What are the extra boards and transformers? I presume regulated supplies for the driver stages?? Nice work anyway!
Levin,
Thank you for the detailed describtion related to the noise issue.
I will start replacing the power supply caps, followed by the main board caps, wires etc.
Shall I be concerned regarding soft start circuit - any risk damaging the amplifier due to the changes, especially change of power caps?
What is the transformer size, and is it possible to replace the two with larger transformer to increase overall power supply, and thereby increasing the amplifiers handling capabilities? Diy newbie so I'm not aware of the consequences upscalingthe trafos may cause!
Thank you for the detailed describtion related to the noise issue.
I will start replacing the power supply caps, followed by the main board caps, wires etc.
Shall I be concerned regarding soft start circuit - any risk damaging the amplifier due to the changes, especially change of power caps?
What is the transformer size, and is it possible to replace the two with larger transformer to increase overall power supply, and thereby increasing the amplifiers handling capabilities? Diy newbie so I'm not aware of the consequences upscalingthe trafos may cause!
hello all , doing some upgrading to one of these. 
I saw a drawn schematic with 2 tantalums near the LM318 marked as 10uf, on mine they seem to be 1uf? any thoughts on this. and are they worth replacing with film types?
Thanks
I saw a drawn schematic with 2 tantalums near the LM318 marked as 10uf, on mine they seem to be 1uf? any thoughts on this. and are they worth replacing with film types?
Thanks
Any other opamp
@Lenin21
Is there any other available opamps than LT318 or LT118?
No luck finding above on stock!
Links to available stock or substitute(s) is much appreciated, thanks 🙂
@Lenin21
Is there any other available opamps than LT318 or LT118?
No luck finding above on stock!
Links to available stock or substitute(s) is much appreciated, thanks 🙂
LT-118 on Ebay
Yes, that's it, but at the same price, I would get the TO-99 cased version:
LT118AH Integrated Circuit | eBay
Yes, that's it, but at the same price, I would get the TO-99 cased version:
LT118AH Integrated Circuit | eBay
LM118H compatibility
Yes, the LM118 is a slight improvement over the LM318, but the LT118 is where it's at.
Do check the LT318 datasheet, which from memory, includes a useful comparison with the LM variants.
Good luck.
Yes, the LM118 is a slight improvement over the LM318, but the LT118 is where it's at.
Do check the LT318 datasheet, which from memory, includes a useful comparison with the LM variants.
Good luck.
The only difference relevant to audio applications is in LT's A suffix parts which have lower input offset current and voltage, hence much better CMRR and PSRR. You don't necessarily have to spend up on industrial cum Mil-spec. parts whose only further advantage is that they can work in extreme temperature environments.
Whatever the reason for thinking the 118 versions must be better than 218 or 318 for audio, the original parts were not the cheapest and there is a very high risk of fakes with those Chinese Ebay parts. Yes, any unusual or premium priced parts are now faked to incredible degrees that were once thought just an occasional problem with certain traders.
It may not matter much if you bought 20 TLO72s when you thought you were getting OPA2134s but this is a critical part. Absolutely, buy from local, authorized dealers if you need key parts like these in your amplifier, where you could do serious damage with fakes.
Whatever the reason for thinking the 118 versions must be better than 218 or 318 for audio, the original parts were not the cheapest and there is a very high risk of fakes with those Chinese Ebay parts. Yes, any unusual or premium priced parts are now faked to incredible degrees that were once thought just an occasional problem with certain traders.
It may not matter much if you bought 20 TLO72s when you thought you were getting OPA2134s but this is a critical part. Absolutely, buy from local, authorized dealers if you need key parts like these in your amplifier, where you could do serious damage with fakes.