jack

Here is the my BOM fell free to use it BOM_KSA5 (version 1).xlsb.xlsx

I do have both. PM me if still interested.

with CRC filer i still get a temperarure of 50c on the PSU radiator...

Thank you Alexcp and Pars. This should solve all my troubles with this great amp, that I'm using as a stage pre-amp. Have a great x-mas and a happy new year

Thank you, this helped me a lot! on DIY forum, that Pars mentioned, Algar added a CRC filer: "Then on the supply added an input CRC filter (4R resistor and second 4700uF cap) to reduced a little the regulator input voltage from 32V to 30V, since I increased the bias current.That will reduces the pass regulator power dissipation.That also reduce the amp already low noise floor. Regulator input ripple went from 300mVac to 100mVac..." How was this connected? is it between the leads of the existing 4700 uF caps?

my quiescent current is a bit too high, and the potentiomere are at minimum, therefore lowering the voltage might help.

Good morning Can I change the voltage of the version 2 PSU. from 22 to 21 or 20V? Could somone please tell me how this change could be made? Kind regards Jack

Hi AlSp I built KG's device as a pre. There is not much information in this thread about how this amp. reproduces sound. IMHO there is no need to use a thicker layer of copper, bearing in mind that you will be using a maximum of 30 Watts. I believe we could use better capacitors and resistors. Cheers

True! If it sounds good does not necessarily mean it will taste good ;-) Since good is subjective what does good mean to you in audio gear? in what area doen an opamp has to excel in order to be qualified as good?

Is it sarcasm or sth. I do not understand? Sent from my iPad using Tapatalk

I am still testing. Yesterday my burson v5i s opamp arrived, they still need to run for a dozen of hours for the final test, however as of now I can tell that they bring much more improvement in my DAC (DIY based on ESS9028) than in my preamp (that is the the KSA5). The idea of "upgrading" the opamps in the KSA5 came after i received counterfeit OP27 from ebay: the sound was terrible with lots of noise. Once i replaced them with Analog Devices original OP27G from Mouser, the KSA5 started to sound great, and then with BurrBrown's OPA445 even better IMHO, as i find it sounding natural. I also think about replacing my nichcons KA with KG, not sure what it will change, or if it will change anything though. Building, replacing, testing is an activity i really enjoy, that relaxes me a lot after a hard day at work. I should have chosen electronics instead of economics for my studies ;-) my lack of knowledge is a serious limiter for me, but you gentlemen and a great support and help. thank you!

Pars. PSU is running @ 23.2 V DC. Transformer is 27.5 V AC. I no not mean opamps in the PSU. as i already know that they either work or or not work. I think you told me that previously ;-) so i changed the op27 to the cheaper op07 and the psu seems fine. I have heard Operational amplifier have their own sound charecteristics or signature, therefore looking if changing OPAMPS in the amplifier will "improve" or change anything. I have testes the op27 and OPA 445 i find the forst one less precise with to much lows.

Hi Did any of you try to play with the opamps? I am tempted to do an upgrade of the opa445. Please let me know your thoughts. Thanks

Hi I tried to test the amplifier in class AB, but the lowest voltage i get is 89 mv (hot). did anyone mange to get it to work at lower voltage?

Thank you. I understand across as measuring voltage between 2 leads of the same R. I have a problem though one channel is significantly louder.... any idea where to start investigation?