[K_19]

 
I'm pretty sure there's no way to use just the ODAC in the typical combo configuration. He'd need another DAC to avoid double amping.

 
Actually, I'm not sure which build the poster's combo unit is (JDS? Mayflower? Epiphany? DIY? etc), but with the most O2/ODAC combo units with the RCA in the back the RCA is for the line out; which means that you can definitely use it as a DAC only to the Crack. There are some units that have the RCAs that act as both inputs and outputs, while I haven't heard of any RCA included units that has the RCA's for line in only (to have another DAC connected to the O2 amp) so I think it's a safe bet that those RCA's in the back does do ODAC line out.

 

[thecrow]

I haven't looked at it for a while but isn't the rcas at the back line outs direct from the dac?

 

[thecrow]

Looks like you just need to plug something in the front 3.5mm jack (if you have that) and then the rcas are dac outs
https://www.jdslabs.com/pdf/Instructions_O2-ODAC.pdf

 

[Jason8777]

Looks like you just need to plug something in the front 3.5mm jack (if you have that) and then the rcas are dac outs
https://www.jdslabs.com/pdf/Instructions_O2-ODAC.pdf

Thank you.  He has the above Amp.

 

[dorino]

   
Actually, I'm not sure which build the poster's combo unit is (JDS? Mayflower? Epiphany? DIY? etc), but with the most O2/ODAC combo units with the RCA in the back the RCA is for the line out; which means that you can definitely use it as a DAC only to the Crack. There are some units that have the RCAs that act as both inputs and outputs, while I haven't heard of any RCA included units that has the RCA's for line in only (to have another DAC connected to the O2 amp) so I think it's a safe bet that those RCA's in the back does do ODAC line out.

Interesting. Neat.

 

[DIscoYou]

  I'm asking this question for a friend of mine.  He has O2 amp + ODAC with RCA in the back.  He recently asked me to build him a Bottlehead Crack and he wants to know if he can use the O2 amp + ODAC as a DAC to connect to the bottlehead crack.  Can he do that or Does he need to get another DAC? Thank you.

 
I asked functionally the same question a few pages back, and I received this informative response from blacknile:
 

  Hi, I asked this question some time ago to Oliver from Epiphany Acoustic, who replied as follows:
 
"the RCAs on the back will output the line level input direct from the DAC so you would connect that to your pre amp as you say.
 
The only little thing to mention, which won't affect usability, is that the DAC can only support one output at a time (the internal headphone amp or the RCA line out) and there is no internal switching mechanism.
 
As such, you simply have to either power off the pre amp if using the headphones or power off the O2Di if using the speaker system. The DAC gets it's power via USB so will always be on regardless of when the red light on the O2Di is on or off."
 
Hope it helps.

 

[diamondears]

Hope this is ok to ask here, but any of you know a portable integrated DAC + amp (not transportable like the O2) that has equal or better SQ than the sound coming out of the iFi micro iDSD + O2?

 

[jring]

   
I asked functionally the same question a few pages back, and I received this informative response from blacknile:
 

 
Hi,
 
I would recommend to plug something into the input jack of O2 while using the RCA outs - this will break contact between O2 and the ODAC line out on the RCAs. Also I would unplug the RCA out (and the input jack) when using ODAC together with O2.
 
Having ODAC drive an unpowered input stage along with a powered one is in my opinion even worse than two powered ones. In the latter case you might get too low an input impedance with two input stages in parallel but with an unpowered input some protective measures on the unpowered input will probably make for funny results...
 
Joachim

 

[Meremoth]

I currently use ATH-AD900X's for everything.  Don't have any other headphones.  I'm going to purchase a O2+ODAC today for my PC.  Questions:
 
1. Where should I buy it or does it matter?
 
2.  Was looking at JDS Labs website and there are different customizable options:  

1. Rear mounted vs Front mounted power jack.  Any difference/benefit?
2. 3.5mm vs. 6.35mm (headphone jack output)  - I need 3.5mm for both AD900X and TH-900, correct?
3. DAC line-output = Default 3.5mm vs Deadicated read line output 3.5mm vs Dedicated rear RCA line-outputs (I have no idea about any of this)
4. Gain = Medium (1.0x , 3.5x), Standard (2.5x, 6.5x), (1.0x, 2.5x)   (also have no idea what to choose)

 
The O2+ODAC will be used for both my AD900X's and TH-900's.  
 

I have finally decided to pull the trigger and get this amp/dac because I've been listening to my 900X's on my iPad lately and realized how much better they sound on my iPad vs my PC (PC using very old Realtek onboard sound).  
 
Thanks in advance to anyone who can offer any help/advice/suggestions/informations/recommendation/tips/opinions etc.    It will be very much appreciated.  
 
