[noobDiyAudio]

asmuch as I can agree with what you said, the whole thread started as support to somebody who has no or minimal knowledge, and minimal tools. AND no titme or possibly inclination to go take a course and buy tools.


the topology of the amplifier is quite simple.

if you remove the OpAmp, you basicaly have the input signal terminating on the Opamp socket input pins. this then goes Nowhere UNLESS the OpAmp is in the socket and working .

if you feed the same signal on each channel ( rca) you should expect to get the same value on each channel input pin on the socket - and if you don;t then you have a problem in the path to to OpAmp socket input pin.

if you do get the same vaolue , then it is likely that there is a dead opamp channel.

the whole discussion has gone the way it has simply because of the assumption of minimal knowledge of electronics and no measurement instruments apart from universal meter - tape and gum so to speak. I still think eliminating cold solder or even something as trivial as short under the board across the positive and negative inputs on one channel is simple enough to do .

But yes, a course and instruments would be great if the interest is there - otherwise it will be much cheaper to simply go to the seller and get a replacement or refund -with the risk that the same problem may happen again.

Hi thanks for the help, I've asked the seller to send me a replacement.

 

[requal]

Hi thanks for the help, I've asked the seller to send me a replacement.

Just want to say: the same problem on this board Anyone had resolved it?

Edit: I found problem. It was broken transistor in my case.

 

[mikaelmark]

If connecting a headphone amp. to a home cinema receivers PRE Out or AV Out, must the receiver be powered on, or will the headphone amp. get the signal also if the receiver are turned off?

And what´s the difference between PRE Out and AV Out? Should´nt both be low voltage, suited for example an external amp? My receivers manual, says the PRE Out will have the same signal as from the speaker cables and AV Out will only output from analog in -sources.

 

[mikaelmark]

I have now replaced the OpAmp from OPA627 to Burson V6 (discrete) for two units, and for one (battery driven), it working fine.

But for the other unit, after a few seconds after first turn on, it was a quiet "Pofff", followed by a smell of burned electronics! And now only the two LED´s near the OpAmp will light - the one in the front beside the headphone jack is off and also the regulator´s LM317/337 will not be heated up.

I can not see any damaged capacitor or anything else, so maybe it´s the new Burson OpAmp exploded!? Do someone have any idea what could have happened?

 

[davveswe]

do you have any good tweak to remove dc offset? some opamps in the amp has high dc offset, especially with 10x gain.

 

[davveswe]

Where can i get opamp bias adapters?

 

[mikaelmark]

You can buy them in your "local" electrical equipment store or at eBay/Amazon for example. They will be quite cheap, and I advise you to look for gold plated one´s.

But, if you´re a bit handy, you can do like me and solder the two resistors directly on the secondary side of the PCB (down side), between pin 1, 4, and 7 at the OpAmp without using any extra socket/adapter.

Note that I removed those resistor´s, when swapping for Burson V6, as there may be risk for everheating otherwise.

 

[UncleGrandpa]

Hi there!
I have been using the Lovely Cube for 2 months now, and I'm planning to upgrade its opamp to SS3602. May I ask if there is any steps I need to take apart from replacing the OPA2134 with the SS3602 itself? I saw some people must did something like "class-A bias".
Also, in you guys' opinion, it is worth to upgrade the 2134 to the SS3602 and what are the changes?

Thank you guys very much!

 

[penmarker]

Every circuit responds differently to opamp changes, you'll need to roll them yourself to listen to what's best for both you and the amp.

No special steps to replace the opamp. Just turn off the unit and unplug, leave for a few minutes so the power caps discharge, and swap out the opamp.
The class A biasing requires another opamp socket and soldering some resistors. The guide is the same across most opamps but I don't recommend it for fear of overheating.

 

[UncleGrandpa]

Every circuit responds differently to opamp changes, you'll need to roll them yourself to listen to what's best for both you and the amp.

No special steps to replace the opamp. Just turn off the unit and unplug, leave for a few minutes so the power caps discharge, and swap out the opamp.
The class A biasing requires another opamp socket and soldering some resistors. The guide is the same across most opamps but I don't recommend it for fear of overheating.

I'm using the original lovely cube which was bought from Alicemagicbox. If possible, do you think it is necessary to upgrade the opamp? Thanks!

 

[penmarker]

I'm using the original lovely cube which was bought from Alicemagicbox. If possible, do you think it is necessary to upgrade the opamp? Thanks!

I wouldn't make it a priority. With my V5 the improvement is subtle and I can't really remember how the stock 2134 or upgraded 4562NA sound like.
The great thing is opamps (except those audiophile marketed ones) are cheap, and you can just buy a bunch and roll through them.

 

[UncleGrandpa]

I wouldn't make it a priority. With my V5 the improvement is subtle and I can't really remember how the stock 2134 or upgraded 4562NA sound like.
The great thing is opamps (except those audiophile marketed ones) are cheap, and you can just buy a bunch and roll through them.

The SS3602 is like 70$ so it is not so cheap. I read a lot on this thread and found some members said that the 2134 was trash? So now I'm pretty confused when you say the improvements are subtle with such a good opamp like the V5.

 

[penmarker]

I upgraded from the 2134 to the 4562, and only later to V5. I haven't compared the V5 to the 2134 and I don't think I can find the 2134 anymore to compare.

The 2134 is certainly not trash, they sound okay as a stock opamp but there are better opamps out there.

 

[UncleGrandpa]

I upgraded from the 2134 to the 4562, and only later to V5. I haven't compared the V5 to the 2134 and I don't think I can find the 2134 anymore to compare.

The 2134 is certainly not trash, they sound okay as a stock opamp but there are better opamps out there.

Yeah of course there are better opamps, just that I don't know if it is worth to upgrade to them, because the best opamp costs quite a lot

 

[penmarker]

Yeah of course there are better opamps, just that I don't know if it is worth to upgrade to them, because the best opamp costs quite a lot

Honestly after you get to a certain price or performance point, the differences between parts or component or product start to shrink. I'd recommend you to go for it and get the 3602. Maybe in the future you get another amp with swappable opamp and you can reuse it if you want to. But if you want an objective experience between that vs 2134 you'll have to wait for someone who had tried to chime in. Or probably look for the opamp thread in the DIY section (IIRC there's one there) and read through their impressions.