Well this is what Google AI says.

The Ampapa D1 features an easily accessible, liftable glass lid specifically designed for painless op-amp rolling. It requires two standard dual op-amps (DIP-8 configuration). [1, 2, 3, 4, 5]
The most highly recommended op-amp upgrades for the D1, along with their distinct sonic profiles, are broken down below:
## Popular Op-Amp Upgrades & Sound Profiles

* Burson Audio V7 Vivid (Discrete)
* Sound Profile: Dynamic, highly detailed, and punchy.
  * Sonic Changes: This option brings a crisp, lively presentation with a massive boost to instrument separation, imaging focus, and a wider soundstage. Note that while they fit perfectly under the D1's glass canopy, these premium modules elevate the amp closer to a high-end sound rather than standard budget hi-fi.
* Burson Audio V7 Classic (Discrete)
* Sound Profile: Smooth, warm, and musical.
  * Sonic Changes: Unlike the analytical Vivid version, the V7 Classics trade an aggressive edge for an analog-like ambiance. It creates a greater sense of acoustic space and a smoother high-end roll-off that pairs beautifully with bright speakers.
* Sparkos Labs SS3602 (Discrete)
* Sound Profile: Ultra-transparent and technical.
  * Sonic Changes: Sparkos discrete op-amps significantly increase clean resolution and transient speed. Bass becomes incredibly tight and controlled, and the background gets noticeably "blacker" (quieter).
  * Warning: While the standard SS3602 dual-modules fit well, larger variants like the Sparkos Pro will not clear the tight physical spacing of the D1 chassis.
* Texas Instruments OPA1656 / OPA828 (IC Chips)
* Sound Profile: Balanced, precise, and transparent.
  * Sonic Changes: These are massive technical upgrades over stock chips at a fraction of the cost of discrete modules. Audiophiles using the OPA828 or 1656 in the D1 note an exceptionally clean, colorless sound with sharp leading edges on notes, excellent bass definition, and no fuzzy distortion.
* Muses 02 / Burr-Brown OPA2134 (IC Chips)
* Sound Profile: Classic "Burr-Brown" warmth, lush midrange.
  * Sonic Changes: Known for adding a subtle "tubey" lushness. They relax the harsh glare of budget Class-D treble, adding weight and organic body to vocals, though they sacrifice a tiny bit of micro-detail compared to Sparkos or the OPA828.
* Oracle II 02 (Budget Discrete)
* Sound Profile: Earthy and full-bodied.
  * Sonic Changes: Available for just a few dollars, these offer an easy entry into discrete components. They deliver a much more 3D sound than the stock chips with good physical weight, though the soundstage depth is narrower than premium Burson models. [1, 2, 3, 6, 7, 8]

## Crucial Swapping Tips

  1. Orientation matters: Ensure the notch or dot on the new op-amp matches the notch marking on the D1's DIP-8 socket. Plugging them in backward will fry the chip and potentially damage the amplifier instantly.
  2. Watch the heat: Some high-bias or discrete op-amps (like the Virtual HiFi Supersonic V2 or certain high-current chips) run incredibly hot to the touch. This is normal for class-A biased discrete op-amps, but make sure the D1 has breathing room. [1, 2, 4, 9]

Are you hoping to tame bright treble or looking for more analytical detail? If you share your current speakers or what you feel your system is missing, I can help you pick the exact right match.

[1] [https://doukaudio.com](https://doukaudio.com/products/ampapa-d1-hifi-bluetooth-amplifier-with-digital-
vu-meters-hpf)
[2] [https://www.head-fi.org](https://www.head-fi.org/showcase/burson-audio-v7-vivid-opamps.28645/)
[3] [https://www.youtube.com](https://www.youtube.com/watch?v=dr7vB-HYPhk)
[4] [https://www.pragmaticaudio.com](https://www.pragmaticaudio.com/reviews/2025/12/ampapa-d1-integrated-amplifier/)
[5] [https://www.reddit.com](https://www.reddit.com/r/diyaudio/comments/ji1nc7/dac_with_swappable_opamps/)
[6] [https://www.head-fi.org](https://www.head-fi.org/threads/ampapa-d1-tpa3255-amplifier-whos-your-daddy.9781...)
[7] [https://www.audiosciencereview.com](https://www.audiosciencereview.com/forum/index.php?threads/ampapa-x-douk-audio-d...)
[8] [https://www.youtube.com](https://www.youtube.com/watch?v=_3HWfNJFcVo&t=2)
[9] [https://www.reddit.com](https://www.reddit.com/r/BudgetAudiophile/comments/1r9wezl/supersonic_v2_op_amps...)

