Modding/tweaking my system


Hi all

I thought I would start this thread almost like a diary.

After living with my system for 12 years, purchased 2nd hand, i find myself wanting to see if i can improve on the sound.

I tried modding a Marantz cd67 player years ago with some success then went too far and wrecked it.

The system is 

Rotel RCD02 cd

Cambridge Audio Dacmagic

RC03pre amp

2 RB03 power amps running as mono blocks

PBC FB1

The first thing I wanted to do was tame the overly bright high end by modding the PMCs to + after years of searching I finally found the crossover layout bought the parts and set about the mods.

1st impressions are the highs are tamed however I have 1 speaker that "sounds" louder than the other, more on that later.

I bought the Dacmagic el-cheapo without the box or instructions. I recently downloaded the instructions and realised the Spdif requires the use of a 75ohm digital cable, I've been using a standard RCA all these years.

The room, HiFi and speaker placement are far from optimal but it is was it is and cannot be changed.

I noted I can feel the CD chassis vibrating with music at reasonable levels so that needs a change.

The overall voicing of the system I would describe as slightly forward with a muddy mid range.

It's the highs and mids I'm looking to resolve.

 

notdeadyet

@millercarbon ty ty ty

Your comment on toe in reminded me of an article where a guy auditioned the FB1s removing a much larger set of PMCs.

The PMC engineer when positioning them had them closer together but with much more toe in than the reference set up.

I've just shifted a bit away from the wall then toed in more than usual and just wow.

Playing my reference back end of the wall I couldn't stop grinning

Things have snapped into position, details never heard before (unless I'm imagining it) bass tighter but remains the same weight. The crashy symbols have shifted backwards allowing more delicate percussion to come to the fore.

Yes its still bright but as you referred to its what I've got.

Rotel kit Fb1s both known as a bright presentation

Now its time to play with those balls

Nobsound springs will allow you to play with loading to tweak the top end down a bit. This will warm up the bass at the same time. Mass loading, adding mass to some of the lighter components like a DAC, is another way of improving bottom end while smoothing out the top. This is all trial and error so can take a fair bit of time and usually no one thing is a silver bullet, but it does add up and you can wind up with a lot better sound in the end.

Thanks millercarbon

The tape you suggested is a bit eye watering! 

Trial and error is the last thing I need, £££s

The Nobsound alone for all components would be £150!

I can re-clock, swap out op-amps and recap for about that price

Do you believe you can over-damp and end up dulling the sound?

Installed the sorbothane hemispheres but had to wind down the volume as even when low the bass can be heard in every room. Can't say if there was a difference other than the a more forward presentation and the bass dropped but that's likely down to the volume at a whisper.

I'll play around with adding toe-in and the bally-bits tomorrow if I find the time.

 

 

 

All good advice thus far. You're going to learn a lot about different damping properties with some of these experiments. Far too many materials over damp, using damping is not the way to tame brightness, Brightness is symptom of something wrong upstream, usually inherent to components and/or parts within components. Need to fix this prior to damping experiments.

 

You're ideas about modding cd player are more on right track. Re-clocking may be problematic, likely present clock circuit won't support clock upgrade. Op amp upgrade may be beneficial, research your op amps, make sure its compatible op amp. Coupling caps good place to start. Discrete voltage regulators can be another nice upgrade. Keep in mind if you're novice, may damage cd player beyond repair if you make mistakes.

 

Not sure you're in position for upgrades in equipment, but that would be of greater benefit than mods. However, if you're intent on mods and learning what they can offer, you're on right track.

The trick with Nobsound, most components will only need 2 to 4 springs per footer, and some only 3 not 4. This leaves you with enough springs to do 2 components per set of 4. Springs fit perfectly into. 1/4" hole. So with a 1/4" drill bit and some wood, MDF, acrylic or whatever you can make your own.

Easily the bargain tweak of the century.

Yes it is very easy to over damp and dull the sound. All these things go a little at a time. Evaluate each step. When something sounds better, listen for what it made worse. Because usually there is a tradeoff with a lot of this stuff. Somewhere. The trick is to avoid using so much that the negatives don't start to outweigh the positives.