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The iBasso D12, dual dacs . images . new Sysconcept optical cable . . Topkit by HiFlight. . - Page 35

post #511 of 601

The OPA627 is stable at unity gain, the 637 needs 5x under most circumstances. I believe the D12 only goes up to 3x on high gain.

post #512 of 601

I am using OPA1611A L/R with dummy buffers, the sound is terrific and it can easily get too loud past the 2 o'clock position

post #513 of 601
Quote:
Originally Posted by Armaegis View Post

The OPA627 is stable at unity gain, the 637 needs 5x under most circumstances. I believe the D12 only goes up to 3x on high gain.



 

Quote:
Originally Posted by HiFlight View Post




While the OPA627 is stable at unity gain, it still specs outside of the supply voltage supplied by the D12.  It cannot meet design specifications at the 4.7 volts provided by the D12 battery pack.  Using a single-sided voltage source such as the D12, the minimum  recommended voltage is 9v. (+/-4.5) There are much better D12 choices, IMO. 

 

 

 


 

thanks, so basically the 627/637 is not the option for D12 just for its technical spec. I actually love the stock of D12 now, but reading this thread make me wondering if it can be better...

 

 

post #514 of 601



 

Quote:
Originally Posted by civilaudio View Post





 


 

thanks, so basically the 627/637 is not the option for D12 just for its technical spec. I actually love the stock of D12 now, but reading this thread make me wondering if it can be better...

 

 


The D12 is fantastic "as is" and I always found it to have a nice musical balanced sound.  The only thing I gained by rolling opamps is a minor amount of detail and top end.

post #515 of 601

would love to try rolling amps but when i went to take the unit apart i found ibasso had sent me a unit with a threaded screw.....the screw stood out as it also had some red rust looking stuff around the edge..not sure what that is....but clearly somethign happened with that screw....cant believe they sent it out like that....

 

what are the options for removing a threaded screw?
Btw i know it should come apart if only one screw is left but its on the faceplate and the screw holding the volume button on is also just spinning and not turning. Looks threaded too but not as bad as the other one.

post #516 of 601
Thread Starter 

Quote:

Originally Posted by giveit2menow View Post

would love to try rolling amps but when i went to take the unit apart i found ibasso had sent me a unit with a threaded screw.....the screw stood out as it also had some red rust looking stuff around the edge..not sure what that is....but clearly somethign happened with that screw....cant believe they sent it out like that....

 

what are the options for removing a threaded screw?Btw i know it should come apart if only one screw is left but its on the faceplate and the screw holding the volume button on is also just spinning and not turning. Looks threaded too but not as bad as the other one.

1. I would contact iBasso as this is not how they normally do things. 

2. Do you have any images?

 


 

 


Edited by jamato8 - 10/22/11 at 8:13am
post #517 of 601

I agree with Jamato.  Ibasso's service has always been great.  I am confident that they will assist.  

 

Otherwise there are tools called 'easy outs' that are like a reverse thread screw which drills into the stripped screw and should unscrew it.  There shouldnt be any torque required unless the screw is rusted but that is very unlikely as it is an alloy case.

post #518 of 601
Quote:
Originally Posted by giveit2menow View Post

would love to try rolling amps but when i went to take the unit apart i found ibasso had sent me a unit with a threaded screw.....the screw stood out as it also had some red rust looking stuff around the edge..not sure what that is....but clearly somethign happened with that screw....cant believe they sent it out like that....

 

what are the options for removing a threaded screw?Btw i know it should come apart if only one screw is left but its on the faceplate and the screw holding the volume button on is also just spinning and not turning. Looks threaded too but not as bad as the other one.



Try using a Torx 6 bit rather than the tool that came with your D12. (tool store or hardware) The Torx should give you purchase on the screw even if it is somewhat deformed.  It is doubtful that the screw threads are stripped, as they are steel and much harder than the aluminum case.  You do not need to remove the volume knob to roll opamps, only the top two front faceplate screws and the rear 2 top screws. 

post #519 of 601

screw.jpg
you can see top left that screw is not the same as the others. Something clearly was amiss there when they sent it out. Look at the red around it. I tried a t6 and it just goes round. I will try i T8 when i get one. As its the top i cant get to the rollamps.

post #520 of 601

removed.


Edited by giveit2menow - 10/23/11 at 1:34am
post #521 of 601
Quote:
Originally Posted by giveit2menow View Post

screw.jpgyou can see top left that screw is not the same as the others. Something clearly was amiss there when they sent it out. Look at the red around it. I tried a t6 and it just goes round. I will try i T8 when i get one. As its the top i cant get to the rollamps.


I noticed that your D12 have all 4 screws all having some type of corrosion... which is quite strange. Are you using it outside a lot ?. How long have you got this D12?

 

I got my D12 and opened and closed dozen times, rolling opamps and have no problem with screws and stock tool.

 

The issues of opamps rolling is that when you have so much choices, it is hard to settle....

 

post #522 of 601

yes it has been used outside. I have had it some time but this was the first time i decided to try rolling amps as i just find the top end a might sharp. I dont see how having it outside could have led to the threading issue. Ibasso have replied now.

post #523 of 601

Did it ever get wet or is it very humid in your region?

post #524 of 601
Thread Starter 

I was recently on Pohnpei, which is part of Micronesia and is very humid, for over a year. No amp I have that was out, did not have some rust on the steel screws, from very expensive and on down. 

post #525 of 601

Having Hiflight topkits and some opamps from avnet, I tried several combinations (I tried to copy some opamp that reported ti work well at D10 thread) and found they worked very well with D12 in addition to topkits. (I put them into class A biased adapter)

- OPA2228P and stock buffers.

- OPA2350PA and topkit buffer..

Has any tried these? what is your opinion?, I have tested with some vocal, rock and contry.

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