requesting a little help (rangemaster debug)

[barret77]

Hello all

So, here I am seeking for advice on debugging a simple rangemaster...
I have read all the debugging faqs and searched the forum already - could not find the exactly same problem....

I built the Rangemaster; terminal strip version, as seen on the austin treble blaster at geofx.

Bypassed: works fine. When I activate the switch, the first thing to be noted is that the volume goes away; almost all of it. You can hear the music going on, but it's really quiet.
If you disconnect the battery, the volume goes up again to the normal;
If you disconnect one of the gain pot wires (no the wiper, not the tranny collector, the other one) the volume also goes up; the typical rangemaster distortion can be noted.

I checked all the circuit with the audio probe, found no problems - the music plays through all points.
I also checked the capacitor polarity, and component values

The transistor is a cv7003; I biased the base at around -7, as specified in geofx. The readings are a bit odd, I'm not sure if I'm measuring right:
-pedal on, with sound source; ground DMM lead clipped at ground lug of the output jacket, hot lead poking the tranny legs.
I measured -9.20 at both emitter and collector; -6.84 at base. (is this wrong? same values there...)
I tested with a different tranny and works the same...

Am I missing something? Is there any other good information I can provide to investigate this issue?
Anyone experienced with this?

thanks a lot!

[nightingale]

Make sure the transistor pinout is correct,
If you have a socket there try to flip the transistor around. Maybe do a google search on your tranny, and lock the pinout. It is also possible that your tranny is faulty, or was cooked while soldering. Try another tranny if you have one laying around. [that sounds pretty slutty]
hope this helps man,


edit: after re-reading your post, you might have a grounding problem there? can you post any pics? maybe sleep on it, and then go back over it with fresh eyes/mind?

[barret77]

hey, I forgot to post the feedback for my thread...

I found the problem, a bad solder in a ground point;

so, if you're building a rangemaster and experiencing:
-sound goes through with no battery attached;
-sound louder without battery plugged
-audio probe shows no problem in the signal path

check the ground solders... the problem might be there.