[HiFlight]

Quote:

Originally Posted by PPkiller /img/forum/go_quote.gif Thanks ron... Are those two cap there to block dc voltage from the dac? what are the values of the blackgate capacitors you used? i'm wondering whether the NX Hi-q 22uf 6.3v is sufficient..

I used 47uf BG Hi-Q NP. I believe they are coupling capacitors for L/R.

Please make note that I am not encouraging that this be done.

 

[HiFlight]

[Quote:
Originally Posted by Skylab
There is absolutely no hidden agreement - I stated it quite plainly. iBasso Audio asked me not to include the D1 in this review, and I agreed. Simple as that. I reviewed it elsewhere.

In their view, it's not the same type of product as these. Fine with me. Unquote]



It is my impression, after corresponding with iBasso, that they are well-aware of the shortcomings of the stock D1 amplifier. They also welcome our input into the possible opamp combinations that improve the amplifier section.

They face considerable difficulty in sourcing many opamps as well as other devices that would actually result in a much improved product.

They feel hampered in their efforts to stock quality componets, but it is a fact of life due to their location. I believe that, in part, is why they are so receptive to our efforts to improve the already superb basic design of the D1.

We will undoubted be able to readily acquire a larger selection of quality components in the US than iBasso is able to stock for production at their location in China, so the future for continuing D1 opamp rolling looks bright!

I continue to be impressed with the basic design of the D1 and the willingness of D1 to interact with our efforts at improving their amp.

 

[jamato8]

The D1 has responded to opamp changes more than Any amp I have worked with. I have also worked with tubes for years and few have responded to such a degree as the D1 to different opamps. To me this is very positive as the D1 seems to reflect the opamp being used and does not obscure the sound with other component in the circuitry. This, to me, is implementation at a high order.

I finally got my iRiver to accept Rockbox! Hello to a new frontier in learing for Johnny. Seems like I am always in some sort of learing curve, as if daily life isn't enough! :^)

 

[itsborken]

Quote:

Originally Posted by HiFlight /img/forum/go_quote.gif I used 47uf BG Hi-Q NP. I believe they are coupling capacitors for L/R.

Thanks to you and jamato8 for the info and pictures for the capacitor upgrades. Do you source your BGs from Parts Connexion or elsewhere?

 

[jamato8]

Parts Connexion or Michael Percy. Get them while you can because they are now out of production. I have said this before but, "There is nothing like Black Gates and I doubt there ever will be again". They are made entirely different from any other caps. I have used them direction in the signal path and have been amazed but they do take a very long time to burn/break in. I have in the past taken them out of a circuit because I thought the sound was poor, which it was but then knowing better due to experience, put them back and waited and they have always come around and I have to state I have Never been dissapointed with what they do in any application.

The D1, as I stated above, has smoothed out and warmed a bit to because very, no exceedingly, pleasing to the ear.

 

[itsborken]

Quote:

Originally Posted by jamato8 /img/forum/go_quote.gif Parts Connexion or Michael Percy. Get them while you can because they are now out of production.

I heard that as well so I'll snag a handful before they are gone. Thanks for the info!

 

[jamato8]

Quote:

Originally Posted by itsborken /img/forum/go_quote.gif I heard that as well so I'll snag a handful before they are gone. Thanks for the info!

I reuse them all the time if I no longer use the equipment they are in and tend to leave a little longer lead in place. I plan on placing a pretty good order soon.

 

[itsborken]

Quote:

Originally Posted by jamato8 /img/forum/go_quote.gif I reuse them all the time if I no longer use the equipment they are in and tend to leave a little longer lead in place. I plan on placing a pretty good order soon.

Good point on the reuse--that is the way to go.

 

[willisv]

Quick question Jamato, is this all the caps i will need to do the same as your D1:

6 - 47uf HiQ Blackgates
1 - 4.7uf nonpolar Blackgate
1 - Sanyo 150uf SQ

You also said something about using 2 150uf oscons in the digital section, but i couldn't see that in the pictures you took. Thanks for all the info!