Only have experience with op amps in one device, Jolida JD9 phono pre. Been awhile, but the memories are with me. That unit used three pairs of op amps. Really they are similar to rolling tubes, back n forth, back n forth. Some would be very evident and others seemed to have no effect. Researching which to use and where to buy was a lot to swallow. As with tubes, the popular, hyped ones are more expensive. Where to buy them was the trickiest part, many people warned others to avoid buying from China as there was a good chance they were counterfeit. I did buy some on eBay from China, more to get a feel of what different versions would bring - or not bring to the sound. Good friend of mine has that unit now (he also has another) and he loves keeping with the sound by rolling op amps. That’s about all I have on the subject, can’t really remember which ones I used. If you go that route, good luck and have fun with it!

My take on Op Amp rolling would be to play the stock ones for a few weeks to both burn them in and to get a idea about what you like/dislike about the sound of the amp.
I'd them look at the list I shared with you to find one that would best "fix" your observation of what is lacking.

I only use my Ampapa for very low listening volumes to lull me to sleep at night. The only thing I have done is to crank both the treble and bass adjustments up to 10. I do that to emulate a loudness button so the sound works well at low volume.

I have used the Ampapa in my main system a few times with the balanced inputs fed from my Denafrips DAC. It sounded pretty good for a $170 amp, but would definitely run out of "balls" at higher volumes.

And it has VU meters! Multiple VU meters at that!

So going down the op-amp rabbit hole I came across an informative article  called “The Ultimate Op Amps for Hi-Fi Guide (2026): Precision Sound, Upgrades & Audiophile Insights”

https://www.shuttergroove.com/reviews/hi-fi/op-amps-ultimate-audiophile-guide/


Here’s another article regarding the popular Oracle -02 op amp.  

https://www.shuttergroove.com/reviews/hi-fi/oracle-ii-02-op-amp-upgrade-aiyima-a...

Donnie…yes the Ampapa showed up late last night.  The packaging of the amp was impressive.  The tolerances were so tight that it took like 10 seconds for gravity to make the two pieces detach from each other.  

Today I’m going to work on cleaning up and rearranging the desk, pulling the bookshelves from the living room, and work on setting up the system.  With motorsports racing going on today, not sure how much I’m going to accomplish.

So yesterday I received my Sparkos SS3602 audiophile op amps for my Ampapa D1 amplifier. While my intentions were to wait a month and let the amplifier fully break in, the anticipation was killing me, so I decided to install the new op amps last night.

Two recommendations… After you completely disconnect all of cables running to the device, make sure you press the front volume dial to help discharge the capacitors. By doing so the amp temporarily lit up and then shut off.  Secondly, I would highly recommend buying an Op amp/ chip puller.  Even with me using the tool… I slightly bent a few of the pins on the first one because I didn’t pull straight up. That was easily fixed by using needle nose pliers to straighten them out. I also made sure to discharge myself before handling the electronics. Installing the new op amps were a breeze and went right in.

First impressions… More clarity and micro detail over stock. The bass got a bit tighter,the background is definitely blacker, and the sound stage was not only wider but more dimensional. It’s like watching a movie on a bowed TV…it was more enveloping .  So far my biggest complaint is that with clarity also came a bit of harshness in the treble.  The cymbals were almost too much to hear…. it had that shrill effect.  But I can say that running the amp overnight, and listening to music this morning,  cymbols have gotten better.  According to the manufacturer, I need to wait between 25 and 100 hours of break in time before the chips settle in. At this time, I would say that I have noticed about a 20 to 30% increase in sonic improvement.

Later on this week, my Schiit Modius E should arrive along with the custom-made Blue Jeans XLR to TRS balanced cable. What’s nice about Blue Jeans is that they give you the specs on their cables. I would highly recommend this company, and not ordering any balanced cables from Amazon, because almost every company that I looked at, does not list the capacitance rating of their cables.  I’ll report back later this week once I get a chance to hook up the new DAC.  

Awesome! Sources are so important, seems like you found and modded one that is just right for its needs now, and will likely sound even better as it "seasons."

Quite nice that there was little difference actually, and as you say the balanced are not broken in yet so that may change a bit. MAC made nice cables, so in a way as you surmise the wire itself and build may be making the comparison so close.

In my system I have identical VooDoo Cable single-ended and balanced cabling to try and with the previous version of my DAC the differences were more profound, as the single-ended voltage was only 1.3 volts and the balanced 2.6. When I upgraded to the Mk 2 the outputs were 2 volts and 4 volts, and the differences were still distinct, but my preferences were not as strong. But I use the balanced because I like to be able adjust the output with a ZBIT and find that really aided in the overall sound.