I posted this on the DC30 forum, user Tonequest suggested me to post the same here, since the effect loops are the same to the 18watters. I do not have one, but if the effect loop works the same, this should interesting for you 18 watters!

I managed to do this by using a LineSelector from Boss. Since I see many people asking about this, I will dare to open an specific thread for this.  Here is a layout of the connections:


By alwalt at 2009-09-09

The main idea is to use the EF86 loop as a send/return path. From the TopBoost loop  only use the send signal. This send is mixed then with the EF86 send (via LS2). The both mixed signals -dry go to the effect chain. At last, from the output of the effect chain the mixed effected signal returns to the EF86 Return of the effects loop.

Since the LS2 has a level adjust for each channel, it allows to level the effected signal to prevent volume loss.

I have tested it on band practice and it's working fine. I hope it could help people who wants to share effects on the loops of the DC30...

Fine, I was looking for a solution and I posted a question for that in another topic related to the 18w.

Sure I'll try it. Only a question:

1)both the send are mixed in the effect input
2)I use a single channel (ch1 or ch2)
3)only the ef86 receive a return....

 is the effect in the chain when I use the top boost channel?

I am trying to do the same. As I just posted elsewhere here, it may be you also need a C'lator in the loop to prevent signal loss and keep the tone. Actually the C'lator changes the tone slightly, in a good way, and its got enough flexibility to shape it how you want. A lot will depend on the FX you are using. However this has not helped me fix the problem of using my fx in the loop across both channels, and also use the amp as a 2 channel amp (i.e. not combine the 2 channels which is one solution). I am no whizz technically, it seems to me I need some kind of patch box which can receive both the send signals from Channel 1 and 2, and merge those into a mixed send, and then take the return signal, and split them and send them back to the 2 effects loops, all without losing signal strength (although the C'lator might give enough boost to mean this is not necessary). if anyone knows the solution here, without buying a $300 box of magic, please share! I live in Indonesia so difficult/expensive to get gear here - except Ceriatone of course! KL is close by, thank goodness..