++- +

-

+

+

+

+

+-

The MXR Hot Tubes is a commercial cousin of Craig Andertons "Tube Sound Fuzz". It differs in that it uses a dual

= 1/6 of CD 4049 CMOS inverter. Vdd on pin 1, Vss on pin 8

opamp input buffer, more stages, and more filtering. Also, there appears to be a DC offset in the bias points of two of the inverter/distortion stages.

1M 120k

20k

20k1uf

75k

8k2

1m5

150k

2m2470k

15k

1m220k

220k

+9v

220k

IN OUT

unknown valueunknown value10K?100k?

= 1/2 of dual 741 or 4558 opamp; +v on pin 8, -v on pin 4

MXR Hot Tubes Distortion

47pf

22pf

0.1uf

30uf

1uf

0.1uf 0.015uf 0.22uf

4.7uf

22pf