Questions about how Headphones Amp and DAC work

[R-Oak]

I recently purchased my first pair of decent headphones (hd650) and I would like to purchase a DAC+Amp to go whit them, but i had some really rooky question to ask first
from all the reading I have done this is what i have learned ( please correct me if i'm wrong ) or add details where you feel that something is lacking, i wont take it personal


1. most 100$+ DAC (schiit modi/ODAC/Audio-GD) can drive headphones correctly and speakers alike?

a. Is it possible using something like the schiit modi uber that has 2 set of output to be connected to a pair of active speakers and to be connected to a headphone amp at the same time (not needing to re-rewire) and to chose the output (if the headphones are plugged in or not)

b. what is low or hight gain and why is it important

2. Most headphones amp in this 100-300$ range can drive a lot of headphones and every single one of those amp has a different signature (compared to DAC, that shouldn’t do a big difference)

a. those amp can also be used as preamp for active speakers.

b. Preamps (when used whit speakers) are technicaly just volume control ?



A few question about imputs

3. Most people use optical to connect their console to a DAC

a. Would it also work whit RCA ? if yes, would it be worst ?

4. Most people like to use USB to connect their Computer to a DAC

a. if using a desktop, isn it beter to use optical if you have the option ?

5. what is the big difference between (normal, balanced and multibit output) why is there a decent price difference between them ?


A few question about headphones amps.

6. When using a system as powerful as the schiit jutunheim amp, is it possible to use, and have a great success using easy to drive passive speakers? in a 2.1 set-up ? in a 5.1 set-up ?

7. When buying DAC+AMP combo like the Schiit jutunheim or the Audio-GD R2R-11 is it possible to use JUST the DAC or JUST the AMP ? if someone want’s to upgrade down the line ?

a. Could a set-up like this work, using a juntunheim, ?


Blueray or computer > juntunheim > headphones
Blueray or computer > Jotunheim (using the Dac) > speaker Amp > 5.1 speaker set-up
and having a way to control if you want the sound to be output to your speaker OR your headphones ?

ps: i am new to all this and i'm trying to make sense of it all before actually shopping for audio gear

 

[onevstheworld]

1. DACs don't drive headphones or speakers, amps do. But a DAC can output to either headphone or speaker amps.
1a. No. Modi normal/Uber/Multibit only have a single pair of RCA outs. You need some sort of splitter if you want to output to both headphone and speaker amps simultaneously.
1b. Most amps are designed to run headphones, which means very sensitive IEMs can be too loud even at minimal volume. Low gain is meant to solve this issue.
2. You've got it reversed. Amps have a larger impact on sound signature than DACs.
2a. Magni 3 can. Not all amps have preamp outputs. The old non-uber Magni 2 didn't have pre-outs.
2b. Not always. Schiit SYS is a switch as well as a preamp. Schiit Saga is a tube preamp so it does colour the sound.
3. Optical is a digital connection. RCA is an analogue one. They are used for different purposes. DACs are Digital to Analogue Converters... by definition, they require a digital input and output an analogue signal.
4. Depends. Both have limitations and advantages.
5. Normal = single ended (grounds are shared). Balanced splits the ground, plus they tend to output more power. Multibit is not related to balanced... it's a type of DAC architecture. Schiit call theirs multibit, others will call it R2R. Balanced costs more because you are doubling the number of certain components. Multibit/R2R costs more because it's a more expensive technology.
6. Headphone amps cannot drive passive speaker. "Powerful" in headphone terms maxes in single digit watts. Speakers can go up to 100s of watts. You need something like Ragnarok which is designed to do both.
7. Yes, but it depends on the item. You need a line-out or pre-out to bypass the amp, and you need a line-in to bypass the DAC. Jot can do both.

 

[ProtegeManiac]

1. most 100$+ DAC (schiit modi/ODAC/Audio-GD) can drive headphones correctly and speakers alike?

A DAC is just the Digital to Analogue Converter. At best all it does to the analogue signal is run it through a line output stage, not an amplified output stage - regardless of how much power and for what impedance it's primarily designed for (ie headphones are typically 16ohms to 600ohms; speakers at 4ohms to 16ohms), which also requires a preamp control.

You might be confusing stand-alone DACs with one-box DAC-HPamp(-Preamp) units.

a. Is it possible using something like the schiit modi uber that has 2 set of output to be connected to a pair of active speakers and to be connected to a headphone amp at the same time (not needing to re-rewire) and to chose the output (if the headphones are plugged in or not)

Possible but how do you conveniently control the volume? Schiit headphone amplifiers come with preamp outputs that skip the headphone amplification stage but still go through its preamp stage, that way the volume control works on the signal going into the active speakers' amplifier or a pure power amp that drives passive speakers.

b. what is low or hight gain and why is it important

Think of it as transmission gear ratios. Even if you don't tinker with your own car, if you've ever played Gran Turismo, it's like tweaking the transmission gear ratios, even just the final drive. High gain is like the settings you'd use for a drag strip or a track that doesn't have long sweeping corners where you'll run the risk of running out of rpms mid corner even in third gear if you manage to set this too high. Gain kind of works the same way but instead of corners you're working on the transducers' sensitivity, ie, how much power they need to get to a given output level. A 105dB/1mW in-ear monitor will get louder a lot easier compared to a 93dB/1mW headphone.

