[HiFlight]

Quote:

Originally Posted by unbiased /img/forum/go_quote.gif Has anyone measured the voltage provided by the D1 at the op amp power supply rail pins? What voltage does it provide. This would help us access what op amps will work best in here. Sorry if this info was posted already, I don't recall seeing it. I am waiting on my new D1 still. Just re-ordered it as it is back in stock now. I have some OPA627 op amps and some AD825 op amps which are working excellent in my Practical Devices XMOY2 tin can (Penguin style) headphone amp. If the dual OPA627 works well in this amp, I am thinking it should work well in the D1 too. Anyone tried this op amp? I like the OPA627 and AD825 op amps in my XMOY2 but don't know how they will sound in the D1. Cannot wait to get my D1.

I measured about 7.8 vdc at the LR and buffer sockets and less than 6 vdc for the DAC.

 

[jamato8]

The voltage at the opamp for the amp section is 5 volts and 8 or 9 volts, within volts, for the buffer section. This is on pin 8. I have measured these and have it posted somwhere.

You would have to use an adapter to mount two soic 627's to make it into a dual opamp but frankly I wouldn't bother as I think there are a number of opamps that sound better.

 

[powertoold]

If I kept the D1 plugged in all day, would it overcharge the battery or make it less effective?

 

[jamato8]

No, once the battery is charged it is bypassed and does not overcharge. This is according to iBasso.

 

[powertoold]

Sorry, Head-Fi lagging double post

 

[jamato8]

Quote:

Originally Posted by powertoold /img/forum/go_quote.gif If I kept the D1 plugged in all day, would it overcharge the battery or make it less effective?

Didn't beleive me the first time, eh? Well, as far as I know, no, it will not. :^)

 

[powertoold]

How long are people's batteries lasting for the D1?

 

[Schalldampfer]

Quote:

Originally Posted by powertoold /img/forum/go_quote.gif How long are people's batteries lasting for the D1?

I think the stated is 20 hours, but I would like to know actual usage hours, too, please.

 

[jamato8]

I have gotten a little over 20 hours of use. I have read of 22 hours but 20 hours is fair and more than enough time for a normal couple of days use.

I use a Tekkeon 3450 external battery and go for a very long time. I can run the Tekkeon at 7.5 volts and I get many, many hours of use or run the Tekkeon at 12 volts and charge the D1 and then run off the higher voltage for a slight increase in sound qualtiy.

 

[unbiased]

Quote:

Originally Posted by jamato8 /img/forum/go_quote.gif The voltage at the opamp for the amp section is 5 volts and 8 or 9 volts, within volts, for the buffer section. This is on pin 8. I have measured these and have it posted somwhere. You would have to use an adapter to mount two soic 627's to make it into a dual opamp but frankly I wouldn't bother as I think there are a number of opamps that sound better.

Thanks HiFlight and jamato8for your voltage readings.

jamato8, I do already have two SOIC-8 OPA627 op amps mounted to a BrownDog adapter. Same thing goes for the AD825 op amps that I am trying. I thought the OPA627 were not as great as they were made out to be also at first listen, but I think after letting them burn in for awhile, they mellowed out and sound pretty good. The AD825 in comparison is not as bright sounding but I prefer less harsh bright sounding. FWIW, I tried the LM4562 op amps and they were way bright sounding and too harsh for my tastes. But this is in my old XMOY2 tin can amp. Dunno how the D1 will mate with each op amp until I get my D1. I think the OPA2134pa and OPA2132 op amps sound decent too in the XMOY2. The OPA2111 sounds great in it also I should say... but seems to draw alot more current and needs voltage rails to remain higher than the other op amps or it starts distorting.
I have a few other soic style op amps not yet mounted to dual-adapters that I want to try out in time. Have to dig out my Opti-Visors and tweezers again to solder them to the boards. It's something to do to pass the time

 

[HeadphoneAddict]

Quote:

Originally Posted by paladinca /img/forum/go_quote.gif I found an article about LM4562-related opamps: http://www.edn.com/blog/1700000170/post/790011279.html

The key info they asked for is in the article:

"The parts National just announced build on the two previous ultra-performance parts they have released, the LM4562 dual op-amp and the LM4702 power amp transistor driver IC. The new amplifiers are now available as singles (LME49710) and quads (LME49740) as well as the LME49720 dual that is the same die as the LM4562. They also spun a LME49860 dual that is a 44-volt version of the 49720."

 

[unbiased]

Quote:

Originally Posted by ehlarson /img/forum/go_quote.gif There are some single op amps available that are not available in dual formats that seem to have a good reputation. With the availability of an adapter like this: http://www.cimarrontechnology.com/in...PROD&ProdID=24 it seems feasible to use these in the D1. I am wondering if anyone has some experience with the potential benefits of these single op amps, and what the pitfalls might be.

ehlarson, I am using these Brown Dog adapters right now with several single op amps paired to make them duals. I am waiting for my D1 to be shipped and delivered, but in the mean time, I have been assembling my op amps and testing them in my Practical Devices Xmoy2 headphone amp (it is practically the same as the XM4 amp they sell now). Some op amp types like OPA627, AD825, AD8610 that I have are single amps and needed to be soldered onto these Brown Dog adapters. They fit perfectly well into the small 8 pin DIP socket areas of many amps. There are no draw backs really other than the extra work needed to build/solder the two op amps to the BD adapter (which requires a bit of skill as these are tiny). Not for the layman with beginners soldering skills...! Other drawback that I can think of is that since the op amps are singles, matching pairs may not be as precise as buying a dual op amp version of same op amp family. That's it. Go for it. They work well those single to dual adapters! I just soldered together my two AD8610 op amps to make it essentially an AD8620 op amp and am listening to it in my Xmoy2. The AD8610's (single version of the AD8620) sounds great. I highly recommend them. (Driving my Grado RS-1's)

 

[ehlarson]

Quote:

Originally Posted by unbiased /img/forum/go_quote.gif ehlarson, I am using these Brown Dog adapters right now with several single op amps paired to make them duals. I am waiting for my D1 to be shipped and delivered, but in the mean time, I have been assembling my op amps and testing them in my Practical Devices Xmoy2 headphone amp (it is practically the same as the XM4 amp they sell now). Some op amp types like OPA627, AD825, AD8610 that I have are single amps and needed to be soldered onto these Brown Dog adapters. They fit perfectly well into the small 8 pin DIP socket areas of many amps. There are no draw backs really other than the extra work needed to build/solder the two op amps to the BD adapter (which requires a bit of skill as these are tiny). Not for the layman with beginners soldering skills...! Other drawback that I can think of is that since the op amps are singles, matching pairs may not be as precise as buying a dual op amp version of same op amp family. That's it. Go for it. They work well those single to dual adapters! I just soldered together my two AD8610 op amps to make it essentially an AD8620 op amp and am listening to it in my Xmoy2. The AD8610's (single version of the AD8620) sounds great. I highly recommend them. (Driving my Grado RS-1's)

Thanks. I have some interest in trying the AD797 in the D1, and maybe the AD627 so I have ordered some of these adapters.

 

[Sieg9198]

Finally!!! I got mine today, planning to try it stock form first, then change the opamp to see how big the difference is

 

[souperman]

Quote:

Originally Posted by Sieg9198 /img/forum/go_quote.gif Finally!!! I got mine today, planning to try it stock form first, then change the opamp to see how big the difference is

I don't think you will be able to appreciate the difference with just KSC75's as I see you have paired them with in your sig

.