Dual rail power supply for class A amplifiers

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#41
I have provided everything that is required to obtain great results, including the complete solution to the front end. You need to read my posts again. I focused on C1 placement and ground fill/common returns routing because the performance will be hampered, and the PS may oscillate. Put a fast oscilloscope at its output and do a time base sweep...

If you are happy with the sound, don't worry about anything else. Happy listening.
 
#42
You may be right about the thin ground lines. C1 is a common part of every PS I have seen. If there was an oscillation for any reason, would it result in a high ripple or a noisy amp operation? That circuit as is, has no ripple at all using the CRC board at its inputs. I have used my oscilloscope and there were no significant remarks. A cheap and low-budget PS is a precious thing for many DIYers. There are surely better PS circuits. Can you present us yours?
Thanks
 
#45
tombo56 said:
@metanastis
You were clear but some of us do not read carefully. There is a line, when commenting someone’s design, that should be not crossed by pushing.
Seems that publishing own design is like exposing your bare neck to wolves. 🙂
And we may wonder why more designs are not published here.
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It is so true!!!! If maximax77 hadn't proposed me to post a thread for this circuit, I would have never posted anything like this. This is definitely my last thread because my neck is not so tender for any wolf😆😆😆😆!!!!
 
#47
There it is.
elektor.png
 
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#50
gary s said:
If you want to use power darlington's - then you would be wise to redo the pcb based on the On Semi MJH6284G/6287G in the TO247 package. These are readily available and rated at 100v/20A/160W. So basically the same as the obsolete and hard to find TO3 types you have at the moment.

That is my thoughts on the pass device. Using these, you might find wider acceptance of the design.

If you want to stay with the TO3 types, then I would look at the available On Semi MJ11015G/11016G darlingtons.
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Gary,
When I decided to present that circuit at this forum, after a member's suggestion, I wanted just to share a tested and reliable circuit I have used for many years in all my class A amps. I didn't really look for acceptance. Everybody can check and decide whether a circuit is good or bad for their taste. XRK has stated that it was an interesting design and I had to try it in building the Alpha Nirvana SE class A amp. As I have five more PCBs left in my drawers, I don't think I will try something different at the moment. I will surely check the TO247 and the Darlington transistors and I might try to create an experimental pcb using those tr types. Thanks for your advice.
 
#58
dieter12 said:
We need TO-3 !!!
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Well that's the thing with designs with obsolete parts, if you want an original part you need to pay for it on an authorized seller, Mouser or Digikey for example. Otherwise, you will need to adapt a modern part using TO-3P.
On alliexpress or ebay most likely you will get fake parts (is a BIG issue when dealing with vintage designs)

Other option for vintage designs are NTE parts (but those parts are can be unreliable)
2N6286 cross to NTE 252
2N6284 cross to NTE 251

As reference, Microsemi parts on Mouser around 67 USD, NTE parts on digikey around $10
 
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