Behringer U-Phoria UMC202HD as a DAC

[solderdude]

When you are going to use the Behringer and have dialed down the volume digitally by -3dB then your output voltage (RCA out) will be around 0.8V.
Output is specified as +3dBu = 1V FSD on the main-outs. You will need to use TSJack to RCA converters. Set the volume control on max. output setting.

The max output voltage the O2 itself can reach = 7.2V (= 200mW in 250 Ohm)
This means that the input of the O2 won't even clip when the Behringer is at max. output voltage (1V) in high gain mode.

So I would suggest to use the O2 on low gain (to get a pleasant volume control range) and if you need to go a bit louder than that at max. volume setting switch to high gain.

 

[Bob-23]

When you are going to use the Behringer and have dialed down the volume digitally by -3dB then your output voltage (RCA out) will be around 0.8V.
Output is specified as +3dBu = 1V FSD and I presume on the line-outs.
The line-outs are fixed in output voltage, the main out (TRS jack) has a volume control on the front.

The max output voltage the O2 itself can reach = 7.2V (= 200mW in 250 Ohm)
This means that the input of the O2 won't even clip when the Behringer is at max. output voltage (1V) in high gain mode.

So I would suggest to use the O2 on low gain (to get a pleasant volume control range) and if you need to go a bit louder than that at max. volume setting switch to high gain.

I can confirm solderdude's data. Just measured it, 1 kHz test signal: Output: 1,096V, and dialed down by 3 dB: 0,779V.
If you had a high voltage source like a cd-player which outputs 2V, gain 1x would be useful, exactly for volume control reasons (more channel imbalances in lower region of volume control), but if necessary that could be down ex post (e.g. by cutting off a resistor). I use mine with gain 1x & gain 2,5x, but as the Behringer is on the lowish side, a bit more than 2,5x is not wrong, in particular when applying eq. So you could go with gain 2,5x plus gain 4x or gain 5x, or just let it standard, as solderdude supposes.

 

[Spinkicked]

ou will need to use TSJack to RCA converters. Set the volume control on max. output setting.

So when I will have the volume dialed down digitally by 3 db, instead of using rca to rca cables, I will use TSJack to RCA converters; going out from Behringer's "6,3mm Main Outs" that are in the back of the device to O2's "RCA inputs" that are also in the back, am I right?

So I would suggest to use the O2 on low gain (to get a pleasant volume control range) and if you need to go a bit louder than that at max. volume setting switch to high gain.

I was actually thinking to use it on low gain. I suppose it is mostly better to use it on high volume in low gain than on low volume in high gain.

but as the Behringer is on the lowish side, a bit more than 2,5x is not wrong

This is what I am afraid of, actually. If I decide on low gain and it is not enough, then I would have to switch back to 6,5x. That is why if there would be a more optimized gain preference that you could suggest, but like you guys said maybe it is better to leave it as it is standart.

All these informations can also apply to JDS Labs Atom, right?

One question always bothers me. Will I ever have to control or adjust any of the knobs of Behringer when using the amplifier volume knob?

 

[Bob-23]

You will need to use TSJack to RCA converters

I did't see it when posting the last post - Op is going to buy the 204HD, not the 202HD, hence RCA-RCA cables are needed.

I was actually thinking to use it on low gain.

The lowest gain possible is mostly preferable.

This is what I am afraid of, actually. If I decide on low gain and it is not enough, then I would have to switch back to 6,5x

I get along well with gain 2.5x - inspite of the lowish output, and inspite of eq'ing - which is lowering dBs by about 6 db in addition. But sometimes I think it could be a bit more. So gain 2.5x plus gain 4x or 5x could be a middle-of-the road if you hook up other souces than the Behringer (a bit stronger ones ). So when 2.5X is not sufficient you switch to 4x or 5x. Then the step is not that big. (But it can be changed even afterwars with a soldering iron .)

One question always bothers me. Will I ever have to control or adjust any of the knobs of Behringer when using the amplifier volume knob

Not when using the Behringer as a DAC - as I said the phone knob is only for headphone out. And the other knobs are for using the device as an ADC/Interface.

All these informations can also apply to JDS Labs Atom, right?

The Atom is capable of outputing higher voltage.

 

[solderdude]

The Behringer UMC202 only has TRS jack outputs that are controled by the volume control in the front. For this you will need adapters.
(in the thread title it says UMC202)
The UMC204 has RCA outs (that are not controled by the main outs volume control) and volume controled main outs. You can also mix the inputs to the main out but can not mix the inputs to the RCA out.
None of the volpots on the 204 have any influence on the RCA outs.

The O2 only has 3.5mm TRS stereo jack inputs. (unless it is a special of sorts)

So when using this combo you need a 3.5mm TRS to RCA cable and TS jack to RCA or, when using the 204 a 3.5m TRS jack to RCA.
To be honest, I don't know if the main outs are balanced and how these like it when the negative balanced half is shorted by the TS adapter.
For my own usage I made a cable that has a TRS jack with the Ring left open to an RCA connector.

The Atom has RCA inputs so an RCA-RCA cable would be needed.

For the best results you would have to dial down the volume on the PC a little bit. When you don't some peaks can have a bit of distortion.
No idea how audible this is.

6.5x gain is not any problem.

