Jeff,

That explains why my '71 Twin sounds so good. I just recently replaced
the jewel with a purple one. You see, the darker colors have higher
capacitance which acts as a low-pass filter. I've since replaced
the caps in the tone stack with various colored jewels. Here's
the capacitance chart for the jewels:

Red 500pf
Blue .047uf
Purple .1
Green .022uf

...As you can see from the above chart, the Red jewel allows too much
high frequency content through the circuit. Maybe RGKeen or MGarvin
can explain this ?

-Jaz

--
>
> Jack A. Zucker | ESP Music
> ja--(at)--n.com or | Voice: 216 349 5881 (home)
> Jack.Zucke--(at)--oftware.rockwell.com | Voice: 216 646 7796 (work)
> | Fax: 216 646 7766 (work)

Index:

AB crossover	Amp Classes Defined	Amp Classes Explained	Amp Mods Harmful
Bass Cutoff Frequencies	Bias adjust safeguard	Bias Cathode Resistors	Bias Shift
Biasing methods	Biasing	Channel Switching LDRs	Choke Input Filter
Circuit Memory	circuits	Drop B+	Eyelet board
Fender Response Curves	FET source follower	Filament Cathode Ground	Fixed to Cathode Bias
FM Transmitter Voltages	Grid Blocking	Identify Power Trans Leads	Load Impedance
LV No PC boards	Output impedances	PC Boards	PCB amp problems
Phase Inverter Resistors	Pilot Light Tone	Rectifier voltage drops	Resistor Design
Resistor Max Voltage	Resistor noise	Reverb Tank Types	Reverb tanks
Screen Grids	Standby Switch Ratings	Standby switches	TAME Digest
Tone Circuits	Transformer Design Book	Transformer Info	Transformer Placement
Zener Voltage Drop