Screw BC...
Q3-4
KSC1815.
Nah , I agree ... most TO-92's are EBC. Easier to source.
Might as well get this right ON !!
Might poll the higher voltage TO-92's too.
At this point it is easy to make these changes.
BCE to EBC might be the hardest , I will poll Mouser/Digikey for the
popular (non - obsolete) ones.
Harry - I just put the lift resistor in. Done (Rlft)
To do -
- Change at least Q1/2/3/4 to EBC ... here we go !!! Arggggg !!
See what is most available for Q5/6/7/8/10/12 , change if needed.
- Change schema to show 12V supplies included WITH the OPS (section). Re-number
the supplies still with R/C/D/Q 2XX numbering. Servo still 2XX , as well.
This will also help with as broad a BOM as possible. I will stress the BOM
and accuracy more on this amp.
Thanks , keep the critique coming.
OS
I would agree years ago.
Now Mouser has run out of 1845's.
After looking at all of Mouser's TO-92's .... 45-60V P/N are just about all
EBC , just a few BCE. About 50 EBC's and just 3 BCE's. KSA and ZTX , 90%
EBC.
80-150V all the ZTX line is also EBC. Just the Ksa/c line from On- semi ,
just some are BCE.
Here we might consider what pairs benefit from face to face thermal coupling.
Q1/2 - LTP... YES
Q7/8 - CCS ...yes
Q5/6 - Cascode ... not critical.
Q3/4 - Current mirror .. not critical.
Q10/12 are slightly separate from Q11/13 , Q10/11 might benefit slightly
from seeing each others heat
.All will look more professional if we GET THIS RIGHT.
OS
KSC1845 still available at Mouser (445pcs), and they ordered 132000! KSA992 is out of stock, but they ordered ~about 100000.
Yeah KSC945 is 300MHz, but with Ic=10mA. KSC1845 gives almost 250MHz at Ic=6mA, so the difference is negligible.
I would not plan any new design based on EOL parts, such as 560C.
The "through hole" world became smaller and smaller
Sajti
Yeah KSC945 is 300MHz, but with Ic=10mA. KSC1845 gives almost 250MHz at Ic=6mA, so the difference is negligible.
I would not plan any new design based on EOL parts, such as 560C.
The "through hole" world became smaller and smaller
Sajti
Through-hole components are disappearing, its just a matter of time before all the low signal transistors will only be available in smd. I don't understand the compulsion to continue to design audio circuits with obsolete leaded components. If you want low noise BC550/BC560 transistors then use the smd equivalents BC850/BC860. Same with KSC1845/KSA992, the smd equivalents FJV1845/FJV992 are readily available.
"Wolverine" (Son of Badger) is technically obsolete from a leaded component availability point of view.
"Wolverine" (Son of Badger) is technically obsolete from a leaded component availability point of view.
I tried before to get the forum to go SMD before. I'm not scared of it.
I even like the idea of those duals in the 6 pin package.
Tubes and phono players are obsolete now.
So are freakin' CD players. I have not even seen a CD in 20 years.
This is a gateway project.
The modular IPS's can be all SMD.
Point is , if they won't build it - why bother. Just go buy a Chinese class D
SMD .... throw it in a box.
Even with SMD , I saw devices and traces so small on my son's new ASUS
motherboard that one could not even repair it.
SMD is going the way of disposable prebuilt modular. NO DIY.
OS
But how many would really do it ???
Lets have a poll !!
I would design the Wolverine (as an add-on) , and a few others. These IPS's are designed
to run cold. The smallest SMD devices would work , The servo op-amp uses almost
as much current as the whole IPS.
OS
The SS9014 is npn, currently the LTP on the schematic calls for a pnp.
I'm ok with surface mount for the IPS. The VAS I would still leave as the TTC004B/TTA004B parts unless we find a really good replacement. Any part that has to dissipate power I'd leave as thru hole and could be tied to a heatsink.
Surface mount would future proof the design longer.
I'm ok with surface mount for the IPS. The VAS I would still leave as the TTC004B/TTA004B parts unless we find a really good replacement. Any part that has to dissipate power I'd leave as thru hole and could be tied to a heatsink.
Surface mount would future proof the design longer.
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