
Okay folks! Almost all the parts have arrived (just waiting on adjustable stainless feet) so let's start the show.
First, nothing gets done without a plan, so here's where I started. I intentionally chose to work in metric since it (theoretically) should get me tighter tolerances on the cut parts from 8020.net. After I had a rough sketch, I went into whatever free CAD software I could find and pulled the dimensions of the extrusions from 8020, swept the profiles, then figured out my final dimensions for each set of cuts. They'll be included in the BOM.
First order of business is to drill out 12 of the 90-degree 20mm tabs to accept some M6 hardware. The existing holes are sized for M5. 1/4" twist drill = 6.35mm so there'll be a little wiggle room on assembly. And don't forget to deburr!
The next step is to tap the bottoms of the 4 40x40mm legs for M8 x 1.25 for the adjustable feet. Remember to use some lube, clean the treads after cutting them, and deburr the final bore!
Now, you can start assembly. First assemble the 20mm x 20mm shelf frames. Don't overtighten anything at this point, everything should just be snug.
Here's the reason why we needed to drill out 12 of the 20mm x 20mm 90-degree brackets: the M6 hardware I chose to use to attach the shelves to the legs is a little more sturdy than the M5 hardware.
Begin attaching the top shelf to the top of the legs by working on everything upside-down.
Add the second shelf frame!
Then the third shelf frame! Then, double check everything for squareness, and tighten everything down. It helps to have a 3 and 4mm allen bit with either a ball-end nose, or a 3/8" drive wobble extension. For the SS M5 hardware, tighten to 2 ft-lbs; for the M6, 3 ft-lbs. If I were really overdoing this, I'd add some blue Loctite everywhere during assembly.
Finally, add the self-adhesive load-rated sorbothane bumpers to the tops of the shelves, and you're pretty much done! Each bumper is rated for 3 lbs each, so add or remove bumpers based on how much the components on each shelf weigh. Each plywood shelf was lightly sanded to 320, then 3 coats of boiled linseed oil were applied with 000 steel wool in between coats. I'll post the full BOM and links to the various suppliers later this evening.
Edit: Feet showed up, so the rack is now in situ:
BOM and Some Notes
So there's any number of industrial supply houses that offer t-slot framing and all the hardware to put something like this together. I chose to use 8020.net for the bulk of the parts since it appeared they do a little better job at machining to an appropriate tolerance without really paying out the nose for it. And I've used them in the past and was pleased with their customer support, especially with smaller orders. I'll break out the BOM by supplier. Please note that for folks who lack power tools or a fancy shop, this should be as close to a hand-tools-only COVID-era delivered to your door type build as one could get. Also note that Craft Cuts offers a wide selection of materials for the shelves, so if you want to save a few bucks and use MDF, then go for it! You could likely get a cabinet maker to cut these for you for cheaper, maybe, if they don't charge you for a full 4x8 and use cutoffs, but using Craft Cuts was a bit of a test to see how they'd do. Also, note, I'm not an engineer, so I probably wouldn't go loading this rack up with 300lbs of $20k amps and a TachDAS Air Force One TT on the top. Use some common sense.
PN 20-2020 20mm x 20mm T-slotted Extrusion 690mm long x 3
PN 20-2020 20mm x 20mm T-slotted Extrusion 335mm long x 6
PN 40-4001 40mm x 40mm Mono Slot T-Slotted Extrusion 680mm long x 4
PN 12260 Cover Cap 40mm x 40mm, Cross = 7, 1mm R = 3.5mm; Slot 8 Cross DI
PN 14122 Slide-In T-Nut 9 x 9 x 3 M5 Clear Zinc x 48
PN 20-4119 20S 2 Hole Inside Corner Bracket x 24
PN 13065 M6 Slide-in T-Nut with Ball Spring x 12
PN 92095A207 Passivated 18-8 Stainless Steel, M5 x 0.80 mm Thread, 8mm Long (100 CT Bag)
PN 92095A224 Passivated 18-8 Stainless Steel, M6 x 1 mm Thread, 10mm Long (50 CT Bag)
PN 6301K87 Corrosion-Resistant, M8 x 1.25 mm Thread Size, 32 mm Thread Length x 4
PN 8215K9 Polyurethane, 3/4" OD, 3 lbs.Maximum Load, Soft x 24 (Use as many or as few as necessary per shelf to achieve the desired load capacity).
CraftCuts.com (direct link to the Square Cut Shape page)
Square Craft Shape Cutout
Material: Baltic Birch Plywood
Longest Dimension: 18 Inch
Shape Thickness: 3/4 inch
Square Craft Shape Cutout
Material: Baltic Birch Plywood
Longest Dimension: 23 Inch
Shape Thickness: 3/4 inch
In hindsight, I think the only change I'd make would be to double up on the M6 Slide-in T-Nuts and Corner Brackets between the legs and the shelf frames (one above the 20mm frame and one below) - I may still add those. Edit: I ended up doing this and it decreases the diagonal-racking a bit to the point where I'd feel comfortable putting a TechDAS Air Force One on the top shelf. Maybe.
That is one very nice system with complementary DACs and Amps. I'll bet you are enjoying a very synergistic auditory zen experience.
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