Update July 2020:
I am now using this socket to hold onto dual Sparkos Labs SS2590, using a few adapters, haha. We have come a long way since SOIC-8 op-amps! Funny enough, this headphone amplifier is going to serve as one of the test beds for the op-amps I am reviewing. By only having a single op-amp location and having no other controls (tone, filters, FIR (like the DAC), etc.), it brings out the details of the op-amps, rather than your ability to configure the HW. You can get around this, by leaving all controls the same, but I prefer using an amplifier. The fact I have custom Blue Dragon and EL-8 connectors from Moon Audio (Cary, NC), also helps. The signal chain to my EL-8 planar-magnetic headphones, is near ideal at this point. I also added an UpTone IsoRegen, on the input of my digital chain.
See more here: [ Ссылка ]
Update June 2020:
The sAp-10 DIP-8 mod is still going very strong! I really couldn't be any happier with how this mod turned out. Even though that soldering was far from my best work, the signal quality is superb. I put unnecessary torque on the DIP8 adapter with the flux pen and solder sucker, but those are very tight quarters. You'll notice a few rounded corners on some of the capacitors, because there is just no way to fit an iron sometimes.
It's not an easy mod, but I do think it was worth the trouble. It turned this amplifier into something totally different and gave me another platform to test/review op-amps on. As I am currently reviewing Sparkos Labs SS2590 Pro-Series op-amps, find a preview here: [ Ссылка ]
The added black plastic/glue, was essential in making that DIP-8 sturdy enough to allow rolling op-amps. I definitely wouldn't want to be swapping in op-amps without that support. You'll end up lifting the pads off the PCB, eventually.
If you do this mod on the sAp-10 and you happen to reverse the direction of the op-amp, you will blow the 250mA fuse, located near the plug. It's a PCB mounted fuse and requires you to desolder the 4-Pin XLR PCB and the 3 pin header on the 1/4" stereo jack. After that, you remove the copper standoffs and you can then remove the entire PCB. Replace the fuse with an equivalent fuse and put it back together.
-----------------------------------------------------------------------------------------------------------------------
See more HW modifications and vintage HW restoration projects at my website here: [ Ссылка ]
I originally made this as a video specific to the sAp-10 by SMSL, but I then realized you can apply this to any circuit with surface mount (SMD) op-amps and SMD capacitors. I hope it helps others looking to modify their amplifiers.
Note: I added in black plastic/glue from my 180W glue gun. This was to add support for the adapter and capacitors, in order to isolate vibrations and increase the longevity of the mod.
You can apply this to any circuit with SMD op-amps and SMD capacitors. I hope it helps others looking to modify their amplifiers.
At less than $200, the S.M.S.L. sAp-10 is a hefty contender in the field of balanced headphone amplifiers. However, it relies on one JRC 5532 surface mount (SMD) op-amp. I decided to upgrade this to a DIP-8 socket, so that I could try different op-amps. To achieve this I used a special adapter that goes from SMD pads to a DIP-8 socket. While I was in there I decided to go ahead and swap out the few SMD capacitors with full-size Panasonic FM capacitors.
Having the ability to swap op-amps are obviously a huge advantage to anyone with op-amps to swap in. Going from a JRC 5532 to a Burson Audio V6 Classic or a Sparkos Labs SS3602 made a clear difference.
I haven’t yet had the time to analyze the circuit to see what configuration the op-amp is in. Op-amps can serve a variety of purposes in a circuit: amplification, voltage followers, buffers and rectifiers (to name a few configurations). Swapping in full size capacitors helped bass response/headroom and seemed to improve rejection of buzz/hum. I also believed it helped the mid-range out.
Get your own SMD to DIP-8 gold plated adapters here: [ Ссылка ]?
