carpenter said:
All right, getting to several issues: besides my weak heart--I'll try not to stare at Mrs. Magura's pic too much., where are you putting the chokes? Did I miss some new schematics? Are you doing something like myself in the JfetBOZ project?
my lips are sealed ........... as always .......
btw - look in your thread ......
Magura said:
I knowbut that's all due to my wussy fellow designer, he wasn't up to the task
Magura
why you didn't asked ?
either increase current through input LTP , or increase values of theirs drain resistors ........... or slightly decrease source resistors of outputs .....that last is maybe best solution
edit :
ya didn't say anything about sound........ ?
Zen Mod said:
And here is the explanation why
http://www.diyaudio.com/forums/showthread.php?postid=1402262#post1402262
Magura
Zen Mod said:
It's in the tube for future playing around. As for now I'm waiting for the boards.
I though did some playing around with my previous prototype, and 200mA seems to be the point of diminishing returns.
I can't be bothered to make a birds nest, when I know that boards are coming soon.....and besides that I have other things to play with ATM
Magura
For the Pumpkin - assuming the max output cap of 10uF - I guess it will still not be adequate for a headphone with input impedance of 300ohm as the LP filter will still be loping off a huge chunk of the bass.
Thinking of using the balanced output to do double duty to drive a balanced headphone too. I guess the only for this is to add an electrolytic
her shann
Thinking of using the balanced output to do double duty to drive a balanced headphone too. I guess the only for this is to add an electrolytic
her shann
hershann said:For the Pumpkin - assuming the max output cap of 10uF - I guess it will still not be adequate for a headphone with input impedance of 300ohm as the LP filter will still be loping off a huge chunk of the bass.
Thinking of using the balanced output to do double duty to drive a balanced headphone too. I guess the only for this is to add an electrolytic
her shann
you can find decent electrolytics in range 100-220 uF, and you can bypass them with something nice , in range of 1-2u2 ;
just hang them ( electrolytics)on inner side of present output caps , solder 47K from output side of caps to gnd ( for bleeding those big caps ) , connect da cans and enjoy .
as I said - I tried my proto Pumpie with AKG K270 Studio ........
nota bene - do not forget to power off power amp, when you are in mood for headphones ........
naaaaaaaah......
I'm ill like a dog ........ flue almost gets me completely ..........
Manu said:
Ditto
In the meantime this should cure the worst symptons, if swallowed in generous quantities
The Flu cure
Zen Mod said:
you can find decent electrolytics in range 100-220 uF, and you can bypass them with something nice , in range of 1-2u2 ;
just hang them ( electrolytics)on inner side of present output caps , solder 47K from output side of caps to gnd ( for bleeding those big caps ) , connect da cans and enjoy .
as I said - I tried my proto Pumpie with AKG K270 Studio ........
nota bene - do not forget to power off power amp, when you are in mood for headphones ........
naaaaaaaah......
I'm ill like a dog ........ flue almost gets me completely ..........
Pardon my poor comprehension - so you mean -ve leg of electrolytic to output of film cap and +ve leg of electrolytic to resistor which is then connected to ground. So the electrolytic is not actually parallel to the film cap at all.
hershann said:
Your drawing is not excactly correct! The Electrolytic cap must be in parallel with the outputcap. Said in another way; you can replace the outputcap, with the electrolytic (and add the resistor as Mr. ZM said)
Edit: And bypass the electrolytic with your faverourite filmcap ofcourse
I beleive there is provided for that on the Shunty boards...Edit Edit: I would use at least 220uF, and even that, I feel is too small. I usally go for 1000uF for headphone applications like that.
One good combo that I can recommend is 470uF Panasonic FC bypassed with a 1uF Rifa PHE426 polyprop. At least that is the best sounding "cheapo" combo that I have ever heard
Using a smallish cap on the output of a Headphone amp does cut the lower octaves somewhat
Yup I was trying to be clever. I know that inductance isn't important for DC so my point is that an inductive resistor is actually better in the power supply as it might (theoretically ) filter out a teeny bit noise and ripple. So part of point was that those who would blindly replace resistors with a "better" non-inductive one might be wrong...
I will never try to be "clever " again...promise...
Variac said:
Yup I was trying to be clever. I know that inductance isn't important for DC so my point is that an inductive resistor is actually better in the power supply as it might (theoretically ) filter out a teeny bit noise and ripple. So part of point was that those who would blindly replace resistors with a "better" non-inductive one might be wrong...
I will never try to be "clever " again...promise...
Naah, dont think so. First you were right, then you were right again!!!!
Use the most inductive resistor that you can find for CRC arrangements"!!!"You better play "clever" some more