[rikk009]

Got my hands on the HPA-1, this unit does sound good. Now have to jump on the LME bandwagon. Thanks for all the feedback on this thread.

Edit: Can't see the US seller selling the opamps anymore. The only other sellers are based in China.
Edit2: Sorry, he doesn't ship to my country.

 

[rikk009]

:Sigh: Had to buy this http://www.ebay.com/itm/181118392690?_trksid=p2057872.m2749.l2649&ssPageName=STRK:MEBIDX:IT
Hope it's not a fake.

 

[393699]

Sadly, buying from China, you are almost guaranteed it will be fake.

 

[rikk009]

Sadly, buying from China, you are almost guaranteed it will be fake.

How to ascertain that?

 

[393699]

Most of the fakes come from China. Also, they usually list the opamps with a much lower price than the genuine sellers do. This is a genuine dual LME49990 at the link below. This is the one that most of us bought here who upgraded to the LME49990 in our M-Stage amps.

http://www.ebay.com/itm/1PC-DUAL-SO...948955?hash=item2eee16855b:g:A9QAAOSw6oBXEnVs

 

[rikk009]

Most of the fakes come from China. Also, they usually list the opamps with a much lower price than the genuine sellers do. This is a genuine dual LME49990 at the link below. This is the one that most of us bought here who upgraded to the LME49990 in our M-Stage amps.

http://www.ebay.com/itm/1PC-DUAL-SO...948955?hash=item2eee16855b:g:A9QAAOSw6oBXEnVs

Yes I know but he doesn't ship to my country so have no other option. If anyone here knows some method to tell the difference it would be great.

 

[bookemJ]

Hey guys looking for some feedback on a problem I've been experiencing with my 2013 M-Stage HPA-1.

Received it about 2 weeks ago from someone who hadn't been using it much. Worked perfectly fine the first 3 days I got it then I put a Burson v5 opamp in it. Worked flawlessly for about 10 days until recently about 3 days ago I started hearing crackling/popping from my left headphone. Figured it was a dirty headphone jack so I sprayed some contact cleaner in there and it went away for the night. The next day powered it on and got the noise again so I repeated what I did the day before, this time the noise was still in the background sporadically, but I dealt with it since the noise was faint.

Yesterday same thing, rinse and repeated and it went away nearly all night til today, turned it on and this time it was much louder in the left cup and I haven't been able to get rid of it with the same methods so now I'm unsure what to do.

Read on this thread that tightening the bottom allen bolt might help but it stripped pretty easily since it was already in there so tight.

If you guys have any ideas or suggestions I'd appreciate it, gonna swap out the opamp back to the stock one tonight and see if that changes anything.

Thanks in advance!

 

[Chris J]

Looks like you tried (or will try) putting the original Op Amp back in, did that fix the problem?
Because that would be the first thing I would to.

 

[Pharmaboy]

Hey guys looking for some feedback on a problem I've been experiencing with my 2013 M-Stage HPA-1.

Received it about 2 weeks ago from someone who hadn't been using it much. Worked perfectly fine the first 3 days I got it then I put a Burson v5 opamp in it. Worked flawlessly for about 10 days until recently about 3 days ago I started hearing crackling/popping from my left headphone. Figured it was a dirty headphone jack so I sprayed some contact cleaner in there and it went away for the night. The next day powered it on and got the noise again so I repeated what I did the day before, this time the noise was still in the background sporadically, but I dealt with it since the noise was faint.

Yesterday same thing, rinse and repeated and it went away nearly all night til today, turned it on and this time it was much louder in the left cup and I haven't been able to get rid of it with the same methods so now I'm unsure what to do.

Read on this thread that tightening the bottom allen bolt might help but it stripped pretty easily since it was already in there so tight.

If you guys have any ideas or suggestions I'd appreciate it, gonna swap out the opamp back to the stock one tonight and see if that changes anything.

Thanks in advance!

I would do 2 things in this order:

 

[Pharmaboy]

Hey guys looking for some feedback on a problem I've been experiencing with my 2013 M-Stage HPA-1.

Received it about 2 weeks ago from someone who hadn't been using it much. Worked perfectly fine the first 3 days I got it then I put a Burson v5 opamp in it. Worked flawlessly for about 10 days until recently about 3 days ago I started hearing crackling/popping from my left headphone. Figured it was a dirty headphone jack so I sprayed some contact cleaner in there and it went away for the night. The next day powered it on and got the noise again so I repeated what I did the day before, this time the noise was still in the background sporadically, but I dealt with it since the noise was faint.

