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Old 31st January 2013, 05:56 PM   #51
Salas is offline Salas  Greece
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The core design is well proven robust. Fetches overwhelming praise in the course of years. From my experience related to hundreds of builds feedback in my version's threads, when things aren't that rosy, is about choosing the wrong amp to drive with unity gain, or minor complaints about not stellar passive parts around it. Usually leads to substituting with better pots. Sometimes to better quality electrolytics also. Only real issue can be fake or wrongly matched semiconductor parts which readily show in DCB1 by excess offset but can hide that tell tale sign behind coupling capacitors in the case of the original complete design by Mr. Pass. Takes a closer technical look on their originality and selection again if there is a suspected issue.
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Old 31st January 2013, 06:28 PM   #52
tinitus is offline tinitus  Europe
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Quote:
Originally Posted by Salas View Post
..... Only real issue can be fake or wrongly matched semiconductor parts which
...... look on their originality and selection again if there is a suspected issue.
my immediate thought was that it appears a little 'suspect' if the matched devices are not properly marked, with the matching specs

wouldn't any serious person mark the devices properly
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Old 31st January 2013, 09:03 PM   #53
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Originally Posted by murphythecat8 View Post
hi danny, yeah Ive been suggest that my pot might not be the best I can have. while the noble is good, what company should I look for that would be definitely better then the Noble?
Pass seems to think the 10.00 PEC pots are just fine, I used them and agree. I would suspect J-fet matching. I know they say they are matched, but something isnt right...

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Old 31st January 2013, 11:49 PM   #54
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Originally Posted by brianco View Post
Fraid I did read it all. You whinged that it didn't sound right, despite advice to measure the FETs and advice from Mr Pass, you did not measure, yet had enough time to continue to complain. That - to me is 'rubbishing' the design. Don't even THINK of upgrading until you have the basic build working correctly.

EDIT: [After Salas post below.] The pot should be linear taper; is yours? Or is it Log taper? To be honest you would most likely do better buying new boards + a set of matched, real FETs from PASSdiy than changing the pot- unless it is a log pot.

From where I stand, my criticism was not personal; it was to try and get you to act on the advice given.... But I note that you have started a new thread asking for advice on pots.
you have a really condescendent attitude, even if I make people loose their time, whatever that means, your attitude is unkind and I find it harrassing, please do not "help" me anymore. seriously, you just had no reason to make me feel the way you did, please dont bother anymore and to be honest, you dont really help. A better pot would be a upgrade no matter what.

Last edited by murphythecat8; 31st January 2013 at 11:58 PM.
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Old 31st January 2013, 11:58 PM   #55
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I have to say though, I'm sorry for not having thought about it at first, I have used a LSK389 jfet, can that be the cause of my dissatisfaction. Really sorry, It totally slipped my mind until now!
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Old 1st February 2013, 12:18 AM   #56
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Not very likely.

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Old 1st February 2013, 12:20 AM   #57
brianco is offline brianco  Ireland
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Condescending I may appear, but the truth is that you gave an opportunity to some misguided persons to assume that the B1 is not an OK design. Now you admit that you used alternative FETs. I am pleased that I annoyed you enough to look! [ LSK389 has incorrect transconductance. [The B version is but marginal], LSK370 is the recommended alternative choice.] Get the correct matched FETs and I think your problem will be solved. I have built several FET buffers and never had problems. Then you can think about that new pot. [I mentioned the different pot tapers because the character difference can be misleading if incorrect]

Good luck.
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Old 1st February 2013, 12:23 AM   #58
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I have an offer. I'll send you some matched Jfets. Install them ands report back. If you don't like it, accept that it is not your taste and try your hand at a different design and let go of the questioning of the sound. What do you think?
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Old 1st February 2013, 02:08 AM   #59
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I have an offer. I'll send you some matched Jfets. Install them ands report back. If you don't like it, accept that it is not your taste and try your hand at a different design and let go of the questioning of the sound. What do you think?
hi, that would be great really. I would love that, if I like them, I just buy them off you?
what is the jfet?
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Old 1st February 2013, 02:09 AM   #60
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Not very likely.

so the LSK389 is ok in this design right?
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