[evilmerlin]

Quote:

Originally Posted by HeadphoneAddict /img/forum/go_quote.gif I am discovering one problem with the LTC6241HV main/THS4032 ground. The sound is great (very much like my Predator) but at low volume levels I am getting less than 7-8 hours of battery life using my RS-1, vs the 15-18 hours I got with the stock D2. And, the Predator gets me over 50 hours everytime. I know for a fact that I get over 24 hours out of the Boa, but have never tried going longer. HiFlight - when you were rolling opamps for the D1, I believe you said these two opamps were low draw opamps. Should I be suspecting that my stock batteries after only 5 months are wearing out, or that the opamps suck more power than we thought? I am switching back to stock to test the battery life, but before I test my top 4 or 5 opamp combos for their battery life (time consuming), can you give us an idea (like you did in the D1 thread) about milliamp draw of these combos vs stock?

You're using the THS4032 as your ground? Ah, i thought you were using the LMH6655.

I too have been trying to find the current draw for the opamps but they don't seem to be listed in the spec sheet at all. Do you have to calculate them manually?

 

[HeadphoneAddict]

Quote:

Originally Posted by evilmerlin /img/forum/go_quote.gif You're using the THS4032 as your ground? Ah, i thought you were using the LMH6655. I too have been trying to find the current draw for the opamps but they don't seem to be listed in the spec sheet at all. Do you have to calculate them manually?

I made a typo, sorry - 6241/6655 is what I had in it.

 

[HeadphoneAddict]

I should note that the AD8620 does not work in the D2 Viper.

I also have the stock opamps running in the Viper with the RS-1 since 10PM, to see what stock battery life is like again. I won't be able to listen again till tomorrow.

 

[HiFlight]

Quote:

Originally Posted by HeadphoneAddict /img/forum/go_quote.gif I am discovering one problem with the LTC6241HV main/LMH6655 ground. The sound is great (very much like my Predator) but at low volume levels I am getting less than 7-8 hours of battery life using my RS-1, vs the 15-18 hours I got with the stock D2. And, the Predator gets me over 50 hours everytime. I know for a fact that I get over 24 hours out of the Boa, but have never tried going longer. HiFlight - when you were rolling opamps for the D1, I believe you said these two opamps were low draw opamps. Should I be suspecting that my stock batteries after only 5 months are wearing out, or that the opamps suck more power than we thought? I am switching back to stock to test the battery life, but before I test my top 4 or 5 opamp combos for their battery life (time consuming), can you give us an idea (like you did in the D1 thread) about milliamp draw of these combos vs stock?

I have noticed the same thing on my D2. Battery life does seem to be lower than with the other opamps. Below are some of the current draws of the TopKit opamps and Predator clone opamps.

If anything, the combinations using the THS4032 should be less, since it draws about 8.5 ma/channel.

The LMH5522 draws 4.3/ch, the LTC6241 draws 2.5/channel, and the LM6172 about 2.3.

ISL55002 draws about 4.5ma/channel at idle.

The real miser is the ADA4841 at about 1.8/channel.

LMH6655 draws about 4.5 ma/ch

The current draw as stated in the datasheets are quiescent
current draws, so it is very likely that high-level signal inputs can result in much higher current draws, and it is my guess that the current requirements under load are not really representative of the quiescent levels.

For max battery life, I would suggest dual ADA4841s.

I have not really timed for exact figures, as I leave my Viper plugged in most of the time for testing.

 

[HeadphoneAddict]

Quote:

Originally Posted by HiFlight /img/forum/go_quote.gif I have noticed the same thing on my D2. Battery life does seem to be lower than with the other opamps. Below are some of the current draws of the TopKit opamps and Predator clone opamps. If anything, the combinations using the THS4032 should be less, since it draws about 8.5 ma/channel. The LMH5522 draws 4.3/ch, the LTC6241 draws 2.5/channel, and the LM6172 about 2.3. ISL55002 draws about 4.5ma/channel at idle. The real miser is the ADA4841 at about 1.8/channel. LMH6655 draws about 4.5 ma/ch The current draw as stated in the datasheets are quiescent current draws, so it is very likely that high-level signal inputs can result in much higher current draws, and it is my guess that the current requirements under load are not really representative of the quiescent levels. For max battery life, I would suggest dual ADA4841s. I have not really timed for exact figures, as I leave my Viper plugged in most of the time for testing.

I'll try to absorb all that, and maybe try my ADA4841-2 with the LTC6241HV, or LM6172 (6 different combos there).

I just got 15 hours with the stock opamps, iMod to D2 Viper, playing through RS-1 at low-normal volumes. How many ma/channel does stock draw for each opamp (1364 and 5532)?

 

[evilmerlin]

So since these are dual channel opamps, I'll have to multiple the values by 2 right?

 

[HiFlight]

Yes, the figures I quoted were per channel.

HiFlight


Quote:

Originally Posted by evilmerlin /img/forum/go_quote.gif So since these are dual channel opamps, I'll have to multiple the values by 2 right?

 

[HiFlight]

Quote:

Originally Posted by HeadphoneAddict /img/forum/go_quote.gif .................................snip............. ............................ I just got 15 hours with the stock opamps, iMod to D2 Viper, playing through RS-1 at low-normal volumes. How many ma/channel does stock draw for each opamp (1364 and 5532)?

Actually, this stock combo draws more than any of the others I have mentioned above. The 1364 is about 6.5 ma/ch and the 5532 about 4. There should, at least in theory, not be that much difference in battery life.

