1 (edited by jouleskey 2020-10-17 11:32:14)

Topic: Heat and constant "3/4 overload short" error message

Just installed an ADI-2 Pro FS which is working alongside my Fireface 800 and Cubase 10.5 on PC. I've a couple of things going on am hoping there are answers to here.
Firstly, its been on for a few hours and is boiling hot. Is that normal and how's users electricity bill as it's like a heater? Touching the top is uncomfortably hot.

Also, keep getting this message when plugging in my headphones saying

"Overload Short Detected PH 3/4 deactivated - pull out PH plug 3/4 to reset output state"

The headphones aren't loud and it's certainly not driven from Cubase monitoring. Have tried different headphones, though still the same issue.

2 (edited by KaiS 2020-10-17 18:03:52)

Re: Heat and constant "3/4 overload short" error message

If you headphones' cable doesn't have a short, - test another headphone/cable, - the headphone amp is very likely broken, probably one of the six OPA1688.
A common fault.

-> Service


Other than that, the ADI-2 Pro gets quite warm, ca. 35-50°C, depending on the external circumstances, that's kind of normal.
Watch out for good airflow possibility.

The idle power is 12W, this would equal 105 kWh or ~ €30 per year, if never switched off - not reccomended!


EDIT: I just measured my ADI-2 Pro: idle temperature on casetop is 12°C, inside 26°C above ambient temperature, under perfect ventilation conditions.

Re: Heat and constant "3/4 overload short" error message

Thanks KaiS. Have tried 3 pairs of headphones to the unit and then tried a headphone amp attached all with the same issue. Tried resetting it though all the same issue. Shame as it sounded so sweeeet.

As for the heat, I am likely to be doing 10hr sessions with it daily, so it would be switched off.

Re: Heat and constant "3/4 overload short" error message

known issue.  If you are still in warranty, you can just ask your dealer to take it and send to RME to fix it for you for free.

I do hope RME could fix devices having this problem for free even after warranty ends, as this is a pretty common issue for the adi-2 family.

Re: Heat and constant "3/4 overload short" error message

It is surprising having only plugged it up yesterday. With the audio running as low as 1/4 of the way up, that's a sad start. Was blown away by the detail.

6 (edited by KaiS 2020-10-17 18:03:35)

Re: Heat and constant "3/4 overload short" error message

jouleskey wrote:

It is surprising having only plugged it up yesterday. With the audio running as low as 1/4 of the way up, that's a sad start. Was blown away by the detail.

The failure rate is highest in the first six months with electronics usually.

Besides that, the OPA1688 seems to have a higher failure rate than average electronics parts have.

I had to replace one already too, and believe me, that's no fun to do.
I would not suggest this to anybody with less than very, very good experience and equipment for SMD soldering.


I just measured my ADI-2 Pro: idle temperature on casetop is 12°C, inside 26°C above ambient temperature, under perfect ventilation conditions.

Re: Heat and constant "3/4 overload short" error message

KaiS wrote:

I had to replace one already too, and believe me, that's no fun to do.
I would not suggest this to anybody with less than very, very good experience and equipment for SMD soldering.

curious how do you know which one failed in the first place?

8 (edited by KaiS 2020-10-17 22:29:53)

Re: Heat and constant "3/4 overload short" error message

ning wrote:
KaiS wrote:

I had to replace one already too, and believe me, that's no fun to do.
I would not suggest this to anybody with less than very, very good experience and equipment for SMD soldering.

curious how do you know which one failed in the first place?

I simply measured across the 6 individual 47 Ohms summing resistors.
Different voltage - found.


But, don't try to repair this by yourself.

The OPA1688's underneath thermal pad is soldered to the multilayer board, through-connected to the board's internal ground plane layer as heatsink.

Because of that, applying heat from above only will not work, before it gets hot enough to melt the solder paste the new chip is toast.

You would have to apply a lot of well dosed heat to that spot from underneath.
Too much heat and the board is toast.
Not enough, and the thermal pad does not connect, the chip will overheat when used.
An infrared thermometer is needed to check the success under working condition.


I want to stress again: without proper equipment and a lot of (very small type) SMD experience this cannot be done!
Some of you might have access to such, everybody else
-> RME service department.


A quick and dirty workaround is, to unlink the defective channel by removing it's 47 Ohm resistor.
Unsolder it, fix it on one side only, so it won't get lost.
This reduces the headphone amp's max output current by 1/6, to 83%, but makes the headphone amp usable again until there's time to order a proper chip replacement at RME's service department.

Re: Heat and constant "3/4 overload short" error message

> But, don't try to repair this by yourself.

Thanks for the advice! Maybe next time it fails I would ask local mobile phone repair shops. They seem to have a lot of experience on SMT parts.

> A quick and dirty workaround is, to unlink the defective channel by removing it's 47 Ohm resistor.

That's actually a good suggestion. Thanks!