DIY Enclosure/Cabinet for PowerAmp & PreAmp

[captrajesh]

Hey Bibin, what are the dimensions and how much did it cost?

 

[bibin3210]

Hey Bibin, what are the dimensions and how much did it cost?

Hi Captain,

The chaise is build using 19mm square tube, 1.2mm CR sheet for Top and bottom covers, 6mm acrylic panel on back and 12mm+12mm acrylic panel on front.

External Dimension
460 x 430 x 203 (W x D x H)

Internal Dimension
300 x 430 x 203 (W x D x H)

Cost Appx. 15K including Heat Sink


Thanks,
Bibin

 

[Santy]

Interest check:
I am planning to sell my B1 since I am not using it. Infact I never used it. It is working great except for selector. I have a spare selector board and parts but I am not getting time or inclination to complete it.

I cannot use my B1 because it will become the third preamp in the chain. What price should I sell it for. Should I complete the selector section and then sell ? Just wondering. I don't want any premium for DIY efforts can I ask for the price of parts only.

 

[linuxguru]

Finished building cabinets for F5 Turbo using N56 heatsink. Cab alone weigh around 25Kg.

Amazing F5 cabinet - Kudos!

FWIW, I managed to have an aluminium cabinet machined locally in Chennai which is similar to the 8Audio cabinet (from EBay):

The original 8Audio cabinet (on the left, with electronics installed) is about 210mm x 300mm x 90mm, while the locally made one (on the right, empty) is larger at about 300mm x 300mm x 100mm. I used countersunk CSK profile stainless-steel Allen-head bolts to fasten the top and botton panels to the side panels:

The exercise was mainly to determine the capabilities/limitations of the machine shops and hardware resources in Chennai. The good news is that it can be done, but requires some supervision. The price is comparable to the landed cost of the original cabinet (including shipping, etc.). However, significant further work has to be done after machining to improve the finish (mainly wet sanding with emory paper to remove scratches, blemishes, etc.) and painting/anodizing (optional, I omitted this).

The costing can be optimized a bit by using stock extruded heatsink panels as the side panels, and using a flat front panel without any ornamental profiles.

 

[Anil kumar]

Nice enclosure siva it needs milling for sharp & accurate edges.


Regards,
Anil

 

[linuxguru]

Nice enclosure siva it needs milling for sharp & accurate edges.

Thanks - yes, it still needs further finishing to remove some burrs in the slots, as well as wet sanding of the front panel to remove scratches/blemishes etc.

The original 8audio case has a cast-aluminium front panel which has only slight milling/brushing done on one face (the area next to the knob). I tried to replicate that (including the 45 degree angles) using profile milling, but it still requires extensive finishing. I now think that a flat front panel is the best option - easy to mill, easy to finish, saves money, and you get to keep more of the aluminium that you pay for by weight.

To economize:

1. Use stock extruded heatsinks and mill/drill/thread them for the top/bottom panels and fasteners.

2. Use standard powder-coated top/bottom slotted steel panels from the power/switchgear industry (check dimensions according to the heatsink length and pick the next larger size, and have it cut with a bandsaw if needed). It's even more economical to use folded steel panels for all panels, if possible, like Raghunadh's Ampcamp chassis - maybe just the front panel can be aluminium/wood (like Rohitmusic's Pass B1 wood front panel), and bolted on.

(I used 8 mm-thick aluminium top/bottom panels and had the slots machined - expensive, and requires extensive deburring and wet-sanding to improve the finish.)

3. Flat front and rear panels - I used 8mm for the rear panel, but it can be reduced to 6 or 4mm (8Audio uses 4mm).

4. Use ready-made rubber or injection-moulded plastic bushings for feet. Custom-machined aluminium feet run to about Rs.100+ each, unless machined in volume.

 

[jls001]

@linuxguru: can you please elaborate on "wet sanding"?

I am experimenting with a small aluminium cab for the Hypnotoad AD 797 phonostage. The surface is rough and needs proper finishing. I went to a laser guy to etch the faceplate and rear panel, but I was told to fist paint/anodise/whatever first, then come back for the laser etching. I had a mind to coat it with primer and spray paint it.