 

[HiFlight]

I have found a very nice-sounding opamp combination that draws only 14ma total for all 5 opamps, (1DAC, 1L/R and 2 buffers) compared to the stock configuration that draws approx. 40 ma. In comparison, the OPA2111/LM4562/AD8656, while a fine-sounding combination, draws about 43ma.

This should result in significantly longer battery life even when using the full DAC/Amplifier combination.

Tonal balance, soundstage and detail are very good, with a clean, open sound.

The following are the opamps I used in this configuration:

L/R: ADA4841-2
Buffers: LMH6643
DAC: LT6234

One can substitue the LT6234 or the LTC6241HV for the ADA4841 with little audible difference. Also the ADA4841 works quite well in the DAC socket in place of the LT6234.

There are slight differences in the sound when changing LR opamps, but please do not ask me which is best. They are very close, and the choice will largely be determined by the choice of music, headphones, and personal preference.

I do find that with these combinations the sound quality is VERY close when switching the same source (iRiver H120) between the D1 Aux input and the Optical input, which tells me that the quality of the amplifier section is now equal to the quality of the DAC.

If using the D1 primarily by battery power rather than with an adapter, one might wish to try some of these low-current draw opamps.

 

[souperman]

Quote:

Originally Posted by HiFlight /img/forum/go_quote.gif I have found a very nice-sounding opamp combination that draws only 14ma total for all 5 opamps, (1DAC, 1L/R and 2 buffers) compared to the stock configuration that draws approx. 40 ma. In comparison, the OPA2111/LM4562/AD8656, while a fine-sounding combination, draws about 43ma. This should result in significantly longer battery life even when using the full DAC/Amplifier combination. Tonal balance, soundstage and detail are very good, with a clean, open sound. The following are the opamps I used in this configuration: L/R: ADA4841-2 Buffers: LMH6643 DAC: LT6234 One can substitue the LT6234 or the LTC6241HV for the ADA4841 with little audible difference. Also the ADA4841 works quite well in the DAC socket in place of the LT6234. There are slight differences in the sound when changing LR opamps, but please do not ask me which is best. They are very close, and the choice will largely be determined by the choice of music, headphones, and personal preference. I do find that with these combinations the sound quality is VERY close when switching the same source (iRiver H120) between the D1 Aux input and the Optical input, which tells me that the quality of the amplifier section is now equal to the quality of the DAC. If using the D1 primarily by battery power rather than with an adapter, one might wish to try some of these low-current draw opamps.

Is your favorite still the OPA2111/LM4562/AD8656 combo if current did not matter? Just wondering.

 

[HiFlight]

Quote:

Originally Posted by souperman /img/forum/go_quote.gif Is your favorite still the OPA2111/LM4562/AD8656 combo if current did not matter? Just wondering.

That is not my personal favorite.

 

[souperman]

Quote:

Originally Posted by HiFlight /img/forum/go_quote.gif That is not my personal favorite.

Ah, I see. What is your personal favorite when current draw does not come into play? I remember you saying you really liked the AD8397's in the buffer position.

 

[HeadphoneAddict]

Quote:

Originally Posted by jamato8 /img/forum/go_quote.gif ...I finally got my iRiver to accept Rockbox! Hello to a new frontier in learing for Johnny. Seems like I am always in some sort of learing curve, as if daily life isn't enough! :^)

I got rockbox on a while ago, but with iRiver flash V1.63 not 1.66 - I skipped 1.66 because the date modified was older than 1.63 and I was afraid to use it.

 

[jamato8]

I used 1.66 and now that I am getting used to Rockbox I can see why it is much better than the iRiver software. So many more possibilities and more user friendly and I can still use the iRiver software if I want to. I would like to drop in a 40G drive to my 120 or pick up a black 140. I like the way the iRiver is contructed and the quality feel.

I have the iRiver 120 now velcroed to the top of the D1 with the optical cable (a very short custom one from Syscon in Canada) and it is a great combination.