1

CP5176 FET compressor / Re: Failed sidechain check

« on: Today at 09:04:51 am »

Congratulations!

2

LA502 Optical Compressor / Re: Error is setup documentation?

« on: September 09, 2022, 09:08:31 am »

This is the documentation for the previous PCB versions: before REV1.4
The correct documentation for REV1.4 is available at https://www.soundskulptor.com/en/docs.php
in the DOCS-24 tab.

3

CP4500 Stereo Bus Compressor / Re: CP4500 Setup trouble

« on: September 04, 2022, 09:32:30 am »

Congratulations!

4

TS500 Tape Simulator / Re: TP2 à 0v

« on: September 02, 2022, 06:37:30 pm »

OK pour les 4 LM339.
Mettez-nous une note de rappel dans votre commande, dans le champs "Informations supplémentaires" du panier.

5

CP554 Diode bridge compressor / Re: Setup Troubleshooting

« on: August 31, 2022, 08:46:11 am »

Congratulations !  

SW2 = PVA2EEH11.7NV2
Available at Mouser.

6

CP554 Diode bridge compressor / Re: Setup Troubleshooting

« on: August 29, 2022, 08:24:16 am »

You can check the forward voltage drop on D20 with your DMM in the diode mode. It will tell you if the diode is damaged. If it is, then replacing it will probably cause the destruction of the new diode if you do not eliminate the short circuit.

7

EQ573 Equaliser / Re: EQ573II - Lowband 70Hz - faint-to-no audio when selected

« on: August 29, 2022, 08:16:17 am »

You mean the high pass filter, I think.
You must check the solder joints of C17, C18 and L1. The pins on the inductors are sometimes oxidized and require some rubbing with the iron tip to make a good joint.
Also check J6 a&b and the rotary switch SW1.

8

501 Single Host / Re: Switcher is not working as expected

« on: August 29, 2022, 08:07:06 am »

I would try to replace D3 (SB160).

9

CP554 Diode bridge compressor / Re: Setup Troubleshooting

« on: August 26, 2022, 10:09:55 am »

C25 destruction could be the consequence of a short circuit in the output stage.
After replacing, unplug the output transformer and check immediately that the voltage on TP3 is negative, around -10VDC.
If not, D20 might be dead also.

10

MP566 Tube microphone preamplifier / Re: High Pitched Whine in 566

« on: August 25, 2022, 08:47:31 pm »

Yes, start with the voltages tests, the heater and the high voltage (steps 3 & 4).
You may have a failed DCDC converter. This happens when the temperature gets too hot in the module.

11

MP573 Microphone preamplifier / Re: Strange behavior when internal connected to EQ573

« on: August 25, 2022, 08:42:30 pm »

Try it. If it fails, the lunchbox will not be able to start. It will switch to a protection mode, believing there is a short circuit.

12

CP554 Diode bridge compressor / Re: Setup Troubleshooting

« on: August 25, 2022, 10:56:44 am »

I imagine it's just pull it apart and make sure again (I've done that 3 times today) that nothing is miss-soldered/in the wrong place/obviously busted/etc.
Correct!

Also check that the connections to the output transformer are good.

13

MP573 Microphone preamplifier / Re: Strange behavior when internal connected to EQ573

« on: August 23, 2022, 09:46:19 am »

This happens in some setups. It is caused by the slow start on the MP573 which creates a pulse in the EQ which is reinjected in the pre and makes a loop.
The best solution in this situation is to remove the slow start on the pre (if your lunchbox can stand some inrush current):
On the MP573, remove U1 (LM317T) by heating the 3 pins together with a blob of solder, it will fall off.
Now link the 3 pads together with a blob of solder.

14

CP554 Diode bridge compressor / Re: Setup Troubleshooting

« on: August 23, 2022, 09:32:20 am »

The next step would be to try a new THAT300.

15

CP554 Diode bridge compressor / Re: Setup Troubleshooting

« on: August 20, 2022, 03:55:38 pm »

If I remove the jumper on JMP1, the VAC goes to .22VAC with bypass button still in
And, in this situation, does the control voltage on the CV pin (and on D14 anode) go to 0VDC?

If I'm going to need another THAT300, would this be the one?
Yes this is it.

16

MP573 Microphone preamplifier / Re: TL074L replacement

« on: August 20, 2022, 10:02:15 am »

I don't think you can put a socket here because the allowed height is limited by the DI board above.

