I request pleased help for your little advice or guidance with a Studio Projects VTB-1 purchased Used (online on foreing country).
I have spent my low budget in this. I am no specialist or electronic, just a poor fool who has been deceived. I decided to learn and change the damaged pieces, but I am not able to identify. I don't have tools for that. everything I've learned has been last two weeks reading every night thousands of threads and component manufacturers informations on internet. Next days will buy a 15w soldier and I will buy the cheap parts on the repair shop.
I've received and the tube circuit does not work. I have a behringer mic2000 and I changed the tube and either the same (work in mic200). without tube gain works perfect. when it comes to the 4 o'clock (right on tube blender) turns off complety the output signal. the insert path works perfect but the line/out loss the signal. I have completely removed the tube and does the same, I think that any component of the tube circuit was damaged but other components are fine.
Theseller (now not give more information) said that he put a phillips 5751 tube, but came with with a Sovtek 12AX7. I think that this damage the tube circuit, because I found in a tubestore page info about phillips 5751, and warning about this tube soft the signal 30% but force the power circuit.
on: http://bounav.free.fr/wp/?s=vtb1 I found a img of the board but is not the same.
The board say "JRP PROD RUN REV-B DEC-01" and all of the opamp are BB OPA2134PA in U1, U6, U2, U5 (I have many nights reading) there are many capacitors and other parts. the board does not appear modded or tampered with, just seems to change the valve and said before send me.Highlights near the tube a three-legged piece indicating 7812ct. At the store, their try to help me little free, but don't know this device and only guided me telling me to prove if this piece was put on a burn. after 12 hours on, all components are cold and not smell burned. is over all the help I can get.
I'veseen on your site that you are a specialist in these questions. if it does not involve any discomfort, you could tell me which part or parts group might try to replace myself?
What would be the most probable components to replace?
I thank you for listening only, and apologize for any inconvenience.
PS: I am very happy found this forum,. I read read read... superb. I think about to learn and begin my DIY's.