Massdrop Objective 2 Headphone Amp: Desktop Edition Discussions | Drop

Massdrop Objective 2 Headphone Amp: Desktop Edition

Showing 1 of 1897 conversations about:

paulieb00

Oct 17, 2015

Any info on changing gain settings on this amp? will be pairing it with the odac and understand the lower 1x and 3.3x setting are what you should be at. right now it is at 2.5x and 6x. thanks for any info.

Oct 18, 2015

paulieb00Will: This is a very good point - was this take into account with the ODAC that you're offering?

Vote

Taub

Oct 18, 2015

paulieb00To change gain you need to replace resistors on the board (as in desoldering and soldering ones with different values). i dont think the massdrop version has the socket pins to change gain without soldering. If it does have the sockets you can just pull out the resistors and put in other ones. to change gain to x1 you can clip off 2 resistors without any soldering but i guess you loose warranty by doing this? http://nwavguy.blogspot.se/2011/08/o2-details.html#gainsettings

Oct 19, 2015

Budget_AudiophileDon't believe the gain settings on the amp really matter as it relates to use with the DAC.

Vote

ulogin

Oct 19, 2015

WillCan't agree with you there. First, the O2 gets too loud easily with the standard gain setting. More importantly, the O2 is going to clip when gain is set at 6x, even when it is paired with its "brother" the ODAC (the latter outputs 2V),
The facts that (a) O2 clips at one of the two default setting, (b) users can't change gain setting themselves given how tight the screws are, and (c) you don't offer a lower gain setting (something that people have been asking since last drop), it's a big failure IMO.

Erix

134

Oct 19, 2015

WillWill, just the opposite is true. The ODAC has a voltage output of 2.0V, which is higher than the typical 1.5V output of most other USB-powered DACs. Therefore, less gain is needed. Having more gain than needed raises the noise floor and adds distortion. For 600-ohm headphones with a less than 90 db/mW efficiently, the 6.5x gain setting might make sense. For 16-ohm earbuds or low-impedance headphones, the 6.5x gain setting is too high.

Oct 19, 2015

uloginLooks like you outlined a bunch of reasons why a low-gain option would be good to have, totally agree with you btw (we're already looking into it), but I don't think gain settings have any impact on the interaction with the ODAC.
Any input on that side of things? Not sure @Budget_Audiophile and @paulieb00 have an answer yet.

Oct 19, 2015

ErixHey Erix,
Ahhh kk, that makes sense, thanks for crystalizing what @ulogin was trying to get at. We're looking into offering lower gain as an option for this, hard part is it would require modifying the BOM we agreed to with our manufacturing partner. Given the minor nature of the change, you'd think it'd be pretty easy, but we're waiting to hear back.
Thanks for your post!

Erix

134

Oct 19, 2015

WillThanks for looking into it, Will. JDS (a popular builder of the O2 amp), for example, allows customers to specify the gain they want. As I said in a previous comment, I think using a 3000 ohm and a 600 ohm resistor in the low- and high-gain positions, respectively, would drop the gain from the default 2.5x and 6.5x down to 1.5x and 3.5x.
See "customize" under "jack configurations" on JDSs' webpage, for example.
https://www.jdslabs.com/products/35/objective2-headphone-amplifier/

ulogin

Oct 19, 2015

WillI would even say that low gain is a "must have" rather than "nice to have". As I said, the ODAC is "too hot" for the O2 at 6x , meaning the latter will clip: http://nwavguy.blogspot.com/2011/08/o2-details.html#maximuminput
I thought the project manager of this product has a EE degree and has extensive industry experience working with major tech companies? That's what someone from your side told me last time.

Oct 19, 2015

uloginHey Ulogin,
Don't know where you got that idea. All our custom projects are run by an outsourced team of highly intelligent guinea pigs. That's the secret really, all these kickstarter and indiegogo campaigns you see failing to deliver products, it's because they're depending on humans. Clearly an oversight on their part.
On the more serious side of things, here's a link to where Nelson explained a couple of those details: https://www.massdrop.com/buy/massdrop-o2-amplifier/talk/239386
Thanks for your input, we're working on options for the low-gain side of things.

Erix

134

Oct 19, 2015

WillWill, I also wanted to mention that others are reporting the screws in the case are hard to remove. One person even mentioned having to drill them out. I'm not sure if the manufacturer is using Locktite or maybe just torquing down the screws. Anyway, it would be nice to be able to get into the case if it turns out that we'll have to swap out the gain resistors ourselves. As I'm sure things sometimes tend to get exaggerated, it might be worth checking for yourself how tight the screws are to determine if this is an issue. It seems that others intending to use batteries might also want access to the case.

Oct 19, 2015

ErixHey Erix, I've seen a couple folks commenting on this. I had five random units shipped our way last week and all of them were easy to take apart with a philips head. No fancy screws.
TBH I'm not sure what I can suggest for those folks, maybe give the amp to whoever opens jars in your household?