 

[Bob-23]

The Behringer UMC202 only has TRS jack outputs that are controled by the volume control in the front. For this you will need adapters.
(in the thread title it says UMC202)
The UMC204 has RCA outs (that are not controled by the main outs volume control) and volume controled main outs. You can also mix the inputs to the main out but can not mix the inputs to the RCA out.

The O2 only has 3.5mm TRS stereo jack inputs. (unless it is a special of sorts)

So when using this combo you need a 3.5mm TRS to RCA cable and TS jack to RCA.
To be honest, I don't know if the main outs are balanced and how these like it when the negative balanced half is shorted by the TS adapter.
For my own usage I made a cable that has a TRS jack with the Ring left open to an RCA connector.

For the best results you would have to dial down the volume on the PC a little bit. When you don't some peaks can have a bit of distortion.
No idea how audible this is.

6.5x gain is not any problem.

OP is going to buy the 204HD!!! And I recommended him the desktop version of the O2 - with regular RCA-line-ins!

 

[Spinkicked]

Ok, I guess it was my title that confused solderdude and made him suggest TRS to RCA cable. I got it now. With O2 + UMC204, RCA to RCA is enough.

I will go with the standart gain 2.5x/6.5x as it would be enough for me, I am hoping.

Thank you both of you, for sharing your time by writing and your wisdom with me.

 

[solderdude]

With some new and older O2 and UMC204 you will need a 3.5mm TRS mini-jack to RCA cable. Not all of them have RCA inputs.
The newer JDS labs O2 does seem to have RCA inputs and a 3.5mm stereo input on its front.
This one: http://www.headnhifi.com/O2-desktop-amplifier also does have RCA in and out so find out for certain what you are buying.
They also sell specials..

 

[Bob-23]

I recommended Op head'n'hifi. So that's what we get:

The O2 (Objective2) Headphone Amplifier is the first design of the US blogger and electrical engineer NwAvGuy which is produced under the Common Creative License


Technical Specifications:

• RCA and 3.5mm Input Connector
• 6.4mm headphone socket
• RCA output
• ALPS Stereo Potentiometer
• 220V~ 15 VAC 500mA Power supply (Euro plug)
• Gain switch (2.5x and 6.5x gain as standard)
• Size 108.5 x 84 x 30 mm (without Volume Knob)
• Black and Silver versions available

http://www.headnhifi.com/amplifiers/desktop-headphone-amplifiers/O2-desktop-amplifier

 

[Bob-23]

I will go with the standart gain 2.5x/6.5x as it would be enough for me, I am hoping.

That'll be alright! And can be modified if not!

 

[Spinkicked]

The links that you have provided were the ones that we were talking, so the connections will be done in final with Rca to Rca.

Bob-23, you have mostly convinced me with the durability, longevity and fixability of O2, so I will probably go with that. It is the same price of Atom. I don't need all that power that Atom and Schiit provides anyway. Everything seems perfect on paper and I hope I will get the volume and quality on low gain with all of them connected together.

 

[Bob-23]

The links that you have provided were the ones that we were talking, so the connections will be done in final with Rca to Rca.

Bob-23, you have mostly convinced me with the durability, longevity and fixability of O2, so I will probably go with that. It is the same price of Atom. I don't need all that power that Atom and Schiit provides anyway. Everything seems perfect on paper and I hope I will get the volume and quality on low gain with all of them connected together.

Good luck & enjoy the music, and - it's all about a hobby...

 

[Bob-23]

durability, longevity and fixability

I've just read a new article of Rod Elliott's, regarding exactly that subject - thought it might interest you. His 'ESP'-site is arguably world's best DIY-audio site. He knows what he's talking about. Here's the content of the article:

• Projects, DIY & Sustainability
  
  ​
• Introduction
• 1 ESP Projects
• 2 SMD (Surface Mount Devices)
• 3 Repairability
• 4 Recycling/ Re-Purposing
• 5 Other Appliances
• 6 A Complete Waste Of Materials
• 7 The IoT and IIoT
• 8 The Environment
• Conclusions
• References

in: https://sound-au.com/
>Articles>Feature Articles

Have a good time!

 

[SaulOteng1467]

Hi I have this U-Phoria UMC202HD, does any body know the brand and model name of the DAC that is used inside of this? I have looked on google but cant seem to see any data on this?

 

[solderdude]

Probably the same as in the UMC204HD

 

[Spinkicked]

Probably the same as in the UMC204HD

Hi there,
I have at last bought some hardware equipment but I couldn't have the sound come from the headphone amp
I bought Motu m2 and schiit heresy and connected as you have described.

 

[solderdude]

And you are getting no sound out of the Motu+Heresy ?

 

[Spinkicked]

And you are getting no sound out of the Motu+Heresy ?

Stupid me, I was using the headphone volume knob instead of the monitor knob. But you know what I have realized? The Motu M2 amp is much stronger than Schiit Heresy. Both in sound quality and quantity.

 

[solderdude]

set the gain switch on the Heresy (on the back) to Hi

HP out from the Motu = +12.5dBu = 3.2V
Heresy (hi gain) = +21dBu = 9V so much more powerful

 

[Spinkicked]

set the gain switch on the Heresy (on the back) to Hi

That I did but the static noise that is coming along with the sound is too much. I don't know why it has that.