I m too not sure about my pass b1

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#42
Murph:

You are just wasting the time of all of those who have tried to help you. The "problem" is clearly of little concern to you! Why should it be to anyone else? All you have done is "rubbish" a design with which very many builders have been happy!
 
#48
Measure the FETs first, then get an Alps Blue. That will be enough to tell you whether you do actually like the amp.

Your post in post no. 41 was so casual about the whole thing that I felt that everyone who had given you sound advice was being given the finger.
 
#49
Brianco, I dont know if you have read the whole thread but I did not wasted people time in here. people have actually helped me and while I dont have the time to do what they told me right now, I will soon... Also, I dont know how I did a `rubbish`` B1, I did everything correctly.

The alps blue is considered less good then the noble, so it will most likely be more like a sideway rather then a upgrade.
 
#50
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.🙂
 
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#51
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.
 
#52
Salas said:
..... 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.
Click to expand...

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 :scratch:
 
#54
brianco said:
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.🙂
Click to expand...
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.
 
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#57
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.
 
#58
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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