Oct 19, 2015

WillHey Will, any Idea on my question above?
Will the original O2 AMP be able to support RCA output instead of the inputs on the desktop unit so I could essentially use my DACport Slim with this like I would've used the ODAC + O2 AMP? (3.5mm output to headphones RCA to speakers)
I liked the Idea of the ODAC having the RCA outputs but If I could get RCA outs modded on the O2 AMP then I could still use my DACport Slim 3.5mm out > 3.5mm O2 AMP input then I'd essentially have 3.5mm output and RCA output if I could mod it on the AMP unit instead of it having the inputs.
Or is the RCA out only on the ODAC because you can't amplify RCA out and only convert it and amplification is only for headphones? (I'm new to DACs/AMPS so excuse my ignorance on the matter.)
vvvv that jar comment though! LOL

Oct 20, 2015

m4rkbr0wnThe ODAC's RCA and mini output are line level - that is, they're not amplified. Amplification for headphones comes from the O2 and amplification for speakers comes from an amp (either built in for powered speakers or separate or passive speakers). It sounds like what you're trying to do is use the O2 as either a speaker amplifier for passive speakers or a preamp for powered speakers, neither of which is the intended purpose. The O2 may work as a preamp if you used a mini to stereo RCA adapter for the output but I'm not sure how well it would work and it's probably not the best solution. There are versions of the O2 with rear RCA outputs for use as a preamp but this particular version of the O2 doesn't have that feature. For passive speakers, you would need to look into an amplifier with volume control built in. For powered speakers (ie, studio monitors), you would need a preamp or a passive volume control if the volume control is hard to reach (like the back on the M-Audio BX5As that I use).

Oct 20, 2015

Budget_AudiophileI know this you must have misunderstood what I was asking, I know why and that the ODAC has line outs but like I stated I was part of the DACport Slim drop which only has 3.5mm out and I'm sure MD wouldn't let me RMA it for the ODAC and plus I enjoy the Slim... I just like brand matching so it kind of sucks that the ODAC dropped after I got the DACport Slim which is my first entry into DACs but now I realize how limited it is output wise compared to the ODAC so I was trying to figure another way I could still use the DAC I currently have but still be able to get more outputs.
He said they would be releasing kits to change our portable O2 from the first drop which I have and I would like it to have RCA out if it can be possible if not hen hey might need to check my support ticket about possibly RMA'ing my DACport to join the ODAC.
I own a Roland V-Studio 100 and a pair of Rokit monitors I know about studio equipment and all that as I have one.

Vote

Oct 20, 2015

m4rkbr0wnm4rkbr0wn - Have you considered using a 1/8" mini to RCA cable from the DACport Slim to your powered speakers?

Vote

Oct 20, 2015

Budget_AudiophileThen I wouldn't have the option of two outputs at the same time I'd have to swap cables whenever I want to use headset/speakers Will stated that the ODAC can output to our original O2 via the 3.5mm and to a pair of speakers via RCA simultaneously.
I was just trying to think of ways around not having to give up the DACport and it probably wouldn't even be possible to do so as I hadn't heard back from customer support yet.

Vote

Oct 20, 2015

m4rkbr0wnWhat about a switch? Output from DACport Slim goes to switch where you select output: either speakers or O2. Something like this: http://schiit.com/products/sys Although there are undoubtedly cheaper solutions, especially if you want to DIY. Some people use old composite video switchers like Radio Shack used to sell and only use the stereo audio portion.
In the ODAC thread I've asked Will about making a little source/output selector for those with multiple sources and/or outputs, which is very common.

Oct 20, 2015

Budget_AudiophileA switch sounds like something that could work but the schiit product you linked has 2 ins and only 1 out I only need 1 input that is my DAC and 2 outputs being headphones/speakers... With the MD ODAC it makes it very easy cause it has the 2 outputs there.
Would there be anything that I can connect DACport Slim to via the 3.5mm that separates it into 2 outputs that wouldn't lessen the quality but give me more connection options other than 3.5mm?

Vote

Oct 20, 2015

m4rkbr0wnThe Schiit SYS can also be used to go from one input to two outputs I believe.
You could try a headphone splitter out from the DACport Slim for a cheap solution and turn the gain to low and max the volume for line level output.

Oct 20, 2015

Budget_AudiophileI'll have to look into it tomorrow it's getting a bit late here, I appreciate you being patient with me and giving responses trying to help!

