Hi all, I was wondering if anyone has heard an Aunt Corey's Homemade Passive Buffered Preamplifier , and any opinions about them?
I started one years ago , I worked on it for a while but didn't really know what I was doing, so didn't complete it. I have the Power Supply mostly built from years ago .... I was thinking it would really good to finish mine.
Unfortunately I can't find my original BUF-03AJ's that I purchased back then. Does anyone have a pair of BUF-03AJ's that they would be willing to part with for a good cause?
I started one years ago , I worked on it for a while but didn't really know what I was doing, so didn't complete it. I have the Power Supply mostly built from years ago .... I was thinking it would really good to finish mine.
Unfortunately I can't find my original BUF-03AJ's that I purchased back then. Does anyone have a pair of BUF-03AJ's that they would be willing to part with for a good cause?
For some reason (rarity? metal can?) i expected the buf03 to sound better than the buf634. It did not.
Hi analog_sa , thank you that is interesting information.
- went and checked --- I read in a thread from about a year and a half ago that Aunt Corey's Passive Buffered Preamp wasn't compatible with the buf634 , I'm not sure why .
- went and checked --- I read in a thread from about a year and a half ago that Aunt Corey's Passive Buffered Preamp wasn't compatible with the buf634 , I'm not sure why .
BUF03 has a JFET input, I'd expect it to do better on high impedance sources. BUF634 is basically a (bipolar) diamond buffer. If used after a pot it'll eventually make the pot scratchy due to needing significant bias current.
Good point. My application did not have a pot. I don't believe i even knew the 03 was a fet input.
If I recall correctly the BUF634 is designed to be used within a feedback loop, whereas the BUF03 can be used on its own.
You can easily use the 634 outside of a nfb loop, but a loop will minimise the offset and make it possible to avoid coupling caps.
Not sure if the microamp input bias current can really damage a pot in the long term but it certainly allows one to hear what a buffered pot sounds like and to decide if this avenue is worth exploring.
Not sure if the microamp input bias current can really damage a pot in the long term but it certainly allows one to hear what a buffered pot sounds like and to decide if this avenue is worth exploring.
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BUF634 has been effectively obsoleted by the introduction of BUF634A. It beats LME49600 on bias current and input impedance, the same (worst case) offset though.
My problem would be not knowing what the new schematic would look like if I was going to try and use the BUF634A in that circuit??
Maybe I could post the schematic and get some feed back?
Maybe I could post the schematic and get some feed back?
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Hi analog, thank you for the design ideas! --- but I have a couple of dumb questions , if that's okay...
- Is there a particular kind of amplifier - say tubes or solid state I should worry about?
- How will I know if an amplifier is a DC amplifying power amp?
- Is there a way to measure if an amp is amplifying DC?
- Is there some way to protect an amplifier that does amplify DC? -
- you recommended that I should be cautious when using the design with an amplifier ... but I'm not sure how to be cautious....?
--- Thank you -- 🙂
- Is there a particular kind of amplifier - say tubes or solid state I should worry about?
- How will I know if an amplifier is a DC amplifying power amp?
- Is there a way to measure if an amp is amplifying DC?
- Is there some way to protect an amplifier that does amplify DC? -
- you recommended that I should be cautious when using the design with an amplifier ... but I'm not sure how to be cautious....?
--- Thank you -- 🙂