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Maverick Audio DAC/Amp - Page 22

post #316 of 2596
There's goes a lost sell from me. Bit perfect via usb was ONE of the main selling points. But if usb can't even play 16/44 but only upsampling to 16/48 what a waste. I can give two craps about 24/192 24/96 ect.....a standard cd is 16/44 and that's all I care about but if it can't even play a normal cd hooked up via the usb port. I guess I'll look elsewhere, even cheaper units like the Aune would be better. Also if anyone is interested the Original makers since the MAV is a clone since the XS and Grant are made at the same chinese factory. another story in itself, they at least the XS or doing custom mods, such as dip sockets and they have changed face plates to black as well, for $40 less shipped if anyone is interested??
I don't care personally but you can save some coin, I think I'll go with the Compass instead. $100 isn't to bad for a better built unit IMO... Just my opinion of corse on all this..
post #317 of 2596
Odd USB implementation for sure
post #318 of 2596
Yeah, it's a bit of an annoyance but if I want bit-perfect I can get a 24/96 USB to SPDIF converter...

EDIT: Definitely points against it in my (forthcoming?) review though...
post #319 of 2596
Quote:
Originally Posted by DannyBuoy View Post
[...] I would hook up the Maverick to a fresh Vista or 7 install and play a CD and a WMA from a known DRM compliant source (another issue having to do with header information). I would not have any additional codecs or audio software installed to impede this test. [...]
Thanks for the hint, DannyBuoy. I'll try this next week, when (hopefully) Ryan answered some of my questions regarding the gain of the headphone amp.

Did I understand you right, that you think, it's a problem of WASAPI by not correctly identifying the USB receiver of the Maverick?! But that wouldn't explain why foobar's kernel streaming and ASIO4All also didn't work, would it?!
I have had quite a few USB DACs in the past and that would be the first time that a "standard" USB receiver wasn't correctly recognized by the OS. Can't quite believe that that's the problem here...

best regards.
bearmann
post #320 of 2596
Quote:
Originally Posted by DannyBuoy View Post
I believe there is a difference of understanding between the hardware and software here....
Hi DannyBuoy, I just sent you a message to see if you can try our unit. Hopefully you can help us find out the real problem..
post #321 of 2596
I've had my unit for a good amount of time now. Purchased one of the earlier units. Just changed the tube to the 5670, and it makes a huge improvement. Everything is so much softer, and relaxed. I can finally listen with my grados!

One major problem I have found is the sound slowly cuts out on one channel for the line outs. This can be only remedied by either blasting up the headphone volume, which sometimes works, or jiggling a 1/4" TRS jack on the headphone jack until both channels kick in. Kind of a hassle. Anyone have any ideas?
post #322 of 2596
Quote:
Originally Posted by elwappo99 View Post
I've had my unit for a good amount of time now. Purchased one of the earlier units. Just changed the tube to the 5670, and it makes a huge improvement. Everything is so much softer, and relaxed. I can finally listen with my grados!

One major problem I have found is the sound slowly cuts out on one channel for the line outs. This can be only remedied by either blasting up the headphone volume, which sometimes works, or jiggling a 1/4" TRS jack on the headphone jack until both channels kick in. Kind of a hassle. Anyone have any ideas?
I think it is probably due to the headphone socket on the front panel. You can plug/unplug your headphone into the socket for a few dozen times, it might solve the issue. If not, you can click here to submit a support ticket and we will fix it for you.

New D1 unit will not have the same issue as the headphone jack will not "mute" the line-out when headphone is inserted.
post #323 of 2596
Some good news... well, sort of.

I changed the gain of the headphone amp today. IMHO you don't need to bother trying the headphone amp with sensitive headphones unless you reduce the gain significantly.
Thanks to Ryan, who provided me with the necessary info.

In order to reduce the gain of the headphone amp you have to lower the values of R54 and R55. At this moment it should be something between 22K and 30K. I replaced both with 4.7K and now the gain is fine (don't know the exact amount though).
With my ATH-W100 9 o'clock is "loud enough" for long sessions. 11 o'clock is nice for a couple of tracks...
And the headphone amp is "dead silent", very nice!

I also tried some opamp rolling - that's not the Maverick's strength, sadly.
With the default opamp (LF353N) I have a dc offset of ~30mV. Which is OK.
First I tried some Analog Devices opamps: AD797 and AD843. Both of which produced significant dc offset (a couple of volts!) and the AD843 oscillated. So don't bother using those in your Maverick!
Then I tried National's LME49860 and LME49720 (~ LM4562NA). Both produce much more dc offset than the LF353N - around 360mV. I am no expert but that should be OK.

