Chassis hardware thread for the Eric amps community

[Randy Bassinga]

I wanted to share some designs that I have been working on towards a dedicated standalone chassis for the FFAxxxx series of amp modules

First up is a mounting plate for the FFA001 module. This one is designed to be 3D printed and can be fitted inside a chassis or into active speakers, including instrument amps

Single fan

Dual opposed fans

Fasteners are M3 with the thread printed into the mounting holes. For instrument amps, M3 threaded rods are needed or long bolts if you can find them. The module is fitted inverted with the PCB side up. A 5mm standoff should be placed over the holes, and this will hold the module down and provide a receptacle for a matching metal sheet as screening cover. This isolates the heatsink which is elec active and protects the module entirely

Still double minded about the standoffs. I might do a version without them and instead use 50mm metal ones. This one is for tomorrow to solve

The back of the mounting plate inlays the fans and has allocation for air filters. Mounted inside a narrow chassis, the dual fan version is optimised for air flow around the module components

This is my priority project, so will soon upload the STLs for more parts such as custom speaker terminals and panel inlays, as well as a chassis that makes provision for a tube linestage for this class D module. Hope the community finds the plate useful and guys, share your custom creations here too

 

[Randy Bassinga]

A teaser for the chassis, inspired by the Indian paisley. The flat bit is where the tubes would poke out from. A roll of polished perforated metal sheet will roll over the tubes to form a shield. Will be a mix of printed and machined parts. I printed the dual fan version of the plate some months back, but the standoffs at those settings snapped. Hence, the recommendation for through bolting. My printer has been in storage since then due to renovations, but I just finished the new cabinet for the CNC and done the framework for the printer cabinet. This thing is huge and can do 40 cm3 prints

 

[zei]

Cool design!

 

[Erica.C]

Nice design, thanks Randy~~

Put an advertisement here

Link the FFA amplifiers in below,
https://www.diyaudio.com/community/threads/2x150w-amp-module-for-sale.388868/

Thanks,
Eric

 

[Randy Bassinga]

Cool design!

Thanks

 

[rrobot]

module is fitted inverted with the PCB side up. A 5mm standoff should be placed over the holes

Nice one Randy! 🙂 Is it crazy of me to think i could print then invert your orientation and have the board upright and fans on top as a kindof cooling shroud over the heatsinks, and then use short metal standoffs as normal to bolt/secure the board through the case floor?

 

[Randy Bassinga]

That should work but I’ll need to check for airflow when I get home later today. The plate relies on the gap under a chassis created by equipment feet height and the resistance of two different temp airflow to mix. The non printed standoffs version can mount the module either way but screening over would be more work. Maybe try the way you described and see? Can always snap the standoffs off if that doesn’t work

 

[Randy Bassinga]

Nice one Randy! 🙂 Is it crazy of me to think i could print then invert your orientation and have the board upright and fans on top as a kindof cooling shroud over the heatsinks, and then use short metal standoffs as normal to bolt/secure the board through the case floor?

Ok
Single fan version, block the rectangular intake slot. Set fan phase to exhaust, firing out and up through the chassis top panel slot. Or, print a matchbox duct from fan output to a cutout on the rear panel. Will need side panel vents in the case for this to flow right

Dual fan version, set both fans to exhaust and port same as above

These are tiny wafer fans and the purpose is to assist flow, not forced spot cooling. The module doesn't need anymore cooling than that during Qld summers when fitted into a small active cab within a dedicated compartment

The dual fan one will setup a weak twin cyclone inside a compartment (not too big a case) and help cool other stuff in the case too by removing the air already getting heated up and injecting fresh air. Spotlight sells a fabric that will allow good flow but trap lint. This is my biggest enemy in my local humid conditions. The filter fabric just needs replacing whenever and costs I think $16 metre meter length and 25cm is the minimum purchase. The material is organza

 

[Randy Bassinga]

The paisley case is the long road. Lots of development work to get it to Sept born levels. In the meantime, I need a stand alone poweramp to mess with all the upcoming speaker funs. This amp will need to sit on a shelf next to a Yamaha MG12UX mixer and another shelf with digital mixers and an electric bass on the wall. Not a place for an all metal Hi-fi case or a PA type work chassis. This unit is installed and not expected to be mobile. Also has to be quick, easy and not bit ticket

At the moment I am considering a blend of home hobby CNC'ed aluminium and wood as well as loads of colour and all in a very glassy appearance. I have some thoughts on this but ran out of time today to take it any further

