Mesa Boogie Studio 22 mod problem or not?

[Dado]

Hi ,
i need help. i have a studio 22 from 1985, the model without graph. eq. I recently did the lead master and lead drive mod for my 22 and i have 2 pots on the back. As i understood it before i did the mod ( actually i didn´t do it, a technician did it for me) i should have two separate channels now and one pot on the back controls the volume of the lead channel and the second one amount of gain (distortion) on the lead channel. well after i did the mods they do that but are not independent from the master and gain control on the front.When i switch to lead channel it´s not the two pots on the back (mod) that control sound. it´s all four together. Should it be so? because i thought that i´ll get the second total independent channel with gain and volume control?

And also the sound of the clean channel is perfect but the sound of the second channel (overdrive/distortion) is lacking bass in comparison with the clean channel unless i turn it up so the overall volume is loud and then the distortion has good amount of bass, but when both channels are of the same loudness (bedroom playing) the lead channel has much weaker bass and has more of the mids and highs and it´s not beacause of the eq settings cause treble and mids are not turned uo very much (treble 6, mid 4,5).
if anyone has the same amp or if anyone could help me i´d really appreciate it.

Thanks
Cheers Dado

 

[RR]

I'm going to bump up your post so others could chime in.

I read about about the Studio .22 mod to add another volume but did not experience it.

If I'm not mistaken and maybe others could confirm it, the lead channel is still using "cascading gain" and still relies on the pre-amp volume setting and perhaps the Master volume of the 'clean channel' too. So all volume settings(4) still effects the lead channel.

I'm just guessing maybe someone could rebuttal my guess.

As for loss of bass, adding more preamp gain may some lose fidelty.

The Studio .22+ with graphic and maybe the Studio .22 non-plus with graphic has an "Auto EQ' so when you switch from clean to lead channel, the Graphic EQ is activated and depending on your EQ graphic setting, it compensate any loss of bass.

 

[Whoopysnorp]

What you're describing with the interaction between the stock and modded controls is normal. The lack of bass in the lead mode sounds normal to me too, especially if it's more pronounced at bedroom volume. The Studio .22 is an unusual-sounding amp, particularly in its lead mode. I like it, but it's vary unique. Mine seems to really like Strats, and not so much my Les Paul.

 

[selectortone]

I didn't like the lack of bass in my Studio 22+ in Lead mode so I changed C5 (which is the coupling cap that links V1 to V2) to .022uf as I found the stock .001uf cap made the Lead mode too thin.

I've done the gain mod to mine and yes, in Lead mode all four volume/gain controls are interactive - V1 is switched into the circuit when Lead mode is engaged as an extra gain stage right at the beginning of the signal chain. All the controls that operate in Rhythm mode are still in the circuit when Lead mode is engaged.

Love my Studio 22+. I've got several amps and for a small venue it's my favourite.