RME User Forum — Octamic D no input signal

Re: Octamic D no input signal

null@example.com (Jeff) — Tue, 18 Nov 2025 21:30:57 +0000

Great, thanks for letting us know. It seems this was the internal power regulator that needed service.

Re: Octamic D no input signal

null@example.com (shredmechanic) — Tue, 18 Nov 2025 21:25:58 +0000

I wanted to update this in case someone else has a similar problem. I sent my original Octamic-D off for service and it was the "internal power supply regulator circuit". I just got it back today and it works like new! A big thanks to Jeff at Synthax/RME and Dave at Doc's Radio in Ohio for the great support and fast turnaround.

Re: Octamic D no input signal

null@example.com (Kubrak) — Mon, 03 Nov 2025 09:06:04 +0000

I do not want to open my Octamic-D (I did that with ADI-2 mk1 when one guy needed photographs of mains section and readout of ellements...) as it would break guarantie label. (Of course, it is not in guarantie, but if I sell it, label prooves, unit has not been open and possibly repaired or whatever...).

And in ADI-2 (that also has external PSU) is mains circuitry, something that converts AD/DC of rather wide voltage range to what is needed for unit circuitry.

So, something similar must be in Octamic-D. Beside handfull of capacitors, coil or transformer and resistors (probably also diodes), there was a simple integrated circuit.

Maybe OP, could open his Octamic and have a look. Those ellements were located close to PSU inlet. I guess, it will be similar in Octamic. It is natural place the power part close to inlet.

Re: Octamic D no input signal

null@example.com (waedi) — Sun, 02 Nov 2025 23:14:06 +0000

The three mic inputs have plenty of gain but the preamp losing power shortly after power up...
It has no internal power PSU but it has some kind of internal power distribution and something seems broken.
As the issue appeard overnight it is not a slow corrosion or drying out capacitors, but something burnt out I guess.

To me it looks like need for repair. I have still no better idea.

Your video is good, thanks for staying on topic.

Re: Octamic D no input signal

null@example.com (shredmechanic) — Sun, 02 Nov 2025 20:03:57 +0000

Sure thing; hope this helps

https://www.youtube.com/watch?v=3cuZ0S177BA

Re: Octamic D no input signal

null@example.com (RME Support) — Sat, 01 Nov 2025 21:22:01 +0000

Can you show exactly what you see at the ADAT inputs? Complete silence or the AD self noise around -100something?

Re: Octamic D no input signal

null@example.com (Kubrak) — Sat, 01 Nov 2025 20:40:02 +0000

If ADAT seems to work, at least some part of power source must work. I do not know, if it is case for Octamic-D, devices often use two or more voltages, so maybe something from power supply works and something does not.

It seems to me unprobable all Mic preamps would fail. It could happen only if something real bad happens like total failure of power source resulting in too high voltage, or the strike of lightning to power net... Or like.

Re: Octamic D no input signal

null@example.com (shredmechanic) — Sat, 01 Nov 2025 20:09:53 +0000

No signal anywhere, no "SIG" light, no analog output, no signals on the ADAT output. The Octamic is connected to a Fireface UFX via ADAT and that connection appears fine, the UFX shows a good sync at 48kHz on ADAT1, however still no signal. The Octamic behaves as if all of the mic preamps suddenly died and have zero gain.

Re: Octamic D no input signal

null@example.com (RME Support) — Fri, 31 Oct 2025 22:08:31 +0000

No signal where? Have you tried the analog outputs? Is there a light on the ADAT output? If yes, what does the device it's connected to show at the input?

Re: Octamic D no input signal

null@example.com (waedi) — Fri, 31 Oct 2025 19:25:12 +0000

I have no other idea than send in the unit for repair.

Contact the RME service partner in your country

Re: Octamic D no input signal

null@example.com (shredmechanic) — Fri, 31 Oct 2025 18:07:09 +0000

I finally got the Octamic D removed from the rack and on my workbench. I don't see anything that looks damaged, but I'm not very experienced with electronics repair either so I could be missing something.

I tried the Octamic with all phantom power off but still no signal.

Is there anything else I should try?

Re: Octamic D no input signal

null@example.com (waedi) — Wed, 29 Oct 2025 21:55:54 +0000

shredmechanic wrote:

The spare power supply specs are 12V/2.5A/center positive.

The specs are ok, polarity doesn't matter, voltage from 8 to 20 V DC is good.

Did you try with all phantom power OFF ?

Re: Octamic D no input signal

null@example.com (Kubrak) — Wed, 29 Oct 2025 19:24:20 +0000

Have a look inside. If it is done similarly, like in ADI-2 (non pro, mk1), there are few caps, one IO (only few contacts) and transformer (or coil, I am not sure).

You could try to check, if there is problem in power section, or other part..... But it looks like, it might be power section.

Re: Octamic D no input signal

null@example.com (shredmechanic) — Wed, 29 Oct 2025 19:01:47 +0000

The spare power supply specs are 12V/2.5A/center positive.

The Octamic D is connected to a Fireface UFX via ADAT and there's no signal at the direct ouptuts.

When the Octamic powers on all of the LED's flash including the "SIG" LED's.

Any other ideas? I'm pretty inexperienced with soldering but if it's something simple like changing out some bad caps I may be able to swing it.

Re: Octamic D no input signal

null@example.com (Kubrak) — Wed, 29 Oct 2025 17:19:01 +0000

RME Support wrote:

Is there a signal at the analog outputs?

Good question! It also may be so, that just SIG LEDs do not work.... And everything else works.