Guyatone - Rolly Box
- Bernardduur
- Transistor Tuner
Got this one in for repair. Cool little box that looks like it was placed on the bottom of the sea, yet the inside was clean. Fixing points were the switch (which was completely dead) and the ELCO's.
The LED on this unit just powers up when connected to the battery. No DC jack in this unit. The Vox 1900 phaser is claimed to have the same PCB. All opamps are sanded off BUT not really well so you can spot the LM1458 markings. The can opamp is worked with black paint but still the 741 is visible. All FET's are 2SK30A's. The Depth potmeter has a switch in it to remove the feedback path or dial in the rigth amount of feedback. PSU is still weird...... My guess is that they wanted a + and - voltage to control the opamps and use ground as the reference.
Here's what it looks like
Schematic:
The LED on this unit just powers up when connected to the battery. No DC jack in this unit. The Vox 1900 phaser is claimed to have the same PCB. All opamps are sanded off BUT not really well so you can spot the LM1458 markings. The can opamp is worked with black paint but still the 741 is visible. All FET's are 2SK30A's. The Depth potmeter has a switch in it to remove the feedback path or dial in the rigth amount of feedback. PSU is still weird...... My guess is that they wanted a + and - voltage to control the opamps and use ground as the reference.
Here's what it looks like
Schematic:
'No more....... loud music.......'
Follow my love for pedals and amps on https://bernardduur.blogspot.com and https://www.instagram.com/bernardduur1
Follow my love for pedals and amps on https://bernardduur.blogspot.com and https://www.instagram.com/bernardduur1
- Dirk_Hendrik
- Old Solderhand
Information
Rather odd to call the net that contains the LFO signal that drives the Fet's "Vref"
And how about a multimeter to measure those zener voltages?
And how about a multimeter to measure those zener voltages?
- Bernardduur
- Transistor Tuner
It was a draft when I made it..... I kept it there!
I'll see if I can measure those voltages......
'No more....... loud music.......'
Follow my love for pedals and amps on https://bernardduur.blogspot.com and https://www.instagram.com/bernardduur1
Follow my love for pedals and amps on https://bernardduur.blogspot.com and https://www.instagram.com/bernardduur1
- Dirk_Hendrik
- Old Solderhand
Information
And where do the sleeve connections of the jacks connect to? To that virtual ground net?
- Bernardduur
- Transistor Tuner
I've added all comments;
'No more....... loud music.......'
Follow my love for pedals and amps on https://bernardduur.blogspot.com and https://www.instagram.com/bernardduur1
Follow my love for pedals and amps on https://bernardduur.blogspot.com and https://www.instagram.com/bernardduur1