... I'll just go over the working points and currents and then send you the schematics, and post it here as well
This is the circuit I have in mind...
Quite sure that the servo can be made different...where it is less in the signal path.. but this will work...only must the fundamental offset in the summing node be adjusted so it' close to zero before engaging the servo..
The showed resistor voltage reduction for the servo opamp is not good enough. think that a 15 V zener solution would be better, but for sims this works OK
The gain here is 56 dB, but can be adjusted by adjusting Riaa network values.
The circuit is extremely fast and has a bandwidth of more than 30 MHz.
Can be used with an octet of BF862. without changing the currents, then noise will be extremely low as well...But for ease and proof of concept i think that the SK170 will be good enough
Quite sure that the servo can be made different...where it is less in the signal path.. but this will work...only must the fundamental offset in the summing node be adjusted so it' close to zero before engaging the servo..
The showed resistor voltage reduction for the servo opamp is not good enough. think that a 15 V zener solution would be better, but for sims this works OK
The gain here is 56 dB, but can be adjusted by adjusting Riaa network values.
The circuit is extremely fast and has a bandwidth of more than 30 MHz.
Can be used with an octet of BF862. without changing the currents, then noise will be extremely low as well...But for ease and proof of concept i think that the SK170 will be good enough
Attachments
OK, i got it. Will build this in the next 2 weeks.
I found an interesting input stage that avoids common mode distortion. It is described as multi tan-h. It is from the ADA4898 that i tried successful some time ago. For me that also looks like a driven cascode, this time in the current sources.
I found an interesting input stage that avoids common mode distortion. It is described as multi tan-h. It is from the ADA4898 that i tried successful some time ago. For me that also looks like a driven cascode, this time in the current sources.
Attachments
Seems to be that this circuit was already discussed in 2009 and Edmond Stuart has simulated it. See the Blowtorch thread.
Common mode linearized input stage and amplifier topology - Patent # 6963244 - PatentGenius
Common mode linearized input stage and amplifier topology - Patent # 6963244 - PatentGenius
No, that was in 2009 as far as i know. I found this interesting, but this is not important at the moment. I have enough to do.
Just today. I wanted to try out the MM stage of the Tanzmusik. I had visited Fink Consulting some time ago and Karl-Heinz gave my an AT95E. He said something like "it is so good that i do sometimes not know what the fuzz is about expensive MC´s". That is strong medicine but i was curious enough to try it out. I put it in my Goldring table that is the cheapest REGA with a wooden platter. It is somewhat modified but this again is not important. The sound i got really surprised me. In a very wide midrange everything is fine. The stage is wide, deep and high. At the extremes of the spectrum there is some loss of grip and punch in the bass and the upper treble is extended enough but a little bit fuzzy. It does not sound as energetic or spontaneous as my reference table either but it is interesting and sweet enough to draw my attention. Fatigue is low too so there is no excuse any more not to try vinyl if you are bored by your crap DVD player. Buy a used REGA or restore a Lenco L75, put this marvel of a bargain in and you are set with maybe 150,-€.
Just today. I wanted to try out the MM stage of the Tanzmusik. I had visited Fink Consulting some time ago and Karl-Heinz gave my an AT95E. He said something like "it is so good that i do sometimes not know what the fuzz is about expensive MC´s". That is strong medicine but i was curious enough to try it out. I put it in my Goldring table that is the cheapest REGA with a wooden platter. It is somewhat modified but this again is not important. The sound i got really surprised me. In a very wide midrange everything is fine. The stage is wide, deep and high. At the extremes of the spectrum there is some loss of grip and punch in the bass and the upper treble is extended enough but a little bit fuzzy. It does not sound as energetic or spontaneous as my reference table either but it is interesting and sweet enough to draw my attention. Fatigue is low too so there is no excuse any more not to try vinyl if you are bored by your crap DVD player. Buy a used REGA or restore a Lenco L75, put this marvel of a bargain in and you are set with maybe 150,-€.
Last edited:
That makes no sense to me. Ones i have adjusted a cart in my Triplanar it is "holy" for at least two years. It is just too stressy to find the sweet spot and then loose it. Just smash your "Sparschwein" and buy that damn thing. I found it new on Ebay for 19,98€. If you do not like it i buy it back from you.
Thanks, then we are in a round about of the third kind.
Charles Altmann likes the cheaper AT91 even better, round needle you know.
The Altmann Phono Stage
Charles Altmann likes the cheaper AT91 even better, round needle you know.
The Altmann Phono Stage