[tranhieu]

thanks for the helpful posts

 

[Iniamyen]

 
Quote:

neat actually has very little to do with it - the real trick is keeping signal wires as far away from power wires as possible, and DEFINITELY not having them run in parallel close to each other.  any time they must cross, it should be done at 90 degree angles.  these two things should reduce noise by quite a margin, but it still takes a lot of time and a lot of tweaking by moving the wiring around until you reach perfection
 

 

In my experience, power wires are ok as long as they are DC, since there is very little *changing* magnetic field around a DC wire, especially if the power supply itself has very high PSRR. AC power wires (with transformers being the worst of all) are much more of a concern. Since AC power wires and transformers can generally be sequestered in the corner of a box, you should be able to avoid it easily. But, like everyone else has said, you have to AT LEAST consider it

 

[bhjazz]

tranhieu, all of the issues mentioned, when combined and done correctly, make the amp what it is.  If the wiring is good but the biasing was careless, no dice.  And the reverse as well.  Or perhaps the builder got a great deal on some cheap parts...that'll kill it, too.  For the wiring, though, you might want to dig through the build thread and look at some of the photos there.  Additionally, check out the '22 build thread as well.  You'll find out pretty quickly how all of these things need to work together.

 

[tranhieu]

Wao thanks! I actually am planning to build a B22 this Oct. for my K1000, I'm now using them with the M3 and they sound magnificently already!
the OP's post quite put me off at the beginning, but things are much clearer now, I actually didnt know about all those wiring things until now (luckily I built the M3 and the S11 in 2 separate boxes)

 

[downsize]

Quote:

Wao thanks! I actually am planning to build a B22 this Oct. for my K1000, I'm now using them with the M3 and they sound magnificently already!
the OP's post quite put me off at the beginning, but things are much clearer now, I actually didnt know about all those wiring things until now (luckily I built the M3 and the S11 in 2 separate boxes)

I really did not mean to put anyone off the B22. I was seriously considering having one built for my own self, but that was because I thought the B22 would probably take me in a big step up with regards to sound quality. Since originally posting this thread, I have had several people who have owned both my amp, and a B22 .... or people who have actually compared them head to head.
This led me to believe building a B22 would be a waste of my time and money, for the kind of gains I was looking for.
        As far as my remarks about the particular B22 I listened to, I do not know any details about that particular amp. I do know it was sterile, cold, and unimpressive .... and that other members at the meet privately agreed with me.
I have no doubts a B22 is one of the very best solid state amps available .... I just doubt it is THAT much better than what I already have.
        I was after info only, and did not mean to offend in any way.

 

[digger945]

To answer your OP, the major part of the differences in any world class amp like the B22, apart from the ones mentioned already, will depend on the source that is used.

 

[IPodPJ]

Source is KEY.

 

[deathg0d]

yes, i must say, source is very important and since op you are not sure or mentioned what were the source and setup you heard from the meet, it is just not the final verdict that b22 is/was not worth building. also, op, you did not gives us an idea what you have not so no one here really have any idea how superb you setup is???
 
you have only heard 1 b22 from the meet. however, there already have been countless of people owning and building b22 who will thinks that your claims has not much facts to it. also "what" was the big step you are looking for? amp from the heaven?

 

[321-Gone]

This is my first post here on head-fi. I finished building a 3-channel b-22 just about a month ago and have to say that I am more than satisfied with the sound quality. I guess that there are many variables to take into account when building the b-22. As other members have already mentioned, I found that a proper DC offset (as close to 0mv as possible) and quiescent current (160ma) to be crucial in the setup of the amp. The proper cooling of components esp. the mosfets would allow for such a DC offset without the internals getting too hot and decreasing the lifespan and capacitance of the capicators (they do decrease in performance as the temperature goes up). Another very important point to consider is the proper matching of the components for optimal sound quality. I know that a lot of this is just repeating AMB's instructions but I have to say that as I increased the quiescent current to 160ma and got the DC offset closer to zero, there was quite an audible difference in sound quality. I too would agree that the wiring setup of the b-22 is crucial to low noise. Also, the source (again mentioned in previous posts by members more knowledeable than me) has a lot to do with the sound quality and also the colouration of the sound since I would say that the b-22 is one of the most neutral amps I have heard. Sorry for the long ramble, hope this has been helpful.

 

[qusp]

haha i'm glad you corrected yourself there
 
 
 
Quote:

I found that a proper bias (as close to 0mv as possible) and a DC offset (160ma)

 
 
to
 
 
 
Quote:

 I have to say that as I increased the quiescent current to 160ma and got the DC offset closer to zero

 
 
it made a little more sense hehe, I knew what you meant the first time around, but worth an edit.
 
i'm also not a massive fan of the beta22 out of any source, taste only, I like solid state, but much prefer Jfets and find the B22 a little bit grey. fast, quite dynamic and transparent, but just lacking the tiny bit of colour that I enjoy, that makes an amp sound natural to me, not warm, just natural. I like the music to flow, I do not want to pick it to pieces
 
jeez I hope the builder hasnt read this thread though, knowing that people were talking 'politely' behind his back about how it wasnt a good example.
 
one thing that should be mentioned about routing as well, which was covered but not explicitly, is proper grounding, which to me is at least as important as power routing, especially for a 3 channel version.

 

[321-Gone]

Thanks qusp for the correction. My first post and my first edit

. I would have to agree with qusp, proper grounding is critical. I ran into some issues in the begining, but got them sorted out after careful consideration of the setup instructions.

 

[qusp]

no problem, wasnt a biggie of course, just had me make a funny face to myself briefly. hey and welcome BTW, sorry I meant to do that. yep grounding is Key, properly and thoroughly, but minimally.
 
you will learn that even in the DIY section the wallet sympathy phrase has meaning

 

[holland]

Quote:

... I like solid state, but much prefer Jfets ......
 

 
Can you clarify the bolded part?  JFETs are used in the B22 input stage.  Do you have a topology example?
 
I'm not sure why the thread was dug up.

 

[BebopMcJiggy]

I think he wants jfet output? :O

 

[samsquanch]

if you want to get real nerd about it, the power coming into the amp could have been dirty.  did each station have it's own dedicated circuit?  was the circuit isolated and filtered?  It's not very likely that the power from the wall would make it sound awful, but weirder things have happened.
 
Also, if the persons soldering skills suck, well....
 
definitely listen to another one when you get the chance.