Quote from: Enzo on April 04, 2022, 09:58:59 PMJust a quick look, seems to me a little reroute of R46 and we could easily convert those jacks to the more common FX loop configuration.   Yes/No?

I'd be curious to know. I'm a little hesitant to modify the amp as I rather like it. Still, could up its versatility.

It's rather limited as a channel switching channel amp as-is because of a rather large volume jump between the channels. Bit of a shame, because the drive is quite usable along with the really nice clean.

My thought was to wire up a combo pot-in-a-box passive volume and channel selector for Drive/Clean on the same switch. Put the passive volume in the FX loop and have it bypassed when clean is selected. Would also be nice to put a delay post-gain.

Boosting into the clean channel with my Soul Preacher was usable on a more compressed setting but didn't seem ideal. Got some distortion with an uncompressed signal (only tested at bedroom levels).

Quote from: g1 on April 04, 2022, 01:57:11 PMThe signal routes through R46 to the power amp whether the jacks are in use or not.
It won't function as a loop.  You can use them as either a pre-out, or a power amp in, but not both functions at the same time.

Thank you, that is a huge help! A bit of a letdown as far as my DIY plans are concerned, but such is life

Hi!

I'm a newbie both to the forum and DIY electronics. I hope this type of thing is alright to ask - if not, let me know!

I'm trying to DIY some stuff related to a Roland Super Cube 100 from the '80s. I'm stuck figuring out the FX loop (or rather "Stack jacks") on this amp. With my present knowledge the schematic is a bit above my head. If someone could help me figure this out it would help out a great deal.

I found the service manual online as a pdf on another forum (in post #12): https://music-electronics-forum.com/forum/schematic-requests/51330-roland-super-cube-100-schematic
It wasn't the easiest thing to come by! It has a schematic on page 4 of the manual, with the stack jacks in the upper right corner (top of JK-2 board).

The user manual (separate document) talks briefly about parallell wiring. This pair of jacks is really intended to string several Super Cubes together (hence "Stack jacks" moniker). The Pre Out/Main In secondary labelling sure suggests it, but is this even usable as an FX loop? I got a noticable volume boost plugging in that way compared to just going to the top panel. I'd reeeally like to know how it works.