Sincerely,
 
Jeremy (wannabe audiophile)

 

[thecrow]

I currently use ATH-AD900X's for everything.  Don't have any other headphones.  I'm going to purchase a O2+ODAC today for my PC.  Questions:

1. Where should I buy it or does it matter?

2.  Was looking at JDS Labs website and there are different customizable options:  

• Rear mounted vs Front mounted power jack.  Any difference/benefit?
• 3.5mm vs. 6.35mm (headphone jack output)  - I need 3.5mm for both AD900X and TH-900, correct?
• DAC line-output = Default 3.5mm vs Deadicated read line output 3.5mm vs Dedicated rear RCA line-outputs (I have no idea about any of this)
• Gain = Medium (1.0x , 3.5x), Standard (2.5x, 6.5x), (1.0x, 2.5x)   (also have no idea what to choose)

The O2+ODAC will be used for both my AD900X's and TH-900's.  



I have finally decided to pull the trigger and get this amp/dac because I've been listening to my 900X's on my iPad lately and realized how much better they sound on my iPad vs my PC (PC using very old Realtek onboard sound).  

Thanks in advance to anyone who can offer any help/advice/suggestions/informations/recommendation/tips/opinions etc.    It will be very much appreciated.  

Sincerely,

Jeremy (wannabe audiophile)

The placement of power jack does not matter - comes down to hiw you want it on your desk.

Size of headphone jack selection comes down to the size of your connection at the end of your headphones. You can always get adaptors if there is a difference. I prefer the 6.35mm but that's because my main headphone has a 6.35 connection.

Dac line out put doesnt matter either. John at jdslabs tells me there are no audible differences between rca or 3.5mm connections. Again if you need something different in the future you can just get a short/cheap adaptor. You can use these outputs if you don't want to use the O2 amp. What it does is it takes the analogue signal (from the odac) before it gets to the O2 so you can say connect it to another amp. Hence its a dac line out.

John at jdslabs recommends the medium gain settings with the odac. It essentially comes down to what dac/source you are using. Your headphones can sometimes alter the choice if they are hard to drive headphones.

You can also buy the odac and O2 as two separate units. The two benefits to that is that you can replace or upgrade them individually in the future as they are not in one unit. The O2 by itself also has a battery in it if you want to transport it around. The O2/odac combo does not.

However that means there are two units on your desk. But the odac is no bigger than a packet of smokes.

Jdslabs also have a free engraving service. You can have an image engraved on the top. I had a couple of black and white friendly images engraved and they came up fantastic.

If you email jdslabs their service is fantastic. If you email them your headphone info I'm sure they'll confirm if the medium setting is what you want.

Hope that helps.

 

[Meremoth]

The placement of power jack does not matter - comes down to hiw you want it on your desk.

Size of headphone jack selection comes down to the size of your connection at the end of your headphones. You can always get adaptors if there is a difference. I prefer the 6.35mm but that's because my main headphone has a 6.35 connection.

Dac line out put doesnt matter either. John at jdslabs tells me there are no audible differences between rca or 3.5mm connections. Again if you need something different in the future you can just get a short/cheap adaptor. You can use these outputs if you don't want to use the O2 amp. What it does is it takes the analogue signal (from the odac) before it gets to the O2 so you can say connect it to another amp. Hence its a dac line out.

John at jdslabs recommends the medium gain settings with the odac. It essentially comes down to what dac/source you are using. Your headphones can sometimes alter the choice if they are hard to drive headphones.

You can also buy the odac and O2 as two separate units. The two benefits to that is that you can replace or upgrade them individually in the future as they are not in one unit. The O2 by itself also has a battery in it if you want to transport it around. The O2/odac combo does not.

However that means there are two units on your desk. But the odac is no bigger than a packet of smokes.

Jdslabs also have a free engraving service. You can have an image engraved on the top. I had a couple of black and white friendly images engraved and they came up fantastic.

If you email jdslabs their service is fantastic. If you email them your headphone info I'm sure they'll confirm if the medium setting is what you want.

Hope that helps.

 
Thanks for the reply, thecrow!  

Awesome advice on getting the units separately!  I think that's what I'll do.  

I think both the 900X's and TH-900's are suppose to be easy to drive.  

Free engraving service, you say?   That's pretty sweet!   Another decision for a super indecisive (me) person, haha.  You said black and white?  Do they do the engravings in color?  Out of curiosity, what did you get engraved on yours?  
 
I just plan on using the O2 and ODAC, my headphones (AD900X & TH900) and my PC, and that's all (for now).  Is there any additional things I need to purchase in order to make this all work (cables, adapters, etc.)?  

Just found out the TH-900's are 6.35mm, so that's the headphone jack output I'm going to get.  Would a 3.5mm to 6.35mm adapter (for my 900X's), degrade the sound at all?  
 
 
Thanks again.

 

[thecrow]

Thanks for the reply, thecrow!  


Awesome advice on getting the units separately!  I think that's what I'll do.  


I think both the 900X's and TH-900's are suppose to be easy to drive.  


Free engraving service, you say?   That's pretty sweet!   Another decision for a super indecisive (me) person, haha.  You said black and white?  Do they do the engravings in color?  Out of curiosity, what did you get engraved on yours?  

I just plan on using the O2 and ODAC, my headphones (AD900X & TH900) and my PC, and that's all (for now).  Is there any additional things I need to purchase in order to make this all work (cables, adapters, etc.)?  


