I understand that this thread is 2+ years old, but...
As a longtime "lurker" on this forum, I came across this thread while doing a little research on a "Little Jewel" that I currently own. The OP's amps are VERY nice amps indeed, cosmetically speaking. However, after seeing the under chassis pictures I feel compelled to speak.
Robert1 is absolutely correct in his last post. Whatever "restoration" that was performed by the seller (or on his behalf) appears to have been done in a very ham-fisted and amateurish manner. At the very least, it's probably contributing to the thin midrange the OP experienced. At the worst, this restoration attempt could possibly burn down the house! Some observations:
- THE BLACK WIRE CONNECTED TO THE NEGATIVE SPEAKER OUTPUT IS AN ABSOLUTE DEATH TRAP!!! The power cord black wire - aka the HOT wire - should be connected DIRECTLY TO ONE END OF THE FUSE. Another wire should then run from the other end of the fuse to one lug of the power switch. Yet another wire should then be connected from the second lug of the power switch to one wire of the transformer primary. The WHITE wire - aka the NEUTRAL wire - should connect directly to the second transformer primary wire. The GREEN wire is the actual mains ground, and should connect directly to the chassis. I'd forget about the the 2-prong socket on the chassis; it was there to power the turntables or receivers of the era, which didn't use polarized plugs.
- There appears to be no strain relief on the power wire. Any good tug on the power cord could possibly pull it through the rubber grommet in the chassis - with disastrous results. The old school method involved knotting the power cord so it wouldn't pull through (the thickness of the wire shown in the photographs may make this a problem). Another quick-n-dirty-and-not-so-great method is to wrap a nylon cable tie TIGHTLY around the power cord just inside the chassis. The best method of connecting a 3-prong power cord is to use an IEC connector like the ones used for computer power supplies, but this would involve enlarging the hole in the chassis.
- The fuse should be placed in a proper fuse holder instead of floating around in the chassis!
- Those electrolytics give me the willies also. First, I'd check and make sure they're of the proper values and ratings. Then I'd mount them to a terminal strip that was firmly screwed to the chassis. That cable tie looks highly suspect...
- All wire splices should be at least wrapped with electrical tape; heat-shrink tubing is much better.
- I suspect that any midrange woes are due in part to those cheesy-looking green caps. I'd replace them all with "Orange Drops" of the proper value and rating.
- It's a little hard to tell from the photos, but the heater wires don't appear to be twisted. I realize the OP said the amps were quiet, but tightly twisting the heater wires would improve the noise further.
A review and schematic of the Grommes "Little Jewel" can be found
here. Please note that the fuse should be placed
between the plug and the power switch, not on the neutral lead as it is shown.
I certainly hope that the most egregious issue - the power cord - has been addressed in the months since the last post. And please bear in mind that I didn't write this post to put the OP down or to pontificate. On the contrary, I just want him to enjoy his beautiful finds to the fullest -
and in safety!