There are many things besides opamps that affect battery life, such as impedance of phones, sensitivity,amp gain, etc. Anything that requires the volume knob to be turned up higher will lower battery life.

Sort of like how the accelerator in a car affects MPG.

HiFlight

 

[dle4e_2005]

I recommend the pairing of LMH6622 main/LM6172 for Etymotic ER4s user.

I'm gonna try it with the Vcap when it arrive in a few more days time. (Can't wait for it)

 

[HeadphoneAddict]

Quote:

Originally Posted by dle4e_2005 /img/forum/go_quote.gif I recommend the pairing of LMH6622 main/LM6172 for Etymotic ER4s user. I'm gonna try it with the Vcap when it arrive in a few more days time. (Can't wait for it)

Yeah, I think that sounds similar (but slightly warmer) to #4 below and is good with IEM too.

Quote:

Originally Posted by HeadphoneAddict So far my ranking #1-4 for opamp combos that are all better than stock: 1. LTC6241HV/LMH6655 - Sounds similar to Predator but slightly smoother and less aggressive , good with everything 2. LMH6622/THS4032 - not quite as warm or forward as #3 but good with everything (I am told similar to iQube) 3. LM6172/THS4032 - warm with more forward mids, good with full size cans, especially Grados - sound is kinda between Predator and 2MOVE 4. THS4032/LMH6172 - less forward and better with many IEM or non-grado full size, more similar to Pico Stock is not bad, it is just a little more recessed than I like in the mids which puts it just below the Pico or HR Micro Amp.

 

[HeadphoneAddict]

I annot get the ADA4841-2 to work in main or ground when I had my LTC6241HV in with it, so I am testing the LM6172 in the ground channel with my 6241.

I'll report back.

 

[HeadphoneAddict]

Quote:

Originally Posted by HeadphoneAddict /img/forum/go_quote.gif I annot get the ADA4841-2 to work in main or ground when I had my LTC6241HV in with it, so I am testing the LM6172 in the ground channel with my 6241. I'll report back.

So far the 6241/6172 is sounding similar to the Predator too, so I am running it until I wake up in 8 hours and see if it is still going or if the battery is dead. I have about half an hour on it already. This should draw 9.6 ma (both channels) vs 21 for stock (per HiFlight). I've got this setup to burn-in some silver cables for Livewires IEM at low normal volume (9 o'clock).

 

[HiFlight]

Quote:

Originally Posted by HeadphoneAddict /img/forum/go_quote.gif I annot get the ADA4841-2 to work in main or ground when I had my LTC6241HV in with it, so I am testing the LM6172 in the ground channel with my 6241. I'll report back.

Larry...
Very strange, as my D2 works fine with the 4841/6241 combo. Both ways, with 6241 in LR and Ground. There is less turn-on noise and volume pot noise with HV in LR and 4841 in ground. Probably due to dc voltage offset difference between the two.
It is a very nice sounding pair either way. Battery life should be quite good.

Another opamp that is very quiet in the ground channel is the OPA2134. Very little "static" when rotating volume knob and very quiet turn on/off.

BTW, iBasso is using dual ADA4841s in the new D3 Python, and it is getting excellent reports.

 

[HeadphoneAddict]

Well, I just had my second LTC6241HV die tonight. The first one "popped" in the Travagans White and I had to buy another. I was using the LTC6241HV in LR, and LM6172 in ground tonight.

I had unplugged my Livewires and changed to a new set of cables that I'm testing for stevenkelby, but when I plugged back in there was no sound. I tested things and it wasn't the Livewires it was the amp. So I took out the 6241 and replaced it with the 6622 and no problems. I then put the 6241 back in to confirm it was bad and I have loud hiss in the right channel and music in the left. So, I put the 6622 back in and listened for a while, then went to unplug the headphones again and this time I got a static spark (case closed and screwed shut) and it killed the 6622. Now the 6622 has hiss in the right channel and nothing in the left.

So, I have it with LM6172 in ground and LM4562 in LR for now, but I have never had sound from the 4841, and added a bad 6241 and 6622 to my inventory now, totalling 4 dead opamps here (two 6241, 6622 and 4841). I'm a little bummed.

Are we not allowed to use the D2 Viper as USB DAC with the wall wart plugged into it? That's the only thing I can think of as a problem because I get some noise that way, but when I'm burning in cables or headphones I want the battery to stay charged. Looks like the Boa or Vivid Tech V1 will have to be used for burn-in from now on, since they both charge via USB.

PS: With the LM4562 in ground I got some sound cutting out, so I left the LM6172 in ground, and with that in ground I found the AD8656, AD8066 and AD8397 don't sound too bad, but I will save extended listening with those for later.

 

[HiFlight]

.......................................snip....... .................................
I had unplugged my Livewires and changed to a new set of cables that I'm testing for stevenkelby, but when I plugged back in there was no sound. I tested things and it wasn't the Livewires it was the amp. So I took out the 6241 and replaced it with the 6622 and no problems. I then put the 6241 back in to confirm it was bad and I have loud hiss in the right channel and music in the left. So, I put the 6622 back in and listened for a while, then went to unplug the headphones again and this time I got a static spark (case closed and screwed shut) and it killed the 6622. Now the 6622 has hiss in the right channel and nothing in the left.
....................................snip.......... ..............................

If the headphones were removed from the jack while the amp is on, it will create a momentary direct short circuit to ground. Depending on the input signal, it can cause a pretty good voltage spike that can exceed the voltage rating for the opamp.

If the amp was turned off when you removed the jack, I can't imagine what caused the problem.