L/R: AD797AN (Not ones from stock but ones mostly used in model like HR-2 and Apache)
Buffer: Transistor buffer (Still looking for BUF634)
3/4: OPA627BP (Yeah...BP...superb power opamp with magic)
Sound.....What should I expect from ones of the best for preamp plus ones from output power combo?
Sorry that you didn't like the LT1028 - it seems like the amp didn't put it at ease. One of its best traits should be silkiness. Very low gain might be the reason. From LT try to hear the LT1357 too, that's easier to use than the LT1028 and easily sounds mellower.
The OPA2132 is better than the OPA2134, and the LT1357 sounds better than both.
The OPA211 is a wonderful new audio opamp from TI. Try it! It's even rail to rail, which in low voltage applications will be precious.
From Linear Technology it is also worth trying the very musical LT1122.
The LME49710 has disappointed me. It destroys the original tonality of records, no matter where I've tried it. Very unmusical. Also the AD8066 sounded tonally unnatural to me, and rough in the upper mids.
Finally, purely from hearsay - the AD825 should e quite musical.
637BP has more details and sounds brighter. I've tried combination with AD797, AD744, AD8620, AD4841-2 and such but this seems to be only one acceptable for harshness with vocals.
My P3 setting primarly with DT880 03...i decided to play a little with 3/4 amp...3/4 amp i think it GND and VGND and it's related to input ground and output ground, so there's so much more configuration could be with different single op amp at 3/4 amp...for now i like :
I have had a chance to try out a few different opamp combinations in the P3. Some of the better trials are listed below:
1. LT1358 LR, iBasso buffers, THS4032 ground:
Powerful, lots of impact. Upfront soundstage. Should work well
with hard-to-drive phones. Linear makes some nice-sounding opamps.
2. TI 2211 LR, iBasso buffers, TI2211 ground:
Very neutral, open-air sound. Lots of detail, somewhat distant soundstage. Should provide very good battery life.
3. TI2211 LR, iBasso buffers, LM6655 ground:
Bright, lots of detail, very nice soundstage.
THS4032 LR, iBasso buffers, LMH6643 ground:
Very nicely balanced, and detailed, Very nice imaging.
The TI 2211 is quite similar in its specs and power requirements to the ADA4841-2. Not surprisingly, it sounds very similar. It is also a very inexpensive opamp.
I will later try some combinations using the LT1358 as a buffer. It has characteristics that should make it a good performer in that position, maybe better than in LR.
I have a problem with the P3 Heron. It is quite susceptible to external EMF radiation, specifically from handphones. I will hear that irritating beeping sound through my earphones whenever a handphone nearby is active! This is a HUGE problem when listening to my rig on the go given that Singapore has more handphones than people and when we're all tightly clustered in a packed subway.
Does anyone know a mod to block out the handphone radiation?
On a side-note, the ADA 4841-2(LR)/THS4032(GD) combi wasn't too good. The 4841/6643 combi was a winner when paired with the TripleFi 10Ps. Hoping to get more Gd opamps to try with the 4841-2.
Originally Posted by shadowmoses /img/forum/go_quote.gif I have a problem with the P3 Heron. It is quite susceptible to external EMF radiation, specifically from handphones. I will hear that irritating beeping sound through my earphones whenever a handphone nearby is active! This is a HUGE problem when listening to my rig on the go given that Singapore has more handphones than people and when we're all tightly clustered in a packed subway.
Does anyone know a mod to block out the handphone radiation?
On a side-note, the ADA 4841-2(LR)/THS4032(GD) combi wasn't too good. The 4841/6643 combi was a winner when paired with the TripleFi 10Ps. Hoping to get more Gd opamps to try with the 4841-2.
I have noticed the RF interference in all of my portables to some degree or another. Separating the amp/cables from the telephone is about the only way...as power decreases with the square of the distance, it doesn't take much, like just on the other side of the seat.
FWIW, the ADA4841-2 is more suseptable to RF than any of the other opamps I have tried.
