mine is 66mF per rail , dual mono,sounds perfect
you have more info , pictures ?
which output mosfets ?
you have more info , pictures ?
which output mosfets ?
I use full range sonido, horn loaded and infinity quatom 5...With mcintosh Ma 6100 I have greater bass fundament for comparison...
The transistors are matched toshibas Mosfets and jfets...
what preamp with M2 ?
first time I hear ( and I can't even think ) of bass deficiency , when M2 is in question
first time I hear ( and I can't even think ) of bass deficiency , when M2 is in question
try connecting M2 directly to source
in case od PC playback , set volume in player to min, power up M2 , then listen
preamp need to sound better than that ......... and only then you can blame (any) power amp for flaws
in case od PC playback , set volume in player to min, power up M2 , then listen
preamp need to sound better than that ......... and only then you can blame (any) power amp for flaws
Already done...preamp sounds and measures ok! I assume speakers missmatch and room specifics...also can I raise power lowering source resistors to 0.39R...
Right now I have 0R5 as source resistors for Mosfets but thought to lower for more power...
I have solved the bass problem a little bit, I have optocoupler volume control and this was the source of problem...
So far its interesting that M2 is driving the Infinity quantum 5...
I have solved the bass problem a little bit, I have optocoupler volume control and this was the source of problem...
So far its interesting that M2 is driving the Infinity quantum 5...
My best 
M-2 questions, Toshiba resistor change and pand preferred J Fet idss
Have completed another set of Tea's M-2 boards for a Toshiba output version and have a couple of questions.
What is the ideal idss for the Jfets used in M2? I have a set from the store, BL grade,and I have a few sets from High 8 to low 9 idss on hand... and secondly,
As these boards are already assembled with stock values, how much of a problem is NOT changing R11 to .1 R (from 100R) and R13 and R14 to .33R (from .5R) as Zen and others suggested? (See posts #891 and #902) Or just R11 changed and source resistors left at .5?(with Toshiba mosfets)
Thanks,
Russellc
Have completed another set of Tea's M-2 boards for a Toshiba output version and have a couple of questions.
What is the ideal idss for the Jfets used in M2? I have a set from the store, BL grade,and I have a few sets from High 8 to low 9 idss on hand... and secondly,
As these boards are already assembled with stock values, how much of a problem is NOT changing R11 to .1 R (from 100R) and R13 and R14 to .33R (from .5R) as Zen and others suggested? (See posts #891 and #902) Or just R11 changed and source resistors left at .5?(with Toshiba mosfets)
Thanks,
Russellc
Those will work fine. The JFETs see the 24V rail, so you want to keep the IDSS under 10mA to keep them running cooler.
I don't have any experience with the Toshiba MOSFETs, so cannot comment on that.
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optocoupler thingie will set Iq , even if you use two submarines as outputs , as long they (submarines) are having proper governing electrode
so - Toshibas , IRFP , 2SJ/2SK ,FQP/FQN , whatever , even bipolars will be biased at approx. 1A2-1A3
edit : that being with original Rs values (0R47)
if you decrease Rs values , Iq will rise in same amount/percentage
so - Toshibas , IRFP , 2SJ/2SK ,FQP/FQN , whatever , even bipolars will be biased at approx. 1A2-1A3
edit : that being with original Rs values (0R47)
if you decrease Rs values , Iq will rise in same amount/percentage
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Anyone have any feelings about bass output when comparing IRF type mosfets with the Toshibas? Same, less, more? (as far as M2 is concerned.)
Russellc
Russellc
just leave everything as in original
my comments from posts mentioned above were strictly to Generg , regarding Iq increase, in fact , decreasing value of Rs , so decreasing deeneration , so increasing xconductance
I believe Generg (Golden Ear ,officially) will have most to say
comparing to him , it seems as I spent several years playing with elephants , while their fave game was farting in general direction of my ears
Well then! Elephants notwithstanding, I am pressing on. I guess I will use the 8.8 or 9.3 idss sets, I assume the store set of Jfets I have, which are BL could be within spec, yet over 10 idss, right? Thinking BL goes up to 12? I would like to try the store set, all I have used on previous builds were Toshiba J fets, but alas, supplies dwindle!
Russellc
Russellc
if you have higher Idss range ones (more than , say , 8mA) , just check their current in circ , measuring voltage drop across R3 and R4 (ref. to post #1)
increase R3 and R4 if needed
increase R3 and R4 if needed
