Selling a pair of 41z boards if anybody wants to try this lovely design:
FS: Sapphire HPA 4.1z
Thanks again Richard for the PCBs!
FS: Sapphire HPA 4.1z
Thanks again Richard for the PCBs!
Hello, Richard,
Long time no tweaking; still listening to my prototype 4.0b, with a resistor kludge on one board, goldpoint volume pot and Mu-metal shielding on my torroidals and separation from the boards. You sent me 4.1 boards back then, and I bought all the components to populate them so I could try the closed (or was it open?) configuration. That second build is still in the hopper - I haven't felt that I'm missing anything - I'm too happy - with my 4.0b. After a quick skip some of the last few years chatter I didn't see anything I felt I needed to try, or have I missed something? Very happy with Sapphire here!
Long time no tweaking; still listening to my prototype 4.0b, with a resistor kludge on one board, goldpoint volume pot and Mu-metal shielding on my torroidals and separation from the boards. You sent me 4.1 boards back then, and I bought all the components to populate them so I could try the closed (or was it open?) configuration. That second build is still in the hopper - I haven't felt that I'm missing anything - I'm too happy - with my 4.0b. After a quick skip some of the last few years chatter I didn't see anything I felt I needed to try, or have I missed something? Very happy with Sapphire here!
After a long break I had time to turn ON the project. 
The power supply is something basic LM317 / 337 and has a little 100Hz. I need to make one right ... Not one, two.
This aspect is very important as well as the selection of the transistors and other components. Keep that in mind!
The sound ...
Compared to SE it is a little different but just as good, or vice versa.
Thank you @rjm.
The power supply is something basic LM317 / 337 and has a little 100Hz. I need to make one right ... Not one, two.
This aspect is very important as well as the selection of the transistors and other components. Keep that in mind!
The sound ...
Compared to SE it is a little different but just as good, or vice versa.
Thank you @rjm.
Attachments
I'm very new to DIY audio.. I wanted to ask, is this a good project for someone who is just starting off with DIY? also I see that there is a blue pot on the board itself, do I need measuring equipment to finish this project? I did do some reading about the project so apologies if I've missed something very obvious..
Hello eveyone,
I have just finished my Sapphire HPA.
I made my own PCBs, because I am always doing it for my projects.
Other than described, I am running the amp on batteries. 2 x 15 eneloop cells (2000 mAh each) giving +/- 18-20 V per rail.
I have set the amp to close loop amplification with R2A set to 680 ohms and R3A set to 2200 ohms.
Sound is very crisp and clear and detailed, I really like it! I am using the amp with Denon AH-D7200 headphones with rather low impedance (about 25 ohms, I think)
The output trannies BD135 and BD136 are getting rather hot (ha, this is the high-current class A version!), so I am using bigger heatsinks, resulting in 60-70 degrees temperature.
I have not measured total power consumption or current draw, but I hope, that my batteries (2000 mAh per rail) will last some hours.
Thanks to Richard for this fine amp!
Best regards and happy diying
Michael
I have just finished my Sapphire HPA.
I made my own PCBs, because I am always doing it for my projects.
Other than described, I am running the amp on batteries. 2 x 15 eneloop cells (2000 mAh each) giving +/- 18-20 V per rail.
I have set the amp to close loop amplification with R2A set to 680 ohms and R3A set to 2200 ohms.
Sound is very crisp and clear and detailed, I really like it! I am using the amp with Denon AH-D7200 headphones with rather low impedance (about 25 ohms, I think)
The output trannies BD135 and BD136 are getting rather hot (ha, this is the high-current class A version!), so I am using bigger heatsinks, resulting in 60-70 degrees temperature.
I have not measured total power consumption or current draw, but I hope, that my batteries (2000 mAh per rail) will last some hours.
Thanks to Richard for this fine amp!
Best regards and happy diying
Michael
Attachments
Another Sapphire is born.
Hi everyone,
After a long time and other projects I have finally been able to finish it.
Unfortunately I no longer have access to the marking laser from the company where I work, so the housing is bare.
An error has crept in somewhere as well, since it is very quiet and starts to distort strongly from a poti position of around two o’clock.
Does anyone have any idea what the error could be?
Hi everyone,
After a long time and other projects I have finally been able to finish it.
Unfortunately I no longer have access to the marking laser from the company where I work, so the housing is bare.
An error has crept in somewhere as well, since it is very quiet and starts to distort strongly from a poti position of around two o’clock.
Does anyone have any idea what the error could be?
