amp15 picture thread

[more10]

Wolfram emailed me these pictures. Apparently he got them from V-bro, rik and/or wadoka, see thread "Wanted: AMP 15 pics". If you object to me publishing these, just drop a note and I will try to remove them (never did this).

I am member of another forum where I can upload pictures, and link to them here, so if you want some pictures on amp15 on this forum, and have no place to put them, you can email me and I will do it.

[more10]

Picture by my friend Per, Canon 40D, bellow and manual Tokina tele zoom.

As you can see I have tilted the caps to make place for the legs on the rectifier. I soldered the caps before the rectifier, but the rectifier legs lay on top of the caps so they didn't align properly. I would recommend soldering the rectifiers before the caps, and check the alignment after soldering the first leg.

[more10]

Shamelessly crossposting one of V-bros pictures :-)

[V-bro]

Never mind! [8D]

Done with an old Panasonic Lumix DMC-FZ20 by the way. These cams are absolutely best value money can get in it's class...All their camera's feature Leica lenses which I find rather great![]

I shall post some pics here soon as well, first have to make them small and post them elswhere, then link them here....sigh....

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

[mikechw]

I just put my AMP15 in a case,
the transformer is 500VA 30VAC 8.3Ax2.
Added a EMI filter plug and a softstart module.
I can hear the transformer vibrate at power up.


The internal height of my case is just 6.3cm.
So I installed 2x shorter 10000uF.
Planning to parallel the 2x27000uF to it, mounting it sideways.



I tried 80ns and it is working fine, so:

I did some modification to the BBM and setting, running it at 40ns.
First I changed the gate resistor to 3.5ohm instead of 5.6ohm.
Then added a diode each parallel to the gate resistors, hopefully it should discharge a little faster.

Now it has been running for over an hour with one channel at near full volume.
The mosfet is just warm.

I will try out 2 channels later.
I want to measure VN10's current to check if 100mA is enough before I run both channel at full volume.

I feel that the sound of it is much better than AMP11 at high volume.
I want to take some pictures of the gate resistors, but it was mounted to the case.
I will take it later.

[dweekie]

Very nice. So you're just using the chassis floor as a heatsink? That's very cool. I'd like to be able to do that with my Amp7, but I'm betting the mosfets will be running quite a bit hotter on that amp. All the pics look great.

[mikechw]

The input cap is a Wima MKP10 2.2uF 160V.

I found it didn't pick up any HF noise if I install it to the left channel (ch2).
If I have the capacitor installed on the right channel (ch1), it is picking up some HF noise.

I suppose the right channel may be closer to the transformer...

[mikechw]

quote:Originally posted by dweekie

Very nice. So you're just using the chassis floor as a heatsink? That's very cool. I'd like to be able to do that with my Amp7, but I'm betting the mosfets will be running quite a bit hotter on that amp. All the pics look great.

Yes, I put my fingers on the screw that attached to the bottom of the chassis floor and it is just warm.

[mikechw]

Actually the output inductors are much hotter than the mosfet.
Next is the TA3020 chip, its warm.

[V-bro]

Nice work Mike!

The hottest running compoonents are the pre-reg transistors and bleeding resistors...

You running it on 40ns is rather a breakthrough... Theoretically I suspected it to be possible with this amp, but nobody has had success with this yet...

I tried with 3,5ohm Rg resistors and with discharge diodes, but my fets were getting REAL HOT due to overshoots...

I would advise to add more 10000uF by the way instead of the 27000....

And place a metal sheet between the amp and transformer...

The start-up hum you hear from the tranny is probably due to the cap inrush current by the way...

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