500 series LA-3A

[Crusty2]

How's the current draw now at 30V?

 

[peter purpose]

How's the current draw now at 30V?

Try to keep up crust.

 

[Crusty2]

I don't try to keep up anymore at my age; I'm just pacing myself to get to the finish...

I would vote for the simpler 30V version for myself, but I could just bypass the dc convertor stuff, right?

 

[peter purpose]

I don't try to keep up anymore at my age; I'm just pacing myself to get to the finish...

I would vote for the simpler 30V version for myself, but I could just bypass the dc convertor stuff, right?

Nurse...... kindly change my colostomy sack.

Just taking -15V to ground is not cutting it unfortunately, so no.
What I was hoping to do was convert everything to +&- 15V, but even that wasn't working nicely when tried.
There's something getting -15v that is bolloxing up the experiment.

I'll fiddle more.

 

[[silent:arts]]

Peter, I need two, hurry on! ;D

DC converters?
I don't like them, but if needed use them ...

 

[culteousness1]

Ok, ordered my lunchbox last week. Need to fill the empty space.

Would be in for two boards.

 

[[silent:arts]]

Ok, ordered my lunchbox last week.

error ;D ;D

 

[horvitz]

Erm... AHEM!! ;D

 

[JBVries]

two more por favor

 

[peter purpose]

The 30V version works a treat, but just ordered another prototype pcb, so I can hopefully run off both rails without a dc-dc converter.
All amps worked perfectly on +&- 16V, but as soon as the autoformer was introduced it was oscillation city.
I'm hoping a new layout will sort it.

I'll keep you posted.
peter

 

[SSLtech]

I'm still scratching my head over that one... Layout might be worth a punt. -Here's hoping!

Keef

 

[haima]

yes, it's a bit beyond my electronics ability to figure out exactly why the autoformer might cause these problems - but looking at the schem, that does seem like a point where thing could get hinky... with the large voltage step up etc.

perhaps because that "autoformer" thingamejig looks so weird to me.. where's the other half of that transformer??!  ??? ;D hopefully some of you larger brained fellows can figure it out.

good luck pete

 

[peter purpose]

OK lads... we now have a dual rail version working like a champ.
No need for that pesky dc-dc converter.
I'll finalise the design and get some ordered.

peter

 

[okgb]

Hey Peter , is this one going comercial as well
should we get in while the getting is good ?

 

[haima]

;D

glad to hear you conquered the beast.

 

[peter purpose]

Hey Peter , is this one going comercial as well
should we get in while the getting is good ?

I'd like it to go commercial, but you lot will get the first taste.
I'm ordering 50 sets of pcbs and metalwork, so if you want in.... gimme your folding..!!

 

[zayance]

Interested in 2 depending on price thanks.

 

[bruno2000]

Maybe 4 for me?
Best,
Bruno2000

 

[haima]

one for me, price depending.... trying to be moderate!  :-[

i think i want a 525 too  :

 

[Rafita]

interested in 2