At this moment I am listening with the LME49860 and I am quite pleased.

best regards.
bearmann
post #324 of 2596
Well I've been following the USB dac discussion and a bit surprise that the D1 may not be capable of standard 16/44.1 interface. I will have to investigate into this to confirm. If not I will have to connect from PC to D1 via toslink, a minor annoyance since toslink connection require quality wire or the sonic quality will suffer, but not a biggie really.

I'm also looking into rolling the opamp, I'm considering the Burr-Brown OPA627AP. Bearmann or anyone try this opamp yet, please give some input.

Also I'm planning to replace two Wima output coupling cap with Gad-Viva or Auricaps and most or all other 10uF caps with Muse(green) caps. Power coupling caps in the D1 are Rubycon so I think they are acceptable.

Ryan if you see anything wrong with my plan please let me know.
post #325 of 2596
Quote:
Originally Posted by lameduck View Post
I'm also looking into rolling the opamp, I'm considering the Burr-Brown OPA627AP. Bearmann or anyone try this opamp yet, please give some input.
don't know if a double OPA627 on a browndog will fit in... seems rather cramped around the opamp socket because of the capacitors.
I don't have any OPA627 - IMHO it's overpriced and not worth the effort.

best regards.
bearmann
post #326 of 2596
Quote:
Originally Posted by bearmann View Post
Both produce much more dc offset than the LF353N - around 360mV. I am no expert but that should be OK.
That's definetly not OK. If you measure that much at the headphone output, it's gonna kill your phones. Generally under 100mV is ok, but i personally wouldn't risk anything over 50mV.
post #327 of 2596
Quote:
Originally Posted by bearmann View Post
Some good news... well, sort of.

I changed the gain of the headphone amp today. IMHO you don't need to bother trying the headphone amp with sensitive headphones unless you reduce the gain significantly.
Thanks to Ryan, who provided me with the necessary info.

In order to reduce the gain of the headphone amp you have to lower the values of R54 and R55. At this moment it should be something between 22K and 30K. I replaced both with 4.7K and now the gain is fine (don't know the exact amount though).
With my ATH-W100 9 o'clock is "loud enough" for long sessions. 11 o'clock is nice for a couple of tracks...
And the headphone amp is "dead silent", very nice!

I also tried some opamp rolling - that's not the Maverick's strength, sadly.
With the default opamp (LF353N) I have a dc offset of ~30mV. Which is OK.
First I tried some Analog Devices opamps: AD797 and AD843. Both of which produced significant dc offset (a couple of volts!) and the AD843 oscillated. So don't bother using those in your Maverick!
Then I tried National's LME49860 and LME49720 (~ LM4562NA). Both produce much more dc offset than the LF353N - around 360mV. I am no expert but that should be OK.

At this moment I am listening with the LME49860 and I am quite pleased.

best regards.
bearmann
Bearmann can i ask which series of AD797 your using? the B series or the A series? Thanks
post #328 of 2596
Quote:
Originally Posted by bearmann View Post
Some good news... well, sort of.



I also tried some opamp rolling - that's not the Maverick's strength, sadly.
With the default opamp (LF353N) I have a dc offset of ~30mV. Which is OK.
First I tried some Analog Devices opamps: AD797 and AD843. Both of which produced significant dc offset (a couple of volts!) and the AD843 oscillated. So don't bother using those in your Maverick!
Then I tried National's LME49860 and LME49720 (~ LM4562NA). Both produce much more dc offset than the LF353N - around 360mV. I am no expert but that should be OK.
Strange how you see a jump from 30mV to 360mV as OK. That's my concern too, if different opamp would not play nice with the circuit, not so much the price because if you gonna put the effort into modding the unit might as well use best possible parts that's compatible with the circuit. I think there's a potential that with about $50 in parts and a couple hours of labor the D1 can be improved significantly. While I'm at it I just might replace the Alps with a better one too.
post #329 of 2596
Quote:
Originally Posted by lameduck View Post
Strange how you see a jump from 30mV to 360mV as OK. That's my concern too, if different opamp would not play nice with the circuit, not so much the price because if you gonna put the effort into modding the unit might as well use best possible parts that's compatible with the circuit. I think there's a potential that with about $50 in parts and a couple hours of labor the D1 can be improved significantly. While I'm at it I just might replace the Alps with a better one too.
Well, I don't beleive in "boutique parts". If an opamp oscillates in a circuit it doesn't matter if you used Rubycon caps and vishay dale resistors - the problem is the circuit design and not the selection of parts. That's just my opinion, of course.

Of course, you can alter the sound by replacing all caps in the audio signal path - but in a good design (except for tubes) there shouldn't be any caps in the audio signal in the first place.

just my 2 cents. (no intention of starting a war... )

best regards.
bearmann
post #330 of 2596
Shippings been delayed a day or two, so I probably won't be able to comment on the Mav until after Christmas. Oh well. Hope the USB issues can be fixed with a patch of some sort.
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