[Jon L]

OPA627

The gold standard in monolithic audio opamps and rich man's NE5532. This one fills in most of NE5532 sins of omission in resolution while building out a little more density of tone, vocal liveliness and sparkle. Still not the last word in detail resolution, top-end air, or bass crunch but good enough in most of these areas as not to detract from enjoying one's favorite tunes. Most of all, the sound signature is instantly familiar and comfortable from years of exposure to the sound signature in various gear and DIY efforts. Two OPA627AU's adapted to DIP board can be found at reasonable prices and still a viable choice.

[viggen]

i've received duelund DC cable from ghent last week. 

in comparison, the stock dc cable sounds mushy. 

after swapping cables, the OPA134PA and GE combo didn't sound as good.  sounded hard and etched. 
so, i went back to muses02 and changed to rca 6189.

maybe try the bb op amp again after dc cable has more hours.

[Jon L]

i've received duelund DC cable from ghent last week. 

I have a couple of Ghent Neotech UPOCC Copper Teflon Solid-Core 16awg DC cable (JSSG360).  Incredible parts and build quality and clearly more detailed and capable than most generic copper/pvc DC cables.  I also have made DIY versions using Duelund and WE wire.  There is something to be said about generic cables (IC, power, speaker, DC, digital, used in recording/mixing) yielding more forgiving and familiar tonality when used for playback IME.  Or, a bunch of re-tweaking and swapping may be necessary to rebalance the sound..

[viggen]

btw the stock dc cable replaced by duelund cable is the one that came with hdplex300 xlr->2.1mm barrel. 

i know the duelund sound signature well as i have rca, spkr and pc cords made out of the.  so, my assumption is the stock cable really is too mushy if the duelund can make it sound mushy in comparison.  since, duelund's sound in other application is very consistently smooth and slightly dark.

tomorrow, going to give the lme opamp another try.  maybe softer and subdued op amps sound better with the new dc cable.

i had the upocc ghent cable too but included it in sale when sold the lta mz2.  i woulda kept it if it had xlr on one end.

[nc42acc]

Impressive for such small amount of money. Laiv uDac, T20, Fosi V3 monos

[Jon L]

Impressive for such small amount of money. Laiv uDac, T20, Fosi V3 monos

Yup, it's a great time to be an audiophile (well, was even better before tariffs). 
What is that box feeding the uDAC via Curious USB cable?

[nc42acc]

It is a MicroRendu renderer for Roon. Works with the Roon server

Yup, it's a great time to be an audiophile (well, was even better before tariffs). 
What is that box feeding the uDAC via Curious USB cable?

[nc42acc]

Swapped in Mullard 12ax7.  Much better. Now I have lower midrange and bass. Really responds to tube swaps!!

[Jon L]

Opamp decoupling adapters with capacitors

After trying these decoupling adapters with various opamps, I was about to declare them not-worth-the-money.  They did seem to smooth out and bring down the high treble a tad, but this direction of change was not truly needed in these systems and opamps tested.  At the last minute, I decided to try them with the venerable Sparkos SS3602 because in the Aiyima T20, Sparkos sounded a bit overly treble-rich and airy, which tended to thin out tonal richness.  Otherwise, the Sparkos has great detail resolution, speed, extension, and soundstaging, all the audiophile goodies. 

With the decouplers, the Sparkos seemed to move that high treble energy straight into tonal girth and richness, while retaining much of its resolution.  Tonal colors became more dense and less pale, more pleasant to listen to. 

Still, these decoupling adapters aren't exactly cheap, so I would recommend them only to those in similar quandry with specific opamps in a given circuit. 

[Jon L]

Well, well, Aiyima T20 measures surprisingly great for tubed equipment 

https://www.audiosciencereview.com/forum/index.php?threads/aiyima-t20-tube-pre-amplifier-review.66604/

[viggen]

received a pair of Muses02 in parallel.

it gets up over 100 degrees f after 5 or so minutes.  i am a bit skittish.

do i need a fan?

[Jon L]

received a pair of Muses02 in parallel.

it gets up over 100 degrees f after 5 or so minutes.  i am a bit skittish.

do i need a fan?

100 degrees Celsius?  If so, that's higher than Muses02 maximum operating temp is 85 C although damage will likely not occur until much higher.  Even with a fan on it, I would check the temp.  If one has to crank up the fan speed  with increasing fan noise to keep the temp down, it might not be worth it.

[viggen]

100 degrees Celsius?  If so, that's higher than Muses02 maximum operating temp is 85 C although damage will likely not occur until much higher.  Even with a fan on it, I would check the temp.  If one has to crank up the fan speed  with increasing fan noise to keep the temp down, it might not be worth it.

100 degrees F (areheit)

[Jon L]

100 degrees F (areheit)

That's 38 C and is perfectly safe operating range per their specs. 

[viggen]

That's 38 C and is perfectly safe operating range per their specs.

Appreciate your confirmation.

[viggen]

Got a fan for the parallel muses02.  Temps at about 90f with fan.



I like the sound.  Less splashy less water down.  But, I do turn the volume up quite a bit.  Not sure whether it's because the overall volume drops with the parallel op amps or just the HF is less pronounced.  But, when I do turn it up, it sounds really good.  Sumptuous mids with good mid high soundstage and detail.  However, the highs are missing hence sounds a bit boring when I have the volume set at my usual listening level.

[Jon L]

Sumptuous mids with good mid high soundstage and detail.  However, the highs are missing hence sounds a bit boring when I have the volume set at my usual listening level.

That's why we roll opamps.  Too bad OPA1612 and OPA1656 don't come in DIP8 package.  It's rumored that Virtual Hifi opamps are paralleled 1612 and/or 1656, so if I could find a good way to parallel these on some sort of adapter..

[viggen]

speaking of bb, i did receive this, bb 828 (2 monos combined, left), but haven't plugged it in yet.  not sure i got the orientation right?



opa134pa (pair) on right