Tentative specs, 200mm x 180mm x 60mm overall, not including feet. Basic wooden sides but finely executed finish, glassy look on the wood but silky feel and not grabby or plasticy. Mirror front panel and coloured top, or vice versa. Gold, silver and wood feet

This thing should be highly module, and during a conversation on this today, I remembered my reasons for hating regular type chassis. It would be cool if this designed to be basic thing turns it nose up at things like working inside a cramped chassis and horror drillings. Let's bring in some enthusiast PC mod scene thinking to this

 

[Randy Bassinga]

This thing should be highly module

The previous update had some typos. This meant to say highly modular! Sorted out the approach to the basic chassis today. Keeping the 200mm x 180mm x 60mm and maybe around 26mm feet height added to that

Today's loot! These are the main chassis components. The wall thickness for the plate is 2.5mm and the channels are 3mm. The stainless rings are 1.6mm wall. This will be on the strong end of audio cases, and we will focus on a showroom level finish while keeping to very basic systems

It's my daughter's 11th today so we are heading out for dinner but will hopefully get to continue with this on return

 

[Gill.T]

Keep the forum posted on the chassis development and loads of wishes to your daughter and your family. Wishing her good health and happiness?

 

[Randy Bassinga]

Thank you for the kind wishes

 

[Randy Bassinga]

Looks like the shop gave me 3mm plate. I don't mind the extra 0.5mm as 3mm is good thread depth. This is still very much just trying ideas. Haven't drawn a line on paper or CAD yet. I feel the whole case can be completed without any digital studio involvement to a very high level of fit and finish, but let's model it and see if anyone has any ideas to try out in a virtual environment

 

[Randy Bassinga]

Here is the spirit of the Silver Lady chassis concept, named after a beloved offshore plate alloy workboat operating in Hervey Bay back in the day. This can be resized to desired channel sizes and plate thickness. My CNC allows 300mm x 180mm, so I am able to make a longer version for some of my other projects too. For FFA001 standalone poweramp project, the model is set to 200mm x 180mm x 66mm not including feet

FFA001 Studio desktop amp basic chassis build - Bassinga 300 Home Stage
I see the openings as the front and back panel locations and the channel sides decorated with wooden trims. The fore and aft panels would cap the body and trims. Master volume and main switch inlaid into the front panel and Erica.C's input module connectors plus my custom copper banana sockets inlaid into the rear panel

What is best as the power input? A mains connector or thru panel cord with a mains male plug? Two or three core/pin? Best practices for fuse?

This one? Model this into the back panel?
https://www.aliexpress.com/item/327...ui4LNTFh&utparam-url=scene:search|query_from:

The finished chassis will have to look the part next to the music instruments but carry its own looks. A build that doesn't look like colour thrown on depends on balancing and terminating colour effects. The planned scheme is purple cut with gold and terminated with silver for the front. Wood grain under glass look for the sides, terminated by the silver and gold of the front. Glass black with popping red cut with gold and terminated with silver for the back. The top, first, will try gold pearl cut with purple and silver. Under chassis might end up being silver. Inside chassis, gold cut with silver and terminated with gloss black


For the FFA001 users, your thoughts on locating the module inside? Offset to allow some space for any front ends? Symmetrical? How has your experience been? The air flow for this chassis will be base panel inlets and rear panel outlets with dual 40mm x 40mm x 5mm fans with cross chasiss flow, for now

 

[Randy Bassinga]

Today, I will get a chance to grab some fasteners for this. As a personal challenge, I am thinking of doing the first iteration as a continuation of by the eye and with a drawing in MAD (mental assisted design). Let's explore what results can be had by some basic dimensions in held in mind, a trip to Steelrite, Spotlight and Bunnings. Let's call this stage 1

We will do a quick and easy type build with off the shelf parts first as stage 1, get the amplifier operational and in use. It's being kept totally modular, so any and all bits can be replaced at any time. The chassis so far also meets what I need from the paisley design, so this will the path to its evolution. This "Silver Lady" chassis will be built as a case for the FFA001 first. Then as a case for Erica.C's other modules. I am considering an "andu" HT system with multiple channels of 120w for 8R full range drivers and multiple channels of 300w for 4 or 8R subs. This would use multiple FFA001 H/B modules stacked on their sides. Another upcoming build will be the EL34 amp kit that I recently picked up

I might also use this case for making a battery bank for the amphibious gokart. I have decided to learn and add aluminium welding skill set to get better results from my projects

Still trying to figure out the best mains power input. Another questions is, would there be any benefit to using copper foil for screening, non-metal parts? Is foil from another metal better?