Things are evolving in good old germany, here's the latest amp pcb so far:
Added the 1µ input cap (should be enuff space even for a freak cap), added the power on LED, changed them both serial resistors for paralleled ones (you win, Martin
), and some other minor things.
Group buy? Certainly, soon. Papa has already given his blessing.
I'll keep you on track.
An externally hosted image should be here but it was not working when we last tested it.
Added the 1µ input cap (should be enuff space even for a freak cap), added the power on LED, changed them both serial resistors for paralleled ones (you win, Martin
), and some other minor things.Group buy? Certainly, soon. Papa has already given his blessing.
I'll keep you on track.
HBarske said:Things are evolving in good old germany, here's the latest amp pcb so far:
.....
Added the 1µ input cap (should be enuff space even for a freak cap), added the power on LED, changed them both serial resistors for paralleled ones (you win, Martin
Group buy? Certainly, soon. Papa has already given his blessing.
I'll keep you on track.
Papa's R6 (series to led) must be 6K8 (not 68K) - for regular led
in case of 6K8 , it must be at least 500mW , better 1W
in case of any supperduper led , which will shine with just 0,6mA , 68K is good ......... and even 250mW will be a killer strong ..........
dunno - didn't tried blue led form chinese cig lighter , at less than few mA........
besides that - adding one little cap (47n upwards ) across both 220uF caps could be nice touch .......
HBarske said:
No doubt you are right. I should start questioning Papa's schematics
nope;
5 to 6 mA is more than enough for your regular 20mA led , no matter what color is ........ unless you want hole in back of your head ......
try and you'll see.
I know that because once I needed led on battery driven little gizmo ; I was surprised on which current led dimmed ........
EDIT:
besides that issue - I know that you boyz will purchase from Digi.... but why not changing to any european BC critter , instead of ZTX450 ?
Papa use them ( seems that it's consensus ) because he have them in buckets ; in both places even BC546C is more than good , not to mention right iteration of BC337 (40 or C)....
don't take me wrong - I'm not splitting the hair ( I have both - ZTX-es and BCs in my drawer for what I need ) but I'm just chatting
You name it, and I am stumbling behind :
:
An externally hosted image should be here but it was not working when we last tested it.
mach.88 said:
welcome to the club .......
but still I know there is no such thing as a japanese super-led...
well - then you don't know too well work of Susumi Sakuma......... fer instance ........... ( that's why I like that super led, also known under super secret name - VT4C) ..............
Choke,
you know very well we still use regular Phili light bulbs overhere.
One day i'll jive talk Elfenreiter into dropping something on Serbia.
Just a repeat:
The ZTX-450/550 are not contemporary developments but really old devices.
The duo was not even developed by Zetex, but by a semi-company that was bought up by the Manchester crowd.
No magic there.
A small LED suggestion for your dripping Pimpky=>
you know very well we still use regular Phili light bulbs overhere.
One day i'll jive talk Elfenreiter into dropping something on Serbia.
Just a repeat:
The ZTX-450/550 are not contemporary developments but really old devices.
The duo was not even developed by Zetex, but by a semi-company that was bought up by the Manchester crowd.
No magic there.
A small LED suggestion for your dripping Pimpky=>
Attachments
AJ is said to clip at +/- 2.5 A. Fuses will be between the big caps and the amp, so no monster charge currents there. Anything wrong with 3.15 - 4 A slow blow?
Since we will have mono amps with 250 VA xformers, I don't see the need for CL60, at least not as inrush current protection. Otherwise, let me me participate from your wisdom again...
...one might argue, some people could use 2 sets of ampchannels in one cabinet.
That is two powersuplies sucking at the same time. Limiting the inrush doesn´t seem too far off to me.
Hey Jacco, blue ice does magic. It hits like a falling rock, on impact it splatters around and when it melts, it leaves a nasty smell that sicks around
That is two powersuplies sucking at the same time. Limiting the inrush doesn´t seem too far off to me.
Hey Jacco, blue ice does magic. It hits like a falling rock, on impact it splatters around and when it melts, it leaves a nasty smell that sicks around
HBarske said:
well - I would not use them at all
but - if collective peaceful sleep is in case ........ use 4A upwards ;
if anything goes wrong - these 22K buggers can be mean , and they will harumph even 6A3 T .....
for peaceful sleep - I will put spk protect , and just mains fuse
two lesser ones ( one per donut) or one CL60 - in case which HimmelWacoo mentioned - both donuts on one mains cable
HBarske said:
another one :
make R27 (68K) from one resistor ( say 62K) and 10K multiturn pot ;
it can be somewhat easier to do little tweedledee than swap resistor or two from board ........ if Q. current isn't where you expect
remember that Papa makes that in situ, swapping mosfets and jfets as popcorns ..........
hehe - he certainly knows most parameters of next transistor , just looking how shiny it is .......... and I can bet that everything in +/-10% boundary is good enough
edit:
you can do this also for R9 ........ 910E + 220E trimpot ;
then everything is covered........if you have just two 2SJ109BLs and just 4 pairs of IRFs ........... devil will bite you,fer sure
