BMP debug

[kyle31]

Built from ggg kit.

Bypass works. When ON signal is cut, most highs are rolled off, and there is no fuzz.

The volume pot works. The sustain pot adjusts volume slightly, (there is no fuzz). I think the tone pot works as it should.

I'm building an audio probe, and i'll have voltages in just a minute.

Triangle Version. No mods.

[kyle31]

ok,

Q1
E: .15
B: .7
C: 4.8

Q2
E: .10
B: .69
C: .69

Q3:
E: .16
B: .71
C: 4.2

Q4:
E: 1.2
B: 1.8
C: 3.6

EDIT: I had my E's and C's backwards. They are now correct.

[petemoore]

Q1
C: .15 C should be between Gnd and V+, I guess about 1/2v.
B: .7  These voltage might be wierd because
E: 4.8  This should be real near Gnd. potential, small resistor should pull voltage real low toward Gnd.

Q2
C: .10  I see a pattern with the collectors starting..
B: .69  Test for connection to Q2E
E: .69  Test for connection to Q2B
 
Q3:
C: .16 Seems like somethings not letting all the collectors get up there
B: .71
E: 4.2 Again, emitter shouldbe real near Gnd potential

Q4:
C: 1.2  Perhaps all collectors aren't actually tracing [through resistors and wires] back to V+
B: 1.8
E: 3.6 Seems high also, unless I forget ir this is a buffer stage [emitter follower].
  Try measuring the E to ground resistances, also the C's to V+, all four collectors are near Gnd., their resistors should be pulling them up toward V+....otherwise they're separate, I can't see why all four would be pulled hard toward gnd.
  All the readings are %ages of supply, measurement of battery voltage under circuit load is the main supply # by which all the other readings equate.
 

[kyle31]

FIXED: I had a 390 ohm where I should have had 390K  . I'm glad that only took a couple of hours.

Thanks for the help!!!

[8mileshigh]

Amazing, I made the exact same error when I built mine