Impressive! I need to try it too.

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Kerry, you should make a few hundreds of those and organize a group sale

14 hours ago, Kerry said:

Thanks. 

You need to get Fusion 360 and learn how to use it    It's from Autodesk and is free to individuals and small businesses.  It took me about 3 hours to model these. 

 

 

Downloaded and installed Fusion 360. Have tried it for a short while (raining today). And maybe…. even me might manage to do something with it.

Thanks for the tip.

There is an ability to do community projects in Fusion 360, which I think is really cool.

For anyone wanting to mill foam, there are some precautions.  I had an issue with my initial tests when milling to close to the edge.  It grabbed a piece of foam and pulled it onto the bit.  Not good.  I used the duct tape on the one side to give it some stability near that edge.  Like everything in milling, make sure your work piece is secured well. 

Also, for clean final cuts you need to use conventional milling vs. climb milling.  This is opposite for aluminum.

Kerry's work with foam might be a good answer to replacing what's inside the 009 pads. At the very least you wouldn't be paying 250 for a pair...

I might implement a bootlegged version of this idea using old 007 foam . Thanks for the inspiration Kerry!

It would also be a good way of adding some much needed angle to the 009 pads. 

Here is my experimental approach to mounting TO-3 devices without the expense of machining angled brackets. Not the most efficient way to mount things, but maybe it will be good enough.

Oh, and yes that's the Harris logo. As it turns out, the IRF240 devices feature larger diameter pins that wouldn't fit in my PCB sockets. The '244 features the same diameter as the IRF9240 as it has it (if you can find them). I would love some Harris 9240 if anyone has a source!

how thick is the mounting bracket?

 

This is a pro bias to normal bias adapter I cobbled together. It's a self bias circuit that taps R+ and gets chassis ground through an RCA plug to the amp. Just to prove the point of how easily one can build a stax compatible jack I rigged this one together with some female XLR pins, hot glue and a piece of delrin. Take that Mr.Speakers!

how thick is the mounting bracket?

 

Your opinion would be great!

It's 6mm bracket, 0.375" copper and then the heatsink back is 8.5mm. Here is a photo:

How d'agostino ish

i would do the whole thing in copper, but that is stupid expensive.

make the holes in the copper a bit big to take care of the thermal expansion differences

Here is one more shot. I just sent off for the Teflon sleeving for the screws and pins.

Also a little lab case with some low distortion oscillators, that is in progress. Needed a bit more voltage swing at times than the QA401 could provide.

A shunt regulated power supply, with some daughterboards replacing the crappy voltage references I was using in the CCS.

 

I've finished this fantastic design of Mr. Per-Anders.

 

 

 

Why only one 3 pin XLR for balanced input?

Long time since I posted around here but I thought I'd come by and show my latest DIY projects:

First Watt F4 running on +- 32V

At the moment I'm using a Millett Hibrid as preamp until I finish th BA3FE for preamp duties.

Salas Folded Phono Stage, waiting for the front and back panels to arive from milling for final assembly.

PSU for preamp

Edited July 16, 20169 yr by MASantos

2 hours ago, johnwmclean said:

Why only one 3 pin XLR for balanced input?

That's a SE-amp (very fun build by the way, I've built two of them) so I guess it has a twin somewhere waiting to be completed?

Yes, I want to make a second unit to use in other room or use in balanced mode with this amp. Since I have this amplifier I have not returned to use my Beta22

Finding myself in need of a stand for my Lambdas and being unwilling to pay the $75 that Stax wants for the HPS-2, I built my own interpretation for free using of scrap lumber from a previous project. In recent years I've developed an allergy to simple butt joints, so dados and rabbets abound in my version.

Edited August 24, 20169 yr by Arthrimus

Portion of your design is copyrighted by Headphile and the other is very "un Dr. Wood"....

Smoke test passed and the new board fits!

So, the white portions here are the four heatsinks with the rectifier diodes on them, in the above picture.

Side view - two power JFETs per side

That’s impressive work Marc. 71°C is very close to my F5X with an ambient of 22°C.
....goes to google “seek thermal”.

Edited October 14, 20169 yr by johnwmclean

Well, dealt with this tiny piece of copper for the last few days.... you can imagine what might have occurred.