This is what is under your capacitors. This fluid causes damage in 2 ways. It eats away the gold traces and if it shorts the capacitor out then the amp can catch fire.

M series notes

M25: 25 x 2 (4 ohms); 50 x 2 (2 ohms); 80 x 1 (4 ohms)

M44: 55 x 4 (4 ohms); 110 x 4 (2 ohms); 160 x 2 (4 ohms)

M50: 50 x 2 (4 ohms); 100 x 2 (2 ohms); 200 x 1 (4 ohms)

M100: 160 x 2 (4 ohms); 250 x 2 (2 ohms); 455 x 1 (4 ohms)

This series was designed to be a lower priced alternative to the MS series. The line started with the M-25 that originally came with power and ground wires hard wired and run through a grommet in the cover. They later came out with the M-25 version II, along with the rest of the M line: M-50, M-100, and M-44.

The M series had a few special edition amplifiers: the Bandit (M-50), the Outlaw (M-50 and M-100), and Route 66 (M-25 and M-44).

Many die hard Phoenix Gold collectors consider the M series to be the best sounding amplifiers from Phoenix Gold, ever.

MS series notes

MS series, or Mobile Series included:

MS-250 (2-channel): 50 x 2 (4 ohms); 90 x 2 (2 ohms); 180 x 1 (4 ohms)

MS-275 (2-channel): 100 x 2 (4 ohms); 140 x 2 (2 ohms); 225 x 1 (4 ohms)

MS-2125 (2-channel): 160 x 2 (4 ohms);  255 x 2 (2 ohms): 510 x 1 (4 ohms)

MQ-430 (4-channel):  30 x 4 (4 ohms); 60 x 4 (2 ohms); 100 x 2 (4 ohms)

MS-2250 (2-channel): 340 x 2 (4 ohms); 517 x 2 (2 ohms): 1060 x 1 (4 ohms)

MPS series, or Mobile Professional Series include:

MPS-2220 (2 channel): 22 x 2 (4 ohms); 44 x 2 (2 ohms); 120 x 1 (4 ohms)

​MPS-2240 (2 channel): 32 x 2 (4 ohms); 64 x 2 (2 ohms); 288 x 1 (1 ohm)

​MPS-2500 (2 channel): 85 x 2 (4 ohms); 155 x 2 (2 ohms); 505 x 1 (2 ohms)

MAC series:

MAC200 (2 channel): 60 x 2 (8 ohms); 100 x 2 (4 ohms); 125 x 2 (2 ohms)

MAC500 (2 channel):(est) 160 x 2 (8 ohms); 200 x 2 (4 ohms); 250 x 2 (2 ohms)

​MAQ450 (4 channel): (est): 50 x 4 (8 ohms); 80 x 4 (4 ohms); 140 x 2 (8 ohms)

. The first 50 MS-2250s came in nickel plating, and all MS-2250 originally came with a fan shroud (needed to help with cooling since the heat sink was meant to only cool the MS-2125).

Phoenix Gold also came up with two variants of the MS series. The MPS (Mobile Professional Series) and the MAC series. The MPS line took the MS series and altered them to get rated power at 2 ohms rather than 4 ohms, and were designed to be high current amplifiers (cheater amps) that are capable of running down to 1 ohm mono. The models included: MPS-2220 (derived from the MS-250), MPS-2240 (derived from MS-275), and MPS-2500 (derived from MS-2125).

The MAC series was only sold outside of the United States, and this series was designed to give rated power at 8 ohms rather than 4 ohms. They had 3 models in this line: MAC-200 (derived from the MS-275), MAQ-450 (derived from the MQ-430), and the MAC-500 (derived from the MS-2125).

How do I know if my caps are bad?

If you have the above listed caps then I guarantee they either are already leaking or they will leak shortly. Please have them replaced ASAP!

What replacement caps are recommended?

