[Fegefeuer]

Remember the warranty though. It's not covered. Good to contact him before.
Anyway. Fried is obviously aware of "better" opamps and how much they really affect the sound.

 

[Joao Paulo Martins]

Hello guys, does any of you have a interference on the right channel output using the pre outs ?

Thanks

Joao

 

[Bonddam]

no mine works perfect. send it out for warranty.

 

[Pharmaboy]

OPAMP ROLLING THE V281 - Initial Progress & Impressions

It has been a busy couple weeks soliciting advice/comments from various helpful people; getting the new Sparkos SS3602 opamps; and installing them. Many thanks to Arthur of Power Holdings (a very responsive & helpful Violectric rep in the U.S.); Fried Reim, CEO of Lake People/Violectric (most knowledgeable & helpful, well known on this thread); Andrew Sparks of Sparkos; and @Geezer Rock 001, who brought this opamp rolling for the V281 idea to my attention & has given me helpful feedback throughout. Since I last posted here:

• I opened the V281's case, located the stock opamps, and per Fried's suggestion, measured heat from an associated transformer & heatsink (90 degrees F after 10"-15" initial warm-up) -- as a baseline/reference point for the new opamps
• Yesterday I replaced the stock opamps w/the somewhat larger Sparkos opamps. A chip-puller was needed to remove the stock opamps (thanks for the suggestion, Arthur!). I measured heat from the same transformer & heatsink for ~6 hrs w/the V281 under headphone load: 90 degrees F after initial warm-up), an encouraging sign of stability/viability of the Sparkos opamps in the V281
• Then today I returned the V281 to the desktop system, where it's both line preamp (an extremely good one) & headphone amp
  • Note: I plan to re-measure internal temp w/the V281 in the desktop system, where conditions are somewhat different than in the headphone-only side system where I measured temps initially. In the desktop system, the V281 is my day-to-day preamp & receives signal from the MHDT Labs Orchid, which has 25% lower output voltage than the Audio GD DAC-19 used in the side system

Listening:
When the opamps were first installed, w/zero warmup (listening through the Fidelio X2s), I heard a relatively closed in treble and somewhat elevated (though obviously taut & dynamic) bass.The soundstaging seemed somewhat wider & better defined than usual. The X2s sounded even better than usual, which surprised me.

Today I heard the V281 w/new opamps at length via speaker system as well as my borrowed Aeolus w/balanced cable -- this after ~12 hours total burn-in. I heard pretty much the same sonic changes from both -- adding up to very encouraging initial sonic impressions. Bear in mind any comparisons to the stock V281 opamps is by memory only:

1. The treble opened up quite a bit & may have a bit left to go
2. The mids seem even detailed than usual, though not at all fatiguing...I kept hearing subtle new things in familiar music
3. Overall, there's greater focus & precision to the sound. Notes seem more distinct & dimensional; it's easier to distinguish voices and instruments in the mix. Resolution seems higher, but the sound remains quite natural. This quality is subtle, but welcome IMO
4. Backgrounds seem distinctly "blacker" -- surprising, as that's one of the strengths of the V281 to begin with
5. The biggest changes are in the bass (another strength of the V281): there's a new qualilty of tautness & dynamic precision to bass notes from all instruments. Bass notes really "pop" & seem to have more texture & "roundness" than usual. The V281 had truly fine bass to begin with, but now it's even better. With the Sparkos opamps installed, I'm consistently hearing "planar bass" (w/its characteristic explosive, dense quality) from speakers & headphones alike
6. The only fly in the ointment is a slightly "clangy" quality to the upper mids. Not edgy or bright, per se--but less resolved & precise than the other frequencies

There are many more hours of burn-in ahead. Based on many comments I've read about these opamps (in connection with a Nord class D amp for which they're an input board option), I expect at least some sonic changes until >100 hrs of burn-in. Some reported significant improvement up to 200 hrs (!). I'm OK w/it; this is how burn-in goes sometimes. I'll post add'l impressions through multiple headphones, incl. a couple planars, after at least 100 hrs burn-in. I may do a full review instead. So far, these Sparkos opamps justify that.

Net/net: With little burn-in, the Sparkos opamps managed to produce sonic gains in the V281, something I wouldn've thought impossible (it sounds amazing w/stock opamps). @Geezer Rock 001 told me when he rolled these Sparkos opamps into his Violectric V100, it kicked up the sonics by 10%-15% to his ears; when he rolled them into the V200 (which shares much circuitry w/the V281), he heard sonic gains of 5% to 7%. I think I'm getting at least a 5% to 7% sonic bump already, with more possibly on the horizon.

 

[Ichos]

Great and very detailed.
Thank you for sharing and please keep us informed after the burn in time.
Now to be realistic 7-10% improvement isn't that much but it should be enough if someone wants to squeeze out every bit of this already great amp.
You got me tempted....

 

[Geezer Rock 001]

Phramaboy,
Great post and outstanding details. One note to all V281/280/200 and 100 owners interested in the Sparkos op amp upgrade. The op amps are located in the "floor" of the amp at the rear. If you have a dac installed in your V series, the dac " deck" is covering the two op amps.

I do not know the difficulty or risk of loosening the dac deck to access the op amps. I will leave that to the long term V series amps owners to advise you on that aspect.

 

[Christoph]

@Pharmaboy
Great post, thanks for sharing!
Do i understand it right, the opamps are not soldered and are located in chip sockets, therefore the change is easy to reverse and not a high risk for the guarantee (as soldering would be).

It would be perfect if you could share also a photo where the opamps are located, would this be possible?

Anyway, if the tighter bass response / texture is really noticeable, i'm definitve tempted to try it with my v281.
Please share also further impressions.

