Thank you, but he had it in a format that could be printed for etching. I have eagle, but everyone seems to be using something else.
Buzz,
He had it in a zipped format back a number of pages. You'll have to find it in one of his recent posts.
He had it in a zipped format back a number of pages. You'll have to find it in one of his recent posts.
This is my 5EF board, using eagle. It is little bit different than OS layout. I make it for easy mounting on my heat sink.
for the time being i only have a 24-0-24 200VA transformer. BY the way which is maximum voltage that can be used for 2 pairs of mjl21193-4?
whoa ! 24V ! 😱 32-0-32V rails , maybe ? Amps will run on this ...
But decrease the resistors feeding the zener regulators on any IPS
that has them (CFA's typically).
Also ,the Hawksford VAS's and any LED CCS .... the LED reference
currents might need to be increased (lower R) for such a low supply.
The rest of the design is pretty much voltage independent.
PS - good thing I added trimmers to the CCS's (will help for low voltage).
OS
I don't think it would be a problem for 4 reasons.
-1. this layout "style" is most common ... HK990 , many DIYA high powered
EF2/3 OPS's , most commercial high powered amps (crown ... )
-2. cancellation , The Re's cross both halves of the output return paths ...
Any inductive field created by + would be negated by the opposite - OP
banks return. (another HK990 "trick" )
-3. The Re's voltage drop is minimal and the current is shared by all.
-4. There is nothing sensitive in this area of the OPS. It is all "dirty"
here. 😀
Now to the actual choice of the Re's - YES , buy some non-inductive
thick film through-hole resistors and populate away.
Cheep 😀 .... http://www.mouser.com/ds/2/219/MOS-16613.pdf
3W metal film .22R ...
Or blessed by Tibetan monks ... (9 usd $ each)
http://www.ohmite.com/
cat/res_slimmox.pdf
These are thick film PPM level , 3W/.22r would fit the 26mm lead spacing.
PS - Member ASTX's similar OPS layout produced 9PPM THD20 ,
even with the IPS out on a long "dongle" .
Edit - IF you use the "other" OP resistor pads (12.5mm nobel pads),
that wirewound would be 12mm above the PCB - cross inductance would be
minimal.
...... 5-pair would run well with just one pair OP -just don't push it !! 😀
OS
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stupid question. What program should I open up the layout to ensure that it is properly sized. I printed both the output boards and the CFA-x boards and the proportions seem to be different.
If you only populated three of the output pairs where would be the ideal placement, near the end of the circuit or the beginning? I was thinking if you spaced them and skipped over every other position you would have a better heat distribution on the heatsink.
Buzz - I use PSP 7/8 ... both are .bmp (7.61cm sq. - below).
No difference.
Kindhorn .... I am "anal" too ... that's why these (projects) should really
"sing" !
Yes , skipping pairs on the monster would be ideal.
Also , look on the monster , there is a augmented rail option ...for "anal"
power requirements 😀 .
OS
No difference.
Kindhorn .... I am "anal" too ... that's why these (projects) should really
"sing" !
Yes , skipping pairs on the monster would be ideal.
Also , look on the monster , there is a augmented rail option ...for "anal"
power requirements 😀 .
OS
Attachments
Spookyamp (leach 2) progress ...
I like to take a bite of " meat" ... 80 component IPS's are the
coolest ... (below).
I added what the Leach should have - (CCS's/Servo/hawksford).
Left out what it should not (VI limiter). Whaaaat ! But it'll blow ??
Nope ... after the IPS's - one BA protection module will be designed.
(Sir Bonsai's SS relay + Japanese integrated protection IC. 😎)
OS
I like to take a bite of " meat" ... 80 component IPS's are the
coolest ... (below).
I added what the Leach should have - (CCS's/Servo/hawksford).
Left out what it should not (VI limiter). Whaaaat ! But it'll blow ??
Nope ... after the IPS's - one BA protection module will be designed.
