Grommes Little Jewel LJ6K

[EWBrown]

Anyone familiar with the Grommes "Little Jewel" amplifier?

Tube lineup is 6X5, 2 X 12AX7, 2X 6V6. Looks to be around 10 watts, mono. Integrated preamp, with magnetic phono input.

Couldn't resist it for the absurdly low price this weekend at the local antique radio swapmeet. Unit is very clean and "mint" appearing for its nearly 50 years' age.

Same seller had a nice clean Heathkit A-7, but someone beat me to it for $30. However, he has two more, and we may yet deal...

One lucky buzzard who got there real early scarfed up on a large batch of NOS/NIB Mullard 12AX7s and 12AU7s. Wasn't me, unforch... Yellow_Light_Colorz_PDT_13


/ed B in NH

[erichayes]

Hi All,

Ed, that was the second amp I ever built, in 1960 (the first was a Lafayette KT-92 in '59). Lafayette sold them for $19.95, and the only "instructions" that came with mine were two blown up pictorial drawings--no step-by-steps--and a schematic.

You'll notice that the bass control is flat at full CCW, while the treble is flat at full CW--no Baxandall stuff here. The "Phono Flat" position on the input selector essentially lopped off the RIAA de-emphasis above 1000 cycles, thus making the treble control a variable rolloff control.

The amp was rated at 10 watts, and had a huge appetite for 6V6s. I don't know what happened to mine, but suspect it was a casualty of my sister-in-law's garage cleaning efforts when we moved out and she moved in.

The "K" suffix indicated that it was a kit, although the Grommes name was only used for Precision Electronics' kit line, to my knowledge. They also had an LJ-5K which used a 5Y3 instead of the 6X5 as the rectifier.

Great memories...

[EWBrown]

Thanks for the info on the LJ amp.. I'll check it out and see how well (or not) it works and sounds, but my first thought was to gut it out and put in all new circuitry. Either the tried and true 6EM7 circuit, or something using those low price Russian 6L6GTs. Depends mostly on power tranny capability at this point...

Might make a good mono power amp to use with my HH Scott 310 FM mono tuner.

FWIW, there is one on e-bay, at least it's good for to see what the amp looks like...

http://cgi.ebay.com/ws/eBayISAPI.dll?Vi ... =WDVW&rd=1

/ed B in NH

[EWBrown]

That Grommes "Little Jewel" on e-bay went for $250!!!! Yellow_Light_Colorz_PDT_10

I guess I got a real steal, at a small fraction of that price.

Now, should I seek another cheap one, or just sell mine on e-bay Yellow_Light_Colorz_PDT_20

/ed B in NH

[erichayes]

Hi All,

Ed, I'd put it on eBay, rather than reconfigure it. As I hope I implied, it was no great shakes as an amplifier (although at the time, I was pretty impressed) and apparently has more "greater fool" value than anything else.

Or you can sit tight and see if another one falls into your lap; if one went for $250, think what a pair of them would bring.

[EWBrown]

It's still in the cellar, the dust layer is just a bit thicker, now. Never powered it up or even pulled the tubes to test them. It also has a screw (or something) rolling around inside the chassis, I haven't opened it up to see what it is.

Too many projects, too little time, though the way things are going around here at work, I ,and quite a few others here may have a LOT of "spare time" on our hands... Yellow_Light_Colorz_PDT_20


/ed B in NH

[EWBrown]

dug up the Grommes "little jewel" this weekend, and upon internal inspection, it turned out that this had been serious and fairly unskillfuly "hacked". It also had a few charred carbon resistors, and the 6X5 rectifier had its locatore pin broken off and it was inserted 90 degrees out of "phase". The 6V6s tested out to be about as flat as week old warm beer, but the 12AX7s and broken-locator 6X5 check out OK...

I went with the "slash and burn" approach, and totally gutted / stripped it, and cleaned / sanded and then repainted the chassis (metalflake gold) , and the power trannie top bell cover. The OPT was some non-standard, and fairly large, 7200 ohm unit that was definitely not original. It looks to be around 25-35 watts capability, and has no markings with which to ID it. Of course the prevoious owner had drilled new mounting holes, and did a rather messy job at that...

This "strange" OPT has a 7200 P-P primary, a 90 ohm CT "tertiary" winding, probably for cathode NFB, and the secondary has 2, 4, 8, 16, 250 and 500 ohms outputs. Lucky 13 leads coming out of it
It'll live to see another day, in another project, sometime... At least it has fairly long leads, the "hacker" didn'tt just shear them off too short, fortunately...

As luck would have it, I just happened to have the correct 9K P-P OPT from a previous flea market find years ago. I dunno if it's a Grommes OPT or not, but it fits the original chassis mounting holes, and the part numbering scheme looks similar to that of the power trannie.

I'll probably re-build this as one of two designs, either a 6V6PP guitar amp, or perhaps a 6EM7 PP mono block, to use for experimentation.

Right now I need some 1 1/8 inch octal sockets, as the only Octals i currently have are either too small or too large diameter to fit properly.

Next AES order...

/ed B in NH