So I made this post in 2017: output boost mod and thought I'd come full circle (almost) a decade later with the following proposition.
Now many of us know not to fully trust in AI, so I hope i've come to the right place and ask some clever individuals if this would be a 'good' or 'bad' idea. Basically, I want to refresh the MPC3000’s audio front end and power for the converters – not a full recap, but targeted ‘audiophile-ish’ parts.
(I've also uploaded the schematics below)
P.S. I know this is not an Audio/sampler forum, but I feel you guys can chime in with an unbiased opinion.
Any input is greatly appreciated. Thanks in advance.

So this was the TLDR recommendation:

• Swap all record + output op-amps for TI LME49720NA.
• Replace all audio-path electrolytics on AD/DA + BDACS boards with Elna Silmic II / Cerafine (values mapped as above).
• Refresh the analog PSU caps with Panasonic FC 470µF/25V and 2200µF/35V.
• Renew the 5 V / ±12 V regulators with modern TI parts.
• Upgrade the 8-out 100 Ω series resistors to Vishay CMF55 metal-film.”

1. What to replace (concrete targets)

To get audible improvement without going insane / risky:

A. Audio op-amps (record + 8 outs) – highest impact

Goal: lower noise, cleaner transients, better stereo image.

• Replace all dual audio op-ampsin:
  • Record input / main analog input stage
  • Individual outs / stereo out driver stages (BDACS / AD/DA boards)
• Choose: Texas Instruments LME49720NA/NOPB – high-end audio dual op-amp, DIP-8. (DigiKey)

Qty assumption: ~6 dual op-amps total across record + main outputs on a typical MPC3K.

B. Audio-path electrolytics (record + outs)

Goal: lower ESR, more stable, nicer “hi-fi” voicing.

Target all electrolytic caps that sit directly in the audio path or as local decouplers around those op-amps:

• Input coupling caps
• Output coupling caps
• Local rail decoupling right next to op-amps

Premium choices from TubeAudio AU (all in stock at time of lookup):

• Elna Silmic II 220µF 16V Radial – silky, warm; great for coupling & local decoupling. (tubeaudio.com.au)
• Elna Cerafine 100µF 25V Radial – tighter, punchier; good for rail decoupling & some coupling spots. (tubeaudio.com.au)
• Elna Cerafine 220µF 10V Radial – for any 220µF parts sitting on low-voltage analog rails. (tubeaudio.com.au)

Qty assumption for audio section:
Roughly 20–24 audio-relevant electrolytics split across record + 8-outs.
I’ve allocated:

• 12× Silmic II 220µF/16V
• 8× Cerafine 100µF/25V
• 4× Cerafine 220µF/10V

C. PSU analog electrolytics + regulators

Goal: quieter ±12 V and 5 V rails feeding the audio / converters.

1. Analog rails decoupling / mid-sized bulk
   • Replace 470µF-class caps sitting on ±12 V near the audio boards with:
   • Panasonic FC 470µF 25V Radial 105°C (TubeAudio AU). (tubeaudio.com.au)
2. Main analog PSU reservoirs
   • Replace the big electrolytics feeding the ±12 V analog rails with:
   • Panasonic FC 2200µF 35V Radial 105°C (TubeAudio AU). (tubeaudio.com.au)
3. Linear regulators (keep it simple and robust)
   From DigiKey AU (all TO-220 through-hole):
   • +5 V: TI LM78M05CT/NOPB 5 V / 500 mA. (DigiKey)
   • +12 V: TI LM7812CT/NOPB 12 V / 1 A. (DigiKey)
   • –12 V: TI LM7912CT/NOPB –12 V / 1.5 A. (DigiKey)
4. Your tech must:
   • Verify pinouts vs originals
   • Reuse or improve heatsinking
     But these are very standard swaps.

D. 8-out series/output resistors

Goal: super-stable output impedance and top-shelf parts right at the jacks.


Replace the 100 Ω series resistors on each of the 8 individual outs with:

• Vishay CMF55100R00FKEB – 100 Ω, 0.5–0.6 W, 1% metal film. (Arrow Electronics)

Not crazy boutique like Z-foil, but genuinely premium and easier to source.


2. Combined parts & price list (approx, no spares)

Assumptions:

• Quantities are designed to match likely positions (no deliberate “extra”),
  but you must have your tech confirm counts against your specific board revision.
• Prices in AUD, approximate, per-piece retail at time of lookup (GST-inclusive where given).

You can paste this table straight into Excel (split on |):

Shopping cart (parts + price)

Stage / Area	Supplier	Part	Qty	Unit Price (AUD)	Line Total (AUD)	Notes
Audio op-amps (record + outs)	DigiKey AU	LME49720NA/NOPB (TI) – dual audio op-amp DIP-8 (DigiKey)	6	13.87	83.23	Replace all dual audio op-amps on AD/DA + BDACS/audio boards (record + 8-outs). Price from DigiKey AU “with GST”.
8-out series resistors	Any (Arrow / Farnell etc.)	Vishay CMF55100R00FKEB – 100 Ω 1% metal film (Arrow Electronics)	8	≈1.25	10.00	One per individual out. Price estimated from ~US$0.83 each → ~A$1.25.
Audio caps – coupling / local (bigger)	TubeAudio AU	Elna Silmic II 220µF 16V Radial (tubeaudio.com.au)	12	4.00	48.00	Use anywhere you have 220µF/≤16V in audio path or local decoupling (record + 8 outs).
Audio caps – rail/decoupling	TubeAudio AU	Elna Cerafine 100µF 25V Radial (tubeaudio.com.au)	8	4.00	32.00	Swap 100µF/16–25V caps around op-amps & filter stages.
Audio caps – low-V bulk	TubeAudio AU	Elna Cerafine 220µF 10V Radial (tubeaudio.com.au)	4	3.00	12.00	For 220µF caps on low-voltage analog rails (e.g. near DAC/ADC refs).
PSU analog decoupling	TubeAudio AU	Panasonic FC 470µF 25V Radial 105°C (tubeaudio.com.au)	4	1.00	4.00	For ±12 V rail decoupling near the audio boards.
PSU main analog reservoirs	TubeAudio AU	Panasonic FC 2200µF 35V Radial 105°C (tubeaudio.com.au)	4	2.50	10.00	Replace the big electrolytics feeding ±12 V analog rails.
PSU 5 V regulator	DigiKey AU	LM78M05CT/NOPB (TI) 5 V / 500 mA reg, TO-220 (DigiKey)	1	2.25	2.25	Replace existing +5 V linear reg feeding digital/ADC sections, if compatible.
PSU +12 V regulator	DigiKey AU	LM7812CT/NOPB (TI) 12 V / 1 A reg, TO-220 (DigiKey)	1	3.14	3.14	Main +12 V analog rail reg.
PSU −12 V regulator	DigiKey AU	LM7912CT/NOPB (TI) −12 V / 1.5 A reg, TO-220 (DigiKey)	1	2.57	2.57	Main −12 V analog rail reg.

Approximate grand total (parts only)

If you add all those line totals:

• Total ≈ A$207.20 (plus shipping from DigiKey + TubeAudio + whoever you use for the Vishay resistors).

If you've read this far. Thank you again I really appreciate it.

 

You are effectively asking people to predict the performance of the updated system and compare it with its current state.

I doubt anyone can do that, you might was well pick up an identical unit from ebay, do your upgrades and then compare their performance.