How to add darkness to a Brighter Jmp Cameron Aldrich?

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adrianher

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Hi guys. I have 3 Cameron's Marshall's but I find my Aldrich JMP too bright at high volume.

It sound amazing at TV volume but it's crap when I crank it. I've turned down presence and treble at 0 and it's still very bright. My LP using the neck pickup sound as my fender stratocaster.

Power cords sound really good but when soloing around 12th fret sound as sh#t, very bright, full of treble and you can hear that noise when pick hit the strings.

I've tried differents preamp tubes, It has now an RFT at v1, RCA nos in V2 and Chinese I'm v3.

Also tried differents power tubes and same results.

I've sent a mail to Mark and he told me to replace all filter caps since it were the original ones. I've changed the 6 and replaced them for JJ 50+50uf 500v.

The amp has more balls but is still full of treble.

Can anyone suggest me anything to try? Maybe change any resistance or a cap to make it darker?

Adrian
 
Man I don't know about changing anything in that circuit..maybe try darker speakers? I think there's a RTer selling old school G12-80 celestions. I had a quad and they were definitely darker than V30s or G12 65s for that matter..but sounded nice and still had good mids...I know when I've had a Cameron I threw a boost in front to change it up and add some lows but it didn't sound anywhere near as good as just plugging straight in. Good luck!
 
What kind of speakers do you use?

The Duncan Custom Custom is supposedly good for fixing what you describe about the lead playing.

JJ preamp tubes..?
 
I forgot to say, sorry, I use a multi amp w/d/w rig.

With this issue I've tested it only with guitar without no effects to see what could be going on. I've tested it with greenbacks, g12t75, and g12h30 speakers. Even with g12t75 (which I personally find it my darknest cab) it lose enought treble.

I've recently bought. 4x 12ax7 JJ preamp tubes, I'll give it a try and let you know.

About eq in the loop, maybe that could be the solution, I didn't think about it. BUT, it's really a crap using an fx to make a Cameron amp sound good. I believe there would be a component to be replace to decrease the treble, who knows.

I don't know what the bright cap is and how to clip it, what do you mean? Do you mean that cap in vol pot which gives treble at low vol and which decrease when you turn the vol at max?

Thanks a lot guys
 
Well those speakers to me are very bright to begin with. The newer Chinese GBs are extremely bright to me, couldn't wait to offload those. Unless you have an 80s cab the 75s are all treble and bass, and the G12 H30 also seemed pretty bright to me. I would shoot for a darker cab/speaker combination and see where you're at, maybe you can try out some different cabs? I had a Vintage Modern cab with the G12 C greenbacks and they are much different than the G12 Ms. Very smooth and pretty dark. G12 65, G12 80...those are also darker than the speakers you have now IMO.
 
I'm wondering why my other amps sound amazing with all cabs and this not.
 
There is some issue with the amp, bring it to a qualified tech and show him the problem, he should be able to offer solutions.
 
adrianher":2m4h6jbo said:
Hi guys. I have 3 Cameron's Marshall's but I find my Aldrich JMP too bright at high volume.

It sound amazing at TV volume but it's crap when I crank it. I've turned down presence and treble at 0 and it's still very bright. My LP using the neck pickup sound as my fender stratocaster.

Power cords sound really good but when soloing around 12th fret sound as sh#t, very bright, full of treble and you can hear that noise when pick hit the strings.

I've tried differents preamp tubes, It has now an RFT at v1, RCA nos in V2 and Chinese I'm v3.

Also tried differents power tubes and same results.

I've sent a mail to Mark and he told me to replace all filter caps since it were the original ones. I've changed the 6 and replaced them for JJ 50+50uf 500v.

The amp has more balls but is still full of treble.

Can anyone suggest me anything to try? Maybe change any resistance or a cap to make it darker?

I don't read too good...

Steve
 
ADD a cap over the mid pot like the 2204 combo's had. That will tame it and fatten it a tadd. 4700pf.

This comes up a lot when discussing why the combos were "darker" , see here a pic from someone's amp:

https://s55.photobucket.com/user/pixpics ... s.jpg.html

I found when tweaking and adding bypass caps to that circuit in the preamp, stuff can get mighty bright on an already bright circuit. That little cap balances well. Sometimes it can make the amp sound a little too dull and hence experimenting with diff values. I have it on my 4010 combo with tweaks to the preamp and it really works, sounds great. I may take it down to a 2500pf but without it, the tweaks I made make the amp too bright.
 
How long have you had it? Has it always been this bright? Maybe something is wrong with it.
 
Lower the negative feedback resistor to as low as 27K. That will take out brightness and keep the amps feel.
 
parntz145":xhou69hq said:
Lower the negative feedback resistor to as low as 27K. That will take out brightness and keep the amps feel.

By lowering the value of the N.F. resistor, you are actually increasing the amount of N.F. in the amp, correct ? Would you say this will 'tame' the amp a bit ?
 
JJs ??



Barring that and the EQ in the loop trick I'd send it to Mark and let him.....wait no.

PS: +1 to the Custom Custom
 
first thing id look at would be speakers, then tubes, then possibly a eq like previously mentioned...LAST case scenario would be to get it modded
 
adrianher":3s5r35cv said:
Hi guys. I have 3 Cameron's Marshall's but I find my Aldrich JMP too bright at high volume.

It sound amazing at TV volume but it's crap when I crank it. I've turned down presence and treble at 0 and it's still very bright. My LP using the neck pickup sound as my fender stratocaster.

Power cords sound really good but when soloing around 12th fret sound as sh#t, very bright, full of treble and you can hear that noise when pick hit the strings.

I've tried differents preamp tubes, It has now an RFT at v1, RCA nos in V2 and Chinese I'm v3.

Also tried differents power tubes and same results.

I've sent a mail to Mark and he told me to replace all filter caps since it were the original ones. I've changed the 6 and replaced them for JJ 50+50uf 500v.

The amp has more balls but is still full of treble.

Can anyone suggest me anything to try? Maybe change any resistance or a cap to make it darker?

Adrian
Not sure how much goop he has on the pretube sockets. I would add a silver mica 500v cap across the V1 plates. Probably start with 33pf and go up from there. You can try a cap across V2 and the PI just to see if one sounds better in a particular spot. You can just carefully clip the cap in or bend the legs around the pin. If it works then solder it in. Pretty easy.If you add one across the plates of the PI also. The amp probably has teh 47pf already there on the board. If you add another across the socket it will increase the capacitance over the 47pf as caps in parallel increase in value where resistors decrease.
 
I had a cameron aldrich that was bright as fcuk and I believe it was down the amp having orange drop capacitors all over the circuit board
 
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