cspirou

Haven't been as active on here lately and I can't believe I missed this GB. Anyway, good work on this everybody

That being said, I'm inclined to do another GB if there's enough interest. I've learned a bit and I know some other vendors I could work with. Plus I think it would be cool to have other colors besides just plain black.

I wish I could help you. I have some partial cases that I would be glad to sell. However they are in storage in the US and I've moved to France. If I get access to them again I'm going to post parts for sale.

I should have some. I need a bunch so I don't know what I can spare. Also I'll only sell with the PZTA56 complement.

My mistake. I just focused on the red text saying "Please note long lead time"

Updating my BOM for the Dynalo Mini. MMBTA56/06 looks to be discontinued. As a substitute Mouser is recommending MMBTA56L/06L. Is there any reason I shouldn't use this substitute for the Dynalo Mini? The datasheets seems to match on most specs and the graphs differ a little bit EDIT: Oh god 32 week lead time! Fuck that!

BTW, even though Linkwitz has passed away you can still do this through his wife

ASP is now available at the diyaudio store. Designed so you don't have to use exotic jfets. The entire kit with enclosure is $300.

@MASantos i need to order some parts for myself soon. I can add the MMBTA56 transistors to my order

I haven't built a 2oz board yet. Just comparing the reported temp of @Whitigir vs what I have, which is closer to 70C max. I'm sure building the 2oz board is much easier. Although the 3oz board wasn't so bad after I got a soldering strategy down. Plus I have a DIY reflow oven which helps with a lot of components.

The heatsinks attach to the plastic casing which I presume isn't a great heat conductor. Not too surprising. Doug is using a heatbar attached to the PCB for his T4 amp, which is a pretty clever solution. Also wondering if this is why my amp with the 3oz board has a lower temp. More copper to dissipate heat.

I think i share this observation as well. Heatsink temp is lower then the naked transistor for sure, but i am not so sure that the transistor itself is actually that much cooler. The vented PCBs like Headamp has on their newer amps would be the way to go, or some sort of PCB mounted heatsink like this.

@Whitigir - Did you drill another hole?

That is one blinding LED. Nice work! Where did you get the heatsinks for the THAT chips? For knobs I was going to go with diyaudio or Parts Connexion

That sounds way overpriced. You can get a KGSSHV from Mjolnir Audio for far less. Most people here use modushop or diyaudio store and get the panels CNC'd with modushop or use Front Panel Express. It's not super cheap, but won't be anything close to $15,000. There's also a bunch of vendors in China that do a pretty good job, but I don't know how to navigate that area.

The jumpers don't transmit any significant current, they just are used to set the voltage. So silver solder is definitely overkill.

My main concern with battery isn't so much noise but the varying voltage as power draws down. Usually this means some sort of power management circuit in between the batteries and the amp which can have their own noise. Also with a bipolar power supply there's an issue of one rail powering down before the other, leading to a large DC offset. I'm sure Sony has a very competent implementation though.

What is the preferred potentiometer value if I go with 2sk170/2sj74 jfets instead of the THAT chips? Still 10k?

I think there's a another version of the SMD diamond buffer used for the ubal -> bal boards with a servo.

Nice @jose! What are the Mundorf capacitors for? I thought this was DC-coupled?

From checking the shipping status it seems like everyone received their cases and there was zero losses. I just wanted to thank everyone for participating in this group buy and trusting me with your money. The PDFs in the OP can be used if you want to order more at Enclosures & Cases Inc or they should work without any modifications at Context Engineering. I'll try to release a generic file of dimensions eventually which you can adapt to any enclosure. I also have some odd n ends that I will have for sale soon. Just few extra front plates and sides that they included, but nothing that amounts to a complete enclosure. I'll also make the prototype case available cheap. Also thank you everybody for covering my cases. It was an unexpected and very welcome gift. I don't really do this expecting a reward or compensation, but it's still very appreciated.

I only know one person so far that did the SMD version. He says it gets pretty toasty and needs heatsinks. He also did a few mods. On my Dynalo Mini I mounted the LEDs backwards initially and it drove the temp really high. Read his posts because he also changed a few things that you should probably implement. I plan on building it too but have some other projects in my queue I need to finish. first thing i would ask is does it work without the buffers?

Oh good. I was starting to worry about yours. Now just two more left. I think they are in some sort of shipping purgatory. Or the tracking just hasn't been updated

Or just put in the IEC socket anyway and use a plug

That's for the IEC power inlet. The single black screw is for the RCA jacks. If you use all the washers the silver screws are a little short, but should still be fine.