Update On Dual-DIP SS2590 + Loose DAC DIP8 (Peek at New IsoRegen)

Update 8/6/20: New DIP8 sockets and mostly new resistors + capacitors. I am waiting on some Pureism models to arrive, for the digital section.

TLDR: After spending weeks trying to figure out why I was getting random noise, coming out of the digital end of my chain, I found the cause. It kept coming through, with nearly every op-amp. I figured out my DIP8 socket (on the ES9038 DAC) was faulty. It feels like some sockets have lost all pin tension. The larger op-amps, especially those with lifted DIP8 adapters, tended to lean in the socket.

I originally wanted to finish this review in July, but due to various reasons and Sr year of computer engineering, I had to delay it until August or September. Had I rushed this, you wouldn’t have been able to see my Dual-DIP SS2590 setup!

I also acquired an UpTone Audio IsoRegen, as this is a must for HiFi on a Home-HPC. High Performance Computing draws a ton of amperage and induces a ton of noise on the ground line (of anything connected to the PC). This issue has been on my mind going back, literally, decades. I can remember distortion through my old Logitech Z5500, while playing BF1942 back in 2002 (Radeon 9500 Pro + XP3200+). In other words, I have been looking for solutions, dating back nearly 20 years.

The Solution:

The IsoRegen totally isolates the USB 2.0 line from the power supply in the computer itself and regenerates the clock (which all helps, on long cable runs too). This is something I had been wanting to get for a while. Got lucky and found one for less than half the normal cost. It looks to be barely used, with the stock power supply, all in great condition.

UpTone Audio’s IsoRegen (USB 2.0 Isolation and Regeneration Board)

There have been a few things happening that have prevented me from proceeding with the SS2590 discrete op-amp review, so I wanted to update the readers. At this point I expect to finish this in February, assuming no more issues arise during op-amp rolling.

The main issue is, one of my DIP8 sockets on my primary ES9038Pro DAC, lacks any clamping pressure on the pin. Any sort of vibration, at all, is enough to cause the right channel to start to break-up and pop/crackle. Using headphones, at medium to high volume, this can damage your hearing (with IEMs especially). For this reason, all testing has been halted, until I can remedy this socket.

I know this is the Dual-DIP8 location on the right channel (bottom left op-amp above), which is causing this (figured this by testing each socket). Of course, the only solution is to replace the socket…

Well, as with anything at HL, we had some hiccups. Although, this time it was due to defective parts.

I ordered some Mill-Max ED90122-ND DIP-8 sockets (above). These looked like a good choice at first, due to the durable design. However, when I received the DIP8 sockets today, Mill-Max had failed to drill/mill out the pin locations, on all of them.

Link to DIP8 ED90122-ND Adapter:
https://www.digikey.com/product-detail/en/mill-max-manufacturing-corp/614-43-308-31-012000/ED90122-ND/

Note: I can’t give a recommendation on if these are good for op-amps, due to what you’ll read below. Note the pin size is larger than almost all other DIP8 sockets. Meaning, it won’t fit in some DIP8-size drill holes. You can widen your drill hole, if you have enough extra pad space (drilling, will logically remove your pad, for the new hole width).

With these new sockets, the female end is intended to be at least 3 to 3.5 mm in depth, for the pins; yet, we see less than 0.5mm (in the picture above).

You can see, from their own datasheet, how the inside of each pin is meant to be hollow (to allow the DIP8 device/op-amp to have adequate clamping pressure on each pin). 🎯

For a company called Mill-Max, you’d think they would remember to do the milling and drilling! 😆🤪

I actually do recommend Mill-Max though, they make some excellent products. I especially like their DIP8 risers, which you can get in almost any type of metal plating. Below, is a Mill-Max 90° adapter, which I purchased for mounting 2x SS2590.

Note: If you run two of these 90° sockets into a 2x Single-DIP adapter, you’ll have to turn one of the op-amps opposite to the standard DIP8 (socket) orientation. This should be obvious, but I wanted to point it out. I will show you this setup during the discrete review/showdown.

The photo above is using JadeAudio’s 2x Single-DIP to Dual-DIP adapter (V4). You can find that adapter right here:

https://www.ebay.com/itm/AudioJade-E4-Dual-to-Mono-DIP-to-DIP-Adapter-Sockets-OP-Amp-Economic-Type-Gold/352681857527?hash=item521d7a11f7:g:bQcAAOSwjVhc86mr

You can pick the E4 for $3.35, the V4 for $8.85 or the V4S for $10.21 (prices are for pairs)

DigiKey really stepped it up! First they told me to keep/trash, the defective units. Second, they allowed me to select new units (at no charge, due to it not being my fault). I had no idea they would waive the difference in cost and by chance, upgraded to the gold and copper, A139197-ND (by TE Connectivity). These are made of much better materials than the Mill-Max units above and perfect for HiFi (assuming pins have good tension).

https://www.digikey.com/product-detail/en/te-connectivity-amp-connectors/508-AG10D/A139197-ND/2258766

While I am inside the ES9038Pro DAC (again), I am also going to upgrade/replace most of the electrolytic capacitors. I have heard from multiple readers that found fake caps used in their ES9038 DAC. It makes sense, financially. If you have to include a $100-$120 DAC, which is just the IC itself, the only way to reduce the cost is through the rest of the parts!

Stay tuned for the Discrete Op-Amp Showdown, with the SS2590 in a Dual-DIP config!

90° DIP8 Adapter (DigiKey):

https://www.digikey.com/product-detail/en/mill-max-manufacturing-corp/299-93-308-10-001000/ED58408-ND/