Search found 9 matches
- Thu Feb 23, 2017 8:03 am
- Forum: Pro Audio Design
- Topic: Using the THAT1646 As A Transistor Pre-Driver/Headphone Amp
- Replies: 80
- Views: 354152
Re: Using the THAT1646 As A Transistor Pre-Driver/Headphone
Hello, Had built several of these for myself and family, very happy with the resulting sound. Do have a question though. As I have a brother that would like a little more volume with the headphones he is using, couldn't I just change out the 1246 chip for the 1243 chip and have 3 DB less loss? THAT ...
- Tue Dec 23, 2014 7:34 am
- Forum: Build
- Topic: Dual Class-A Line and Headphone Output Board Construction Information
- Replies: 133
- Views: 596630
Re: Dual Class-A Line and Headphone Output Board Documents
Hi Wayne, Did try to attach some pictures, but didn't seem to be able to. Don't have a web site to post them on as haven't really needed one for anything else. If there is easy way to attach some pics, let me know and I will do so. Have a good shot of the transistors. If you want to, let me know you...
- Mon Dec 22, 2014 7:22 am
- Forum: Build
- Topic: Dual Class-A Line and Headphone Output Board Construction Information
- Replies: 133
- Views: 596630
Re: Dual Class-A Line and Headphone Output Board Documents
Hello, Got a little carried away trying to make this amp good enough to keep me happy for a number of years. Sounds very good indeed, limit is my headphones at this point. Used a MR room proof box that had 1/2" thick aluminum walls, good brass with gold plate connectors, alps blue pot for volum...
- Thu Dec 04, 2014 5:47 am
- Forum: Build
- Topic: Dual Class-A Line and Headphone Output Board Construction Information
- Replies: 133
- Views: 596630
Re: Dual Class-A Line and Headphone Output Board Documents
Hi,
No, exposed metal on the back side. Glad I hesitated and checked before applying power. Should have insulators tomorrow. Thanks for the help.
Regards,
Greg
No, exposed metal on the back side. Glad I hesitated and checked before applying power. Should have insulators tomorrow. Thanks for the help.
Regards,
Greg
- Wed Dec 03, 2014 11:53 am
- Forum: Build
- Topic: Dual Class-A Line and Headphone Output Board Construction Information
- Replies: 133
- Views: 596630
Re: Dual Class-A Line and Headphone Output Board Documents
Hello,
Transistors were from Digikey.com, detail on one of them below. Both were from same company and the collector of all the transistor shows a short to the heat sink.
Regards,
Greg
Manufacturer STMicroelectronics
Manufacturer Part Number BD139-16
Description TRANSISTOR NPN 80V 1.5A SOT32
Transistors were from Digikey.com, detail on one of them below. Both were from same company and the collector of all the transistor shows a short to the heat sink.
Regards,
Greg
Manufacturer STMicroelectronics
Manufacturer Part Number BD139-16
Description TRANSISTOR NPN 80V 1.5A SOT32
- Wed Dec 03, 2014 7:16 am
- Forum: Build
- Topic: Dual Class-A Line and Headphone Output Board Construction Information
- Replies: 133
- Views: 596630
Re: Dual Class-A Line and Headphone Output Board Documents
Hello,
Thanks for the feedback. Did get a chance to check these transistors and they indeed do need insulators. Have some on order and should have the amp working this weekend.
Regards,
Greg
Thanks for the feedback. Did get a chance to check these transistors and they indeed do need insulators. Have some on order and should have the amp working this weekend.
Regards,
Greg
- Mon Dec 01, 2014 10:36 am
- Forum: Build
- Topic: Dual Class-A Line and Headphone Output Board Construction Information
- Replies: 133
- Views: 596630
Re: Dual Class-A Line and Headphone Output Board Documents
Hello, Was hoping to confirm something before I get to applying power to my new headphone amp. Believe I read somewhere that the BD139 & BD140 transistors used in this project did not need a insulator pad between them and the heat sink. Heat sink is not grounded to the case and I did apply a tou...
- Tue Jul 22, 2014 8:00 am
- Forum: Build
- Topic: Dual Class-A Line and Headphone Output Board Construction Information
- Replies: 133
- Views: 596630
Re: Dual Class-A Line and Headphone Output Board Documents
Hi Wayne, Thank you for the feedback. Seems likely should be able to drive them loud enough as is. As far as biasing further class A, I have collected heat sinks off old boards and such going in the trash for years and have quite a selection already on hand. Haven't yet had one wear out. ;) Really i...
- Thu Jul 17, 2014 12:51 pm
- Forum: Build
- Topic: Dual Class-A Line and Headphone Output Board Construction Information
- Replies: 133
- Views: 596630
Re: Dual Class-A Line and Headphone Output Board Documents
Hello all, Had been looking for a really good headphone amp to build for some time and believe this is likely it. Would just like to ask if anyone has experience in driving Planar headphones with it. I believe that it should have plenty of drive from what I am reading, but as am going to be buying r...