JLM AUDIO

OK, changing the buffer input to that position did it!...phew!!!!! Changing those resistors to 2K2 made it better, but I still cannot get 0dB VU, I can with 1K, so will leave it at that. Thank you again for your time and effort in getting this sorted, I really very much appreciate it! I purchased a ...

OK, so connect the buffer before the 1uF C107 and C207, just confirming
OK, will change those two resistors on the buffer to 2K2 and see how that goes.
Thank you Joe, will let you know how it goes.

OK, emailing now, thanks Joe, really appreciate it!

the EQ output is unbalanced, I have just send you the EQ schematic via pm.
Note, the DEFEAT function/switch on the EQ is not used

sorry, my bad, when I stated 2 or 3, I meant -2 or -3 Can you cal +4dBu = +4dBm = (1.23vac RMS on multimeter at input) to correct 0VU? and then if you put in +7dBu does the meter show +3 ? I will need to check that again with my tone generator tomorrow What is feeding the input of the buffer? the au...

thank you for your quick reply, I appreciate it. In this post, you mentioned that the 3K3 buffer resistor may need to be lowered, dated October 26, so I just started to experiment with a value and see what happens. It was doing the same, ie no VU meter movement after power down and power up again wi...

Hi, could you please tell me which R numbers are the output buffer resistors, I need to reduce the value to increase the calibration range for the VU meters I am using, I assume that is the way to go about it in order to increase the calibration range, thank you. Also, any chance you coult post the ...

further to my recent post, I tried the VU2 driver in the same preamp, I do not have the same issue as with the VU buffer & peak LED. I am wondering if it has something do to with the peak led driver section?

so the saga continues! This has been very frustrating. In order to have more VU calibration, I changed the output buffer resistors, R11 & R12 from 3K3 to 1K, this has 'increased' the calibration sensitivity. Now, this is the problem I am still facing. I turn the VU driver on, calibrate it and the pe...

thanks for the quick reply. I think the confusion here is what is +4dBu/dBm in PP volts. I thought it was 1.0024VPP, but looking at it again it is 3.743VPP, is that the correct value, in that case, I should be able to calibrate 0dBVU at that signal level. I will not be able to check that until later...

Hi,

I am using a TN-73-HS-9213H VU meter.
Measured internal DC resistance is 50 OHMS on a digital meter. It has no diodes or resistor inside.
Using +4dBm, which I equate to 1.0024V PP, I only get a max deflection between 3 and 2 on the VU meter.
Any advise would be appreciated, thank you.