Studio .22+ owners please chime in, I need your help

[Mrmot]

Okay guys, lately my amp has started to sound strange and i realized that the problem is somewhere in the preamp since the sound can be heard even when i pull a cable from fx-send to my PC, obviously nothing to do with the poweramp.

- Still, i have changed all tubes in the amp, played with various tubes in all postions and various combinations of tubes and nothing.

- by recommendation of BoogieBabies, sprayed all jacks, tube sockets and pots (except the "lead master" which doesn't have a cavity, so i can't spray it) with contact spray. nothing.

- did the fx-loop test - nothing.

so, next option is changing the "lead master" pot, since the problem sound appears only the lead channel and as you can see in the pictures below, that pot is not the original one on my amp, but some small, rather cheap looking plastic pot.

so, could someone please tell me what does it say on the original "lead master" pot on your amp, or if if you know which value is it?

THANKS A BUNCH!

p.s. yeah, i haven't described the problem. It some strange percussive sound that only appears if the treble is above 8 AND gain below 2, if you raise the gain or lower the treble, it's okay.

 

[Monsta-Tone]

It is a 10k Linear pot.

Send me your email and I will send you a copy of the drawing. You will need Adobe Acrobat to open it though.

As for your mystery sound, you might try re-tensioning the tube sockets, especially V1. I use a set of probes that I bought at Radio Shack (crappy American store), it looks like a bunch of baby dental probes.

Make absolutely the caps are discharged though, or you will get a nasty surprise.


It wouldn't hurt to change the Lead Master pot, but it may be a tube socket problem. Also, you might want to change the filter caps for the Bias and High-Voltage (mains) Power Supplies. These will do funky things when they start to go, and it may be that you only hear it in the Lead channel because you are pushing the amp harder.


Also, just because a tube is new, does not mean that it is good. Try another tube in V1 and see what happens.

Hope this helps.

 

[Mrmot]

It is a 10k Linear pot.

Thank you very much!

Send me your email and I will send you a copy of the drawing. You will need Adobe Acrobat to open it though.

PM sent!

As for your mystery sound, you might try re-tensioning the tube sockets, especially V1. I use a set of probes that I bought at Radio Shack (crappy American store), it looks like a bunch of baby dental probes.

okay, i'll see if i can get them somewhere or maybe taking the amp to a tech for him to do it.. but i think i'll first replace the lead master pot, i really suspect that it might be the problem.. even if it turns that it's not the problem i really feel like i should do it cause god knows which pot the owner before me put in here

Make absolutely the caps are discharged though, or you will get a nasty surprise.

just touching one end of the cap with a screwdriver discharges it, right?

It wouldn't hurt to change the Lead Master pot, but it may be a tube socket problem. Also, you might want to change the filter caps for the Bias and High-Voltage (mains) Power Supplies. These will do funky things when they start to go, and it may be that you only hear it in the Lead channel because you are pushing the amp harder.

yeah, i think i'll first try to replace the pot, then tighten the tube sockets and then replacing the caps. THe thing is that this sound happens only in lead mode but with the gain around and below 2.. if i raise the gain, that sound can not be heard.

Also, just because a tube is new, does not mean that it is good. Try another tube in V1 and see what happens.

i've tried putting different tubes in all positions, and that sound can always be heard....

Hope this helps.

everything helps! thanks a lot! :wink:

 

[Mrmot]

I made a clip, guitar to amp, fx-send to boss ge-7 to line in on my mixer, added cab-sims in cubase. Just to assure you, i've tried different guitar, cables, removing the boss ge-7 and that sound is always there.

clip can be found here: Bad sound

"volume" is actually gain level on studio.22+

************************************************
first take (00:00-00:16)
volume - 1.5
lead master - 8
treble - 6
bass - 8
mids - 7.5

it sounds ok this way cause the treble is on 6

************************************************


second take (00:17-00:34)
volume - 5
lead master - 8
treble - 6
bass - 8
mids - 7.5

same settings as the first clip, only gain raised to 5, also sounds ok

************************************************

third take (00:34-00:57)

volume - 1.5
lead master - 8
treble - 8.5
bass - 8
mids - 7.5

here's the problem! hear that nasty mid-hi percussivness? in this take you can also hear how i raise the gain to around 5, and then the "noise" is non-existant

************************************************

fourth take (00:57-01:17)

volume - 1.5
lead master - 8
treble - 10
bass - 8
mids - 7.5

treble maxed, gain still on 1.5

************************************************


fifth take (01:17-01:36)

volume - 1.5
lead master - 8
treble - 10
bass - 8
mids - 7.5

treble maxed, gain going from 1.5 to 5

************************************************


sixth take (01:37-02:04)

volume - 1.5-5
lead master - 8
treble - 8.5
bass - 8
mids - 7.5


this is the clip without the Boss GE-7 graphic eq. I start with gain on 1.5 and later on put it on 5

************************************************


seventh take (02:05-end)

volume - 1.5
lead master - 8
treble - 8.5
bass - 8
mids - 7.5

Clean, first with eq, than without and then again with. I see nothing wrong with how this sounds.


************************************************

 

[Monsta-Tone]

The screwdriver trick is really a bad idea. You can seriously burn something in your amp if the caps have too much of a charge on them.


I read somewhere that this was written in an old book that was supposed to be the holy grail of tube knowledge.\




I have a 1k, 5 watt resistor that I use. It has an alligator clip lead on each end. This will allow you to discharge it safely. Otherwise, you are basically running the chance of arc welding something.