The search for tone may be over.

[123thefirst]

Yes! The search for tone may be over. At least we've come very close to perfection...

I've lived with a Road King II for about 10 years. Truth be known, most of the time I actually have used a Bogner Alchemist instead for practicing and working out things. The Road King has one of the best clean channels anywhere, especially in Tweed mode. The Lonestar's clean is similar but not quite the same. I think it is basically the Fat mode of the Road King when reverb is switched to classic. However, the Lonestar's 10 watt class A single ended power mode and option for 6V6 tubes adds new wonderful possibilities for clean.

Where the Lonestar really comes to life, in my experience, is channel 2 especially with drive on. That channel is so much fuller in tone and more articulate than any other gain amp I've used. I had stopped using channel 3 and 4 of the Road King since it gives only that "Recto" type of tone, not an articulate, dynamically responsive rich palette I've felt I need when guitars are forefront in the mix and not purely rhythmic in nature.

But Lonestar channel 2 does seem to need some adjustments. I will change the coupling capacitor for the drive section to a 1200 pF ceramic disc version. I'll also change the cathode capacitor on the following stage to a radical .39 uF variety. I figure that will cut the bass and lower mids about 6 dB early in the circuit. The result of both changes should be a much better tone balance, a much reduced murkiness and ever more pronounced articulation. It that is successful I will make some extensive modifications to Road King's channel 3 and 4 to give them much of the same tonal magic.

Speakers: yes, I sold or gave away the factory Celestions in both amps and now use a pair of M Creambacks or JBL D120's.

 

[Guizan]

Let us know how those mods turn out 123!

I've loaded up the 1x12 now with an A type and THAT is by far the best speaker I've heard with this amp. I'm actually shocked that a cheap(er) speaker is this good. I have a scumback j75 that will be here today. I honestly can't imagine how it could be better than the A-type, but we'll see.

 

[123thefirst]

Will do. I'll look into more information about the A-type. The first time I used the Lonestar in practice I plugged the speaker out into a Celestion 70/80 in the room's Blackstar HT40 and was really surprised how good the clean tone was. It was very, very close to a Fender Super Reverb or Twin with a kind of spongy compressed feel that the older Fender amps have. Sounded great even with heavy gain from the drive channel. I'm not necessarily recommending that speaker but maybe there is great synergy between it and the Lonestar.

 

[123thefirst]

I made a lot of circuitry changes this weekend. It was difficult work because many of the components are tightly packed together and because resistors and capacitors that are soldered to the ground plane on the underside of the board just about refuse to come unsoldered. I made several changes to the drive stage. The cathode bypass capacitor went from 15uF to .39uF as I planned as well as the .005uF to .0012uF changes. I also bypassed the 1M drive pot with a 330pF/47K capacitor resistor pair. That was done to add just a bit more upper mids and highs when the drive knob is lowered.

I also made a bunch of changes to the non-drive circuit to essentially put it into Road King II territory which is noticably brighter and zestier than the Lonestar circuit. Channel 1 is now incredible in tone, dynamics and feel - perfect even. I could turn the treble all the way down and the bass all the way up and get a beautiful fat, sweet tone with no weakness. Or turn the bass all the way down with the treble and presence high and get a sizzling, searing sound. Everything was so much more bouncy and full and the tone controls have enormous power. The gain seemed much more effective so that at higher settings it sounds like channel 2 used to with the drive up high (but with a whole lot more presence and sizzle).

The drive changes made strong improvements too. Much more varied sounds are now possible. But still, sizzling highs and upper mids just didn't come through nearly as much as I wanted. There is apparently something in that drive stage that absolutely kills upper mids and highs. Or at least smears them so that it feels like you're in the clouds and not presented with something real and clear. I'll investigate more how to fix that.

As amazing as the amp sounds now a new problem was introduced. When I turn the mids and gain up in either channel I get intermittent scratchy noise and whistling. I'm thinking that something is going microphonic - could be the preamp tubes or maybe the bypass capacitor resistor pairs I added that are physically bound and therefore resonating together. Strangely enough, when I set the power to Tweed mode this disappears. So investigation here is needed. The plus side is that now, Tweed power, even with the tube rectifier, sounds great whereas it sounded way too weak before these changes.