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Old 2nd December 2009, 09:10 PM   #2021
Arick is offline Arick  Canada
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Quote:
Originally Posted by udailey View Post
Secret manufacturer?
Yes (just did not want to sound like a sale's rep.)
They are called Brownsburg Electronics and they manufacture all kind of transformers and inductors. All of there products are custom made.
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Old 3rd December 2009, 11:51 AM   #2022
Atilla is offline Atilla  Norway
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I've a question regarding the possible devices used in this circuit.

What happens if JFETs with lower transconductance are used than the specified ones? Given that we're not having gain in this configuration, does it change anything but the output impedance of the buffer? Which is in the default configuration mostly dominated by the output resistor, if I'm understanding things right.

I've got proper 2sk170s available, fairly well-matched, just waiting for the caps to arrive to build one of those I'm just curious.
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Old 4th December 2009, 08:52 AM   #2023
AndrewT is offline AndrewT  Scotland
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Quote:
Originally Posted by Atilla View Post
I've a question regarding the possible devices used in this circuit.

What happens if JFETs with lower transconductance are used than the specified ones? Given that we're not having gain in this configuration, does it change anything but the output impedance of the buffer? Which is in the default configuration mostly dominated by the output resistor, if I'm understanding things right.

I've got proper 2sk170s available, fairly well-matched, just waiting for the caps to arrive to build one of those I'm just curious.
both the jFETs in the B1 should be sk170. That's a Pass design.
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Old 4th December 2009, 09:24 AM   #2024
Atilla is offline Atilla  Norway
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I've got the signal path wired up with matched 2sk170s.

Oddly enough, this still doesn't answer my question
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Old 5th December 2009, 08:46 PM   #2025
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Quote:
Originally Posted by LucasAdamson View Post
I have the B1 board all populated and soldered. Now I need a power supply.
Many thanks
Lucas
I like batteries as it sounds much better to me, but a wall wart also sounds good and is very convenient. Once I stick it in a final chassis I will most likely use 3x high current 6V SLA batteries for a long lasting supply. A couple of 9V last quite a long time too, at least it is exceedingly cheap to try.
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Old 5th December 2009, 08:56 PM   #2026
jleaman is offline jleaman  Belgium
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Quote:
Originally Posted by chrismercurio View Post
I like batteries as it sounds much better to me, but a wall wart also sounds good and is very convenient. Once I stick it in a final chassis I will most likely use 3x high current 6V SLA batteries for a long lasting supply. A couple of 9V last quite a long time too, at least it is exceedingly cheap to try.
diy is all about cheap, and preferred ideas will you have the batteries in the case or external ?
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Old 5th December 2009, 09:31 PM   #2027
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Quote:
Originally Posted by Atilla View Post
What happens if JFETs with lower transconductance are used than the specified ones? Given that we're not having gain in this configuration, does it change anything but the output impedance of the buffer?
It will work fine, perhaps not the pinnacle of perfection that
you get with the 2SK170's, but very acceptable, as long as
you can get a few mA of bias.

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Old 6th December 2009, 12:13 AM   #2028
Atilla is offline Atilla  Norway
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Thank you for the answer Mr. Pass.

I'm looking forward to getting my capacitors and finishing the circuit
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Old 6th December 2009, 03:41 AM   #2029
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Originally Posted by jleaman View Post
diy is all about cheap, and preferred ideas will you have the batteries in the case or external ?
most likely external, but the batteries really aren't all that big. I have a lot of Neutrik PowerCon stuff I haven't been able to use yet.

For those of you that haven't tried it, a pair of 9v batteries sounds great.
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Old 6th December 2009, 04:13 AM   #2030
CFT is offline CFT  United States
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How about using matched pairs of 2sk79 VFETs, anything I should be aware of? Would increasing the supply voltage enhance any performance?
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