Hi Ostripper THANKS FOR REPLY.Nice red pCB's !
BC can be used for the current mirrors (see just 12V vce ).
BCxxx you would have to reverse the device ,(and swap C/B around)
as BCxxx is a CBE pinout.
Most to-92's are ECB , the reason for my layout choice.
Input can also be BCxxx , provided the amp is powered by 50V rails.
You made the 5 pair version , so I assume you mant mega power !
BCxxx couldwork (<50v rails) , but your application
(desire) seem to be for high power/high rails.
The to-126 BD139/140 are OK for the Cap multipliers (<60V rails), and
any Vbe (any rail V- they also "fit" - ECB).
Personally , unless it was the "baby" I was building ... stick to
the higher Vceo KSA/2SA -KSC/2SC devices ... they fit the layout and
are properly derated to ensure years of service.
OS
I want use bc...just for first step.I must get these ksa from Mouser....so i can't wait!
Best regards.
Thimios.
"Spooky" ooooohhhh ...
Leach amp - "spooky" is done.
WHAT an amp ! Never tried my hand at this topology , I like it.
Massive slew , got it down to single digit PPM without beta enhancement.
Goes real well with the Hawksford/servo combo.
Stole the HK-990 servo (inverting servo) , amp will run without an
input cap (DC). Slew is awesome with the DC input (200+).
(below) is schema + .asc.
Slewmaster.txt is now (Keen + ksa1015/ksc1815).
(Below 2) is static offset ... WOW !
PS- I like laying out the ones that are " a' drippin' with parts.
Sorry...Mlloyd1 , the hafler folded cascode is not even close (.05% vs. 5ppm)
OS
Leach amp - "spooky" is done.
WHAT an amp ! Never tried my hand at this topology , I like it.
Massive slew , got it down to single digit PPM without beta enhancement.
Goes real well with the Hawksford/servo combo.
Stole the HK-990 servo (inverting servo) , amp will run without an
input cap (DC). Slew is awesome with the DC input (200+).
(below) is schema + .asc.
Slewmaster.txt is now (Keen + ksa1015/ksc1815).
(Below 2) is static offset ... WOW !
PS- I like laying out the ones that are " a' drippin' with parts.
Sorry...Mlloyd1 , the hafler folded cascode is not even close (.05% vs. 5ppm)
OS
Attachments
I had the Hafler up and running. It is a "HOT" VAS . The emitter
follower VAS half supplies the class A , and is "helped" by the folded cascode.
While this VAS is nowhere near the hawksford in terms of distortion ,
it is faster with low Z.
The folded cascode runs in class B , allowing for massive slewing capabilities.
I ran it up to 1Kv/us .... nearly unheard of with a typical VAS.
I suppose david (hafler) wanted to drive them FET capacitance's with
a bit of overkill.
OS
Leach amp - "spooky" is done.
WHAT an amp ! Never tried my hand at this topology , I like it.
Massive slew , got it down to single digit PPM without beta enhancement.
Goes real well with the Hawksford/servo combo.
Stole the HK-990 servo (inverting servo) , amp will run without an
input cap (DC). Slew is awesome with the DC input (200+).
(below) is schema + .asc.
Slewmaster.txt is now (Keen + ksa1015/ksc1815).
(Below 2) is static offset ... WOW !
PS- I like laying out the ones that are " a' drippin' with parts.
Sorry...Mlloyd1 , the hafler folded cascode is not even close (.05% vs. 5ppm)
OS
almost had a seizure focusing on all those parts
68 freakin' components .... it will fill that 76.2 X 88mm blank of mine.
It will have 2 trimmers for the CCS's , adjust both total IP current and
compensate for any offset the servo misses.
Since it is a big one .... I wanna' do it first.
I think it is finalized , it will run with 10pF cdom before the square wave
"rings" - VERY stable !
PS -Finished PCB will be a very similar layout to the "NAD-S" IPS.
(CFA/hawksford/servo) .... almost a perfect rumble (symmetrical CFA vs. VFA).
OS
With the VFA's you could just run 2 - 10K resistors from PD+/ND- back to NFB,
IPS should run independently.
As I explained to NAF for the OPS ... 2 -15K from the OPS rails to PD+/ND- simulates a "phantom IPS"
.... allows one to even set bias/check voltages.
Can't do this with your typical DIYA project !
OS
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take a look inside some mark levinson gear sometimes ...
speaking about lotsa parts
wowsa
mlloyd1
i'm probably gonna show my age with this one ...
anybody remember the walkie-talkie transistor count wars?
i actually saw some products that had transistors soldered onto the pcbs but providing NO functionality - pins were all shorted together - just there for the transistor count!
speaking about lotsa parts
wowsa
mlloyd1
i'm probably gonna show my age with this one ...
anybody remember the walkie-talkie transistor count wars?
i actually saw some products that had transistors soldered onto the pcbs but providing NO functionality - pins were all shorted together - just there for the transistor count!
almost had a seizure focusing on all those parts
Here you are mistaken.
The independant CCS adjustment trimmers will not require cross gender matching (P/N),and the servo will "clean up" same gender differences ...(N/N - P/P).
To just match the same gender pairs will offer better performance , but it is
not crucial. The original leach had neither of these "fixes".
To Maouna ... I'll do the CfA-X next, as I already have this one
90% complete.
OS
"Simple" must be laid out as such. VERY short paths ....just a few CM's
between input pair and VAS ... compensation caps "huggin' the B-C
junctions. Had to split the NFB (NFB 1 and 2) as the amp has dual feedback.
Split NFB wire should be no issue.
CFA-X is my
only sim that will run without ANY compensation. I was amazed when
I first tried one a few months ago (the "alien" CFA
).It also will do 300+V/us slew. this layout , (below) should allow for 10pF
compensation/ 250+V/uS reliable operation.
It also should be a 10-15$ IPS .... cheep !!
OS
Attachments
CFA-X is my
only sim that will run without ANY compensation. I was amazed when
I first tried one a few months ago (the "alien" CFA
It also will do 300+V/us slew. this layout , (below) should allow for 10pF
compensation/ 250+V/uS reliable operation.
It also should be a 10-15$ IPS .... cheep !!
OS
[looking for 200W-250W/8]
Thx-RNMarsh