Sound Skulptor: Pre's, Compressors, Tape Simulator, Professionnal Audio Kits

Hi Jean-Pierre,

After a few years of happy tracking, my MP12 suddenly has super low output. What's the first thing I should check before doing major troubleshooting? Box has been mounted and not moved and has worked fine for quite a while....It seemed the output started dropping and I needed more and more gain for the same mics, until it's very low now.

Thanks much,

Mike

Hi Mike,

Check the output pad potentiometer. Is it working smoothly from min to max ? With the pot at max and sending a constant sine on input, you could measure the AC voltage on output and compare it to the AC voltage across RL2.
Check the supply voltages on TP2, TP3 (what voltages are you using?).
Are you using the servo to null the output voltage (what DOA are you using?)?

Thanks Jean-Pierre.  I'm using a "red dot" doa. I'll check what you suggested when I get a little time and I'll report back here. Odd that it would work for a couple of years and then suddenly start having trouble.

Thank-you!

Mike

Finished my MC624 and have to say its a really nice unit and feels very professional. Love the clicking sound from all the relays and its a really good future that you can control most functions through a IR remote. Im actually using a smaller apple remote for the functions I use most giving me the possibility to change inputs, volume and different monitors from different positions n the room.

Ninuz said:

Finished my MC624 and have to say its a really nice unit and feels very professional. Love the clicking sound from all the relays and its a really good future that you can control most functions through a IR remote. Im actually using a smaller apple remote for the functions I use most giving me the possibility to change inputs, volume and different monitors from different positions n the room.

Click to expand...

Very cool!
Can you shine a light on which Apple remote it is and how you have set it up?
Very interesting for me and I think some others too.
Congrats to the successfull build of course,


best regards,


Udo.

Thanks Udo,
I set it upp as described in the manual. Really easy.
The apple remote used is a standard apple one which is used for their computers. I attached a picture.
It doesnt have that many buttons but its enough for me.
I have mute, volume up/down, input select 1 & 2 and output select 1 & 2.
You could probarly use even a smartphone if it has IR and using and IR remote app.

Regard Asbjorn

Thank you very much indeed Asbjorn,


best regards,


Udo.

Quick question: I have the version of mp573 before the impedance switch.

I can see by the assembly guide that the middle connectors of JMP 1 is 1200 ohms. Which two are 300 ?

o-o o-o

Will the STS run nicely on +-16V? (api rack)

And is it available only as a pcb?

It could but the PCB won't fit in a lunchbox.
We are currently working on a 500 series tape sim.

Great news! Will it be building upon the STS, or something completely new?

Built on the STS with the addition of in/out transformers and more sound options.

JPK said:

Built on the STS with the addition of in/out transformers and more sound options.

Click to expand...

Hello Jean-Pierre,


will it be mono for 1 slot or stereo/dual for 2 slots?


Thank you in advance,


Udo.

Mono 1 slot. Use 2 for stereo.

Any ETA? Before/after summer?  8)

Probably during summer...

Hello Jean-Pierre,

Just got my Sound Skulptor kits in the mail and I am busy building them!  I've got my first MP566 assembled and I'm currently running through the testing sequence.  So far so good -- got 224 volts for the High Voltage check (step 3), and nothing's on fire, so I must have done something right.

Moving on to step 4, I'm testing the heater voltage.  The test says we should expect +12v between V- and TP8, but I'm only seeing a solid 10 volts.  The unit's been on for about 10 minutes now.  I thought it might rise a little as it warmed up, but no -- sticking right to +10v on the nose. 

Is that "around" 12v for purposes of the test?  If I'm undervolt, how would I begin to troubleshoot that?

Thanks!  Looking forward to using this preamp!

Matt

Awaiting 2x MP566 kits

MattM said:

The test says we should expect +12v between V- and TP8, but I'm only seeing a solid 10 volts.

Click to expand...

Hi Jean-Pierre,

on my MP566 the same solid 10 volts between Pin 4 and 5 on the tube socket. This is 2V underheating. Ok i use a cheap SM-Pro Rack :, but it have 320mA per slot.....
the preamp sounds great with high gain and incredibly low noise floor.
in microphone builds 2V underheating have a drastic effect of the complete mic operation.
Have the 2 Volts underheating a negative effect in your MP566 preamp?

Best
A.