[raoultrifan]

I assume if the quiescent current of the V5/V6 is 7mA/channel (single op-amp) per https://drive.google.com/file/d/0Bxn23njCr8VCR19ELS1YOTMxV00/view then it's still biased to Class-A a little bit (it's working in ClassAb actually).
However, SS3601 is biased 15mA per https://testing.coreysblackwell.com/wp-content/uploads/2014/06/SS3601_SS3602.pdf.

 

[omegaorgun]

Has the V6 Vivid been soldered and then unsoldered from the board (PCB)?

What country do you live in, and do you want anything for the shipping? I live in Sweden.

No has not been soldered, US.

 

[DjBobby]

Deleted. Solved.

 

[omegaorgun]

Anyone have a classic they would like to trade?

 

[mikaelmark]

For my V6 Vivid´s, I now have 50+ hours at my headphone amp and 500 - 1000 hors for my AK4490 connected to my home cinema with B&W 683 S2 and modded Proson Tower 701 Twin - and the sound is gorgeous! No need for my B&W 12" sub.

 

[lantian]

Perhaps you guys can help me. i wanted to upgrade the op amps in my lakepeople g5hp. Since I could not find the burson v5i anywhere in Germany, I ordered opa134 for the time being, till I get the v5i's in there. But now I have a problem with the thermals, it seems that the transistors are overheating in about 3-5min. Any ideas on how to mitigate this? Here is the schematic:

 

[raoultrifan]

Is audio out working or there’s no audio at all? Can you measure BD transistors temps?

 

[lantian]

Is audio out working or there’s no audio at all? Can you measure BD transistors temps?

The audio is working great for the first couple of minutes, though it is bit quieter it seemed. after about 3-5 minutes it starts to stretch the sounds out, everything sounds wrong and kind of slows down, like it would be braking. Unfortunately can not measure the temps but those transistors are hotter than hot, can not touch them after 5 min. While with the original tl071 they are barely warm at all.
Thank you for your time.

 

[raoultrifan]

Maybe your OPA134 are oscillating, you need a scope to test the amp with square signals. You should probably stick to the original TL071 unless you’ll find perfect compatible opamps.

 

[lantian]

Maybe your OPA134 are oscillating, you need a scope to test the amp with square signals. You should probably stick to the original TL071 unless you’ll find perfect compatible opamps.

Thank you, will try and obtain one for measuring.

 

[raoultrifan]

Meanwhile, you could try adding some decoupling caps between V+ and GND, and between V- and GND. One 10...100nF in parallel with 10...100uF for each rail. Nit sure will hel, but worth a try.

 

[mikaelmark]

The audio is working great for the first couple of minutes, though it is bit quieter it seemed. after about 3-5 minutes it starts to stretch the sounds out, everything sounds wrong and kind of slows down, like it would be braking. Unfortunately can not measure the temps but those transistors are hotter than hot, can not touch them after 5 min. While with the original tl071 they are barely warm at all.
Thank you for your time.

Transistors will normally be hot, especially in BIAS Class A (can be up to almost 100 degrees Celsius).. But OpAmp´s sould not be too hot.

 

[mikaelmark]

In many schematics, it will be fine to swap OpAmp to almost anything (that will PIN-compatible and work within it´s specific voltage area).

In my headphone amp - Lovely Cube, almost anything seem´s to work fine.

In my CD player Harman Kardon HD970, LM4562 did´nt seem to work at all. Replaced with THS4031, and it works gorgeous now!

 

[sha007]

In that case, you want the V6 Classic.

So you are suggesting v6 classic for HD 700? I thought the vivid is the right one for smoothing the highs of Sennheiser hd700. Can you please elaborate why classic is more suitable for hd700?

Thank you.

 

[393699]

The Vivid opamps are brighter in the upper frequencies than the classics. It is not a "bright" opamp, but is very detailed. This additional detail in the upper registers will probably cause you some fatigue with the HD700. A friend of mine owns the HD700. I have heard it a few times. The mid treble on that headphone is quite bright. I created an EQ set to use with that headphone. It improves it greatly. He finds that it sounds much more balanced, while still keeping the overall sound signature. Give this EQ a try on your HD700 and see what you think. This removes the recessed upper mids, and decreases the mid treble spike quite nicely. It makes the headphone sound much more balanced. Be aware as well that the reduction in the mid treble spike also ends up improving bass impact and extension a tad.

Pre-amplifying: -2

1.5 kHz: + 1
2kHz: + 2
3.15 kHz: + 2
4 kHz: + 1
6 kHz: - 1
6.5 kHz: - 1.5
7khz: - 1