
Opti-maxxing!
Ok so before anyone flips out, no this is not my speaker placement! These are still on the work bench. I have a few small repairs, and want to get a picture of the insides before I make a little rack and speaker stands. I just thought this was a nice way to take a picture!
Crossposted in r/vintageaudio and r/budgetaudiophile
Well once I started getting into audio and thrifting vintage gear, I promised myself I wasn't gonna be one of those guys who chased down matching stacks, and now I've broken that promise to myself. But I've done it in the most budget way possible.
Total cost: ~$100
Optimus LX5: $25, and $25 for the refoam kit
Optimus STA 2160: $10
Optimus CD 1750: $20, plus another $20ish in gas and tolls (rip)
I picked up the Optimus LX5 speakers a few months ago for 25 bucks, knowing they'd need a refoam. I like weird driver designs and wanted to sample them. I finally got around to the refoam this past weekend and buckled down and restored my first speakers. I'm a sculpture teacher, so pretty good at most manual skills, but was kinda terrified of this. Honestly it wasn't as nearly scary as I hyped it up to be in my head, though I did have a few issues with glue bonding to the poly cones when I really pushed them (see below).
I have a crummy Sony receiver I use as bench amp, but it only puts out like 30 WPC and from what I could find online, the Optimus LX5s want more than that to really open up, so I started scrolling FB market and found the receiver, an Optimus STA-2160, just a few minutes from my work for the comically low price of $10. It's a bruiser of a receiver and is rated at 100 WPC. It was sold untested, but I took the chance at $10 and it powered right up when I got it home. I have a few scratchy pots to clean up, but I'm not complaining for a $10 receiver! Also, it picks up strong FM stations easily without an antenna which is nice.
The night I picked up the receiver, the Optimus CD 1750 popped up on FB market for $20, about an hour and a half away and across state lines. I swear to god the FB market algorithm knows me too fucking well. It's scary.
Now I need another 30+ year old CD source like I need a hole in the head. I have two currently racked up in my main system (Denon DCD-610 and HHB Burn-it recorder), another two working ones in storage, and 3 or 4 more with issues in a "one day I'm gonna fix this" pile (lol). This is exclusive of several old CDJs, a CD mini system bedside for headphones and another in my classroom, a collection of boomboxes that I pull from for b-day/ housewarming gifts, and just one trusty discman. What can I say, I'm a CD guy!
But I had the day off work, so I made the trip. The other draw is that the CD1750 has a Sanyo LC7881 DAC chip in it (according to the internet), which is a vintage DAC flavor I don't have yet. From what I can gather, it's a multibit design that isn't a classic R2R ladder and also uses Pulse Width Modulation in the conversion. It also has a reputation for sounding even warmer and more analog than my beloved Burr-Brown R2Rs, and it does sound very warm and liquid, but I haven’t done a controlled A/B yet. Also, it just looks freakin awesome. I love the chunky buttons on 80s and 90s gear.
The CD 1750 is doing a weird thing where it opens and retracts with one button push, there is just enough time to remove and drop in a disc with my cat-like reflexes so it's not "broken", but I suspect something might be going on with a belt or physical switch so I'm gonna open it up and investigate. I will say the laser picks up really fast, like <1 second, so that is healthy at least.
So far this set up sounds great, and certainly better than $100 all-in has any right to sound. It imaged really, really beautifully with some incredibly dense layered female vocals. (If anyone is curious the album is Seleniko by Värttinä a Finnish folk group. It is a random thrift find that has stayed in heavy rotation and earned its keep as a torture test). Also did great with Philip Glass and orchestral music, though a little light in the lowest registers. When I put some cheesy Europop through them at volume with some heavy kick drum, I did get some chuffing and they are not my favorite speakers by a long shot for dance/electronic music. When I really tried to see if these speakers indeed would want the full 100 watts like the spec sheet claimed, I noticed a change in tone and realized one of my surrounds started peeling a bit, so a re-glue is drying. But, I don’t think they liked being pushed that loud (at least without a HPF), regardless of my amateur glue up.
This weekend I'm gonna figure out a little rack and set it up in its forever home in my studio/workshop. I'll post REW measurements on the speakers and more subjective listening impressions this weekend after my touch up glue dries. I also want to open up the receiver and CD player to see if I can determine who was making the amp internals for Radio Shack and to confirm the DAC chip/trouble shoot the CD tray, so keep an eye on the comments here if you are curious!
But I wanted to share now cuz I had a bummer of a day and the Optimaxx stack deserves some love.