Hiraga Class A30 w amplifier

[saraswat]

Dear Saraswat,

Excellent work. Looks like professional fabrication. You have used Dale resistors on the board, who is the seller of Dale resistors in India. I am at Lucknow and unable to get any quality component here. Please share the test results with us.

R.K.Katiyar

Hi, R.K., Dale resistors can be procured online from theaudiocrafts ...but you may not get all values, which was the major reason for series and parallel connection of resistors, as I didn't want to put anything other than dale.it also got me to match the values exactly..so good luck...test results will share shortly...hardware is wip. Regards ss😀

 

[saraswat]

BTW how have you drilled the FR$ PCB.

FR7 PCB can be easily drilled with a handheld pcb driller with a 0.8 to 1mm bit. Both the drill and hardware can be procured online...just google the same. I had bought the drill from onlinetps.

 

[saraswat]

some more pics...

 

[saraswat]

All power tracks beefed-up with solder...and board cleaned with accetone..

 

[sergiu2009]

Hi, Guyz...pls check the completed board...cheers

Hi saraswat,
Thing are looking really really good. Now you have to double check the polarity of the diodes and caps and quadruple check the transistor pinout on the pcb. I cannot check from the pictures..
Cheers
Sergiu

 

[bhpistorqintorpm]

@Saraswat
any progress on the build? i have received my pair of PCBs from Jim's audio. now have started hunting for PSU and other components!
how about your power supply? are you done with PSU?

 

[saraswat]

@Saraswat
any progress on the build? i have received my pair of PCBs from Jim's audio. now have started hunting for PSU and other components!
how about your power supply? are you done with PSU?

Hi Buddy, sorry very busy with work and not yet started the PSU, hope you will start earlier than me pls do post pics of your PSU built as well as board...all the best...Regards

 

[captJackSparrow]

Hi Sergiu,

Initially i went through F5 but pricy+scarce FET's made me look into this amp

1. Can you please share Mouser/Digikey/element14 Manufacturer part# or URL for these transistors
2SA872 used BC258B
2CS 1775A used BC 639
2SA634 used BD237
2SC1096 used BD238
Outputs used 2SC 5200 and 2SA1943

Once i decide which amp i want to build(F5 or Hiraga class a 30 w amplifier) i'll get back with more questions 🙂

Regards

 

[kndas]

Suggestions for Jean Hiraga

For replacement of transistors for Jean Hiraga super 30 schematic is suggested as below.
For input stage transistors use BC 546 and BC556
For driver stage transistors use TIP41C and TIP42C for 90%match or MJE15030 and MJE15031 for 100% match.
For output stage C5200 and A1943 is well ok as these are available easily. Instead of so called original Toshiba, try using CDIL product.
These suggestions are based on circuit simulation performance and making many boards.
Thanks
K N Dad

 

[Hjalmar]

Hello All,
I hope someone can help troubleshooting my Hiraga 20W amplifier.
One channel dropped out the other day after 40 years.....
There was a negative voltage at the loudspeaker output

I ordered a couple of remplacement output stage: 2SB688/2SD718
After swapping the old output stage transistors (originals from La Maison d'Audiophile) with the new transistors I noticed there is still a negative voltage at the loudspeaker output. I could not balance the idle current properly and the heatsinks did not get warm at all.
So something is wrong. Can somebody give me a pointer of how I can fix this problem?

Thanks in advance,
Hjalmar