Just found out the TH-900's are 6.35mm, so that's the headphone jack output I'm going to get.  Would a 3.5mm to 6.35mm adapter (for my 900X's), degrade the sound at all?  


Thanks again.

The headphone adaptor would be fine. Sound would be fine.

With the separate odac you also get the choice of rca connections out rather than 3.5mm. I would just leave it with the standard 3.5mm.

Check with jdslabs re what else you need. You get the usb cable cable for the odac. You'll need to buy the power cord thingy to connect the O2 to the wall - they sell that. And from memory you'll need a cable to go from the odac to the o2. Either a 3.5mm cable or a 3.5mm to rca connections if you choose to get the rca connections on the O2. You would use that if you wanted to connect , say another dac to your O2 in the future via rcas. But you still could always use the standard 3.5 mm jack with any other dac if you had a cable adaptor (rca to 3.5 mm) so again no real need for rca jacks anywhere on these if you haven't got other equipment you're akreadybpkanning to hook up.

The engravings are just black and white. There's a video somewhere on YouTube or the jdslabs website of an engraving. It's simply engraving on the black top cover of the O2 or odac. I decided to choose 2 images that were black and white as I thought if the images had a bucket load of different colours it may not have done up as well.

Do a google images search and you'll get some ideas.

I have an odac on sale in the ckassifieds. If you have a look at that posting you'll see my odac's image.

 

[Meremoth]

The headphone adaptor would be fine. Sound would be fine.

With the separate odac you also get the choice of rca connections out rather than 3.5mm. I would just leave it with the standard 3.5mm.

Check with jdslabs re what else you need. You get the usb cable cable for the odac. You'll need to buy the power cord thingy to connect the O2 to the wall - they sell that. And from memory you'll need a cable to go from the odac to the o2. Either a 3.5mm cable or a 3.5mm to rca connections if you choose to get the rca connections on the O2. You would use that if you wanted to connect , say another dac to your O2 in the future via rcas. But you still could always use the standard 3.5 mm jack with any other dac if you had a cable adaptor (rca to 3.5 mm) so again no real need for rca jacks anywhere on these if you haven't got other equipment you're akreadybpkanning to hook up.

The engravings are just black and white. There's a video somewhere on YouTube or the jdslabs website of an engraving. It's simply engraving on the black top cover of the O2 or odac. I decided to choose 2 images that were black and white as I thought if the images had a bucket load of different colours it may not have done up as well.

Do a google images search and you'll get some ideas.

I have an odac on sale in the ckassifieds. If you have a look at that posting you'll see my odac's image.

 
WOW!  That engraving is screwing fantastic!  Way better than what I was thinking.  I love "Rikki Don't Lose That Number"!  
I would purchase that from you if I wasn't super OCD about buying used things.  
Out of curiosity, why are you selling it? 

 
So the RCA outputs for the DAC offer no improvement in quality vs. 3.5mm?  
 
 
Thanks. 

 

[thecrow]

i upgraded my dac. And then my amp.

I bought an arcam irdac at a good price second hand which suits me and my headphones. the timing was just right - I had been looking for that dac and the guy I bought it from was upgrading to the next level too.

I used to be careful about second hand stuff initially too. Just be a little cautious. Here you'll find reviews on most sellers. That helps. And quite often you'll notice they may have bought the equipment off someone else from here so you can even go back to the classified when they were first selling it.

also one thing I've learnt here is you can get many positive recommendations and reviews on something but nothing beats hearing what you're thinking of buying - you probably found that in choosing your headphones.

Having said that....I have found, for me, the odac is a fair/ok dac for its price but the O2 is a great neutral/transparent dac well priced too. I'd recommend it to my own mother easily.

If I was looking for an amp around that price I would look at buying the O2 again. The only reason I haven't put that in the classifieds yet is I might keep it as a back up. Probably not though.

 

[Meremoth]

i upgraded my dac. And then my amp.

I bought an arcam irdac at a good price second hand which suits me and my headphones. the timing was just right - I had been looking for that dac and the guy I bought it from was upgrading to the next level too.

I used to be careful about second hand stuff initially too. Just be a little cautious. Here you'll find reviews on most sellers. That helps. And quite often you'll notice they may have bought the equipment off someone else from here so you can even go back to the classified when they were first selling it.

also one thing I've learnt here is you can get many positive recommendations and reviews on something but nothing beats hearing what you're thinking of buying - you probably found that in choosing your headphones.

Having said that....I have found, for me, the odac is a fair/ok dac for its price but the O2 is a great neutral/transparent dac well priced too. I'd recommend it to my own mother easily.

If I was looking for an amp around that price I would look at buying the O2 again. The only reason I haven't put that in the classifieds yet is I might keep it as a back up. Probably not though.

 
@thecrow
 
Little confused about the sentence, "Having said that....I have found, for me, the odac is a fair/ok dac for its price but the O2 is a great neutral/transparent dac well priced too. I'd recommend it to my own mother easily."

You said the O2 is a great neutral/transparent DAC, but I thought the O2 was an amp?  Are you saying the O2 is an awesome amp, but the ODAC is only decent?