Yesterday same thing, rinse and repeated and it went away nearly all night til today, turned it on and this time it was much louder in the left cup and I haven't been able to get rid of it with the same methods so now I'm unsure what to do.

Read on this thread that tightening the bottom allen bolt might help but it stripped pretty easily since it was already in there so tight.

If you guys have any ideas or suggestions I'd appreciate it, gonna swap out the opamp back to the stock one tonight and see if that changes anything.

Thanks in advance!

(oops...1st reply sent too soon).

The 2 things I would do, in this order:
1. Try a different set of headphones + cable (assuming you have both). I don't expect the problem to go away; this is really just to rule out the headphone & cable as variables.
2. Assuming the problem remains w/new HP+cable, time to open it up and swap out the Burson for the original opamp. Make sure to visually inspect the Burson, ensure that it's fully seated in the circuit board (it probably is), Swapping opamps may "cure" the problem.

I thought the Burson was a very tall opamp....pictures I saw made it seem doubtful it would even fit the HPA-1.

GOOD LUCK!

 

[bookemJ]

K got the original opamp in it right now, warming up no noise so far, notice it usually happens after the amp has hit peak operating temperature, so I'll keep you posted.

@Pharmaboy I forgot to put it in my post, but I've tried other cable and different headphone, same issue, also unplugged my dac too and it was still there.

Thanks for the quick responses guys btw!

 

[bookemJ]

Alright so I had the original opamp in there for about 30 minutes, no noise, swapped out to the v5 again and after an hour of no noise started hearing it again, so I took the v5 out and noticed its surprisingly hot to the touch, not untouchable but just hotter than the rest of the components inside.

So I got the original 1 back in and we'll see what happens once its at peak temp.

Also to note when the v5 made noise it was completely silent til I unplugged my headphone and walked away then came back about 10 minutes later and the noise instantly was there as soon as I plugged my headphones back in.

 

[leeperry]

Measure DC offset, you'll most likely have a surprise.

 

[Strangelove424]

There are multiple accounts of Burson v5 overheating and frying themselves all over head-fi and the internet at large. Ridiculous z height makes implementation in many amps and dacs difficult or impossible, and complicates the heat problem. They stuffed a tiny daughter board into a tight enclosure with no ventilation. Burson must be nuts, especially for the price they charge for these ridiculous failing op amps.

Also, Burson says their v5 are direct replacements for the popular lme49860, but have a close look at specs: lme49860 voltage range is +/- 2.5v to +/-22v, Burson v5 is +/- 3.5v to +/-15v. Lord knows how these Burson op amps are operating in the lme49860 circuits they're being dropped into. Possibly frying themselves slowly. It's wrong for Burson to suggest it can be used as a direct replacement for almost any op amp. What's important is how the op amp operates in the circuit, not the op amp itself. I've learned op amp rolling can cause a lot more harm than good.

 

[bookemJ]

There are multiple accounts of Burson v5 overheating and frying themselves all over head-fi and the internet at large. Ridiculous z height makes implementation in many amps and dacs difficult or impossible, and complicates the heat problem. They stuffed a tiny daughter board into a tight enclosure with no ventilation. Burson must be nuts, especially for the price they charge for these ridiculous failing op amps.

Also, Burson says their v5 are direct replacements for the popular lme49860, but have a close look at specs: lme49860 voltage range is +/- 2.5v to +/-22v, Burson v5 is +/- 3.5v to +/-15v. Lord knows how these Burson op amps are operating in the lme49860 circuits they're being dropped into. Possibly frying themselves slowly. It's wrong for Burson to suggest it can be used as a direct replacement for almost any op amp. What's important is how the op amp operates in the circuit, not the op amp itself. I've learned op amp rolling can cause a lot more harm than good.

Wish I heard about this before buying ha! Seems the amp is running just fine on the stock opamp with about 4 hours of continuous use no issues. Gonna swap back the burson and see how long it lasts, definitely starting to believe this to be an op amp problem.

I can only fit it in the HPA-1 with the top lid on if i take the DIP8 socket that came with the burson off and just plug it into the socket in the amp, which still only leaves about a cm of head room.

Is it possible to take the casing/cover off the burson, if so would that help it ventilate?