Bloody Little Bastard ll solid stage power amp

rcustoms · Post by **rcustoms** » 06 Apr 2015, 03:36

This is an audio amplifier, simple but very stable and with good characteristics.
we can do it , with a few components and especially is very cheap to assemble( intermediate to advanced level ).
Another important aspect is that the same circuit can be configured with various wattages and mono or stereo modes, Ideal for fitting with our preamps projects.

rcustoms · Post by **rcustoms** » 06 Apr 2015, 03:53

now see some check points and made the bobbin for zobel network

rcustoms · Post by **rcustoms** » 06 Apr 2015, 04:48

rcustoms · Post by **rcustoms** » 06 Apr 2015, 05:02

rcustoms · Post by **rcustoms** » 06 Apr 2015, 05:12

rcustoms · Post by **rcustoms** » 06 Apr 2015, 05:19

PCBS.pdf: (441.92 KiB) Downloaded 229 times

rcustoms · Post by **rcustoms** » 06 Apr 2015, 05:24

like i said we can accommodate the pcb to made a 200w,400w mono or stereo versions stay tuned for this schematics and layouts

tip142 · Post by **tip142** » 07 Apr 2015, 20:07

Hi very interesting,only one question ,how much is estimated be the quiescent current across R16-R17?

grrrunge · Post by **grrrunge** » 07 Apr 2015, 20:47

tip142 wrote:Hi very interesting,only one question ,how much is estimated be the quiescent current across R16-R17?

Given the choice of emitter resistor values in the power stage, my guess is around 100mA

rcustoms · Post by **rcustoms** » 08 Apr 2015, 03:34

i replace the amp stage completely on a Laney HA200 combo amp,the original one blow and burn the factory pcb ,the cheapest solution in 200w stereo mode was this amp,i dont remember exactly but i think cost me around us 40 dls (without main transformer )i use the original preamp stage and the original transformer.

rcustoms · Post by **rcustoms** » 08 Apr 2015, 03:50

layout for other modes

blackbunny · Post by **blackbunny** » 08 Apr 2015, 04:07

Thanks for sharing the details of this amplifier with us rcustoms

This is just what I need to fix a scorched Laney R4B bass combo amp I have here. It has the usual shorted SMD diodes, transistors and resistors that I see in blown Laney bass amps, and I really don't want to try and rebuild that PCB, so I will give your BLB II circuit a try.

I owe you some beers!

rcustoms · Post by **rcustoms** » 08 Apr 2015, 04:17

blackbunny wrote:Thanks for sharing the details of this amplifier with us rcustoms

This is just what I need to fix a scorched Laney R4B bass combo amp I have here. It has the usual shorted SMD diodes, transistors and resistors that I see in blown Laney bass amps, and I really don't want to try and rebuild that PCB, so I will give your BLB II circuit a try.

I owe you some beers!

jaja someday my friend
for me is a pleasure to contribute with fsb.
many people do not appreciate the time taken to draw the graphics and share with everyone

phatt · Post by **phatt** » 08 Apr 2015, 07:30

What happens when you short the speaker terminals?

I can't see any overload protection which means instant death to power transistors if/when output shorts out.
Unavoidable when using 6.5 phono plugs for speaker connections.
Phil.

rcustoms · Post by **rcustoms** » 08 Apr 2015, 15:20

phatt wrote:What happens when you short the speaker terminals?

I can't see any overload protection which means instant death to power transistors if/when output shorts out.
Unavoidable when using 6.5 phono plugs for speaker connections.
Phil.

hi phil asap i upload this speaker protection i work in the graphics

rcustoms · Post by **rcustoms** » 08 Apr 2015, 15:24

rcustoms wrote:
phatt wrote:What happens when you short the speaker terminals?

I can't see any overload protection which means instant death to power transistors if/when output shorts out.
Unavoidable when using 6.5 phono plugs for speaker connections.
Phil.
hi phil asap i upload this speaker protection i work in the graphics

if you or anyone have designs ,schematics or something to mod this amp ,please welcome

sinner · Post by **sinner** » 08 Apr 2015, 15:44

Small value, high wattage resistor across switched jack terminals?

rcustoms · Post by **rcustoms** » 08 Apr 2015, 15:57

sinner wrote:Small value, high wattage resistor across switched jack terminals?

For me sound good, when I upload the speaker protection will be done. This amp coming from many brands like Sansui electronics and many others. I really don't know who's the first one to launch this design but is very common and cheap

tip142 · Post by **tip142** » 08 Apr 2015, 18:35

grrrunge wrote:
tip142 wrote:Hi very interesting,only one question ,how much is estimated be the quiescent current across R16-R17?

Given the choice of emitter resistor values in the power stage, my guess is around 100mA

sinner · Post by **sinner** » 08 Apr 2015, 18:41

To be honest I know nothing about solid state amp "physic laws"

Which is shame as I need some know how right now

But this is a simple method used in valve amp world

I can't see it "sounding" at all. It just faking load without speaker connected. It's removed from the path when speaker jack is plugged