José Eduardo Silveira, a Brazilian, have assembled Dx Super A
With Fábio Zimmer Brazilian pcboards.
If you have questions about, then contact Zimmer:
imap.eletro@gmail.com
regards,
Carlos
With Fábio Zimmer Brazilian pcboards.
If you have questions about, then contact Zimmer:
imap.eletro@gmail.com
regards,
Carlos
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Joined 2009
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Very slow progress, but forward anyway. Next motnth prapobly will be fully furnished
Two pair of latefts driven with buffered hitachi vas fallowed by 12AU7A tube.
very good,interesting to see diagram)
amptech
I have wasted some gain using VAS resistors but THD now is higher
and it is exacly the same threw all audio band from very low output swing to nearly clipping condidtion, so amp is playing allways the same.
I have taken some home made measurements (I still have big meas on the bench). There really is audiable difference, top octave is much smoother (I do not know if it can be measured but It can be heared anyway).
kees52
Thanks a lot. I like the way It sounds but next time prapobly I will go for IRFP or BJT output stage.
I have wasted some gain using VAS resistors but THD now is higher
and it is exacly the same threw all audio band from very low output swing to nearly clipping condidtion, so amp is playing allways the same. I have taken some home made measurements (I still have big meas on the bench). There really is audiable difference, top octave is much smoother (I do not know if it can be measured but It can be heared anyway).
kees52
Thanks a lot. I like the way It sounds but next time prapobly I will go for IRFP or BJT output stage.
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I've got the same amplifier, don't forget to take a look on the main filter capacitors. They are quite sexy in this copper finish. Another interesting detail is the battery driven preamplifier, something not usually seen on commercial offerings.
I was going to say to just fix it ... but if it's a SE-A1000 (stupid monolithic IC amp)
Blah!!
Se-a5 is better ... dual pair toshiba "LIN" "super A" discrete. (like that!!)
Meters are the coolest on both models !!
OS
amptech
I have wasted some gain using VAS resistors but THD now is higher
I have taken some home made measurements (I still have big meas on the bench). There really is audiable difference, top octave is much smoother (I do not know if it can be measured but It can be heared anyway).
kees52
Thanks a lot. I like the way It sounds but next time prapobly I will go for IRFP or BJT output stage.
Adding resistors to "burn away " some VAS closed loop gain is good. As you say ,
THD stays consistent with freq and amplitude.
SQ improves , too. This trick is used by many a OEM.
OS
Se-a5 is better ... dual pair toshiba "LIN" "super A" discrete. (like that!!)
Meters are the coolest on both models !!
SE-A3 is better and rarer.
What a waste . You know the P3A could easily do 70V rails with
big MT-200 Sankens and higher voltage Q1-3 ....
Double the bootstrap R's - good to go.
2X scaled P3A should sound/.perform the same.
OS
Plenty of advices to listen ..
@OS
For some reason you think that trussing the guts of the broken Technics is a waste ?? Please explain ...
@OS I wouldn't trust a CFP at 70+70 volts with one or two pairs of the Sanken with out safety measures like Vi limiter or something like that even worst when its bootstrap
With boards ready made from previous project it really works quick
Trafo is around 400W bank is 4X15.000 ...
@OS
For some reason you think that trussing the guts of the broken Technics is a waste ?? Please explain ...
@OS I wouldn't trust a CFP at 70+70 volts with one or two pairs of the Sanken with out safety measures like Vi limiter or something like that even worst when its bootstrap
With boards ready made from previous project it really works quick
Trafo is around 400W bank is 4X15.000 ...
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Joined 2009
Paid Member
That's a lovely chasis.
Maybe the TGM8 version with the additional MOSFET protection ?????