Cheers!

 

[cj3209]

The things we do for questionable and marginal improvements...lol.

I'm guilty as well...so I'll just be quiet...

 

[Geezer Rock 001]

@Pharmaboy
Great post, thanks for sharing!
Do i understand it right, the opamps are not soldered and are located in chip sockets, therefore the change is easy to reverse and not a high risk for the guarantee (as soldering would be).



Anyway, if the tighter bass response / texture is really noticeable, i'm definitve tempted to try it with my v281.
Please share also further impressions.

Cheers!

They are push in connectors. Check my Sparkos post in this forum for pictures in a V100.

 

[Pharmaboy]

@Pharmaboy
Great post, thanks for sharing!
Do i understand it right, the opamps are not soldered and are located in chip sockets, therefore the change is easy to reverse and not a high risk for the guarantee (as soldering would be).

It would be perfect if you could share also a photo where the opamps are located, would this be possible?

Anyway, if the tighter bass response / texture is really noticeable, i'm definitve tempted to try it with my v281.
Please share also further impressions.

Cheers!

photos on the way tomorrow (hopefully)

 

[Pharmaboy]

OK, time for before & after photos of V281 & my recent swap to Sparkos SS3602 opamps:

BEFORE: Showing position of the 2 stock opamps on input board at rear of the V281. Also note the heat fins associated with a nearby transformer that Fried suggested I measure temps of. Note that I don't have a DAC board in my V281, so have clear/easy access to the entire input board. Also note how little space there is between the stock opamp and the nearby (red) component at the front of the input board. This is why a simple/cheap chip-puller suitable for 8 pin chips is so helpful in removing the stock opamps.

AFTER: Showing the Sparkos opamps in place. They fit well in all dimensions and are easy to install.

As mentioned in a previous post, I'm now measuring the temp of those heat fins w/the V281 (top removed) installed in its usual place in full desktop system, where it functions as both line preamp & headphone amp. After 1.5 hours under preamp & headphone loads, the temp is 91 degrees F. That's either .5 degrees higher than my previous measurements in side system--or essentially the same, since this is an analogue/dial type thermometer used in darkrooms, and it's awfully easy to misread.

The DAC in the desktop system is the MHDT Labs Orchid. I thought its output voltage was 2V, but just rechecked the specs. It's 3V!! So I misstated that in a previous post. That means that the Orchid's output voltage is 20% higher than that of the Audio GD DAC-19 I did initial test/temp on (it has 2.5V output). I have no idea if that matters concerning opamp performance.

I'll continue measuring temps all day & will update here if any instability is seen. Not expecting that, though. So far these opamps have been very well behaved.

SOUND:
After ~25 hrs burn-in, the sound continues to be very good. The treble and upper midrange continue to open up noticeably through the Aeolus, and the bass remains noteworthy in quality & quantity. It's so easy now to hear every note from the electric bass--and better appreciate the force with which it's plucked, pulled, or stretched.

I'm hearing more apparent detail & resolution--and maybe a bit of remaining clanginess in the upper mids--but the musical/organic nature of the overall sound is unchanged. One of the cuts I use for roughly gauging sonics is a live-in-the-studio performance by Scary Pockets on youtube covering Sheryl Crowe's "All I Want to Do." The group's guitarist, Ryan Lerman, is a gifted colorist; he plays few notes, but whatever he plays highlights & accentuates the harmony or rhythm. I'm hearing his spare, modestly amped playing (never forward in the mix) way better than I remember hearing on the V281 before swapping opamps. Mainly, I'm hearing more clarity, not more brightness.

Of course, all this comparing is by sonic memory (of stock opamp sound)--so all these comments might just be smoke blowing through the hole in my head. We'll see how things sound after 100-200 hrs burn-in, complete w/a switch back to stock opamps for the final test.

 

[Ichos]

Great , respect for your detailed guide and info.

 

[Christoph]

@Pharmaboy
Thanks for the pics and additional infos.
Then the swap is easy as i assumed.
The Sparkos SS3602 is declared especially for a high quality audio performance.
I have to admit, I'm not very familiar with different types of opamps for audio. Was there a specific reason to pick exact this opamp type?
Just for my curiosity, do you know the type of the stock opamps?
Anyway, great post, makes me curious about the upgrade.

Sound comparsions from sonic memory are always a bit difficult when the difference is not big or obvious.
It would be ideal if you could find another v281 to compare them side by side, but i know this is also difficult.

 

[Pharmaboy]

I had 2 reasons to choose the Sparkos SS3602:

1. I recently became interested in a British class D amp that's getting some love on audio boards (Nord NC500DM). Buyers can choose between Sparkos SS3602 or Sonic Imagery opamps on the input board. I've read many comments about both types and was struck by things people said about the Sparkos, usually describing them as musical, organic/natural, weighty in lower registers (in the way live music is), not bright, etc (all qualities that align w/my sonic preferences). I have yet to get a Nord amp, but I've heard many good things about these Sparkos opamps.
2. Then a Head-Fi pal, @Geezer Rock 001, told me he'd rolled the SS3602 opamps, 1st in his Violectric V100, and later in his V200. He suggested I try them in the V281. That got me started down this path.

I don't know what the stock opamps are. @Geezer Rock 001 says the ones in his V100 are Texas Instruments, but I can't verify this (the legend on each opamp is miniscule).

I also had very good results opamp rolling a smaller/older HP amp/preamp, the M Stage Matrix HPA-1. I tried 3 sets of opamps & the 3rd was the charm. It significantly improved the overall sound, making an already musical/pleasing amp even more so. That was my first experience rolling opamps.

 

[Bonddam]

I put my order in for the Sparkos.