I've been reading posts about replacing better quality components on a minidsp 4x10 and wondered if I could do the same with my minidsp 8x12 v2 DL.
I noticed there are x12 Nichicon KC 47uf 25v on the first row which I believe are the coupling caps, and there are another x12 100uf 25v on the second row, but I don't know what those are exactly.
Lastly a shot of what I believe to be the power supply caps
This would be my first time modifying a DSP so any tips would be appreciated.
- Should I first replace all through-hole capacitors with better-quality caps of the same rating? (couplings - Nichicon Muse bipolar)
- Could I replace the power supply capacitors with higher quality ones like the Panasonic Fc?
- Could I replace the JRC2068 opamps with the OPA1642 without additional modifications?
I noticed there are x12 Nichicon KC 47uf 25v on the first row which I believe are the coupling caps, and there are another x12 100uf 25v on the second row, but I don't know what those are exactly.
Lastly a shot of what I believe to be the power supply caps
This would be my first time modifying a DSP so any tips would be appreciated.
My initial impression is I wouldn't dare try something that ambitious - its a lot of parts and even with experience I'd baulk at doing all that without trashing a pad... The surface mount stuff is easy with the proper hot-air workstation, but its fiddly and you need a good magnifier with lighting to make it uneventful. Without a hot-air rework station it will likely go wrong.
Pulling the through-hole caps is not something I'd recommend, especially as you can't snip the leads, the usual prerequisite for clean desoldering of through-hole parts.
And I think those opamps are SSOP8 package, so you are unlikely to find any compatible replacements you'd like. Or at least you are going to have to look carefully of the footprints of VSSOP and SSOP to see if they are compatible.
Pulling the through-hole caps is not something I'd recommend, especially as you can't snip the leads, the usual prerequisite for clean desoldering of through-hole parts.
And I think those opamps are SSOP8 package, so you are unlikely to find any compatible replacements you'd like. Or at least you are going to have to look carefully of the footprints of VSSOP and SSOP to see if they are compatible.
Gotcha,
It is a lot of components to work with, I was planning of using my Hakko desoldering vacuum to get the caps outs. but looking at Opamps yeah its a more daunting task that does require a hot air station. I might just stop at the caps and leave the opamps alone then.
It is a lot of components to work with, I was planning of using my Hakko desoldering vacuum to get the caps outs. but looking at Opamps yeah its a more daunting task that does require a hot air station. I might just stop at the caps and leave the opamps alone then.
Be aware that this is most probably a 4-layer board, meaning there are internal pads and traces you can't get to.
It's an extremely high risk undertaking.
What is your plan in case it doesn't work after you finish?
What's the going rate for a replacement 8 x 12?
Most importantly, what do you expect to gain??
Jan
It's an extremely high risk undertaking.
What is your plan in case it doesn't work after you finish?
What's the going rate for a replacement 8 x 12?
Most importantly, what do you expect to gain??
Jan
Thank you for the heads up on the potential difficulty of the job. Ive considered this and will be sticking to through-hole components if i decide to move forward. I got x3 of these units and doing this purely out of curiosity and testing. I got decent experience working on PCBs and heavily populated boards.
As per gain on this, reduce noise as much as I can and possibly increase fidelity.
As per gain on this, reduce noise as much as I can and possibly increase fidelity.
I doubt either one of those (gains) will be achieved. And, you'll most likely turn a working board into a non-working board in the process.
Unless you're just looking for (de)solderfication practicing, I can't see any worthwhile objective for this sort of modification.
Dave.
Unless you're just looking for (de)solderfication practicing, I can't see any worthwhile objective for this sort of modification.
Dave.
I have very little experience with repair and upgrading. I replaced the output op-amps with Burr Brown Sound Plus. Replaced the electrolytic caps with polymer. And upgraded the power supply caps. So far its the lowest distortion (automotive) DSP I've measured.
The 2068 isn't a TERRIBLE opamp----it's a little slower, noisier, and more distorted than some, but not by a LOT. Certainly a LOT better chip than say, a 4558. I would question whether the spec improvement would be audible.