The Opamp thread

[P701]

/t/432749/the-opamp-thread/5055#post_12185207


 

When listening to music, does it interfere with satellite tv broadcasts?

 

[pelopidas]

When I know that a satellite will be overhead I take them out so they don't bonk into each other.

edit:
- Perhaps that answer is too dismissive. I don't detect anything weird happening on the AM band when turning on or off or playing music. The opamp is an analog circuit and the cap is on DC. The V5 does get a touch above ambient but I do not in any way suspect that it is oscillating at all. I would need an oscilloscope to really test it, but my guess is that if anything, having another cap on the DC would suppress frequencies and not amplify them. The Burson circuit is really well engineered though. Regular cellphone interference that does get transmitted through regular opamps is filtered out by the V5. -

 

[zilch0md]

I've ordered the V5 duals.

And some SILMIC II 35V 10uf caps.

Joy!

 

[pelopidas]

I can't wait to hear your impressions. Just give it a full 100 hrs on the Silmic and the v5. They both need a full burn in.
What equipment will you be using it in?

 

[zilch0md]

I can't wait to hear your impressions. Just give it a full 100 hrs on the Silmic and the v5. They both need a full burn in.
What equipment will you be using it in?

 
The only gear I own in which I can roll op-amps is the iBasso PB2 Pelican (balanced portable amp), previously pictured, above:
 

 
I will be using the two V5 duals in the input voltage stage, with either dummy buffers or the very transparent LT1028 singles as output buffers.
 
Thanks for the advice regarding 100 hours of burn-in.  Even Burson says to do this, so I will gladly be compliant.  
 
Mike

 

[SpudHarris]

Hey Spud,
I am really curious if you will hear much of a difference on the Lycan if you bypass the opamps with silmics. Silmics are what are already being used for the power supply as far as I can tell on the lycan. When your caps come, can you also test the opamps in your Fiquest to see if it behaves similarly or differently?

Hey, well since I got a decent break from work this Chistmas, I indulged in some serious rolling. The results are that the Lycan does still benefit from bypassing but nowhere near as much as the Fi-quest. My favourite bypassed OpAmp on both the Lycan and Fi-quest by a decent margin is the ADA4627-1BRZ. This OpAmp just comes alive with a Simlic II across the power pins. My Fi-quest has become my home amp for the foreseeable future with the HD800's fed from the HP out of the Oppo HA-1.

LME49990 and AD797 are my next favourite bypassed OpAmps. Not got around to modding the V5 yet but as I can realistically only use it in the Lycan I'm not sure there is much mileage in it. Just had some more Simlics II delivered so may give it a go anyhoo....

 

[Mad Max]

Hey, well since I got a decent break from work this Chistmas, I indulged in some serious rolling. The results are that the Lycan does still benefit from bypassing but nowhere near as much as the Fi-quest. My favourite bypassed OpAmp on both the Lycan and Fi-quest by a decent margin is the ADA4627-1BRZ. This OpAmp just comes alive with a Simlic II across the power pins. My Fi-quest has become my home amp for the foreseeable future with the HD800's fed from the HP out of the Oppo HA-1.

LME49990 and AD797 are my next favourite bypassed OpAmps. Not got around to modding the V5 yet but as I can realistically only use it in the Lycan I'm not sure there is much mileage in it. Just had some more Simlics II delivered so may give it a go anyhoo....

 
4627 is still my all-time favorite, I'll be sure to try it out soon with the Silmic II caps I ordered a while ago.

 

[zilch0md]

Pelopidas,
 
I like this photo so much, I cleaned it up.   

 

 

[Audio Addict]

Pelopidas,

I like this photo so much, I cleaned it up.   

You can't do that with the v5 single, can you?

 

[zilch0md]

You can't do that with the v5 single, can you?

 
Yes, you can, but for the single you would use Pin 4 and Pin 7, where for a dual you would use Pin 4 and 8.
 
Have a look at trooper05's post:
 

  Here is the pinout for both a dual or single OPAMP:
                           DUAL                                                  SINGLE

              
 
The longer leg is normally the positive, so the shorter leg will go to pin 4. Unless of course you have a bipolar capacitor then it wont matter. 
 

 

[Audio Addict]

Yes, you can, but for the single you would use Pin 4 and Pin 7, where for a dual you would use Pin 4 and 8.

Have a look at trooper05's post:

Thanks

That must be difficult to solder and have the capacitor be in front.

 

[zilch0md]

Thanks

That must be difficult to solder and have the capacitor be in front.

I hate soldering, as I just don't get it, but I'll soon be attempting this myself. I really like pelopidas' idea of soldering the caps to reusable DIP8 extenders instead of to lots of individual op-amps, especially since my favorites, the LME49990, have been discontinued. (I wouldn't want to damage them.)

 

[Audio Addict]

I hate soldering, as I just don't get it, but I'll soon be attempting this myself. I really like pelopidas' idea of soldering the caps to reusable DIP8 extenders instead of to lots of individual op-amps, especially since my favorites, the LME49990, have been discontinued. (I wouldn't want to damage them.)

 
I have absolutely no soldering skills and to avoid burning everything in sight have no soldering tools

 

[pelopidas]

Soldering is not so difficult. Just start by soldering some wires together for practice. Once you have the feel for it, you will find it a useful skill.
So, I have a few caps that I am now playing with. I'm not quite ready to spill the beans yet but I thought a nice pic would be fun to share.


In this picture you can see the Muse KZ under the V5. Behind it is a red arrow pointing to a mod that I did a while ago but did not mention till now. Those are the output capacitors. I bypassed them with some wire from one of the legs of a Silmic that I had used in an amp. (I tend to save the clipped legs from the caps since they are oxygen free copper and extremely useful for a tinkerer like me) Since most headphone amps have input caps, there is no reason to have output caps also. Bypassing these is a hugely rewarding 5 minute mod. It is also safer than trying to remove the cap and ultimately is reversible with no damage.
 
Next up. These are what I am currently playing around with.

From left to right:
Panasonic Sepf 22uf 35V
Nichicon Muse BP 10uf 25V
Panasonic FC 10uf 25V
Elna Silmic II 10uf 35V
Nichicon Muse KZ 10uf 100V (all I could find on short notice)
FT-1 Teflon 0.018uf
K73-17 3.3uf
 
Thanks to Spud for bringing the bipolars to my attention. I have some first impressions on these caps but until I get them all burned in I will reserve my opinion to make sure I am accurate.
Once I knew that just adding a cap to the dip adapter works I ended up shortening the cap legs to make it look less stupid. This is ultimately a much more economical way and safer way of trying these out since you don't need to buy caps for all your opamps. You can reuse the same cap for all and you don't need to touch your opamps with a soldering iron.

 

[SpudHarris]

I love soldering and have become very proficient over time, I get great enjoyment in creating things for my favourite hobby. Cables, OpAmp mods, Cmoys, Headphone mods etc... I enjoy it immensely.

You guys should get into it honestly... However, if you guys need these DIP adapters? I have loads of gold plated sockets and a limited qty of Simlic II's so can knock a few up if you cover parts and postage....