H22
100+ Head-Fier
- Joined
- Jan 29, 2009
- Posts
- 328
- Likes
- 17
Ok, now for some good news! All the parts arrived (finnally) and I assembled another amp. I changed 3 things when I built this amp:
1, the opamps I used on this one are opa1641s
2, used the pn4392 for Q3
3, used 1uf polyester caps for the C5 location.
Absolutely no oscillation, DC offset is 1mv or less! I am using my "test" headphones, a pair of beats solos, so I won't get into how it sounds, other than to say it does sound very promising. I think got the other amp I will replace the C5's, and possibly change the opa637's out for 627 units. I have one set of PCBs left, think that will be used for the AD8610 opamps I have. Pics comming soon. Now all I have to do is built the faceplate for the Hammond case and I will have a truly pocketable PPA!
1, the opamps I used on this one are opa1641s
2, used the pn4392 for Q3
3, used 1uf polyester caps for the C5 location.
Absolutely no oscillation, DC offset is 1mv or less! I am using my "test" headphones, a pair of beats solos, so I won't get into how it sounds, other than to say it does sound very promising. I think got the other amp I will replace the C5's, and possibly change the opa637's out for 627 units. I have one set of PCBs left, think that will be used for the AD8610 opamps I have. Pics comming soon. Now all I have to do is built the faceplate for the Hammond case and I will have a truly pocketable PPA!