jacco vermeulen said:
punt? I mean the collector needs a few tenths of a volt more than the emitter so that the device is on. The voltage divider will set the base to be half of the 24.2V that is above. Perhaps if the 499 is changed to 1k, then the transistor won't be in the active region?
The ONO has a similar circuit. It can have 1K in the 499R position in the Pearl, no problem, as long as the current draw from the four JFETs is sufficiently low. I never knew why this was, but I'm guessing your leading me to the reason. I also noted that a 2sc1844 is used in the ONO instead of the ZTX450 for Q5...
In other news, I finally scored an illusive headphone that I'm very excited about. See pic:
http://img243.imageshack.us/img243/9269/img1803yk7.jpg
Yeah, i'm a pig.
You should have noticed there's no Idss grade mentioned for the JFETs in the Ono schematic, but the Ono also has the 2 times 10k divider to set the voltage at the drain of the JFETs at 10 to 11V besides the single/dual 499R switch.
Suppose you put 0.1mV on the input, say 4 JFETs in parallel with a total transconductance of 80mA/V, how much bias current would be sufficient ?
Have you read Borbely's articles on MC stages ?
You should have noticed there's no Idss grade mentioned for the JFETs in the Ono schematic, but the Ono also has the 2 times 10k divider to set the voltage at the drain of the JFETs at 10 to 11V besides the single/dual 499R switch.
Suppose you put 0.1mV on the input, say 4 JFETs in parallel with a total transconductance of 80mA/V, how much bias current would be sufficient ?
Have you read Borbely's articles on MC stages ?
Ok, first things first, no calling me honey!
The model holding the bottle is the one and only Mrs. Magura
AKA the princess.
I was real surprised, to find such intense and gentle taste. I would dare to compare it to very good Cognac. I found it to be finely balanced between the taste of oak and plum. A very nice and long aftertaste is also worth mentioning.
Magura
The model holding the bottle is the one and only Mrs. Magura
AKA the princess.I was real surprised, to find such intense and gentle taste. I would dare to compare it to very good Cognac. I found it to be finely balanced between the taste of oak and plum. A very nice and long aftertaste is also worth mentioning.
Magura
http://picasaweb.google.com/luvdunhill/Pearl
still deciding what to do with all 4 shields and the earth post. I just connected the earth from the cartridge to the chassis and it sounds very, very quiet... Something in the manual about trying the two supplies together and the input / output jacks or something... then there is the missing papa thermistor ... like I said, it sounds quiet... well, too quiet.. because... there isn't enough gain
There there is the second Pearl ... okay, okay, I'm reading Herr-Borbely..
jacco vermeulen said:Very bad location/orientation of the transformers, especially for a phono stage.
Congrats on the T-50, you're turning in a relic hunter like the three pooftahs.
(if Magoora handles the digestif properly as intended he should be a fat prince shortly)
yes, I was worried about the transformers... I figured I'd try it and see what happends... perhaps ZM has some extra tuna cans or something. It's very quiet though ... and very compact. The other Pearl will use some dumpster transformers, once I figure out which 2 wires are the primary and which are the secondary
I'll post pictures of them sometime...
WTF! are you spyin' on me !!
it is ..... for starters , and to determine what amount of attenuation you need ( not for you , but usually for squaker
)
in days of my youth , I made for one guy pretty decent system :
AR SP8 replica (even if I begged him to not force me to make that drek;
at least I implemented my own toob PSU reg , not sissy original one , with burnin' meltin' 12BH4)
toob 2-way active xover
pair of PP EL34 triode monoblocks
one SS dreky amp
....... all that for feeding pair of ancient , but mint KHorns ;
SS amp for bass cab , toob blocks for squaker and tweeter ;
off course - I ditched everything redundant from xovers ; smarty farty ZM almost tossed autoformers in nearest container , exchanging thenm for plain resistive attenuation ;
later - ZM really tossed resistors in nearest container ; autoformers are still in place
simply - with proper xformer attenuation , energy level isn't compromised , as with resistors ; point is - you must have really good xformers (autoformers , in fact ) to have all virtues of that approach
ya CY !
mpmarino said:
Good resistive is good 'nuff .... no?
(not meaning rheostat)
it is ..... for starters , and to determine what amount of attenuation you need ( not for you , but usually for squaker
)in days of my youth , I made for one guy pretty decent system :
AR SP8 replica (even if I begged him to not force me to make that drek;
at least I implemented my own toob PSU reg , not sissy original one , with burnin' meltin' 12BH4)
toob 2-way active xover
pair of PP EL34 triode monoblocks
one SS dreky amp
....... all that for feeding pair of ancient , but mint KHorns ;
SS amp for bass cab , toob blocks for squaker and tweeter ;
off course - I ditched everything redundant from xovers ; smarty farty ZM almost tossed autoformers in nearest container , exchanging thenm for plain resistive attenuation ;
later - ZM really tossed resistors in nearest container ; autoformers are still in place
simply - with proper xformer attenuation , energy level isn't compromised , as with resistors ; point is - you must have really good xformers (autoformers , in fact ) to have all virtues of that approach
ya CY !
I have some autoformers ... just trying to figure out how to use with Pumpkin and F4. Fancy balanced ones too:
http://picasaweb.google.com/luvdunhill/TVC
http://picasaweb.google.com/luvdunhill/TVC
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