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alvin1118

DIY: AMB Lab Mini3

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Bro...I was trying to desolder the battery connector to file down the parts but wasn't successful so i reflow the solder on the battery connector. But now my mini3 suddenly has high quiescent current reading > 150mA, does anyone knows which part is causing the problem? :helpsmilie:

 

The amp sounds fine using the power adaptor mode though. :rclxub:

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how much would it cost if I got someone to set up a mini3 for me? could someone PM me the average price or something? many thanks!

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hm.. hand itchy again, and i'm too free during this long vacation :bash:

 

modded my mini^3 :grin:

 

removed 2x 100u25v FM, 2x 470u16v FM, 6x 0.1u

IPB Image

 

modded with 2x 47u25v Cerefine, 2x 470u25v Made in Germany Frako, 6x Wima Black Box

IPB Image

 

IPB Image

 

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it sounds better indeed! better sound stage and musical! :thumbup:

 

burning in now to find out more :drool:

 

 

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hm.. hand itchy again, and i'm too free during this long vacation :bash:

 

modded my mini^3 :grin:

 

removed 2x 100u25v FM, 2x 470u16v FM, 6x 0.1u

IPB Image

 

modded with 2x 47u25v Cerefine, 2x 470u25v Made in Germany Frako, 6x Wima Black Box

IPB Image

 

IPB Image

 

IPB Image

 

it sounds better indeed! better sound stage and musical! :thumbup:

 

burning in now to find out more :drool:

 

sweet!! tempted to try.. does it still fit in the case?

 

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Should still fit as the caps look smaller than the battery. If I am not wrong, the caps removed were Panasonics FCs which are already very very good caps for power supply, as these are. I would suggest that if there are any benefits from the mods, it will be from the smaller Wima caps beneath.

 

But do note as stated in the headfi forum, this amp has been engineered precisely for the opamps and extending the leads to caps may cause instability and oscillations.

 

Just my 2 cents. :)

Edited by heady

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exactly, changing bypass caps of OPA would cause stability and oscillation issue :cry:

so..mod it at own risk. :D

 

check out my post @ headfi.

 

amb has pointed out some useful feedback to my mod :shocking:

 

after reading his reply, i did a A/B test with original mini3 using my ipod LOD as source.

i still prefer the mod ones as it has (*slightly) better sound stage and mellow vocal. no doubt the stock components already sounds decent :lust:

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Yeah. Think I won't mod mine since I'm very happy with mine. (both of them!)

The SQ of the Mini3 is almost comparable to the Hornet, especially after 30 hours burn in time.

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after reading his reply, i did a A/B test with original mini3 using my ipod LOD as source.

i still prefer the mod ones as it has (*slightly) better sound stage and mellow vocal. no doubt the stock components already sounds decent :lust:

 

I have a Mini3 with the high performance opamp and another with the extended battery life opamps and I actually prefer the latter as it is more mellow. Sound stage wise, I am not discerning enough. And battery life is good. Two days listening before running out of juice.

 

 

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I have a Mini3 with the high performance opamp and another with the extended battery life opamps and I actually prefer the latter as it is more mellow. Sound stage wise, I am not discerning enough. And battery life is good. Two days listening before running out of juice.

 

wow, two days is consider very long as compare with performance version!

i will try the extended battery life opa next week :lol:

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wow, two days is consider very long as compare with performance version!

i will try the extended battery life opa next week :lol:

 

I better clarify before I mislead someone. :P Two days as in listening in the office, ie 12-14 hours and not 48 hours.

 

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i've just de-modded the golden frako and cerafine after reading the replies & feedbacks.

 

i did not remove the wima black box, but i did solder 10uf35v silmic parallel to wima caps to provide good power supply decoupling as recommended in AD8397 datasheet.

 

pic:

IPB Image

 

IPB Image

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Alvin,

 

I want to change the LED to a different colour. Do you know the kind I should get? What's the recommended power rating?

 

Sean.

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OMG.. is me again.. lol :DD

 

I have done a newly DIYed Mini3 with OPA2107AU, which claims to have 90% performance of the legendary OPA627!

 

The operating voltage of this small little OPA2107AU is +-4.5v, which is just nice for a fully charged 9v battery in mini3 :dance:

 

OK, let have some photos, it might be bored to read words only >"<

IPB Image

*Cant see the baby OPA2107, it's hiding under the caps :wacko:

 

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*dont have Wima Black Box anymore..left 2pcs <_<

 

Moded the bypass caps of OPamps to 10uf35v Silmic // with 0.1uf Wima Caps, Gain 2x, BC 036 220uf Power Rail Caps, and White LED :lust:

 

In fact i was a bit worried how long would the fully charged 9v battery last since the min. operating voltage of OPA2107AU is 4.5v, if battery voltage drain lower the rating, the OPA will simply don't works.

 

Luckily it doesn't, i have been running in my OPA2107AU Mini3 since 10am to now, still full of energy! No performance degradation issue !

 

Measured current rating of the Mini3_2107 is 10.x mA, theoretically, with 170mA battery, the Mini3_2107 should last 16hrs! I am rather happy with this battery life (much longer than AD8397!)

 

Equipment: Ipod Classic 80GB-> DIY Cardas Ipod LOD-> Mini3_2107-> Shure SE110 & ATH-M50 & HD650(Cardas-ed)

 

IPB Image

 

How Mini3 sounds with OPA2107AU?

  • Excellent Vocal, forward, smooth, mellow and detailed
  • Tight & Deep Bass
  • Darker Background, Quieter
  • BurrBrown OPA Signature - Laid back
  • Less fatigue for long hours listening
  • Slightly narrower sound stage as compared with AD8397, but 'deeper'
  • Might be a little muddy for some genre especially for more music instruments
I'm very happy with Mini3_2107, using it as portable rig now :thumbup:

 

My next try would be Linear Technology Op amp! still hunting :grin:

Edited by alvin1118

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hi hi. Will like to post my finished mini3.

 

Change signal resistors to kiwame. 470uf Power caps to Elna n Fine Gold. 100uf Caps to Oscons. Same as Alvin, parallel Wima at th bottom for te silmic caps.

 

post-1439-1215830522_thumb.jpg

post-1439-1215830546_thumb.jpg

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