Search:

@rubberear

If you need to economize:
- a 400VA tranny will get you quite far as well,
- 800VA of power might only be used on full-tilt with hard-rock music.

OK, got it, thx.
The jumper post is/was for -real- noobs, not you.

This:
spent some time trying to figure out the polarity on the film caps too before i realised the note about the cap...

PS
A reminder for a lot of people: a jumper just connects two spots on the PCB, there is ONLY a metal clip inside.
Not a special circuit or anything. A jumper does NOT mind any polarity.
Permanent...

[QUOTE=eightyape;34888]
I would also like to add potentiometers to the next amp 9-
> 4x mono, 2x stereo or the great ALPS quad-pot? (ca. 35 euro)
Yes I'm going to build another i have decided not...

Hey! I'm here!

This:
But..the ai is also shockingly incomplete and also rather confusing for a noob.

I should make it simpler? Give me some hints. And I KNOW it needs to be updaated to rev.1.2...

Look.
You seem to need power, and the Lepai is nice....for at home, bike or other usually low-power use.
The PCB is low-Q, but the main problem is veeery thin copper lines on it. Just amazing,...

I think it's a challenge to keep it working. Then it works, then not. Maybe vB is becoming too complex, so if you change something....other parts follow...very naughty. (just read the new Storm, nr....

There is an amp9basic thread with the answers...this article-comment thingy has become quite a big thread by now. Please create threads/post in forum?
PS: I thought you had to close 2 jumpers now to...

@wurtel
You made me do a post, unusual these days.

You ask here, at 41hz.com + about the boominator and you have the nerve to order that LEPAI ?!?!
Even ask if parts are OK??

No, they're not!...

J is testing the backup-system.....backup is now in, J is configuring php/vB events.

So basically, with no signal but with sources connected, if I connect A- to P-gnd and output different, then I have a ground-loop.
If not, I still have it, but it doesn't matter. All clear now.
...

Before I move on........
I need to have a -good- description of how a ground-loop problem sounds like, can't find much useful on the forum now.
What exactly will/should happen?
- specifically for...

Better not: there is 12.23Vdc over it now. Exact: Pre-amp gnd is 12.23Vdc above 9b Agnd. But...maybe.
Music is OK though.

While I was busy with this post, you wrote a big post. I know velleman aint that great, but can be acceptable. Point is: BUDGET.
I need to do this with low-budget or else it will un-usable. This...

Yep, they don't do much now. >ok, so the four diodes on the board there are the rectifier?
Just TL072, good enough. >What opamps are those?

It is running on the 9b 24V smps, I could put another...

Pics....well, it's:
- an 9b, you know that one
- a k8084 http://www.41hz.com/forums/attachment.php?attachmentid=1120&d=1296072464
- and a small smps 24V 4A, can't find on eBay anymore.
...

Gave it a go..
With de-caps it does work, but lots of humm and I can hear an engine in the background...revving up and down.
Some sort of whining? Could that be the ground-loop?
Less humm when I...

And you had the microphoning problem then too...nice.

OK, you seem to have exceptional hearing.
I'm OK with the bass using a 1uF on 50k impedance. (other amp, same physics apply)
What R-in did...

No, I haven't. Should be OK with a zener following it.
But I'm more interested in ditching the two small 6Vac trannies anyway.
So I would like some more info on running the pre-amp on 24Vdc:
I...

Yes, of course, but that is not really AC anymore; that does not 'dip' under 0V=mass of 5V anymore.
In essence, we're talking about a low-DC-fed, audio modulated, smps.

My points of view are...

Those 10uF caps: is that because of bigger-is-better? What about less-is-more?
And did you first try the original caps? Not good?

But amp is almost silent with nothing on the inputs or only mp3, so the weird noises and humm must come from the pre-amp. I guess the way it rectifies the AC is just not adequate?? Disappointing and...

OK, got it.
If it is that sensitive, there must be something wrong.
And if it works that way without anything on the inputs (I mean the PCB here, not the connector on the case), then I'd say that...

Scary. Does not sound right to me. Carefull: one knock too much and it might be the last knock.
Please compare soldering with pics on this site/forum, there are lots.
It does NOT happen with my...

That would be this one: http://www.41hz.com/forums/showthread.php?3487-Roskilde-DIY-AMP6-B-component-fried&p=30244#post30244 post#25, there.
But I do seem to remember a similar one for the...