• These commercial threads are for private transactions. diyAudio.com provides these forums for the convenience of our members, but makes no warranty nor assumes any responsibility. We do not vet any members, use of this facility is at your own risk. Customers can post any issues in those threads as long as it is done in a civil manner. All diyAudio rules about conduct apply and will be enforced.

Combined Onaudio thread. (23 threads)

Status
This old topic is closed. If you want to reopen this topic, contact a moderator using the "Report Post" button.
new dawn using ksa992

Hi Harrison,

pls. check.

regards,
joel
 

Attachments

  • ksa992 1diffqc.jpg
    ksa992 1diffqc.jpg
    467.5 KB · Views: 477
updated ksa992 new dawn

Hi Harrison,

I retain the supply in front to easily twist the supply of the board.then the gnd screwed to chassis via copper tube as a source of high quality gnd.I have dedicated lots of time on this board and do some reading.besides what the importance of a good design,good chassis, high quality parts,huge transformer and high value of storage capacitor then at the end you hear a humming and hissing at speaker.at first you can tolerate that...but after spending lots of time in the end it is much better those china made amp which can be bought at lower price and is more quiet than the oneI treasured.

Cant consider an audiophile quality.:ashamed:

right now I have been asking my friends here(technician) where I can bought parts for this amp.I also have with me this supply of basic ef of sloan so about power supply I will have no problem.tools may be I can borrow.

regards,
drowranger
 

Attachments

  • NEW DAWN FOR UPLOAD.zip
    190.3 KB · Views: 68
  • TOP VIEW.jpg
    TOP VIEW.jpg
    429 KB · Views: 361
Hi Drowranger ,
Nice PCB , but you have to reconsider some details . Output tranies are to close to each other (see attached pic in red circle ) they can't work well regarding heat spread. Elyt caps are to close to power resistors and will dry quickly, and you mess signal ground with power ground , and more you need larger trace for C and E of finals tranies .:)
Regards Alex.
 

Attachments

  • TOP VIEW.jpg
    TOP VIEW.jpg
    474.5 KB · Views: 311
I've been listening to the DIFFQC today and I can't decide wich I like most - the DIFF or the SYMEF. They're both very good sounding amps and choosing one between the two is quite dificult. I've also been playing with the bias setting and latter I'll post my findings. I think Harrison has reason to be very proud of his two babies. ;)
 
regarding pcb,

Hi Drowranger ,
Nice PCB , but you have to reconsider some details . Output tranies are to close to each other (see attached pic in red circle ) they can't work well regarding heat spread. Elyt caps are to close to power resistors and will dry quickly, and you mess signal ground with power ground , and more you need larger trace for C and E of finals tranies .:)
Regards Alex.

about capacitor I think they will not quickly dry because ac voltage at output is not constant.it depends upon the amplitude of music.star gnd is useless when u use wire that is longer than the tracks connected to star gnd(pcb).a well designed pcb dont use 10 ohms resistor:D.that is why star gnd should be close as possible to amp.same way I did in SYMEF.;)

regards,
joel
 

Attachments

  • 04012012294.jpg
    04012012294.jpg
    884.1 KB · Views: 190
  • 04012012293.jpg
    04012012293.jpg
    861.4 KB · Views: 308
Thank you for the kind comments Paulo, looking forward to your bias findings ;) . The formula seems to be spot on. Now I need ideas on how to get 29998 people to experience this phenomena :D and report back to this thread. Then use the data to create another hot paper for publishing.

Yes Joel, borrow those tools and lets get a review :D . You have great workmanship.
 
Last edited:
Hi Paulo,

Thanks for confirming that the flat pack version of the amplifier can be safely biased at 33mV across the emitter resistors (Correct me if am wrong). Thank you for the work you have put into the amplifier and the information you have provided.

I have a few more requests for you ;)
What do you think of the amplifier when playing

1. Piano
2. Acoustic guitar
3. Rock
4. Rap with pulsating beats
5. Techno
6. Vocals

etc

Your contributions, those of Drow and others are instrumental in confirming the validity and universal acceptability of the models. Thank you.:up:

kind regards,

Harrison.
 
Status
This old topic is closed. If you want to reopen this topic, contact a moderator using the "Report Post" button.