Very nice work dude!

Well, I've added the resistor and it works perfectly now.

Thanks a bunch.

I understand, and thanks for the quick responce.

hello,

I've build a LM3886 amplifier recently.
When I start to play it works perfectly but after a few minutes the LM3886 turns of. After letting it rest for a minute, it works perfectly again, but only for a couple of minutes like before.
First I thought it was the powersink that was to small, so I placed a bigger one. Still, the same problem.

Then I read on a forum somewhere to measure on the output of the amp with a DC-voltmeter.
I measured while starting to play on the LM3886 and noticed that the voltage started around 1Volt to end up to 30Volt when it shut down.

Does this mean my amp is oscillating and what can I do about it?
Could it be because I haven't placed the inductor parallel with a resistor at the output?



Thanks, Robin

Looks great!!

got any pictures from the back and inside the chassis?

thnx, here's a picture of the back,
I made it so, that I can attatch a back-panel for closed-back,
and for open-back operation I can use 2 slices of wood with a space between them as rearpanel

I've checked your movies, sounds really great, what preamp did you use?

My little LM1875 Amp on top of the 2 fender-style cabs I recently build

No problems with running it on the +side of the supply,

the tonestack, it's ok I guess, not that experienced on that level,
if you don't like it, you can still change it by another (like the marshall one on the page)
but with my tele, it sounds quite good, nice clean tone, and good distortion,
I'm really happy with the result I'm getting,

Robin

Just feeding it with a positive voltage, I don't know how to let it work on bipolair supply

Finished, just needs a lick of paint, it really sounds great with my tele,

I just need around 1V to go to my poweramp, I just wanted to know if these circuits give me this voltage, or do I have to amplify them some more with an opamp,
planning to use 2 TDA2030A's in bridge on a single supply,

just build a proper power supply without voltage regulators, like the one I gave you
it could be that the capacitor exploded because of undervoltage

succes with the building,

@syndromet and others: I'm planning to build a 4 channel amplifier with some of the projects with fet's of runnoffgroove for use as channelpreamps,
but do they give enough output voltage to the power-amplifier? Is it then better to run them on 18Volt for use as a preamp?
or should I just place a real preamp between these fet based circuits to boost the signal enough to run it to the power-amplifier?

forgot to tell you that it's possible to make your amplifier with the transformer you've got, (without the voltage regulator)
you just need to adjust your circuit of the LM, look in the datasheet of the LM and search for "single supply application circuit"
it just won't go as loud as the one you wanted to build though,

I believe you have build the wrong supply for the job,
what you need to have as transformer is one with 3 (or 4) wires coming out of it,
as you can see on the link that I've posted there is a +35, a -35 and a GND,
these 3 connections need to be connected to you amplifier,

what you have done is build a single supply, with just a +35Volt and a GND,

also, your transformer is to light for the poweramp you use,
just go out and buy a symmetrical transformer of 2x25V of 80VA,
perhaps print the schematic of the link I've posted and ask the salesman,
they will know what you need if you give him this information,

remember to put a heatsink on you LM3886, or else it will overheat,
and check if the LM in mute posistion or not,

the reason probably why your supply regulator broke, is because your circuit needs to much current which the regulator can't handle, these things aren't build for this,

good luck,