Clarett 2Pre USB

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bernatvm

Well-known member
Joined
Dec 4, 2016
Messages
130
Location
Mataró, Catalunya
I have a Clarett 2Pre Audio interface with no input or output sound. When I plug it in all 3 Leds on the front panel power up (Power, Usb and lock). If I plug a microphone I can't get the meter (led arround the potentiometer) to work and the control software doesn't show signal on input either. With outputs I get signal in the software but no real audio output on the TRS. The pot for volume control of the outputs is correctly picked by the software and I can modify the playback volume. Headphones doesn't output a thing.

I opened the interface and the electronics are very samll smd (obiously). Is there any thing I can check without giving it up and sending it to Focusrite? (Warranty finished a year ago)
 
Sounds (no pun intended) like there may or may not be an issue with the converter chip (assuming it's a codec), ooooor perhaps an internal clock issue. Converter chip doesn't get the right clocks (or not all three of them), and thus can't output any digitized audio, or convert any audio to analog.
 
Lets start with some basic obvious questions that are often over looked?

1. do you have the wall wart it came with and are using that?
2.are you on a mac or PC
3. does the control software recognize that a device is connected
4. is it a driver or firmware issue related to the OS?
5. Can the OS use it as an I/O device?
6. is something else using it as an I/O device causing a conflict?
 
3. does the control software recognize that a device is connected
5. Can the OS use it as an I/O device?
6. is something else using it as an I/O device causing a conflict?
I believe these are already answered in the original post (yes / yes / no).
 
Did it ever work? Did you just get it? Did it work before and is this a different computer?
I got it from a friend that gave it to me to take a look at it before sending it to the official focusrite repair. He has used it before with no problem, it just stopped working.

Sounds (no pun intended) like there may or may not be an issue with the converter chip (assuming it's a codec), ooooor perhaps an internal clock issue. Converter chip doesn't get the right clocks (or not all three of them), and thus can't output any digitized audio, or convert any audio to analog.
How can I check that without any of the schematics?
 
Lets start with some basic obvious questions that are often over looked?

1. do you have the wall wart it came with and are using that?
2.are you on a mac or PC
3. does the control software recognize that a device is connected
4. is it a driver or firmware issue related to the OS?
5. Can the OS use it as an I/O device?
6. is something else using it as an I/O device causing a conflict?
1. Yes and using it. Seems the unit is powering up as it should
2. mac
3. Yes the control software indeed recognizes it and changing the monitor control pot on the unit changes the monitor volume on the software
4. It shouldn't
5. Yes, I can select it as an output and input device
6. Not that I'm aware

I really feel its a hardware issue, more than a software one.
 
Best choice would be an oscilloscope. You'd then be able to check both an analog test signal you feed into an analog input, as well as the clock signals. Not at the same time though (kHz range vs. MHz range).
 
Tested with another 12V source?

I see these external PSUs fail all the time. 12,17V would be on the low side if there isn't anything attached.
 
Since all three status LEDs come on (including the power AND USB connection)... I seriously doubt that road's worth going down on (anymore).

If you had bothered reading through the whole thread (more carefully), you might have noticed things like post #8.

https://groupdiy.com/threads/clarett-2pre-usb.79762/post-1023321
Since the computer, OS and the device's own control panel detect it just fine, i think we can safely conclude that the power side, ar least on the input and digital side, is fine. Otherwise, how do you explain the computer connection, if the input power (wall wart) failed under load?
 
One of the RME FF400s I use comes from the bin. It had been thrown out because nobody could get it to connect to the computer. It was tested on Windows, Mac, both with external and firewire bus power.

I couldn't get it to work either, until I connected it to an old G4. Suddenly, it worked with an old driver, of course. I was mystified. I tested on a G5 and that worked too. Same driver.

I was happy with the free FF400, even if I could only use it on a very old Mac. Months later, I decided to try it on an Intel Mac, but couldn't find the original external 12V PSU. So I used another one. Hey, it worked on an Intel Mac too. But not on FW bus power.

What was happening?

When I found the original PSU weeks later, I tried that too. Didn't work. The original switching PSU had a lot of noise, but provided around 14 volts unloaded. And the voltage didn't cave in when connected to a load.

We're years later now. The FF400 still works on my most recent Mac, a 2012. Not the same machine as before. Better bus power?

I've talked about this with a number of people. The theory is that the caps in the internal PSU section could have reformed. I don't know, but it's plausible. The FF400 spent a long while on the shelf before the previous owner threw it out. But it spent six months on the shelf here too. And still worked afterwards.

A test with a known good 12V source is easy enough.

I don't know the recent Scarlets, so I'm not saying your analysis is wrong. Just that strange things happen sometimes. I have other equipment that only seems to work for me... :D

And these external wall warts do fail a lot. In various ways. It's only simple if they go completely dead.
 
Is it a phantom powered Mic ?
If so try it with a dynamic. That will tell you if the phantom power failed.
(or use volt meter on a mic cable plugged in to it)

Try plugging a guitar (TS plug) into it, sometimes that bypasses some of the mic preamp circuit.
If it works, then you know the problem is somewhere in the mic preamp section.

If you playback on it from your DAW over USB, does it come through the headphones?
 
Sounds (no pun intended) like there may or may not be an issue with the converter chip (assuming it's a codec), ooooor perhaps an internal clock issue. Converter chip doesn't get the right clocks (or not all three of them), and thus can't output any digitized audio, or convert any audio to analog.

Now re-reading this post I read three (!) clocks and realized I don't know a damn thing about AD DA and interfacing with computers. Do you happen to know a source I can check to lear about this matter?

The three clocks are audio (44.1kHz), serial/usb timing (something GHz) and... what?
 
I meant strictly the clock signals pertaining to the codec chip (a/d and d/a). Datasheets of those usually describe those well enough.

If you post some internal photos of the thing, i could at least try to point you in the right direction. Reading up on the I2S interface (not to be confused with I2C) might help as well.

In an older TC Electronic Studio Konnekt 48 (that i'm still using to this day), in addition to FireWire issues, it turned out that some of the clock outputs from the main controller were dead, so some of the analog ins and outs were not working (the converter chips weren't getting the required clock signals). Fortunately, those clocks were coming out of several pins, through series resistors, and i managed to jumper some together, and gain use of all the ins & outs. That's until i bit the bullet and replaced the entire (big fat BGA) controller with a scavenged one...
 

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