I have been looking at valve amps lately. There are a lot on the market and at the low price range most are made in China.
The Gretsch 5222 and the Fender 600 are among the cheapest and appear to be identical in circuitry, although they do have slightly different enclosures, with the Gretsch having more open area at the back.
The Gretsch 5222 is well recommended for harmonica playing, with Adam Gussow giving it a mention.
But more research showed that there was a mod kit available for both these amps from alnicomagnet on e-bay, so the plan was get a Gretsch and mod it to get the best sound.
So I was set on the Gretsch, guessing that the slight difference in the back of the enclosure enhanced the sound, however I was offered a deal on a Fender 600 at 30 GBP less than the Gretsch so I took it in spec without trying it in the store.
Got it home and was really disappointed, at any serious volume the sound broke up and was horrible with a terrible crackle, how could the mod kit make this anything worth using?
As the plan was to void the warranty by modifying the amp I decided to go ahead.
Within minutes of opening the amp I noticed that one of the capacitor leads was loose in the PCB, not just a dry joint but no solder at all. So before any mods I soldered the capacitor back in place and voila no horrible break up and crackling , just a really noticeable hum that varied with the volume setting.
On with the mods, about 5 hours in total, more down to my long layoff from any PCB and soldering work, like about 20 years!
The kit comes with full instructions and detailed pictures explaining every step. If you have basic soldering skills it is easy going up to the triode/pentode mode. I did not do this step as I had no need to reduce the power/volume and as alnicomagnet explains in the instructions it is fiddly.
For my part I did all the other mods in the kit, which would probably take a lot less time if you are ‘up to speed’ in basic soldering and desoldering.
After the mods the amp is a new beast, the hum is gone and the sound is great. After doing the mods and testing I did replace the stock valves. With a standby switch installed as one of the mods I felt it worth upgrading the valves with better quality and this did improve the tone.
In summary the amp I bought was less than perfect but after the mods I must say I am really impressed with the tone.
If you have basic skills, some free cash, and the tools I would thoroughly recommend trying this mod.