Sound — 7
I have tried it with LP's SG's and Gretsch. Works ok with all. The clean sound is pretty clean... With the gain at half, it compresses some. Doesn't sound bad at all. I was honestly expecting this to be a total joke... Yet it's actually pretty usable for practice or studio play. It's not noisy, but when turning on the "Tube Stack" switch (overdrive) it makes a POP! The general consensus is, Clean is clean, Distortion is heavy rock. It has a decent volume... About the same as the 8" 10w tube amps I have hanging around. For how cheap these are, they actually sound pretty good. I actually feel weird giving a good review to something this inexpensive, but it's one of the best little student amps I've come across.
Overall Impression — 8
As a practice amp for Rock... Sure. As a student amp... Sure. Clean tones... Sure. It gets clobbered by the small tube amps like Gibson GA-5, But those cost over 10x the price. Comparing it to practice/student amps from Epi, Fender/Squire, etc... It's a pretty good value. It sounds pretty good for the size. I've asked other musicians a bit older than me about these. (I started playing in 2001). And many have said "Yeah... Everyone who started in the 80's had one of those." and I also heard lots of "Shouldn't have sold it" comments. It's overall a decent little amp. Video from YouTube:
Reliability & Durability — 8
It's 25 years old, yet all it needed were the pots cleaned... Thus, I'd say it was built pretty well considering. It's a PC board, and the solder joints were all clean, and all components looked in good shape. It was made of pretty good materials. Across the board, I've heard similar things about these amps. They generally hold up, and all they need is the occasional pot cleaning. I don't think it will ever be collectable, but it should continue to make music for quite some time. If my guess is right, it's a lower voltage DC circuit inside...
Features — 5
The GG-25 was made in the mid 80's. It's claimed to be 25 watts. All Solid State. 8" Speaker. 120V AC, or alternatively DC/battery power with adapter. Headphone jack for private practice. Single Channel, Gain, Master Volume, 3 band tone stack. Volume is adequate, power is fair. There's an overdrive switch labeled "Tube Stack"... (yeah right). This unit is likely marketed to rock musicians. Black Tolex cover, Rubber handle, press board cabinet. Metal corners. All things considered, the design is smart. The knobs are recessed enough that they won't get broken off if it bumps the wall. I assume they were going for toughness as well as function.