Boost on RM22 sounds too dark and compressed

[metareal]

Hi All,

I am the happy owner of an RM22, which I love!

The only thing that kind of bugs me about it is that the boost function on both channels sounds very dark and overly compressed when engaged. I have had this amp from new and the sound has always been like this.

I know that the boost is pre-preamps and that it uses a 12AX7, which may be the problem as I have not tried to swap it out yet.

What I wanted to know from other RM22 owners is whether your boost circuit also sounds quite dark and compressed.

Thanks
Ed.

 

[hunter]

I find the boost pretty useless. Instead I use different booster pedals in the loop.

 

[crankyrayhanky]

:lol: I love the boost for leads on my rm20

 

[k9blek]

I have found the same on my RM22. I find the boosts useless on my modules as it's too compressed. Please let me know what you find out if you change that tube and it makes a difference.

 

[Ampoholic]

Same here. I use pedals for boost.

 

[metareal]

I end up having to use a pedal too, which is a shame considering we have such a nice feature built in.

From having modded other amps in the past I feel the problem may be related to the boost circuit having too much bass. When you dont roll off bass early in the signal chain you end up with a mushy tone like that...

 

[nomad100]

I don't have a schematic of the amp, but couldn't you just change caps on the cathode of the boost stage and remove some of the bass?

 

[metareal]

I don't have a schematic of the amp, but couldn't you just change caps on the cathode of the boost stage and remove some of the bass?

Yes! Definitely!

I just wanted to know if it was a common thing with the amp first and if anybody has ever tried to do anything about it (valve swap or whatever)

Cheers
Ed

 

[JKD]

I can't find a happy medium on volume / gain boosted vs unboosted and find it much easier to use pedals to boost.

Sound seems to muddy up when adding gain via the boost, even tried different tubes even though not 100% sure which one drives the boost.

 

[metareal]

I will investigate more and report back!

I had a quick look the other day, but gave up in the few minutes I had because it is actually not that easy to take the RM22 out of the chassis!

Ed.

 

[rhequiem]

I have an RM22 in-route, and the dedicated boosts per/channel were a big part of the reason I bought it. It's unfortunate to hear that they don't appear to be too usable. Would love to hear people's experiences/suggestions with modding the RM22 to make the boosts useful. Don't give up, metareal

 

[GtrGeorge!]

Im VERY interested in this,as well.
Iam buying an RM22 and if you guys find a way to make the boost better please share!!!!!
GtrGeorge

 

[hunter]

would this help?

(RM22 schematic - or part of it)

http://www.thegutbusters.com/temp/Schematic.pdf

 

[Julia]

The pedal route is the least invasive and safest way to make a boost.

 

[Daryl]

The pedal route is the least invasive and safest way to make a boost.

Not to mention BEST way!! You get to choose the right boost or OD for the particular job you are working on.

 

[GtrGeorge!]

Yeah,
a pedal boost has advantages...but set-up time is lengthened, you now have less floor space, you have to worry aboutbatteries (whhich over a year adds up..and they are nasty for the environment).

Hows about this CRAZY notion..
how about a boost that works properly in the rm22???
You know, just adds some volume to what you already have???


..How weird, it could appear to some that I am off topic.

The truth is, Bruce or whomever should have corrected the darkness thing before they mass produced the amp.
GtrGeorge

 

[nomad100]

plus you have to turn the boost off and switch channels at the same time.

 

[Daryl]

Yeah,
a pedal boost has advantages...but set-up time is lengthened, you now have less floor space, you have to worry aboutbatteries (whhich over a year adds up..and they are nasty for the environment).
GtrGeorge

No worries about battery power, George. :wink: Energizer has some new rechargeable batteries out there that work great. Check em' out.
http://www.energizer.com/batteries/rechargeable/Pages/9v.aspx

 

[GtrGeorge!]

Daryl,
thanks for the link I will have to look into those batteries. About 2 years ago I tried rechargeables..but they werent up to snuff...short usable time..long recharge time and even when fully charged not enough power to for some applications (Digital camera wasan epic fail).
But maybe they've gotten it right, now...I will look into it.
Thanks again
GtrGeorge