EvLoutonian Posted April 20, 2016 Share Posted April 20, 2016 They look like a pair that my uncle built many years ago using huge Trimax transformers which was ultimately thrown in the bin (!!!!!) before I was into this kind of stuff, unfortunately... Oh, the shame.... Link to comment Share on other sites More sharing options...
EvLoutonian Posted April 20, 2016 Share Posted April 20, 2016 Here's a pic of my single Centre Industries monitor amp (well, the front panel, anyway!) Link to comment Share on other sites More sharing options...
Beeman Posted April 20, 2016 Share Posted April 20, 2016 Are these the broadcast monitor style mentioned above, or different? They are the Type 54 broadcast studio monitor amps Link to comment Share on other sites More sharing options...
EvLoutonian Posted April 20, 2016 Share Posted April 20, 2016 They are the Type 54 broadcast studio monitor amps They look good, Beeman. I sent you a message via the PM service here. Link to comment Share on other sites More sharing options...
Beeman Posted April 20, 2016 Share Posted April 20, 2016 Hi EvLoutonian - message received & replied. The main characteristic I find with these amps is the amount of power they produce. Much higher than the stated 18wpc I guess it has to do with the huge iron they posses. Link to comment Share on other sites More sharing options...
tvcollector Posted January 12, 2017 Share Posted January 12, 2017 Hi all, i have a set of A54 Trimax amps and restoring them but they dont match up to any of the schematics ive found all the A54 and A54A diagrams are completly different to my amps like R1 is a resister but in the parts list and diagram its a 20k pot? there is a 56uf electro and it doesnt exsist on the diagram or parts list? Link to comment Share on other sites More sharing options...
trobbins Posted January 12, 2017 Share Posted January 12, 2017 (edited) Toby, It's unlikely to be too different in the main part of the amp, and quite likely to be related to a different input source, or someone's idea of 'an improvement'. If you mark up the schematic, showing the differences then it should be relatively easy to work through what is happening. Perhaps if you don't work from the component labels on the tag board, and just work from a schematic - as the tag board labels are obviously not correct. Given its age, you would be well served to do a thorough restoration and to add some protection parts in, if you have done that before? Ciao, Tim Edited January 12, 2017 by trobbins 1 Link to comment Share on other sites More sharing options...
RCAJack Posted October 2, 2021 Share Posted October 2, 2021 A revival for this old thread and my Trimax Type 3s. I have the A54B variant, seemingly the last iteration (circuit diagram below -- I'm not sure if this is online anywhere else so I hope it helps somebody). These amps have been sitting idle for a while and I'm just going through them with some fresh parts. First one is basically done and it has heaps of power and sounds great, just as it used to but a bit quieter. Now onto the second. I'm very proud to own a small piece of Melbourne-made audio history. Link to comment Share on other sites More sharing options...
THOMO Posted October 2, 2021 Share Posted October 2, 2021 (edited) 34 minutes ago, RCAJack said: A revival for this old thread and my Trimax Type 3s. I have the A54B variant, seemingly the last iteration (circuit diagram below -- I'm not sure if this is online anywhere else so I hope it helps somebody). These amps have been sitting idle for a while and I'm just going through them with some fresh parts. First one is basically done and it has heaps of power and sounds great, just as it used to but a bit quieter. Now onto the second. I'm very proud to own a small piece of Melbourne-made audio history. You are in for a treat when you have a pair up and running.With the right speakers they have a huge room filling soundstage.No other amps I have used have quite that big holographic sound.Not just depth and width but height too. Edited October 2, 2021 by THOMO 1 Link to comment Share on other sites More sharing options...
trobbins Posted October 3, 2021 Share Posted October 3, 2021 That's an interesting schematic. Trimax obviously put effort in to LF and HF stability, so it would be interesting to see how stable the margins ended up as. And even for 1962, the power supply CLC uses quite low levels of C, and a secondary winding snubber, so it would interesting to see how the 400V rated C10 survived. I've found a few OA211's that shows PIV leakage, indicating that vintage of diode should be considered suspect and needs to be tested for 1kV leakage. 1 Link to comment Share on other sites More sharing options...
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