My latest project - DAC + headphone amp - Page 11

CarHifi-Store · 14th June 2009, 03:54 PM

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 · 14th June 2009, 04:25 PM

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 · 15th June 2009, 09:22 PM

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 · 10th August 2009, 10:16 PM

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 · 18th December 2009, 06:24 PM

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 · 13th December 2010, 02:31 PM

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

10th August 2009, 10:16 PM	#104
jeff-o2000 diyAudio Member Join Date: Aug 2009	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!

18th December 2009, 06:24 PM	#105
jeff-o2000 diyAudio Member Join Date: Aug 2009	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!

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14th June 2009, 03:54 PM	#101
CarHifi-Store diyAudio Member Join Date: Jun 2009	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

14th June 2009, 04:25 PM	#102
kct diyAudio Member Join Date: Dec 2006	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

15th June 2009, 09:22 PM	#103
CarHifi-Store diyAudio Member Join Date: Jun 2009	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

13th December 2010, 02:31 PM	#106
oogly diyAudio Member Join Date: Dec 2010	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