18Watt.com

Hi there folks;

Quick background...... about me;
I was helping to design and build my own ham radio gear as a kid back in the 1960's, but that was a LONG time ago.... and now my eyesight and soldering is not what it was back then.

I've got a Baby Will Litellb here (not my personal build, came from someone else) that just seems . . . . well.... tame?
No experience with a JMP (though I've owned and played Marshall amps from the '60's & '70's plenty), but this little 18 watter just seems kinda . . . hate to say the word . . . lame.

It's not all that "loud", and compared to a similar Crate (USA) or Fender (Blues Jr) dual EL-84/6BQ5 just seems to be quite meh.... so-so by comparison.

The two EL-84's are Russia Mullards, one preamp tube is a JJ, and the other preamp tube, all that I can make out is Britain (12AX7/7025?).

I've tried two different speakers (Celestion Alnico Blue, Electro-Harmonix 12TS8 30 Watt, which actually sounds better), with similar results.

Change tubes? Any circuit component values?
Any ideas?

Any help, suggestions or advice appreciated . . .

Thanks!

Welcome to the site.

You'll want to test the circuit voltages to see what's actually going on. You can use a voltage chart for the regular Lite IIb or IIb(ish) from the downloads section.

Thanks,
Josh

As mentioned above, start with checking voltages.

It looks as though you have a decent set of transformers so that should put you in a positive space. You are using solid state rectification, so the voltage measurements will help to make sure that B+ has been put where it needs to be.

Once you have confirmed that voltages look good, tubes are behaving properly and component values are correct, you can consider removing the split load resistor at the input tube and replace it with the standard 100K dropping resistor. I think this split load setup was put in to make it work better when doing a Valve Jr conversion. But from a scratch build it reduces gain that is fed through the tone stack and onto the phase inverter. Removing that may the resolve the "meh" factor.

I can see on your image that you have the split load installed. If you decide you would like to try putting it back to stock values, you will need to figure out which one is R24 and replace it with 100K and then remove R8 and use a wire to jumper that slot.

That should get you close to stock 18 Watt territory. After that there are a few things you can mod to tighten things up, particularly if you are using humbuckers. It looks as though the baby will uses a variant of the tremolo tone stack which is interesting.

There is a discussions on this forum that discuss Baby Will vs Lite IIb but the focus is on the downside of the Valve Jr. PT + split load:

viewtopic.php?t=24311

You are in a position to get in the zone with your transformer set. This assumes that you are using the correct Classic Tone tranny's for the 18W.

FYI .. I jam with a guy that uses a Blues Jr., and can tell you with confidence that it doesn't hold a candle to my Trinity 18W. Should give you something to look forward to.