McIntosh A-129 Mono Tube Amplifier - Super Rare - All Original and Unrestored


The McIntosh A-129 appears to be a modified version of the MC75 for commercial use. The silk screen on the chrome reads: "Square D Specification #30522-503-50"

This amplifier is unique in that both the power and speaker output connections are located on the external barrier strip. The normal convenience outlet, octal socket, and power cord are absent.

The output transformer is identified as: McIntosh Transformer Type 043-343. It looks like only one speaker tap is present on the transformer, and we are not sure of its exact output impedance.

The amp was brought up (powered on) very slowly on a variac and does show signs of life. Plate voltage and negative bias voltage are both present and it does pass an audio signal, though it is very distorted.

We have opted to leave this super rare and unique piece in its original "as found" condition for the time being. But are open to restoring it to working condition for a separate fee if desired. Please give us a ring to discuss (201-879-0000 x101).

The original set of tubes that were found with this unit include a nicely testing Telefunken 12AU7, RCA 12AX7's and a single RCA 12BH7, and a pair of original Genalex Gold Lion KT88. All tubes tested on the weak side with the exception of the Telefunken 12AU7.

Click below to add our recommended matching cables from Kimber Kable, all brand new as SkyFi is an official Kimber dealer.

Kimber Kable - RCA Interconnects

Kimber Kable - Speaker Cables

Kimber Kable - Bi-Wire Speaker Cables



Original Box

Not Included


Not Included


Not Applicable


Yes - Power Only

Physical Condition

6 / 10

Working Condition

10 / 10

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