I'm a bass synth guy and have been using the Roland 13 pin systems for years. I've been aware of this bass for a while now, and I contacted the shop about it. Rare for sure, but here are the problems and what would be involved to get it operating and why I chose to pass on it:
1.
No way to test it. The shop doesn't have the additional gear you'd need to even test the electronics or pitch to mid capabilities of the bass. This uses the original older 24 pin Roland system. Today's Roland synth guitars use 13 pin. The 24 pin cable alone, even a 3rd party clone of the Roland original, will run you
$100-175. Then you need a 24 pin Roland guitar or bass synth like the GR300 or GR33B. The GR300 on the used market will run you about
$1000-$1200. As for the GR33B bass-specific model? Forget it. You'l never find one, and if you do, it'll run you thousands. So unless you have all this older gear lying around, you won't be able to confirm the bass even works, and it's a lot of $ to invest in all the additional gear just to find out. But wait, there's another cheaper option:
2. Roland made the BC-13, which was a 24 pin to 13 pin converter to make the crossover to 13 pin at the time to utilize the older 24 pin gear. If you find that converter on the used market, it will run you around
$300-$350. (Korg also made the Z3 24 to 13 converter. Those are around $250-$300). That would at least bring you up to modern day compatibility, then you could test the bass with a newer GR33 (that's what I use) or GR55. Used Gr20s or GR33s are around
$250-300.
3. If none of the GR systems interest you (and admittedly, the sounds are pretty dated and limited by today's standards), then your other synth option would be to find a used Roland GM70 24 pin to midi converter. Those are around
$170-$250 used. With that, you'd be able to run a midi cable into a midi sound module, computer, or keyboard, and access those sounds instead (which would give you an endless supply of sounds that sound far better). But then you'd have to consider the latency issue with systems like these and whether or not it's even worth it. I know when I run midi out from my GR33 the latency is so bad it makes that option practically useless. And, whether you're running sounds via a pitch to midi converter or using a Roland GR system, the latency on bass is pretty terrible unless you're playing in the upper register. This is why I have my Carvin LB50 strung with piccolo strings (octave up from standard bass range), which gives me the best possible response time. It is my dedicated midi bass.
So bottom line: You'll need to spend a lot of money above and beyond the price of the bass for all the additional gear to get this up and running as it should (provided it's even functioning properly), otherwise you're spending a lot of $ on a glorified 1 single coil PUP bass with a ton of electronics innards you either don't need or would be impossible to replace or repair. Collectible, sure, but functional? Who knows, and it will cost you a lot just to find out. (Plus the shop's all the way in he UK - too far from me - and I don't think they'll accept returns on gear that they won'/can't confirm works).
And consider this: today's newer Boss SY-300 and SY-1000 systems perform much better with much lower latency and can replicate most of the original sounds of the older GR units.
I encourage anyone who's fascinated or interested in this vintage technology to check out Wayne Scott Jones's website on the history of Roland guitar and bass synths:
https://www.joness.com/gr300/index.htm
