Hi Guys,
Got myself a pair of small amp boards today based on either LM1875 or TDA2030 for my christmas
project and on schematic says you can run them OCL or BTL
Is that one of them is monoblock and the other way is as a 2 channel ?

Regards,
Kjell.

BTL is Bridge-Tied-Load or a Bridged amp

OCL is Output Capacitor Less - this may mean not capacitor on the input.

Cheers

Hi Gio,
OK ! so what is the difference exept for not having cap in one of modes ?
I haven't run into this before that's why my question.
I guess that bridged means like run a stereo amp in mono mode or ?
Regards,
Kjell.

Hej Kjell,

think you'll get crazy about chipamps, he? Yep - nice toys

BTL / OCL configs: Maxim and Nat. Semicon This are two examples for bridged amplifiers. They are a bit different, but the result is the same. Usually, a resisted symmetrical output is the best choice to get some ICs in parallel (Nat. Semicons BPA-200 design, chapter V.). You already have this layout lying around somewhere at home (4*LM). No and Yes. There are some amps that can be bridged at the output. Then, they should have 2 symmetrical outputs on both sides (L/R). The channels can be tied together to fire up one channel at each side. Mono is not bridged.

OCL is Output Capacitor Less. OCL is most used with chipamps, as they provide a internal DC-Out protection (afaik)... The TDA and LM amps are OCL designs. This design uses input caps to block incoming DC voltage..

Can you shoot a pic and post it?

Hej Tom,
He he, you are so right regarding my addiction to chip's
i proberly end up in a nut hatch before christmas
Naah, it's not THAT bad i just building a small stereo for my 6 year old nephew for christmas,
found these out on flea bay for total of €11,50 ($17) incl shipping and 12 pc of 22uF e-caps






at least this time i got a decent schematic,

i have both chip's in ( stock ) of LM1875 and TDA2030 so i can go either way according to schematic but i really don't know which is the "best" choice of chip's,

Regards,
Kjell.

Lill hot things...

IMO:
Your nephew could live well with one pair of TDA2030s @ 12VAC @ OTL (One board). That's more than enough for a kiddie (except he enjoys listening to Apocalyptica or Metallica). 12Watt per channel is more than enough to damage little ears. The LM1875s are more on the serious side of output power + sound and slightly the same like the TDA2050s. 50 VA - 80 VA are hefty fine for this boards.

So your prefered choich would be TDA2030 for this !
always do what doctor order
perfect then i have a spare one
to bad about those trannys i found in the dumpster ! in a box of 12 units was only 4 alive rest of
them was crushed
A little tone controller from Kitsrus for €12 gotta be perfect for this build.

Regards,
Kjell.

Hmmm, TDA2030 = 12V and my newfound tranny on 18V =
sounds like a good idea to put a regulator board togheter ,
easiest gotta be to take a 7812 and "piggyback" 1 MJ15015 to that.

Regards,
Kjell.

Now - if you have the 18VAC tranny use the LM1875s. They sound much better and have more power.
BTW - it's your choice.

Yep.
I thought, that we should take care of your nephews health. My son (7) sometimes likes to play the music loud.
He thinks that it's very funny, but he doesn't know much about healthcare and ear damage... How should he?!?
That was the only reason, why i suggested to use the 2030s. I feel a bit responsible for younger people that will need their ears.
We can decide it, but they don't know it. Sry!

With this boards you can use what you want. TDAs or LMs - whatever you like. The configs are printed on the datasheet. If you already have one 18VAC you surely can use it with the LMs. The rectifiers are "on board". Only hook up the tranny, the other stuff... and enjoy it. IMO - one stereo board is more than enough and the BTL config is way too hard for kiddies...

Not so good. A bit too much for a little 7812 and the boards are already rectified...

Sry - i didn't want to annoy you - if i did...

Hej Tom,
No problem at all, i already have a feeling that it's me that annoys you guys
was only if i would go for 2030's that a reg board would come to mind and of course i wouldn't
draw all current thrue 7812,
that's why MJ15015 as a "slave" to 7812.
To do a "piggyback" you only draw about 160-180mA thrue 7812 and rest of current go over 15015
or whatever you have in bin's and add a heatsink to the power transistor and you have a cheap
and simpel regulator with just a few external components.
And of course back to a old subject at least from my side,
these tiny boards already have rectifier and "powerboard" onboard and i still have that question mark hanging on my shoulder regarding power feed to it,
as you described earlier with feed in form of pos - 0 - neg to board so far i understood i need to
make a small board with 2 rectifiers to get a 0 "Null" or is there a other way to get a 0 out of it ?
Or is this Null guy out of work when this rectifier guy is already resident on board

Regards,
Kjell.