Regal Palm Tree Amp Thread

[PRR]

6(s)J7 is THE audio pentode. Many other octal pentodes are higher gain, at high current, for radar and VHF.

This is not a Rock or even Swing amp, it is for little ukuleles, guitars, and other folk instruments. The 6SC7 is two "instrument" inputs which today we might call "lame". The 6SJ7 input is higher gain for Microphone.

It MAY indeed need "fudging" to play well with modern guitars and wild picking. But right now it looks wrong even for very mello music.

[bmccowan]

Undoubtedly sold for and with lap steels. The only other octal pentode I've seen in use in guitar amps is the 6SH7, which is very similar to the J.
When plugged into the mic input that thing ought to wail pretty good.
Here is a nice Regal Lap steel and amp combo

[yorgle]

I've taken a break from the circuit for a few days and and have really been enjoying playing this thing.  As I said, despite the questionable plate voltages on the preamp tubes, after implementing Slukey's filter cap suggestion, the amp has decent volume and a warm, sweet vintage sound- especially when overdriven through the mic input.  So... I've decided "if it works, don't fix it" is the prudent approach and I'm going to leave the circuit as-is. Eventually, something will release its smoke and then I'll have incentive to do a proper re-cap. 

[yorgle]

Tonight I gutted the can capacitor and stuffed the first three filter caps inside.  I need to order an axial 10uf to replace that ugly radial hanging off the D node.  And doesn’t that NOS 500 ohm KOOLOHM look right at home as the cathode resistor on the 6v6.

[yorgle]

The only hint of the can cap mod is a barely visible seam where it was glued back together.