Hi
I've build ccda preamp octal like a year ago . Bought lots of 6H8C (6n8s) and 6sn7gt as lot of nos tubes from ebay just for test . Some tubes was noisy , some have microphonics , some broken not work. I choose 2 working good and been very happy with the sound . Mean time build lampizator octal output for my rpi dac and also no problem. I follow many projects from lampizator and i've build tester for tubes then i find out how not matched they are . I get to point if it sounds so good on not matched random tubes I want better matched tubes , so I bought some matched pair from ebay . Here is problem like non of ebay sellers checking tubes according to sound , just match them electronically , so they send me more tubes and I have now just more tubes , but no good tubes . Some of sellers stating is something wrong with my circuit , then why if tube is noisy I swap tubes beetwen channels and noise is in other channel ? I've build all on new parts , no cheap parts , every part matched beetwen channels , make my own cases , no transistor in circuit , no electrolitic caps , point to point soldering , psu in separate case with ez80 rectifier . Some time ago I've build tetra sans PS with 6n1p same point to point solder and it sounds awesome with out problems . My experience with tubes is like a novice so I could make mistake but where ?
I'm not sure now is it me doing something wrong , or maybe i did it too good ?
I've build ccda preamp octal like a year ago . Bought lots of 6H8C (6n8s) and 6sn7gt as lot of nos tubes from ebay just for test . Some tubes was noisy , some have microphonics , some broken not work. I choose 2 working good and been very happy with the sound . Mean time build lampizator octal output for my rpi dac and also no problem. I follow many projects from lampizator and i've build tester for tubes then i find out how not matched they are . I get to point if it sounds so good on not matched random tubes I want better matched tubes , so I bought some matched pair from ebay . Here is problem like non of ebay sellers checking tubes according to sound , just match them electronically , so they send me more tubes and I have now just more tubes , but no good tubes . Some of sellers stating is something wrong with my circuit , then why if tube is noisy I swap tubes beetwen channels and noise is in other channel ? I've build all on new parts , no cheap parts , every part matched beetwen channels , make my own cases , no transistor in circuit , no electrolitic caps , point to point soldering , psu in separate case with ez80 rectifier . Some time ago I've build tetra sans PS with 6n1p same point to point solder and it sounds awesome with out problems . My experience with tubes is like a novice so I could make mistake but where ?
I'm not sure now is it me doing something wrong , or maybe i did it too good ?