Any 16v capacitor with operating range of -40-105*C temp range, with a lead spacing of 7.50mm, 18mm diameter, and maximum of 31.5mm height will work. Some amps will work with caps 35.5mm tall (ZX, ZPA, MS) and other can only fit 31.5mm (M, ZXti)

Here is what I use:

31.5mm tall:

Nichicon UHE1C562MHD6: dark blue with silver stripe

                        5600uf; 16V; -40 - 105*

Panasonic EEU-FC1C562: Dark Blue with gold stripe

                        5600uf; 16V; -40 - 105*

35.5mm tall:

Nichicon UHE1C822MHD: dark blue with silver stripe

                         8200uf; 16V; -40 - 105*

Panasonic EEU-FC1C822: Dark Blue with gold stripe

                         8200uf; 16V; -40 - 105*

The suggestion for this page was made by Steve Cross. Thank you for the suggestion as this info should be pretty useful. Any other suggestions, please email me

What about rail caps?

Any capacitor can go bad, and as these amps approach 20-30 years of service it is never a bad idea to replace all caps. That being said, the rail caps are significantly more complicated to replace than the filter caps due to being snap-in style. The opportunity for error and damage to the board is increased.

That being said, they are  not the caps that typically go bad on these amps (powercore capacitors are the exception, they do go bad if you have the 10F or 20F version). If the amp is being fully recapped professionally I would recommend you have the tech inspect the rail caps, but if they are not leaking or damaged(heat is the common damage) then I would leave them alone.


How do I know if I have the original (bad) caps?

The bad caps were Panasonic HF or HFZ series. They are rated 16V, 2200uf, 105*. The HF series are dark blue with silver stripe. The HFZ series are dark blue with gold stripe.

This is a comparison of the origin HF series panasonic (right) and the Nichicon HE series (left).


Copyright ©  Phoenix Gold Registry

 This page was created to compile random notes regarding Phoenix Gold, their amplifiers, and some of the intricacies of their products.

Here is the original HFZ cap on the left vs the new FC cap on the right.

Which amps are effected?

MS series: 250, 275, 430 (MQ), 2125, 2250, FAS, SOFAS, 1000

MPS series: 2220, 2240, 2500

M series: 25, 50, 44, 100, Route 66, Outlaw, Bandit

ZX series: 200, 250, 350, 450, 500, 950, reactor

ZPA: 0.3, 0.5

ZXti: 400, 500, 600, Octane, Outlaw

ZX series notes

The ZX series was the follow up to the MS series. It was their flagship line until being replaced with the titanium series (which was closely related). The series came in two color options, black or white. The models included: ZX-200 (2-channel without crossover), ZX-250 (ZX-200 with a crossover added), ZX-350 (2-channel), ZX-500 (2-channel), ZX-450 (4-channel), and ZX-950 (6-channel, included a ZX-450 and a ZX-500 on one chassis).

While the ZX-950 was not officially a special edition amplifier, they only made 100 of them, making it more rare than the actual special edition ZX amplifier, the Reactor (which also contains the ZX-450 and ZX-500). Due to the integrated fan, these amplifiers had less overheating issues than the MS and M series.

It can be argued that the ZPA series was a special edition of the ZX series. They contained two models: ZPA0.3 (2-channel) and ZPA0.5 (2-channel). They were essentially a ZX on steroids, containing many of the same electrical components, the smallest of the two (ZPA0.3) was equivalent to two ZX500s, although instead of butting together two amps the entire boards were designed to be one amplifier. On this sub-series each model contained 2 fans, and a large plexi-glass display cover for the center portion of the board. They came in default without a built in crossover, but had an optional card that could be swapped in that gave a high-pass/low-pass option with frequency selector. These are also the only Phoenix Gold amplifiers with a 'Balanced' input. The balanced signal could come from any of three options: a TBAt (balanced signal line driver), EQ-232 (30-band equalizer with balanced output), or ZPX2 (a special edition 3-way active crossover with RCA or balanced input and 3 balanced or RCA outputs).