I find 2SK170BL. I think it is close.
How can I measure Idss ? I newer work with JFETs before.
Wen I find pairs, better is larger Idss or smaller, for first stage, for second ?
How can I measure Idss ? I newer work with JFETs before.
Wen I find pairs, better is larger Idss or smaller, for first stage, for second ?
Can one stack the SK170 devices for better characteristics?
Is this circuit really worth while? 😕
D
Is this circuit really worth while? 😕
D
Connect gate to source. Then the FET will be a constant current source. Connect it to 9 to 15V and measure the current. Excpect around 5mA, in any case less than 20mA.Zigis said:
Hello.
The 2SK170 is easy to find in ebay, very cheap, and in matched quads.
Sorry for my english. Bye.
The 2SK170 is easy to find in ebay, very cheap, and in matched quads.
Sorry for my english. Bye.
You can use 2SK170BL .. Idss iun the 8-to12mA is no problem. You can insert a 10-22 or even 47Ohm resistor betwwen the source and ground to properly bias the stages, whitout altering noise and transductance too much...
I did bought some 2Sk170GR just this week from ebay... 3$ a piece no less!!
I did bought some 2Sk170GR just this week from ebay... 3$ a piece no less!!
Good idea about Ebay!
I purchase 2SK170BL yesterday:
http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&rd=1&item=200226753902&ssPageName=STRK:MEWN:IT&ih=010
I purchase 2SK170BL yesterday:
http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&rd=1&item=200226753902&ssPageName=STRK:MEWN:IT&ih=010
GlidingDutchman said:
My friend, what characteristics?
Noise: will go down with the square root of parrallel devices, but idle current for be proportional increased, and you need to degrease the load resistor to keep the same idle drain voltage.
Linearity: does not nessecerely improve, but you might end up with less low order, and more high order distortion.
input capacitance: will also go up, and likely bandwidth will go down.
Hi Gliding Dutchman!
Would you mind sharing your layout? I happen to have exactly the same strip board lying around and I'd love to build this to try out on my Denon 103R and Garrard 401.
Many thanks 🙂
- John
Would you mind sharing your layout? I happen to have exactly the same strip board lying around and I'd love to build this to try out on my Denon 103R and Garrard 401.
Many thanks 🙂
- John
johnm said:
John
I just soldered the parts onto the tag strip in a "random" fashion with no "propper" layout (ofcoarse according to the design!).
A friend of mine and I am working on a higher gain stage in a similar fashion to MAD K's - I'll send you the details of that circuit as I believe it would be a better match for your Denon 103R.
The above circuit works well with low output MC cartridges but higher gain would be a benifit.
Also checking out the circuit to run from 12vdc (incl IC regulators etc).
Cheers
Dewald the GD
Hi GlidingDutchman,
nice building, I am on half way building this too.
What kind PS you use, battery or regulated?
Thees violet el caps are on output?
Zigis.
nice building, I am on half way building this too.
What kind PS you use, battery or regulated?
Thees violet el caps are on output?
Zigis.
Zigis said:
Hi Zigis - currently I am running it from a Pb Acid battery (2x 12vdc) but I am looking into doing a IC regulated PSU.
The violet caps are the outputs yes - will be replaced by some plastic film types in due course.
D
johnm said:
John - I'll post the new schematic for discussion. I am having trouble getting the thing to work. Actually back to the original design as per Mads K.
In comparson with the EAR 834P it can most certainly do with a touch more bass or will that be treble attenuation?
D