My Babelfish J Monoblock Project

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A little over a year ago I started building a pair of amps based on Zen Mod’s Babelfish J boards. These amps were built to install into my console project so the case was a pair of used telecommunication boxes since they wouldn’t be visible. Ugliest amps ever;

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After I decided that I was never going to be happy with the sound from a smaller speaker cabinet I remodeled the cabinet and deleted the speaker/amp areas on each end. I love the cabinet in its new form, and I love the performance of the amps, so new proper cases are the order of the day.

I used 5 of the China/ebay Pass Lab look a like heatsinks per amp. But for the rebuild I’m upping to 6 per amp.

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I originally started down the road of building typical Class A case, 3 sinks down each side, all aluminum case. But it takes up so much floor space, so looking to stay vertical. In my first F5 build I had heat sinks stacked on top of each other and lots of criticism over the effectiveness. But my amps now, have less than 2 degrees Celsius difference between the top row and the bottom row. Maybe the gap between and minimum connectivity between helps?

Anyway, I ordered up some double milled Medex and went to work. Since I have access to such serious woodworking equipment I just have to take advantage. Some of the cabinet makers there have become friends and enjoy discussing HiFi and help teach me tricks. After I cut and mitered the perimeter frame I laid all the pieces together in a straight line as they would be attached. Put tape tight across the miter, carefully roll everything over, keeping in a straight line, then spread the glue. Then start at the end and raise the first piece closing the miter and keep going. Tape the last corner, spread glue to the perimeter miter and drop on the back panel.

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If everything is cut right, you end up with this and no nails or fasteners.

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To shield the Medex some from the heat in the cabinet I lined it with laminate.

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The cabinet and the front panel sprayed with the first round of primer

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I ordered back panels from Panel Express. Then set up to recess it.

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And today I received the nameplate for the front. If everything goes well I will spray out with finish this weekend and start the rebuild.

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Thanks for the positive comments guys!

I had routed the front panels before the front faceplate arrived, hopeing that front panel express was consistent in making what you order exactly. They didn’t disappoint. Will look better in black though!

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Back panels have some new parts, some parts will come over from the amps. Also proper support and feet.

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Thanks vdi_nenna, Dennis Hui, Zen Mod, dBel84 for the positive comments and encouragement.

I’m really excited to get to the next step of assembly. Hoping the vision I have in my mind will be successful in reality.

After spot putty and sanding, another round of Primer. I’m using all professional automotive products. Chromax 2k high build primer. Works better on steel than wood because you can wet sand on metal, water and wood don’t work so well together! Medex is more moisture tolerant than almost any other wood product, but don’t want to take any chances. So the sandpaper fills quickly and you have to keep blowing off the dust with compressed air. Its worth the time to get to a glass like finish, if I’m lucky.

Tomorrow a final sand and then paint.

A couple progress pics

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Painted

Everything went well today. Spent 5 hours sanding and another hour spraying. Perfection takes time!

I block sanded the primer by hand with 320 grit, then partial by hand, partial by orbital with 600 grit.

The paint laid down like glass, does have some specs of dust, they will come out with color sanding and buffing tomorrow.

Pics make the paint look bad because of the distortion you see reflecting off of the ceiling.

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Ran over to the cabinet shop and picked up the freshly painted parts early Sunday morning and spent the day wet sanding and polishing. Now that 100% of the wood was sealed I felt comfortable wet sanding, but still kept everything as dry as possible. Paint came out great, like a black mirror!

Today I spent some time installing the feet, face panel attachment, and cutting the openings for the rear connectors.

In the current build I have 2 1/2 heat sinks top and bottom. This time I’m increasing to 3 heatsinks top and bottom. So I have 4 new ones here so went ahead and mounted three up on the 10” x 16” x 3/8” aluminum backer plate.

Here are some pics to give you an idea how they are going to look.

I’m about as far as I can go without killing Babelfish #1 for parts. I guess that’s up for tomorrow. Listening to them now, hate to have them down. Who knows, with matched mosfets and source resistors, increased bias due to larger heatsinks, maybe better performance and looks! Who knows.

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This old topic is closed. If you want to reopen this topic, contact a moderator using the "Report Post" button.