Product Archive

MS-2250

High-output MS-series model with archived owner manual and strong collector/restoration interest in vintage Phoenix Gold circles.

Specifications

Output Power (4 ohm @ 12.5/14.4V): 250/340 WRMS x2
Output Power (2 ohm @ 14.4V): 520 WRMS x2
Output Power (4 ohm bridged @ 14.4V): 1050 WRMS x1
Frequency Response: +/-1dB from 20Hz to 20kHz
Signal to Noise Ratio: >100dB
Input Sensitivity: 200mV to 5V (manual reference)
Input Impedance: 10k ohms (manual reference)
Typical Idle Current: 3A
Power Supply Efficiency: >80%
Damping Factor: >400 @ 60Hz into 4 ohm
Maximum Battery Voltage: 15.5V DC
Minimum Impedance: 2 ohm stereo / 4 ohm bridged
Amplifier Dimensions: 17.0"L x 11.4"W x 2.4"H
Fan Shroud Dimensions: 25.5"L x 11.75"W x 3.35"H

Visual Identification Notes

Fan-shroud references appear frequently in historical discussion and ownership records.
Manual pages in gallery support panel/control identification.
Capture condition and configuration details before restoration changes.

Known Issues

Supply-stage wear and thermal cycling in long-served units.
Missing original accessories (e.g., shrouds) is common in present-day listings.

Recommended Service Actions

Run controlled startup and validate rail symmetry before full-load testing.
Inspect thermal path and output-stage health before recalibration.
Archive provenance notes and measured performance data after service.

Parts List

Main power reservoir capacitor (4700uF / 50V class)
Original: 4700uF 50V radial electrolytic (legacy OEM variant)
Replacement: 105C low-ESR radial capacitor, matched lead spacing
Verification: Community Verified
Dual op-amp for preamp / crossover stage
Original: Legacy dual DIP-8 op-amp (marking varies by production run)
Replacement: Low-noise audio op-amp DIP-8
Verification: Proposed

DigiKey Recommendations

4700uF 50V low-ESR radial capacitor
DigiKey: P12345-ND
Placeholder DigiKey reference. Confirm ripple current, lead spacing, and can diameter against board footprint before finalizing.
Open DigiKey reference
Audio-grade dual op-amp replacement
DigiKey: P23456-ND
Placeholder DigiKey reference. Verify stability and compensation in original circuit before bulk install.
Open DigiKey reference

Related Repair Guides

Signal-path noise diagnosis (generic workflow)
Template process for hum, hiss, and channel imbalance root-cause analysis before replacing semiconductors.

Related Forum Threads

Catalog scans and ad archive (contributor thread)
Crowdsourced scan quality standards and indexing conventions for source documentation.
Route 66 recap BOM sanity check
Community checklist for capacitor substitutions, lead spacing, and verification photos.

Gallery

MS-2250 amplifier photo
Archived MS2250 product photo from Phoenix Gold FAQ MS/MPS page.

MS-2250 manual cover
Owner-manual cover extracted from archived PDF for visual identification and layout reference.

MS-2250 manual page 2
Manual interior page used as technical and historical reference material.

MS-2250 manual page 3
Additional manual page for control labels, tables, and period styling details.

Historical Notes

MS-Series Manual Archive Baseline
The Phoenix Phorum manual archive includes original MS-series documentation for MS250, MS275, MS2125, and MS2250, while the archived Phoenix FAQ indicates a 1992-1995 MS/MPS production window.

Source-Backed Verification

MS-Series archived FAQ specs and timeline
Cross-checked
- The FAQ provides per-model output tables for MS250, MS275, MS2125, and MS2250.
- The page states MS/MPS production years as 1992-1995.
- The FAQ distinguishes MS as high-impedance-optimized and MPS as low-impedance-optimized designs.
Source: Archived Phoenix Gold FAQ - MS/MPS Amplifiers
Open source page
MS-Series models with archived owner manuals
Cross-checked
- Manual index lists MS250, MS275, MS2125, and MS2250 owner manuals.
- The same directory also includes MS TA documentation and MAC-200 reference material.
- Archive PDFs provide direct model-specific material for visual ID and technical page expansion.
Source: Phoenix Phorum Manual Archive - MS/MAC Amps
Open source page
MS-2250 special series context
Imported - Needs Primary Verification
- MS-2250 is described as based on the MS-2125 with increased output capability.
- The source mentions fan shrouds as part of the original package and notes many are missing today.
- Source data suggests around 1000 units while explicitly noting official production numbers were not published.
Source: Phoenix Gold Registry - MS-2250
Open source page
MS-1k high-power context
Imported - Needs Primary Verification
- MS-1k is described as a dual-MS-2250-derived platform on a single heatsink.
- The source references a limited run of around 100 units and notes serial behavior differences across early and later units.
- The source describes winding-color variation across units (green and later red transformer windings).
Source: Phoenix Gold Registry - MS-1k
Open source page

Sources / Notes

Archived Phoenix Gold FAQ - MS/MPS Amplifiers
Primary source used for MS2250 output table values and product photo.
Open source
MS2250 Owner Manual
Primary manual source used for shroud dimensions and electrical-limit details.
Open source
MS-Series Manual Index
Directory listing confirms archived MS-series documentation.
Open source
Phoenix Gold Registry - MS-2250
Contextual historical notes only; registry owner/serial rows excluded.
Open source

Model Disclaimer Block

Repair information is provided at user's own risk. Verify all measurements and polarity before power-up.