Vote

stinkyTheDonut

Oct 20, 2015

WillOn the front plate, I almost stripped one screw. On the back side I completely wrecked one. I had to save it for last and hope I didn't mess up another one along the way. In the end, i was able to remove the other 3 and spin the entire plate to get the last screw loose. Couldn't have done it if it was the front plate. =P

dudetato

Oct 21, 2015

Budget_AudiophileIts actually 2 inputs to one output. I found out the hard and stupid way

Vote

Bulbulas

Oct 31, 2015

WillMaybe it's the climate here.

Vote

View Full Discussion

PRODUCTS YOU MAY LIKE

Massdrop x Sennheiser HD 6XX Headphones

$199

Massdrop x Sennheiser HD 58X Jubilee Headphones

$169

Massdrop x Sennheiser PC37X Gaming Headset

$99

Drop + HIFIMAN HE4XX Planar Magnetic Headphones

$149

Massdrop x Koss Porta Pro X Headphones

$29

Drop + EPOS PC38X Gaming Headset

$169

Massdrop x Koss KSC75X On-Ear Headphones

$20

Massdrop x Meze 99 Noir Closed-Back Headphones

$179

Drop + EPOS PC38X Yellow Gaming Headset

$139

Drop BMR1 Nearfield Monitors

$79

Trending Posts in Audiophile

SsButerbal

Ringing in PC38X's

I recently got this headset, and wow is it good. My only issue is when certain people talk on discord, I can hear a really high pitched ringing. I fiddled with a bunch of settings, computer audio and discord, and nothing seems to solve the issue. It is primarily if not all in my right ear only. Is there something wrong with my headset, or was that ringing always there I can just hear it cause the headset is THAT good? I haven't had any issues with any other application, though I have yet to test if I can hear the ringing on a different version of discord, say on my xbox instead of my pc. Only other issue I've had is occasional static, but I can't tell if it's from the headset or the show/game/etc.

Apr 24, 2024

Questions

Vote

itsamepe

Sennheiser PC37X randomly goes bad after disconnecting the cable ?

Greetings, Yesterday I was using my headset like normal with my macbook, just listening to music and on a call with people like usual, and the headset was perfectly fine. The stock wire that came with the headset is extremely long and yesterday it annoyed me very much that it kept getting tangled with itself, so I decided to see if the cable is replaceable. I pulled out the cable from the headset and saw the adapter, and looked online for a replacement. Upon plugging it back in, the audio sounded extremely muffled and washed out. Im not sure what I did wrong to make it mess up like that as I've always taken good care of it, ive had it for about 2 years and its always just been chilling on my desk, but anywho I thought the cable just went bad and ordered a replacement. The replacement came, and the issue is still persistant, so I am not sure what the issue is I've tried multiple different headsets and the issue is not with the port, and I also tried it with my windows laptop and...

Apr 23, 2024

Questions

MrChiSox

Big changes coming to my tiny little music room, I've recently purchased a new stack. Currently figuring out where to locate it all and ordering up the necessary cables, it won't be too long before I'm up and running. I am now the proud owner of a brand new stack. It's a European brand called Earmen. Amp, DAC, Streamer & Linear Power Supply. It won't be long!

https://www.youtube.com/watch?v=MB15yM4UptQ

Apr 23, 2024

General

Vote

Briankan

Recommendation for my next headphone set? I have Koss 95x

Hey all, What would you recommend I get next and why? I have Koss ESP-95x electrostatic massdrop headphones. These are my first and only audiophile set. I love them. I think my only real requirements is $500 or less for the headphones and that they have a little more low end. I don’t need thump but these are really light on lows…but the experience is still awesome. Also any recommendations on an amp? I only have my electrostatic thingy. I am using the Topping D50 DAC. thx!!

Apr 22, 2024

Questions

Vote

Simthaniel

Rigs

Modded headphones with qudelix at the core

When I received the Qudelix 5K, I had already modified a pair of Superlux HD-681 headphones. I previously soldered my own balanced connections to the drivers, providing multiple ways to connect and...

Apr 14, 2024

Rigs

brothamike

A decent set of IEMs

I am in the midst of a 300 hour burn-in but, I will say I am enjoying how this set sounds so far. Before I received these which was btw late by a few weeks, I purchased a Sony/Kimber Kable MMCX...

Apr 12, 2024

Photos

merrick97

Should I exchange the PC38X for better headphones?

I bought the PC38X headphones FOR GAMING and they are great, but I have NO use for a Microphone since I don't do competitive gaming and I was wondering if there were better headphone options at a similar price without a headphone, where (presumably) more of the cost was put into making it sound better. I also find that my PC38X don't get quite as loud as I would like and I was wondering if a cheap amp like the iFi Go link would draw a little more volume out of my phones. https://www.amazon.com/dp/B0BN6MM822?psc=1&ref=ppx_yo2ov_dt_b_product_details I went with the PC38X since it was considered the best bang for buck headphones. I care most about using spatial apps like DOlby Atmos and DTS Headphone:X. Suggestions are welcome.

Apr 11, 2024