Search found 5 matches
- Tue Nov 30, 2021 10:55 am
- Forum: JLM Audio Kits
- Topic: VU2 stereo VU buffer kit Build thread
- Replies: 139
- Views: 484613
Re: VU2 stereo VU buffer kit Build thread
The opamp and power are working fine as pin 1 and pin 7 outputs are still at 12v. The rest are a bit out because you have the gain fully cranked which for a XLR input should be way too much gain. Something is wrong with the input or the meter wiring. You do have the meter going to +M-? and remember...
- Mon Nov 29, 2021 1:26 pm
- Forum: JLM Audio Kits
- Topic: VU2 stereo VU buffer kit Build thread
- Replies: 139
- Views: 484613
Re: VU2 stereo VU buffer kit Build thread
The VU buffer pcb makes a half voltage rail reference for the TL072. So all the pins of the TL072 except pin 4 = 0v and pin 8 = V So your setup measured from 0v on the buffer pcb pin 1,2,3,5,6,7 = 12v and pin 4 = 0v and pin 8 = 24v. Let me know if the voltages are correct on all pins of the TL072 P...
- Sat Nov 27, 2021 2:12 am
- Forum: JLM Audio Kits
- Topic: VU2 stereo VU buffer kit Build thread
- Replies: 139
- Views: 484613
Re: VU2 stereo VU buffer kit Build thread
Looks fine. Not sure if that 24v is tied to the same 0v as the power amp voltage. You should be able to measure the ohms across the gain pot on the buffer with the buffer off. Takes 25 full turns end to end. What meters are you running as they may have an internal resistor and/or diode bridge? I me...
- Wed Nov 24, 2021 1:45 pm
- Forum: JLM Audio Kits
- Topic: VU2 stereo VU buffer kit Build thread
- Replies: 139
- Views: 484613
Re: VU2 stereo VU buffer kit Build thread
The buffer outputs have a cap so no dc can make it to the meter. Leaving those resistors out will not damage anything. Best first to send me some photos of the wiring and setup you have so I can see if I can spot the problem. Otherwise, as always top and bottom photos of the pcb helps to check for ...
- Wed Nov 24, 2021 1:06 am
- Forum: JLM Audio Kits
- Topic: VU2 stereo VU buffer kit Build thread
- Replies: 139
- Views: 484613
Re: VU2 stereo VU buffer kit Build thread
Just got mine assembled and am having an issue. Possible user error as I didn't notice that R2R and R2L weren't installed before powering up. Both meter outputs showed around 0.2 DC volts regardless of input. Once I did notice the missing resistors and installed them, not much changed. Meter output ...