And another Amp6 makes beautiful music...

[waaronw]

Or is that "makes music beautiful"

I'd been lusting after a Tripath-based amp for a while, and a 41hz one specifically. Being a DIY-er, I figured I should build one myself - though this was my first DIY audio project since building speaker boxes 15yrs ago.

Apart from a mix-up on the RIN and RFeedback resistors (resulting in a low gain) everything came together great. I'm powering it with a 19.6V laptop SMPS and have it running a pair of 6.5" 2-way Infinity bookshelf speakers.

As others have mentioned, the case was the hard part! I used a lot of locally-available parts (but ordered an ALPS Blue Velvet pot) so you'll probably recognize many parts. I was going for a bit of a retro look, and wanted to incorporate some wood, so this is what I came up with not having a workshop to fab anything anymore. (No comments about the spring terminals, please. I know, I know, but in this case they were convenient and since this is for on-the-road sorts of audio, I'm happy with them - till I replace them!)

Thanks to everyone on the forum (esp. V-Bro & Sparky) the existing messages helped me through the few questions I had!
~w

Other images can be seen at http://www.waychoff.com/Amp6/

[Scratchy]

Nice to hear it worked the first time, "right out of the box" []

19.5VDC is at the upper limit for the heat dissipation of the voltage regulator.
You must be using the 14.6V setting, but it must still be running quite hot?

***It's so easy, everyone should be doing it***

[waaronw]

I am using the 14.6V setting - but after about 6hrs of continuous listening, the side of the enclosure was only slightly warm. I pulled the case to check the Tripath and VR and both were only slightly warm to the touch! (The entire enclosure is actually aluminum, and I have some decent air moving most times in the house)

However, now I have a problem!! (wouldn't you know it? Get excited about it working then BAM!) [EDIT - One should think twice about playing with this stuff after being awake for 20 hrs...]

So, I found that after leaving the amp plugged in, but turned off for about 4 hrs (after playing for 6 hrs fine) that it would not power back on. After testing, I found my power supply output was suddenly only 7.6V. After unplugging the PS for a few mins and plugging it back in, it was back to full power and the amp works great. Is this possibly what a symptom of a SMPS that doesn't play well with capacitive loads looks like? If so, do you suggest I work around the cap or swap the PS?

[V-bro]

Thanks for the kind words![^]

Nice amp you've built![]

I shall not make any bad comments on the spring loaded speaker terminals, as a matter of fact I would rather have commented on big gold plated silicone coated and cotton&silk insulated teflon lubed and snake oil treated spade clamps to be COMPLETE nonsense. Really even if you swap them, it may give you a better feeling, it may last longer and work more reliable but I would be most doubtful to persons that say they HEAR the difference...



------X-max. can be several meters on any driver, too bad it can be done only once...------

[Scratchy]

Using a SMPS on an AMP designed for AC input is completely redundant.
You'd been better off with the AMP6-basic.
As you have mentioned, SMPS do not play well with gobs of capacitance connected.
You could try removing the filter cap and see how it goes.....

***It's so easy, everyone should be doing it***