17

CP554 Diode bridge compressor / Re: Setup Troubleshooting

« on: August 20, 2022, 10:00:22 am »

OK, the attenuator control voltage seems to work.
Do you get the same output AC level as when bypassed when you remove the jumper JMP1 (it cancels the attenuation)?
Were you able to set the 0dB gain and check the max gain in step 7 of the setup guide?
There may be an issue around the diode bridge in U1. Check that it is well inserted, and the socket well soldered.

18

CP554 Diode bridge compressor / Re: Setup Troubleshooting

« on: August 19, 2022, 08:46:05 am »

Can you check that the trimmer TR5 is OK by measuring the resistor value between the 2 side pins? it should go from 0 to 4.5k depending on the screw rotation.

In the same configuration as "Control voltage adjust",
what is the minimum DC voltage (TR5 fully CCW) you get on U1 pin1?

19

MP573 Microphone preamplifier / Re: TL074L replacement

« on: August 18, 2022, 10:40:15 am »

Do not try to desolder it! You will very likely damage the PCB.
Cut the 14 pins, remove the pins by tapping the PCB while the solder is hot and remove the solder from the holes with a desoldering pump.

https://www.mouser.com/ProductDetail/Texas-Instruments/TL074ACNE4?qs=odmYgEirbwz65PB0zQNngg%3D%3D
https://www.buerklin.com/en/Quad-JFET-Input-Operational-Amplifier-PDIP-14-TL074CN/p/49S5602
https://www.reichelt.de/de/en/operational-amplifier-dil-14-tl-074-dil-p21557.html?&trstct=pos_0&nbc=1
https://www.tme.eu/fr/en/details/tl074acn/tht-operational-amplifiers/texas-instruments/

20

CP554 Diode bridge compressor / Re: Setup Troubleshooting

« on: August 18, 2022, 10:30:21 am »

The DV at the 3V test pin is 3.00V and the anode of D14 is .94V.
How many VDC on the CV test pin (near the CV trimmer)?

The reading at the CV test pin is now .28VAC
The voltage measurements on the CV test pin are DC only.

21

MP573 Microphone preamplifier / Re: Older model impedance switching

« on: August 16, 2022, 06:06:46 pm »

I wonder was the second jumper included the kit?
It isn't.

Or can I use the jumper on the Eq socket? Not gonna connect the Eq any time soon.
The jumper on the MP573-CN1 is needed when the EQ is not connected.

Jumpers

22

CP554 Diode bridge compressor / Re: Setup Troubleshooting

« on: August 16, 2022, 09:32:12 am »

It doesn't make a difference between TI and BB.
In the same configuration, what DV voltage do you get on the CV test pin (3V) and on the anode of D14 (1.05V) ?
If you don't get similar voltages, you must check the value, direction and solder joints of R83, R85, R86, R87, D12...D15, U6, trimmer TR5.
In order to check U6, you can try with U5 in the U6 socket (in this test configuration U5 is not used).

23

MP573 Microphone preamplifier / Re: Older model impedance switching

« on: August 16, 2022, 09:08:59 am »

Yes, via jumpers:
The jumper header is JMP1, near the input transformer, near C31.
Standard 1200 setting (1 jumper) :
o o-o o
300 setting (2 jumpers) :
o-o o-o

24

MC624 Monitor Controller / Re: Quelques soucis lors des tests...

« on: August 10, 2022, 08:40:48 am »

Bravo !

25

MC624 Monitor Controller / Re: Quelques soucis lors des tests...

« on: August 01, 2022, 10:02:10 am »

Vous avez raison, les afficheurs sont à anode commune donc on teste avec la pin 3 au plus.
Est-ce que les segment s'allument lorsque vous faites le test ?
L'afficheur 3 est commandé par U17, à travers RN12 et RN13 , CN37a et CN37b.
Vous devez mesurer une résistance de 1k5 entre les pins de sortie de U17 et les pins de l'afficheur 3 :
U17-pin3 --> DISPL3-pin7
U17-pin4 --> DISPL3-pin6
U17-pin5 --> DISPL3-pin4
U17-pin6 --> DISPL3-pin2
U17-pin11 --> DISPL3-pin1
U17-pin12 --> DISPL3-pin9
U17-pin13 --> DISPL3-pin10
U17-pin14 --> DISPL3-pin5