Why does the 15C have a loop but the 15H doesn't? What a stupid idea! I really would have liked the 15H for my basement . They even put one in the 1 watt. Sometimes I wonder.
Silly really I agree. One of the main reasons I got rid of mine. I knew it didn't have reverb on it and no loop when i bought it. But I didn't realise how much I would miss it. All my amps have either had loops or built in reverb. I got mine in the January sale so didn't loose anything when I sold it.
This is just a guess. .The loop usually sits between master volume and p.i. on the 1 and 5 watters, a line level signal into the p.i. is probably enough to drive the output into the full output level. So all you need to do is take the preamp signal down to line level.
somewhere between 10 and 20 watts, you probably need a stronger signal into the p.i. To drive the output to full level, so the loop needs to be active, which equals cost and pcb real estate beyond just the two jacks, and this being somewhat a budget model...
...But looking at the competition, it seem stupid not to take that leap. ..It was this very reason that made me go with a dsl1h and an old valvestate 8008 instead. ..
Again just a guess
j