Firstly the service manuals for these following items are located in the service data library. It includes, circuit descriptions, plan views, component listings and schematics.
For some considerable time I’ve been looking for a small audio system for my late 60’s early 70’s themed room. I had considered a Sony TA-88 with an ST-88 or the Goodmans Max system. On e-bay I’d found an ST-88 and thanks to the kindness of forum member Colin (Turretslug), just before Christmas he gave me a Maxamp30 which he’d stored away some thirty years prior. Back then one of the channels was low which was cured with a replacement transistor.
For Christmas my wife had also sourced me the accompanying Goodmans “StereoMax” Tuner to complete the set. Of course I don’t have the original speakers and I doubt I’ll find them as the “Maxim Bookshelf” pair fetch ridiculous sums ( a pair on e-bay currently at £500). I do have some very nice Grundig round “Hi-Fi Box” speakers currently attached to my Grundig RTV 900 which could be pressed into service, though I would prefer to have some woody speakers.
MaxAmp 30 & StereoMax Tuner
The amp is nicely constructed and easy to get at for servicing and is in very good condition. A few problems noted such as switches and pots but you’d expect this of a 50 year old amplifier.
First thing I wanted to do was check and reform the main smoothing electrolytic C58 a 2500uF @ 64V. There was some evidence of venting but the cap easily reformed. The push buttons were all sticking, they would not latch/unlatch. These and all the pots were treated to a dose of “Servisol” switch cleaner. This cleared up the latching troubles.
C58 on the reformer, as can be seen below some leakage (neon struck) but the voltage was steadily climbing and the cap was cool to the touch.
C58 reformed, leakage neon indicator extinguished and cap holding at rated voltage.
The amp was then test powered up and connected to a signal source and performed admirably.
Next instalment the StereoMax Tuner.
There’s noting much wrong with the tuner except for three things, the wave selector knob is missing, I’ve ordered a similar replacement from e-bay. The second fault is the dial cord for FM is broken, it cannot be repaired. I did have some NOS dial cord in stock but its way too thick. Therefore I’m stuck until I can find something thin and suitable. Finally sticky switch latching, this was again cured with some application of Servisol.
I tested the tuner, it works on A.M. and I manually rotated the FM gang to select stations, FM works just fine as well.
Dial stringing diagram for the Goodmans StereoMax
With special thanks to member “Cathovisor” (Mike) who supplied me with the correct dial cord, I was able to restring the tuner. The replacement wave selection knob is fitted and although not like the original, its the best I can do as I’m unlikely to find the unique original knob unless someone can 3D print one for me.
Tying a dial cord loop-end
Next? Rather than using headphones test it with the Grundig speakers.
Whilst on the subject of speakers, the original bookshelf ones that would have been supplied with the system were Goodmans “Maxim”, see below.