(Sir Bonsai's SS relay + Japanese integrated protection IC. 😎)
OS
Attachments
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OS,
How do you think the NAD and the CFA-X will differ in actual sound? That is a question I am wondering.
This looks like either one would satisfy what I am looking to do.
I guess I would like to incorporate and active cross-over filter with the ips section if that was practical, with one set of outputs going to a separate secondary amplifier of lower power than needed for the mids and lows.
How do you think the NAD and the CFA-X will differ in actual sound? That is a question I am wondering.
This looks like either one would satisfy what I am looking to do.
I guess I would like to incorporate and active cross-over filter with the ips section if that was practical, with one set of outputs going to a separate secondary amplifier of lower power than needed for the mids and lows.
My 2 cents ... 
CFA-X .... this is truly the entry level , simple "CFA toy" amp. Don't get me
wrong , but you are asking a lot from 2 small to-92 devices. For the
"baby" and low voltage .. build as is - 20 year MTBF. For 60-85V , be very
choosy for your input pair , that's why I posted a heavy duty (TO-92L)
pair as a high output alternative to the ksa/c 992/1845.
NAD-H .... diamond input sees no load , second stage is the one subjected
to the "evil" current feedback and would benefit from the heftier TO-92L
devices. This is a 2 stage amp (more refined) , as the diamond buffers the
CFB stage. The Hawksford cascode VAS eliminates the early effect (much lower
distortion here) and looks cool (UV led's). 😀
Add the servo , and you have the offset stability of wolverine.
A better amp for the 3/5 pair at high rail voltages.
Both should be reliable , but each has it's own range of application.
PS - I don't like being subjective , BUT .... I have built the Hawksford and it IS
the best sounding VAS ... we REALLY actually listen to the VAS ( OPS just increases current 50-100K).
The Hawksford is more than "airy" .. more like breathtaking...
The first amp I heard with a Hawksford was an old luxman (below) ... these hawksford's are based on it.
OS
CFA-X .... this is truly the entry level , simple "CFA toy" amp. Don't get me
wrong , but you are asking a lot from 2 small to-92 devices. For the
"baby" and low voltage .. build as is - 20 year MTBF. For 60-85V , be very
choosy for your input pair , that's why I posted a heavy duty (TO-92L)
pair as a high output alternative to the ksa/c 992/1845.
NAD-H .... diamond input sees no load , second stage is the one subjected
to the "evil" current feedback and would benefit from the heftier TO-92L
devices. This is a 2 stage amp (more refined) , as the diamond buffers the
CFB stage. The Hawksford cascode VAS eliminates the early effect (much lower
distortion here) and looks cool (UV led's). 😀
Add the servo , and you have the offset stability of wolverine.
A better amp for the 3/5 pair at high rail voltages.
Both should be reliable , but each has it's own range of application.
PS - I don't like being subjective , BUT .... I have built the Hawksford and it IS
the best sounding VAS ... we REALLY actually listen to the VAS ( OPS just increases current 50-100K).
The Hawksford is more than "airy" .. more like breathtaking...
The first amp I heard with a Hawksford was an old luxman (below) ... these hawksford's are based on it.
OS
Attachments
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Your 5 pair SpookyAmp (Leach 2) looks truly interesting. I look forward to seeing your final draft of that beast.
With modern devices , it performs similar to the NAD-H (very high slew).
2-3 times faster than the best blameless.
I will leave the option to use the good professors original compensation
scheme intact.
OS
Thanks again OS. The Nad doesn't look that complex to build, just more time to assemble. Have you settled on the feedback topology for the Nad and the Slewmaster ops? You just give me a bom with currently available devices that won't be gone next week or in 6 months and I will be happy. Whatever would be the most stable and last for a lifetime would be my choice if given that choice. Something that will take the abuse that a consumer would give a product and keep on ticking! Hopefully not really ticking, but if your old enough you'll remember the Timex ads!