: Does anyone have experince with these amps, specifically for amplified harmonica? Want a low watt, 8" speaker vintage amp. Would appreciate any info. Mike

While I have no experience with the Gretch 1650, I do have some experience with the Supro 1610, not your 1606. I love the my Supro 1610
for that true vintage tube sparkle. IT IS THE REAL THING! I'm surprised that Supro's are not more collected..
I'll take any Supro I can get my hands on. With only about 5 or 6 watts output they will still scream. I play a mexican made Fender Strat
through mine and the out of phase pickup positions have a real nice "pop." The sound will vary a lot depending upon what size speaker you use.
With an 8" speaker you'll get a pretty thin sound, but with a 12' you get a full lush velvety feel. My original speaker was replaced before I got the amp.
The distortion is nice and warm up to a point and at maximum volumes it's a bit too broken-up.
I'm thinking about miking the Supro and running the mic through a power-amp with all the effects, reverb, etc.
The Supro is a blast.

Have fun and see ya, Silky John Perrin.