[drweincpa]

Does anyone have any impressions on all the amplifier cards for the HM-901? I have the balanced and was wondering if there is a different sound to the Minibox. Also would it be worth looking into the IEM card if I have higher end earphones?

 

[HawkInOz]

  Does anyone have any impressions on all the amplifier cards for the HM-901? I have the balanced and was wondering if there is a different sound to the Minibox. Also would it be worth looking into the IEM card if I have higher end earphones?

 
Bump.  I, too, would be very interested in a comparison of all the available amplifier cards - before making an initial purchase of the HM-901.  Thank you!

 

[noxa]

Bump again, if anyone can explain the differences that would be greatly appreciated.

 

[Mimouille]

Go to one of the two threads, do a search. Kkcc compared a few of them, I did too and many others. It's all there.

 

[rcadog]

There are differences in sound. Absolutely  For example, I recently tried one of the older standard cards with discrete transistors and it is notably superior to the balanced card.  It would be really helpful if the manufacturer provided some guidance as to generations of its product.  I recently looked at the standard card on the new 650 and it is very sparse in componentry. The balanced card sounded better than that one. The minibox card was available to me to try (thinking of getting) and it was also superior to the balanced card (a disappointment)  So far, the old standard card wins the day.

 

[KT66]

Most prefer the balanced card here. I use and love Minibox but don't dismiss the current standard card which does sound very good, enjoy that for a while before changing it.

 

[lostinclarity]

Would the standard card sound better than the balanced one with Shure SE846 with Silver Dragon V1 cable with 3.5mm trss balanced termination?

 

[parfaitelumiere]

didn't find threads with card differences, especially the standart-balanced-elfidelity, and discrete cards.
I would find wich one is the most neutral, with the strongest treble response( frequency, not power)
I checked the standart and the discrete( yellow color board), the discrete has a serious lack of treble for me, very good with my 1+2, but too weak with my main display, I mean my oppo PM-3,so I use the standart card.
If the balanced or elfidelity brings better treble, and not a too warm sound ( as warm as the standart is correct for me) , I will be interested in.

 

[rellik]

The MiniBox Gold card sounds considerably better if the buf634's are stacked to double. This would increase the buffers from 8 to 16. I have not noticed much of a difference in battery life either.
 
Overall the amp sounds much less veiled.
 
DIY intsturctions:
1. Glue the new bufs atop the old ones paying attention to orientation.
2. Wait for the glue to dry... 
3. Bend the pins of the new buffers down with pen knife.
4. Purchase 28-30 gauge wire. Strip off a section and tin the exposed section with very little solder. Just draw the wire through a blob on the iron.
5. Put a small drop of solder on tip of iron. Then while holding wire, touch the wire and iron to the pins to be attached. (It helps to have the card taped to a surface and your eyes at level with the pins)
6. Use a clipper to remove exess wire to be used on the next pin.
 
Overall the DIY requires condsiderable patience as there are 64 pins within close proximity.
 
You will hear the difference.
 
Sorry, no photos as mine is now encased in candlewax. No way am I putting a 3rd level...............
 
Xin, please make us something that can really unleash the OPA627/637.

 

[nakedtoes]

Dr xin?

From what I know balancd card if run single ended is sound same as Iem card cause only half of the components in the amp card used. I comparing balanced out with single ended out using balanced card now.. After burning in the circuit then would share mine findings.

 

[HeadHigh]

any one knows what's the best amp card for iem , more dynamic,  fun sound ?
I own 901 sound laid back and dull

 

[Shure or bust]

I to am on the fence with amp cards. I have the power 2 amp card. Looking at either balanced or mini box gold. I currently have no balanced headphones, not to say that might change later.

 

[nakedtoes]

Try both yrself.. But if u intend to run balanced in future the balanced card is the best.

 

[Shure or bust]

Try both yrself.. But if u intend to run balanced in future the balanced card is the best.

Mini box gold vs balanced amp ? Or other module. I only use sub 100 ohm headphones and iems that are unbalanced. Currently i use audeze isine 20, k3003 and other headphones thrown in.. I have the power 2 stock card. I want something that improves on its sound.

 

[nakedtoes]

Both balanced and minibox gold should improve in term of SQ. I do not have minibox gold but listened to it before.. It sound quite like paw gold but less digital and aggressive. It sound muddy compared to balanced card. Thus I prefer balanced card and since got my TG334 balanced no looking back. Balanced sound the best of all that's IMHO.