Different density/presence boards

[Spencer4hire]

I have 2 RM100s. One of the first ones and a newer version. The old one always sounded like it was missing something. Not crisp and bright sounding no matter where the presence was set. The density knob just made it sound booming and muddy. I talked to Rob (Jaded Faith) and he talked me into pulling the boards and taking some pictures to get the pot values so I can switch the parts on the old board to get that amp to sound as good as the new amp. Here are some pictures if anybody is interested.
Old board

New board

 

[m0jo]

Nice, finally some clear info on this!
But are the caps the same values though?

 

[Jaded Faith]

I'll be offering this conversion as a service for those interested but not wanting to do the work themselves. Email me for details.

 

[Kapo_Polenton]

Good point Mojo.. what is the cap value? This could be a HUGE reason as to why some people absolutely hate their RM100's or note that they are woofie.

 

[Spencer4hire]

If the orange/rust colored lumps that look like candy are the caps I couldn't see any values or writing on them. The board is going to Rob this week!

 

[m0jo]

If the orange/rust colored lumps that look like candy are the caps I couldn't see any values or writing on them. The board is going to Rob this week!

They are As are the black/grey cylinders.
Could you take a pic from the side maybe?

 

[Spencer4hire]

The cap and resistor values are obscured or blocked by the pots. When Rob replaces my stock ones I will see if he can let me know what they are.

 

[m0jo]

The cap and resistor values are obscured or blocked by the pots. When Rob replaces my stock ones I will see if he can let me know what they are.

Okay thanks for checking.

 

[Disciple]

The cap and resistor values are obscured or blocked by the pots. When Rob replaces my stock ones I will see if he can let me know what they are.

Dental mirror

 

[Anomaly]

I have 2 RM100s. One of the first ones and a newer version. The old one always sounded like it was missing something. Not crisp and bright sounding no matter where the presence was set. The density knob just made it sound booming and muddy. I talked to Rob (Jaded Faith) and he talked me into pulling the boards and taking some pictures to get the pot values so I can switch the parts on the old board to get that amp to sound as good as the ]

Never played RM100's does RM22's have the same presence issue?

 

[Spencer4hire]

Never played RM100's does RM22's have the same presence issue?[/quote]

I would of thought Randall would of fixed the issue by the time they made the RM22s. I had an early RM20 combo that had the same issue. I have a RM20 head that sounds perfect and I never could get the 2 amps to sound the same through the same cabinet with the same module and tubes. The combo would just sound "woofy" if you barely turned up the density knob.
The presence controls crispness just was missing.

 

[Anomaly]

What about RM50's?

 

[iekobrid]

I would of thought Randall would of fixed the issue by the time they made the RM22s. I had an early RM20 combo that had the same issue. I have a RM20 head that sounds perfect and I never could get the 2 amps to sound the same through the same cabinet with the same module and tubes. The combo would just sound "woofy" if you barely turned up the density knob.
The presence controls crispness just was missing.

Sounds like my RM20 combo too. Turning up the density and presence knobs has no effect below 9 o'clock and 3 o'clock respectively, but then any higher is instantly WAYTOOMUCH.

 

[Jaded Faith]

My impression is that it's an amp-by-amp issue based on time of manufacture more than what kind of amp you have. I wish I could pinpoint when the change occurred but that's really hard to do. Safest assumption is the newer your SN#, the more likely you are fine.

The test is simple enough though: do the knobs do much of anything before 2:00 and come on WAY too quick from there on?

 

[Kapo_Polenton]

Pretty sure my Lynchbox has this issue.. I think it is the ALpha vs. linear pot and the value of the POT that is making the diff here. Would you agree Rob? Below 2 p.m my presence is useless to me. What are you charging for this mod? I haven't opened my amp yet, does the presence board disconnect easily?

 

[Whoopysnorp]

So does this mod get you tones that aren't available on amps that are affected by this issue, or is it simply a question of where the dial is for a good clear tone? I must say I have been having issues with my RM100 sounding woolly compared to my Mesa Mark III and my Rivera M100.

 

[Anomaly]

Was looking to buy an RM50 there's a way to find out which serial# does and does'nt have this issue? What about Eggy Mod50's?

 

[GuitarGuyLP]

This is interesting. I have an older RM50 combo, and I am getting a new RM50 head on Tuesday. I am going to compare the two boards. I think that my combo has the older style board. It does not make too much of a difference. I will check, and post pics, and pot, and cap values.

 

[MarcoR]

Was looking to buy an RM50 there's a way to find out which serial# does and does'nt have this issue? What about Eggy Mod50's?

I do not have this issue with my MOD50. It's from 2007.

 

[Spencer4hire]

I want to try and clarify a little about the sound/tone of the different boards.
Some people are saying what difference does it make if you have to set the knobs at different positions to get the same sound but what I am saying I
that with the defective/improper loaded board it never sounds like it should.
The amps sound like they are bound up and all the tone and power can't get out. Regarding the Egnater amp I am sure Bruce knew what parts to put in his amps. Randall not so much.