Points well taken, and reminds me of the Ongaku article back in SP mag. ie. dont bother unless xyz.
Twenty years later there are some pretty good caps available in the small values required and tantalum and/or old stock carbon comps cant be 'that bad'.
Theres no silver wound iron required. A couple inches of silver or enamelled copper wire, copper chassis, hybrid rectifier and.. it might sound different, but you'd think it'd not necessarily be worse. ??..
Like you say, un-inspiring, and I agree - Looks like the stock version of the $99 bottlehead foreplay lineamp from 10 years ago with a different tube.
Question is: how to turn a sows ear into a silk purse?.. hocus pocus cant be the answer. The operating points are all there.
Is it just me?. (dont answer that part)
Shane
Shane, .
Broskie has the answers....CCDA: constant-current-draw amplifier
the best sounding tube to my ears is the russian 6H23-eb...wavebourne introduced me to this tube and i never looked back...
this is a public forum, as long as no rules are violated, anyone can post....since joining here in 2013, i have learned a lot about tubes that it is a crime not to share them...
i conducted a build out / teach ins last year about this topology using the 12au7....about 30 boards were built to the satisfaction of people who joined up.......
You made me curious (OP,sorry for the digressions!) about this.Like in the picture,I always routed the HT wires as independent (not twisted or touching,double-isolated) because I always had a fear for the rather large potential between the two (more than 800V sometimes) and not very confident in the PVC/whatever isolation to withstand a possible accident.
Otherwise,the RFI supression you mentioned...am I wrong if I trust the rather generous ammount of uF's and H's following the rectifier?
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the late AndrewT keeps a close eye on ac lines not twisted.....it is a good practice in any book...i have not encountered problem because of twisted wire pairs...
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Looks like you missed my point.I wan't asking about AC lines in general (eg.AC mains,AC filament wiring wich I'm familiar with) but of this specific given situation - AC wires between XFMR and rectifier valve.
Also,excuse my ignorance,who is AndrewT?
i criticized your drawing for not twisting wire pairs, the main reason for twisting is so that the loop area between parallel wires are minimized, it is not so hard to see, your parallel wires from the traffo to the rectifier has the biggest loop area, twisting them minimizes the loop area, did you get what i was driving at...? any field created is effectively cancelled due to the twisting...
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now where is the like button?
i build the line stage of 77 with a regulate power suply i had,i lisen many cd ecm,act, classic music,and i dont like it.The sound is mood,the treble is thin.The version i make is with 8.2k and 5.1k parallel in gain stage and two 250k parallel for another stage,250v b+ and the tubew ecc82,ecc81
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