Hi all
Although I've had my edb for a while now, it's not been out much. I regularly play in pit bands in theatre (usually on electric bass) and on the couple of shows where I took my stagg I was embarrassed by flat battery issues (usually accompanied by a loud tthhhhppp!)
Anyways - had a night spare so thought I'd tackle the issue. Many years ago I completed a btec in electronic design and spent 20 years as an electronics service engineer -however please feel free to pick up from where I left off and let's develop this further.
The current consumption of my standard preamp was 20ma
It's now 3ma
Here's what I did:
1. The first preamp chip is a tl072. Replace with a tl062. Still sounds good to me and no excessive hiss or noise
2. Disconnect the supply rails to the two LM386 power amp chips (pin 6 on each -heat and lift with a pin)
3. Put two cheap red LEDs in series with existing blue led
With the mods the headphone socket will not work - you could introduce a switch to power up the lm386 if that was a problem to you. Personally I always found the headphone jack noisey and never used it.
The series led mean that you get a true battery indicator. As the battery voltage falls from 9v the led stays full brightness until 6v - at which point it goes out. On my unit the preamp still worked right down to 3.2v so you would get plenty of warning.
I have found that the tone at the jack output is unaffected by the modifications.
I hope this is of help to someone.
Cheers all
Stagg edb short battery life mods!
in EUB and Double Bass
Posted
Hi all
Although I've had my edb for a while now, it's not been out much. I regularly play in pit bands in theatre (usually on electric bass) and on the couple of shows where I took my stagg I was embarrassed by flat battery issues (usually accompanied by a loud tthhhhppp!)
Anyways - had a night spare so thought I'd tackle the issue. Many years ago I completed a btec in electronic design and spent 20 years as an electronics service engineer -however please feel free to pick up from where I left off and let's develop this further.
The current consumption of my standard preamp was 20ma
It's now 3ma
Here's what I did:
1. The first preamp chip is a tl072. Replace with a tl062. Still sounds good to me and no excessive hiss or noise
2. Disconnect the supply rails to the two LM386 power amp chips (pin 6 on each -heat and lift with a pin)
3. Put two cheap red LEDs in series with existing blue led
With the mods the headphone socket will not work - you could introduce a switch to power up the lm386 if that was a problem to you. Personally I always found the headphone jack noisey and never used it.
The series led mean that you get a true battery indicator. As the battery voltage falls from 9v the led stays full brightness until 6v - at which point it goes out. On my unit the preamp still worked right down to 3.2v so you would get plenty of warning.
I have found that the tone at the jack output is unaffected by the modifications.
I hope this is of help to someone.
Cheers all