Note a couple of things though. First, it doesn't literally mean that a 93dB/1mW headphone will hit 93dB as soon as you move that volume knob, and related to this, position on the knob does not determine outright how much power in (m)W is used as the impedance can affect whether it relies on current or has to crank up the voltage (ie a 93dB/1mW 62ohm headphone will sometimes need less travel on the knob than a 98dB/1mW 300ohm headphone). Second, one reason for why this is needed is because analogue volume potentiometers have uneven output until they get past 8:00 on the dial (and this is typically considered a good quality potentiometer). Meier used to need -10dB low gain just so their amps can be used on IEMs but newer ones use a digital pot with nearly zero imbalance but with an analogue knob for control (instead of buttons) with very precise incremental adjustments, so now they need only about -4dB on low gain mode.

2. Most headphones amp in this 100-300$ range can drive a lot of headphones and every single one of those amp has a different signature (compared to DAC, that shouldn’t do a big difference)

Depending on output power in quantity and profile (ie some can drastically drop output at 300ohms; OTL tube amps have this reversed), yes, they can drive most headphones out there. Also "sound signature" is more like "how much and what kind of distortion" you're going to deal with. There's also noise levels but newer amps tend to not have this problem unless they're broken, or you're trying to get the same levels of inaudible noise as the O2, Meier amps, Violectric, etc.

a. those amp can also be used as preamp for active speakers.

If they have a preamp output. If not, then no.

b. Preamps (when used whit speakers) are technicaly just volume control ?

Yes. Another way to look at it is putting the volume control in a convenient location, unlike for example using active studio monitors and then reaching over to the rear of each speaker to move each of their gain knobs.

A few question about imputs

3. Most people use optical to connect their console to a DAC

a. Would it also work whit RCA ? if yes, would it be worst ?

That depends - does the DAC even have the 75ohm coaxial RCA input? Does the console have it? If both have that then yes it can work. And no there won't be any difference.

4. Most people like to use USB to connect their Computer to a DAC

a. if using a desktop, isn it beter to use optical if you have the option ?

Not anymore. Used to be USBs had inconsistent current when all USB ports are powering devices, but motherboard manufacturers mostly fixed that (unless you're using a prebuilt with a cheap motherboard). Some music are being sold now in DSD or high res, so if you buy these, you'll have a problem - DSD only goes through HDMI or USB and some high resolution levels only work with USB.

If you only plan on using regular audio then it won't matter. But given how sometimes even subtle movements tend to break the glass fibers on optical cables, the only real advantage to these is that you can use the audio processor on a motherboard or a soundcard to implement features like Virtual Surround but then you can feed a DAC to keep the analogue signal path short towards a powerful amp that your headphones might need or work better with, like if you use lower sensitivity headphones for gaming.

5. what is the big difference between (normal, balanced and multibit output) why is there a decent price difference between them ?

I wouldn't really bother with these. In some cases like the Schiit Modi and Modi Multibit I'm going to bet some of the audible differences reported by listeners could be attributable to not being able to set the volume levels evenly, so the 2V Multibit version ends up sounding better by a mile vs the Uber version. You also don't necessarily need balanced drive when some single ended amps can produce just as much power, unless you want to be able to use a Class A balanced drive amplifier (ex AudioGD NFB-1Amp) instead of a Class A/B single ended amp (ex Schiit Lyr3).

A few question about headphones amps.

6. When using a system as powerful as the schiit jutunheim amp, is it possible to use, and have a great success using easy to drive passive speakers? in a 2.1 set-up ?

It doesn't have an output stage that can drive speakers and even if you hook up 93dB/1W at 1m sensitivity fullrange horn speakers to the headphone output stage via the headphone XLR jack, I'm not sure if its preamp output will still send out a signal to the subwoofer.

You're going to need, at minimum, either active speakers or a power amp. That gets complicated with the subwoofer. With the first option you just need to get a pro audio sub to take the XLR line input and then pass it on to the active speakers. HT subs might not have the same input-output option since they're designed with the assumption that you only have something like a splitter out of a preamp to both the power amp and subwoofer, or the Subwoofer output on a stereo amp or a Subwoofer/LFE output from an HT receiver/processor.

in a 5.1 set-up ?

The Jotunheim only has two channels of amplification and preamplification. If you want an all out HT system you need to buy a 7.2 Pre-Pro (stand alone units now don't have any less than that) that can pass a digital signal via SPDIF to a DAC that will then feed the Jotunheim.

7. When buying DAC+AMP combo like the Schiit jutunheim or the Audio-GD R2R-11 is it possible to use JUST the DAC or JUST the AMP ? if someone want’s to upgrade down the line ?

Jotunheim has analogue inputs so you can upgrade the DAC. You can't upgrade to another amp and use the Jotunheim DAC since it only outputs via preamp output or the headphone amplified output.

Entry level AudioGDs do not have analogue inputs so you can upgrade the amp but not the DAC. You still have to rewire a few jumpers inside to have them operate as a DAC or DAC with preamp output.

a. Could a set-up like this work, using a juntunheim, ?

Blueray or computer > juntunheim > headphones

BluRay Player will only work hooked up to the Jotunheim using the analogue output on the BluRay player and analogue input on the Jotunheim.

a. Could a set-up like this work, using a juntunheim, ?

Blueray or computer > Jotunheim (using the Dac) > speaker Amp > 5.1 speaker set-up
and having a way to control if you want the sound to be output to your speaker OR your headphones ?

No. BluRay can't send a 5.1 signal to the Jotunheim which only has USB 2ch or analogue 2ch inputs. You need a 7.2ch Preamp-Processor for HT with a bypass output into the Jotunheim via analogue (if it doesn't have that, you need a DAC or DAC-HPamp that can take SPDIF, if the pre-pro has SPDIF bypass output) and then a 5ch (or 7ch) amp and at least one active subwoofer on the LFE output.