 

[magma]

sanding is a killer
milling is a must

stamping is cheaper - but die investing

 

[linuxguru]

"Wet Sanding" is the use of waterproof emory paper (the ones with cardboard backing and dark gray abrasive surface) to smoothen/flatten a surface, either with a motor-driven sanding machine, or manually by hand. On aluminium and other metals, it helps to use water to maintain a liquid abrasive film while sanding the surface, hence the term "wet sanding".

Emory papers come in various grades from coarse to fine, denoted by the grit size/number, with a coarse paper being ~80 grit, to fine around 400, and very fine around 1600 to 3200.
Usually, it helps to sand the surface with coarse paper to get rid of the major scratches/blemishes, and then with finer papers to get a smooth, flat finish. In practice, you can use 80 and 400 grit papers on aluminium panels, and go with even finer grit papers if you want a mirror-like finish (not really required, since it tends to show fingerprints and scratches easily).

After wet sanding, you can give it for black or silver anodizing, etc. I personally think that paint covers the best quality of aluminium, namely diffuse shine, and should be avoided if possible. However, clear lacquer sprays mentioned earlier in the thread may be a good option after sanding.

 

[linuxguru]

sanding is a killer

Yup, absolutely correct - it's a lot of work. It took about 2 weeks to refinish all 12 flat surfaces of the 6 panels with 80, 400 and some 1000 grit emory, followed by an acrylic clear coat to protect the finish from oxidizing back to dull grey-blue. Pics show the re-finished cabinet (with electronics installed - this is a Jim's Audio Symasym clone kit obtained from EBay a few years ago) :

I probably won't repeat this approach exactly the same way again, but may do future cabinets with just 1 or 2 milled & slotted aluminium panels (for rear and/or front panels only). However, it's been a useful learning experience.

Tip: If you want to paint aluminium with an opaque colour like grey or flat black, use Zinc Chromate primer followed by aerosol spray paint. You can use acrylic clear coat if you want a gloss finish over the opaque colour. The acrylic clear coat is fairly tough and can be wet-sanded using a fine grit emory like 1000 or 1200 grit, or polished using a variety of car polishes and wax polishing compounds. Aerosol spray paints are the most convenient approach for a DIY home-builder to get a high-quality finish at a reasonable cost, without investing in expensive spray-painting equipment.

 

[auxie22]

I apologise for resurrecting an old thread but the main reason I did is to see if Bibbin is still taking requests for his B1/F5 chassis. I tried PM but it doesn't seem to be an option.

 

[bijinmb]

I apologise for resurrecting an old thread but the main reason I did is to see if Bibbin is still taking requests for his B1/F5 chassis. I tried PM but it doesn't seem to be an option.

Hello auxie22,

A new revised version of power amp cabinet, DAC cabinet (mainly optimised for ODAC and O2 from JDS Labs) and pre amp cabinet is in pipeline and will be available by the end of next month.

The Power/Pre AMP cabinet will be in aluminium and the front (acrylic or wood) and back panel (acrylic) can be customised as per requirement.
The DAC cabinet will be in a single chunk of CNC carved wood and its back panel (Acrylic) can only be customised as per requirement.

 

[baswamin]

Bijin,

So we cant order the B1 cab now? Will that still be available?

Thanks

 

[bibin3210]

Bijin,

So we cant order the B1 cab now? Will that still be available?

Thanks

Few more B1 cabinets are available.

Thanks,
Bibin

 

[bibin3210]

DAC/Headphone amp cabinets are ready and posting few images of the new cabinet for ODAC:

Thanks,
Bibin

 

[omishra]

Keep it up Bibin and Bijin. This is quality and I personally like it. PM'ed.

 

[Kittu]

@Diyaudiocart team,

No words... Just respect..... Keep up the great work. :clapping:

 

[hydra]

Really beautiful cabinets guys! You should promote these on the international forums too. I'm sure there will be a lot of takers.

 

[grubyhalo]

Classy and gorgeous!

 

[nraghunadh]

Looking beautiful,
Very impressive finish, I don't have any DAC yet.
Now i have decided to buy one ODAC for this cabinet.

Thanks
Raghunadh