I'm driving a pair of Goodman Twinaxiom 10's with a Pioneer SM-83 bought from Kent Kassler . :2thumbs: I'm really enjoying the set , Thanks Andre .
Anyway , the Twinaxioms are a little screechy with the tone controls flat , and " loudness contour " switched off , that is , with the stock compliment of valves installed -
Phonostage - 1x 12ax7 per channel
Input/pre - 1/2x 12ax7 per channel
Gain/Driver - 1x 6an8 per channel
Push-Pull - 2x 7189's per channel
BTW - all the stock valves are Japanese - Toshiba 7189's , Hitachi 6an8's and Matsushita 12ax7's - Andre reckoned that they're probably the original valves .
So ... yesterday I replaced the 7189's with NOS OTK 6P14P-EV's , and the Jap 6an8's with NOS RCA 6an8's . Now for the 12ax7's .
First of all I tried 1x New Sensor production Mullard 12ax7's " stolen " from my Mullard 520's in the input , sound was clearly better , sparkly well-defined highs , OK-ish mids and no definition in the bass registers at all . I then tried 2 of them in the phono-stage , similar story . Then 1x RCA 12au7 on input , with the same 2 mullard 12ax7's on phono-stage . This yielded a marked improvement to the bass , still not quite there though . I then tried 2x RCA 12au7's in the phonostage and 1x Edis-something ( can't make out the rubbed out name on the valve ) 12au7 on the input - best yet ! Bass is defined , mids are defined and clear , highs are sparkly and defined , separation between different instruments is well-defined ( not blurred ) . A radical improvement - to say the least .
I also tried 3x 12BH7's in these positions , and the sound was very good , if not even better , but the higher filament current of the 12bh7 ( 1 Amp more between the 3 valves ) concerned me . So I stuck with the 12au7's - a happy compromise .
Next I'll try and find the perfect cartridge to compliment the Audio Technica AT-1100 ( low effective mass / straight ) tonearm . ATM I have an Ortofon FE15 XE mk2 on the arm , somewhere I have a JVC Z1 cart with aftermarket Z1-EB stylus , which I seem to recall delivers very good bass . ;D
Anyway , the Twinaxioms are a little screechy with the tone controls flat , and " loudness contour " switched off , that is , with the stock compliment of valves installed -
Phonostage - 1x 12ax7 per channel
Input/pre - 1/2x 12ax7 per channel
Gain/Driver - 1x 6an8 per channel
Push-Pull - 2x 7189's per channel
BTW - all the stock valves are Japanese - Toshiba 7189's , Hitachi 6an8's and Matsushita 12ax7's - Andre reckoned that they're probably the original valves .
So ... yesterday I replaced the 7189's with NOS OTK 6P14P-EV's , and the Jap 6an8's with NOS RCA 6an8's . Now for the 12ax7's .
First of all I tried 1x New Sensor production Mullard 12ax7's " stolen " from my Mullard 520's in the input , sound was clearly better , sparkly well-defined highs , OK-ish mids and no definition in the bass registers at all . I then tried 2 of them in the phono-stage , similar story . Then 1x RCA 12au7 on input , with the same 2 mullard 12ax7's on phono-stage . This yielded a marked improvement to the bass , still not quite there though . I then tried 2x RCA 12au7's in the phonostage and 1x Edis-something ( can't make out the rubbed out name on the valve ) 12au7 on the input - best yet ! Bass is defined , mids are defined and clear , highs are sparkly and defined , separation between different instruments is well-defined ( not blurred ) . A radical improvement - to say the least .
I also tried 3x 12BH7's in these positions , and the sound was very good , if not even better , but the higher filament current of the 12bh7 ( 1 Amp more between the 3 valves ) concerned me . So I stuck with the 12au7's - a happy compromise .
Next I'll try and find the perfect cartridge to compliment the Audio Technica AT-1100 ( low effective mass / straight ) tonearm . ATM I have an Ortofon FE15 XE mk2 on the arm , somewhere I have a JVC Z1 cart with aftermarket Z1-EB stylus , which I seem to recall delivers very good bass . ;D
