2020 is the year I ended up swapping out pretty much my entire desktop, main stereo and home theatre setups. I think the COVID-19 situation and actually spending more time under remote working conditions did free up additional time for me; leading to changing out my setups. Of the most recent changes, I sold both the Sony MDR-7506 Studio Monitoring Headphones and the Philips SHP-9500 open-back headphones. I figured spending a little time talking about my experience with them over the past 6years of ownership.
The Sony MDR-7506 are budget professional studio monitoring headphones that has been in production for 40years now. They continue to be trusted by professional sound and mixing engineers. The compact and very durable on-ear monitoring headphones are also preferred by field engineers. These are easily available on Amazon and retail between $80-90 USD typically.

In the box, you get a fabric pouch to store the headphones on field trips. The 3m long coiled cable is of very good quality, definitely never post an issue for me over the last 6years. The cable is however attached permanently to the housing of the left driver. For some, it maybe a deal breaker but I found the MDR-7506 to be highly compact and not being able to detach the cable should not be an issue. At the other end of the 3m long cable, you have a standard 3.5mm headphone jack. Sony also includes a 6.3mm screw-on adapter if you need to connect these to full size headphones jacks. I do prefer screw-on adapters over normal plug-ons.
My use case for the MDR-7506 are far from what a typical sound engineer would probably use them for. I typically have these on when I rip my analog records in Audacity for storage on my PC as digital FLAC files. The other time I use them is for critical listening of either mastering of digital files or, when comparing component sound quality in the chain (eg. new DAC in the setup). On occasion, I might just have these on for causal listening when I am just lazy to swap headphones.
The Philips SHP-9500 are in my books the Ultimate Budget Audiophile pair of open-back headphones. For $70-80 USD on Amazon, I find these in a class of their own and nothing comes close at that price point. The newer SHP-9600 released in 2020 retails at double the price and based on early reviews, the most significant changes appear to be skin deep (cosmetics). Key design cues and driver technology are similar to the acclaimed SHP-9500. My sense is Philips decided to retain much of its winning formula for good reason. Whether you are willing to shell out double the price for ‘updated’ looks is something for you to decide.

In the box, you get pretty much no-frills. There is of course the massive pair of 50mm driver headphones, a detachable not-so-straight 3m long cable that is terminated with a standard 3.5mm headphone jack at each end. Yes, you get a screw-on (yay!) 6.3mm adapter as well. These are my go-to pair of headphones for general music and extended listening sessions. The open-back nature of these headphones deliver a wider spatial soundstage unlike close-back headphones (MDR-7506) which are better suited for critical listening. The lower impedance of 32ohms means you can easily plug these into the 3.5mm jack on your mobile device and blast your ears away too without worrying about sufficient power to drive them properly.
The 3 most common complains about SHP-9500 are the cable that came in the box, the earpads and the upper frequencies. The included cable is what I describe as not-so-straight. They are not coiled, run a length of 3m and quite frankly impossible to get kinks out of them. I never used the included cables. Instead, I found a really beat up pair of Sennheiser (can’t remember the model) specifically to salvage the coiled 3m cable to use with my SHP-9500. Yes, I prefer coiled cables over straight cables on any day. When coiled, they are typically about 1-1.2m in length but will stretch out to 3m if you need them to.

The stock earpads are made of some kind of fabric material. They are no silk, huge and will go around your ears comfortably. General complain here is some folks find they pickup stray strands of your hair and what not. Frankly, I do not have an issue with the stock earpads. The fabric material actually helps keep my ears cooler over extended listening especially in the humid climate here locally. The MDR-7506 on the other hand have synthetic (protein) leather pads that are on-ears and not ideal in humid conditions. I replaced the stock earpads on my MDR-7506 to velour for better comfort but left the SHP-9500 as they were.

As for the upper frequencies on the SHP-9500, it is true that you will likely hear more sibilant on lesser recordings. That to me is a minor trade-off I can live with. For the money, the SHP-9500 will knock the socks of most other open-back headphones for overall frequency response. In fact, these are so good that gamers are picking them up with a detachable microphone like the V-Moda BoomPro Microphone. Coming in at a total cost of about $100 USD, the SHP-9500 + Boom Pro combination presents gamers with the ultimate budget audiophile gaming headset that even more expensive dedicated gaming headsets are not able to beat. In terms of value proposition, the SHP-9500 on their own are hard to beat. Plugging in a boom mic simply puts them out further away from mainstream and more expensive solutions.

Why did I sell my MDR-7506 and SHP-9500 if they were so good you might ask? Simply put, for upgrade reasons. I like the MDR-7506 for their extremely compact form factor but on-ear design is not exactly comfortable especially for someone who wears spectacles. I will be picking up a pair of Audio-Technica ATH-M40X ($99 USD) to replace my MDR-7506. I am hoping the ATH-M40X will be more comfortable for my use with their larger earpads while providing similar if not better flat frequency response. Keyword here is ‘hoping’ that the ATH-M40X will work out.
As for the SHP-9500, I am curious to try out my 1st pair of open-back planars. The Hifiman HE-400i (2020 version) is potentially the likely candidate ($169 USD). For a little more, the Monolith M570 ($199 USD) is another option. I will likely go with the Hifiman as I can get them locally. If it wasn’t for the planar urge, I would have probably stuck on with my SHP-9500. The next upgrade on dynamic open-back headphones to the SHP-9500 will be the Philips Fidelio X2HR going for about $149 USD on Amazon at time of this post. There is absolutely no reason to pickup a SHP-9600 if you can get the X2HR for $150 USD or less.

In the meantime, I’m relying on my Cooler Master MH751 at $89 USD and a separate UGREEN USB External Sound Card for $15 USD; both of which I picked up for work calls to bridge the gap of no available headphones at the moment. There is the MH752 which includes a faux 7.1 channel DAC dongle but quite frankly, I think the standard MH751 + UGREEN is the way to go for work calls. The low-cost and cheerful UGREEN will do 24/192k and I have not faced a single issue since I had that plugged in for Teams/Zoom Call since a month back. These are what I am left with until I pick up my new pair of replacement headphones.
With the 2020 Black Friday Sale around the corner, you might just be able to pickup a pair of headphones at the best prices. The Cooler Master MH751 can be had for $70 USD when on sale if you simply need an All-in-One headphones. Otherwise, a good pair of open-back headphones such as the Philips SHP-9500 for $70-80 USD. Some gamers love that with an add-on V-Moda BoomPro Microphone typically for around $25-35 USD giving them the Ultimate Budget Audiophile Gaming Headset for $100 USD. Or you could just go for an immediate upgrade with the Philips Fidelio X2HR for about $150 USD and still use the V-Moda BoomPro Microphone. For close-back critical listening or studio mixing, the Sony MDR-7506 usually goes for between $70-80 USD then. If you wear spectacles and value comfort (or detachable cables), shell out 30% more will get you the Audio-Technica ATH-M40X at $99 USD instead.