My latest project - DAC + headphone amp

[CarHifi-Store]

Hello,

i´m Frank an im new here. I´f build a simple DAC with near the same schematic, but it make trouble.
DAC is the PCM1792, I/V-Stage the OPA4134. It works and sound, but the OPA heat up that he burns my fingers after a few seconds. Over the resistors (750 Ohm) i have a voltage from 4.4V, so the output current is 5.8mA. It´s all in green range for the OPA, why he heating? Normal?

thx for replay
Frank

 

[kct]

Hi Frank,

das kann normal sein, mein HPA wird auch ganz schoen warm. Gemessen an der 120V AC Zufuhr zieht meiner 35mA ! Kleb ein kleinen Kuehlkoerper auf den Chip und vielleicht auch auf den letzten Verstaerker Chip.

mfg

Kay

 

[CarHifi-Store]

Hello,

thanks for replay, i will try it with an heat sink on the OPA.
Additional informations:
In Bipolar Zero Stat the current to the OPA 4134 is 12mA on the +15V-Rail and 60mA on the -15V-Rail. Each Amp drives 12mA - thats IMHO seems to be OK, can everybody confirm this?

Hallo kct,

vielen Dank für Deine Antwort. Heute hab ich noch mal gemessen, der OPA zieht 60mA an -15V und 12mA an +15V. Jeder Kanal treibt 12mA - sieht für mich alles OK aus. Dennoch wundere ich mich etwas über die Erwärmung.
Werde es mit einem Kühlkörper probieren, mal sehen ob was abbrennt....

Gruß Frank

 

[jeff-o2000]

Any PCBs floating around?

Hi all,

I was introduced to this forum by another member (and co-worker). I'd love to build one of these myself, but before I go to the trouble of having a board fabbed I thought I'd ask if there are any still floating around, ready to populate.

Let me know!

 

[jeff-o2000]

It works!

Funny, I thought someone else might have replied in the meantime, but I guess I'll reply to my own post!

I just finished building an amp of my own, after lots of mods and late nights... It sounds fantastic, of course. More details eventually!

 

[oogly]

Hi gmarsh,
i'm new here and i'm just a crazy Audiophile. I found your topic very interesting but i have a question. Is it possible to be made with USB port?

Thanks in advance.

Best regards,
O