1

MP573 Microphone preamplifier / Re: No input when testing

« on: March 24, 2021, 09:15:45 AM »

brown: 0
yellow: 0

don't know if it's ok or not?
thanks.

2

MP573 Microphone preamplifier / Re: No input when testing

« on: March 23, 2021, 09:07:07 AM »

so here's the results:

V+: 15.8
TP2: - 9.13
R24: 15.1 / 15.9

3

MP573 Microphone preamplifier / Re: No input when testing

« on: March 20, 2021, 06:18:57 PM »

Sorry, but I don't get it?

I should put the negative to V+ and then with the postive on TP2, R24 and pin 13? 

4

MP573 Microphone preamplifier / Re: No input when testing

« on: March 18, 2021, 10:47:56 PM »

Hi, I've checked the solder joint everything looks ok

I've done more tests and I can have an output line (through the daw) but the signal is very low, I had to push the preamp and gain at max.

here's the output transformer DC resistances:

CARNHILL VTB1847 (unplugged) :

• Yellow-Orange : 7,9 ohms
• Red-Brown : 6,7 ohms
• Blue-Green : 21,4 ohms
• Violet-Black : 21,4 ohms

CARNHILL VTB9045 :

• 2-4 : 24,7 ohms
• 3-5 : 24,7 ohms
• 7-9 : 132,2 ohms
• 8-10 : 133 ohms

Thanks[/list]

5

MP573 Microphone preamplifier / No input when testing

« on: March 16, 2021, 03:49:00 PM »

Hello, I did the LA502 on one shot but the MP573 was my first DYI, so I did some mistakes I guess because I got no input (either on xlr or jack). I can hear some click when switching to the 1200 ? and the gain / trim reacts. 
The 1st generics tests was ok but here's the results of the error procedure:

A: 2v70
B: 4v16
C: 23v
D: 13v92
E: 2v08
F: 13v33
G: 0v50
H: 1v07
I: 0
J: 4v27
K: 0v41
L: 0v15

thanks for your help.

6

LA502 Optical Compressor / Re: about P3

« on: March 16, 2021, 03:34:30 PM »

ok thanks you

7

LA502 Optical Compressor / about P3

« on: March 13, 2021, 12:02:41 PM »

Hello, how to be sure that P3 is really at 0?
is it a way to check it?

thanks