ADA Depot Too - A Forum To Support Users of ADA Amplification Gear

Please login or register.

Login with username, password and session length
Advanced search  

News:

Temp "Time Format" issue Fix in Discussions

Pages: [1]   Go Down

Author Topic: no sound on outputs A and B, effects loop works  (Read 128 times)

0 Members and 1 Guest are viewing this topic.

ang3lus

  • Newbie
  • *
  • Offline Offline
  • Posts: 22

Hey all,

I know this is somewhat of a double post, but the last thread got too crowded with my ground loop problem.

I've recapped the PSU and tube board and now have got no hum but also no sound thru outputs A and B, when i connect SEND to a power amp or another amp i get sound

what is left now is this

Front volume doesn't do anything (all other controls work)
no outputs from A or B

I measured the front pot (back side as it is dual ganged) and it reads 50k from pins 1 to 3 and whene connected to pins 2 and 3 (ohmmeter) i can see the resistance changing.

any ideas on what can i check ?

Logged

rnolan

  • Administrator
  • Superhero Member
  • ******
  • Offline Offline
  • Posts: 5060

Hey ang3lus, I put my ideas on your other thread based on the send works, I'm thinking maybe Fx return jack problem ? as it comes just before the chorus > A/B outs.  Front volume controls A/B output, seems the signal is not getting that far.
This is out there but I have to ask, have you turned up the patch master vol ?  It comes after loop > chorus stages and wont affect the send volume (which, as you say, works).  It also defaults to 0 on new patches until you program it.
Guit > input > gain (OD1/OD2) > eq > send > rtn > chorus > master vol > front vol > A/B out
« Last Edit: Time Format by rnolan »
Logged
Studio Rig: MP2/MB1 > Eurorack UB2442FX-Pro > TC M-One XL > Behringer Truths (with Truth Sub) / QUAD ESL 63s
Live Rig: MP2/MB1 > Alesis Quadverb > Alesis Midiverb 4 > Yamaha AM802 > B200s/Carvin TS100/DCM200L > ADA Split Stacks/Mesa P112s

ang3lus

  • Newbie
  • *
  • Offline Offline
  • Posts: 22

well i connected the headphone out and am getting good output and also the chorus works well, so the chorus is good i think.

i also plugged the RECIEVE jack into an amp, very low output but am still getting sound and the patches are working well.

so what's left ? volume pot and NE5532 opamp ? any way to test in circuit ?
Logged

MarshallJMP

  • Superhero Member
  • ******
  • Offline Offline
  • Posts: 4056
    • marshalljmpmodshop.net

Do you have a MP-1 with a  top switch?
Logged

rnolan

  • Administrator
  • Superhero Member
  • ******
  • Offline Offline
  • Posts: 5060

Do you have a MP-1 with a  top switch?
Good point MJMP, the outputs may be switched to Inst level not line (which is what the top switch does (slider switch located on the top panel in the middle, used in the earlier model MP1s)) or it may have a dirty switch...
So headphone out works well, it feeds off the output area I think just before top switch attenuation for A/B out

Guit > input > gain (OD1/OD2) > eq > send > rtn > chorus > master vol > front vol > top switch > A/B out...> caps > Headphone out
The signal is split off through some caps to reduce top end (sudo cab sim) to feed the headphone out just before the A/B outs.  The top switch units reduce the A/B output to guit/inst level (to plug into a guitar amp input) or leave it at line level to feed amp returns or power amp inputs.

Logged
Studio Rig: MP2/MB1 > Eurorack UB2442FX-Pro > TC M-One XL > Behringer Truths (with Truth Sub) / QUAD ESL 63s
Live Rig: MP2/MB1 > Alesis Quadverb > Alesis Midiverb 4 > Yamaha AM802 > B200s/Carvin TS100/DCM200L > ADA Split Stacks/Mesa P112s
Pages: [1]   Go Up