Studio .22+

[Dinoss101]

I have a Studio .22+ that is use for amplified harmonica. I notice that if I try to get too much volume out of it that the amp seems to have some kind of a built in circuit breaker, where the amp cuts out for a while. If I go to standby and back, it starts working again. Then if I bring the volume down, it doesn't happen again. It only happens with a mic plugged in, I never see this happen with a guitar plugged in.

Does anyone know if it is somekind of overload protection on these amps?

 

[Mrmot]

Hey man, did you get my email? I'm asking cause I got no response. Nevermind, I'll write again. I really don't think that there is some sort of "circuit breaker" like you say, or I haven't ever heard of something like that. Maybe the problem is the different impedance or whatever from the microphone, maybe the mic you use needs phantom power, I really don't know. Hope someone else will help you. :wink:

 

[Dinoss101]

No I never got your email. Thanks for your response here though.

My microphones are both hi impedance bullets and work fine with my other amps. The Studio .22+ has a built in graphic EQ, that's where I first noticed the "cutting out" problem. When I have the graphic EQ and auto EQ turned off, I can put the gain up and get a good amplified harmonica sound, if I try to get a little more umph out of it, it starts the "cutting out" problem. I think I mentioned that when I plug a guitar in, which has much lower output than the microphone, I never experience the problem.

I've tried to poll other harmonica related online groups but most harp players avoid the Mesa Boogie amplifiers and prefer older vintage tube amps (like Fender, Gibson, Premier, Silvertone, ...).

I haven't tried putting in a 12AU7 or lower gain preamp tube yet, it's kind of a pain to get the tubes in an out. It's on my list of things to try when I have time during the day so I can crank the amp up and see what a lower gain tube will do. I did this on a Fender Pro Jr and it really increases volume before feedback with a microphone for amplified harp.

 

[Monsta-Tone]

It sounds like you are making the EQ circuit "Clip." Maybe the signal is too hot for the circuitry.

Did you try the lower gain tube? It just might do the trick.

 

[6L6C]

Hi
I use to own the same amp (sold it and kick myself in the *** ever since) but when I first got mine I use to have strange intermittent problems also. Mine where across the board did not mattered what was plugged in but had allot more problems if the EQ was engaged. At first though it was heat so put a fan back there, was perfect for a while (2 or 3 days) but started again. But there where less drop outs with the fan in the back
Long story short took to my local tech there was a bunch of bad solder joints he corrected them and the amp was flawless the three years I owned the amp.

Although our problems are not identical the reason I’m writing: my tech had told me that he had done allot of 22,s with bad solder joints.

BTW I left the fan in the amp after the problems where corrected, that little sucker use to get hot as hell.

OO I use to be able to put the amp on standby for 15-30 sec’s and get my sound back also

 

[Dinoss101]

Hi 6L6C,

Thanks for your response. I spent some time with the amp this weekend. I swapped V2 preamp with a 12AU7. This seemed to make the problem worse, in fact it was happening with the guitar now. I got to thinking that maybe I should replace the power tubes. I put the EL84's from my Fender Pro Jr into the Studio .22+ and that turned out to be the problem. This amp really sounds good for amplified harmonica! I just can't figure out how to use the lead channel, it sounds really good on the rythm channel, I guess that's as good as it gets. I seems louder than 22 watts to me. I'm planning to take it to a blues jam this Thursday night and see if it can hold it's own in a small club.

 

[Dinoss101]

Hi Monsta-Tone,

Wow I didn't get a notice of your post. I had the same idea you had about using a lower gain preamp tube. It turns out there was nothing wrong with the EQ, it just caused the bad EL84 to act up worse.

I'm not sure what kind of tubes to get, the Fender Chinese tubes sound pretty good. Maybe I'll put the new tubes in my Pro Jr and leave the Fender tubes in the Studio .22+.

Thanks for the help!