Some other good opamps to try:
AD8599, LMH6622, LTC6241HV, ISL55002, AD8066, OPA2111 OPA2604, AD746, LM6172 LT1358. Don't overlook some oldies, like the OPA2227. The best sounding opamp I have ever used is the AD743. It draws quite a bit of quiescent current, but if you are using external power, this is a moot point.
Believe it or not, the LMH6643 sounds good in LR also.
Lowest current draw opamps are: ADA4841 and TI2211.
Originally Posted by shadowmoses /img/forum/go_quote.gif I have a problem with the P3 Heron. It is quite susceptible to external EMF radiation, specifically from handphones. I will hear that irritating beeping sound through my earphones whenever a handphone nearby is active! This is a HUGE problem when listening to my rig on the go given that Singapore has more handphones than people and when we're all tightly clustered in a packed subway.
I tested my P3 with Nokia N81 for the EMI issue. Music was played on iPod nano with P3 connected to it through LOD and ESW9 portable headphone was used for monitoring.
When the handphone was stacked on top of P3 and a phone call was made to the mobile phone, loud peeping noise could be head. But when the handphone was transferred from top of P3 to the side of P3, the noise disappeared completely. Radio wave and hence EMI definitely susceptible to orientation and distance between devices. Even in a packed subway, orientation and distance must be right (unlikely unless handphone is with your girl friend) to cause interference.
Running out of empty opamp adapter (SOIC8 to DIP8) for opamp rolling. Any idea which online store selling cheap adapter ? Does iBasso offer empty adapter for purchase ? iBasso should have offered various customer recommended opamps for online purchase instead of bundling some free ones with P3. Customer should be allowed to pick a set of opamps on purchasing P3 at iBasso online store, thus no unused opamp is wasted and price of P3 can be lowered (remove unreliable power adapter and pouch from P3 bundle as well).
Originally Posted by littletree76 /img/forum/go_quote.gif Running out of empty opamp adapter (SOIC8 to DIP8) for opamp rolling. Any idea which online store selling cheap adapter ? Does iBasso offer empty adapter for purchase ? iBasso should have offered various customer recommended opamps for online purchase instead of bundling some free ones with P3. Customer should be allowed to pick a set of opamps on purchasing P3 at iBasso online store, thus no unused opamp is wasted and price of P3 can be lowered (remove unreliable power adapter and pouch from P3 bundle as well).
It would be extremely costly for iBasso to stock the dozens of opamps that can be used successfully in the P3. They included a very nice assortment of free opamps. Thats more than any other manufacturer provides with their amps.
If you want some special opamps, you can PM me for information.
I spent some more hours tonight testing some different combinations of opamps in the P3.
Phones used for testing were my recabled RS-1s and ATH-ESW10s and the source was my iRiver CF32.
1. LT1358 LR, iBasso Buffers, LT1358 Ground:
Laidback, smooth highs, good soundstage.
Without buffers, more upfront, wider soundstage.
2. LMH6622 LR, bypassed buffers, LT1358 Ground:
Forward mids, detailed. Good for vocals, acoustics, etc.
3: LMH6622, bypassed buffers, LMH6643 ground:
Nice overall balance and detail. Could live with this one.
4: Pick of the night!
LMH6655 LR, bypassed buffers, LMH6643 ground:
Warm, tubey sound. Very smooth, good soundstage.
Tamed highs that tend to be prominent in Grados.
Added iBasso buffer: Smoother highs. Volume about the same with or without buffers.
This is a combination that one would likely not pick based on datasheet specs, but it sounds better than expected.
I find that the iBasso-supplied transistor buffers sound markedly better than BUF634.
my p3 is yet to arrive on thursday.... so, what opamp is used by default (new p3), and how's the SQ? do i need some soldering iron or other stuff in changing the op-amps?
This site uses cookies to help personalise content, tailor your experience and to keep you logged in if you register.
By continuing to use this site, you are consenting to our use of cookies.
