Help needed to restore Ahuja TM 50

[tnvijay]

Hello Friends,
I am bumping this thread again. I am thankful to the knowledgeable folks here. I enjoyed my set of TM 50 for a while and had put them aside. I was using Bogen AP-35, which has developed some issues, have put my TM 50s back into use.

Now that I have travelled some good distance in this hobby, I could realise that the noise floor of my TM 50 is much higher than the Bogen AP-35. I can’t expect same performance because TM 50s are basically built as PA Amps. However, I was wondering if there is a way, I can reduce this noise floor. They are too powerful for my Jensen P12N Alnico Speakers. I have to only turn 10% of the volume pot to reach full volume. I was told if I can reduce the ‘gain’ I can reduce the noise floor. I am ok with reducing the ‘power’ of the amp from 50W to say 20 W, but in return I will be happy with a lower noise floor.
I will be grateful for any ideas and thoughts on this. Thank you for your time.

Please send me the schematic, I think I can find out the way... basically to reduce the gain we can reduce input stage gain or increase the feedback etc,but it can be done

 

[amit@1984]

Some Ahuja circuits, I don't specifically have the TM50's circuit but I can tell you for sure that the output section (with bias) is the same as the A50 HB.

Pic courtesy: FM Greenhorn
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hi i am looking for ahuja 100 w circuit if you have kindly share

 

[reubensm]

hi i am looking for ahuja 100 w circuit if you have kindly share

would you have the model number of the amp?

 

[ronthedon]

I have a broken "Arphi Super Series Free Field Amplifier" which is a 100W amp. It runs 4x6L6GC tubes and 5xECC83 tubes and has 3 transformers - I guess power, output and choke. Aux Selector has 4 positions-Mic4/Phono/Tape/Radio. 7 other pots are MIC-1/MIC-2/MIC2/MIC-4,AUX/MASTER/BASS/TREBLE. Power Switches are H.T-ON and FIL-ON. Can anyone please provide me with a circuit diagram for it.

 

[ronthedon]

I recently purchased two dead Ahuja TM-75 tube amplifiers and repaired, restored and recapped them and I should say I am pleasantly surprised with their clarity and soundstage. I have changed all electrolytes to Nichicon capacitors and ceramics to polyprophylene film capacitors. I have bypassed the tone controls to remove coloration added by the capacitors and am planning to mod the amplifiers by adding selectors for biasing of the ECC83 inputs for different tonal qualities. I would like to thank this thread and reubensm for the schematics without which I would never put my hand in them considering I have never worked on or heard a tube amp before. I also purchased a Bogen M120 amp and plan to convert it into a stereo amp alongwith the Arphi some time later.