Wayne's BA 2018 linestage

[gary s]

Keep us updated Gareth as I would like to buy 2 of these - not very good quality control from the fab house - I assume in China!

Cheers

Gary..

 

[Manolo47]

I need advise as to how handle smd transistors in kit

very small, one already flew away from tweezer, impossible to find. So anybtips on how to solder this easily? Thanks.

 

[pfarrell]

very small, one already flew away from tweezer, impossible to find. So anybtips on how to solder this easily? Thanks.

I have found that "painting" on a little paste flux to the pads on the board will cause the parts to stick nicely enough to nimbly touch down with the iron and a bit of solder whilst holding the part firm with some tweezers. Worked awesomely when I recently made Norwood boards, from M2X.

 

[Russellc]

I used 6l6's helping hand plus bamboo skewer to hold it still. I found touching a tiny amount of solder to tiny pads, then use contraption to hold in place. Touching iron to one pad will attach it, then solder other 3, going back to finish first one.

YMMV,

Russellc

 

[Manolo47]

thanks farrell, worked like a charm. And those 4 220uf caps in the blue board that are not in the purple board?.. did not order these,...are they necessary?

 

[6L6]

Not necessary. If you want to stuff them with something that fits, go ahead, but they can be empty as well. Just a little bit of additional PSU filtering.

 

[flamethrower1]

very small, one already flew away from tweezer, impossible to find. So anybtips on how to solder this easily? Thanks.

Those things are hell on an old mans eyes.
Wish I would have ordered a couple of extras.
I am going to do those first as everything else after that should be easier.
Not looking forward to it though.

 

[Manolo47]

Q21 and Q22 identifications in the blue board are transposed, so you know. Correct me if I’m wrong.

 

[Manolo47]

its of no consequence if you do not check continuity from the smd transistors to other parts of the circuit though the transistors are all the same.

 

[Gaz2613]

Anyone still after Dual Rail PSU boards that don't mind the silkscreen being a little screwed up. Drop me a PM. They are discounted because of this error. I have got the fab house to make another batch but that will be another few weeks. Physical board size which I measured is 219mm x 94mm.

I also have Single rail positive boards too for anyone interested which are approx 170mm x 70mm

 

[Manolo47]

Hum!

Looked into this topic in this thread but did not find it. Offset at 0v in both channels. Replaced the ba-3 board in my linestage using the Salas v1.3 bipolar powe supply set at 24/-24v., both channels produce music but there is a loud hum in both. I wonder what could I have done wrong. I guess it has to do with a ground issue, a lot of ps wiring from the ps board, etc,. maybe too many “grounds” what should I look for? I am including a photo of the connection setup.

 

[6L6]

Could we see a photo of the actual wiring as well?

And please bring the amp to a well-lit area so the photos are in good focus and sharp.

 

[Centurion53]

Up and running!

Well I finally got my BA 2018 pre up and running! Easy to adjust P1 and it worked perfect on powering up and it sounds great. Now I have to take it apart and figure out an enclosure. Thanks for the pointers! I'll post a photo when it's in the case.
Bill

 

[6L6]

Fantastic news!!

Looking forward to seeing it

 

[Manolo47]

and does this thing need a chassis ground? ....

 

[Manolo47]

It looks that is solved. A couple of cold joints in the wiring.

 

[6L6]

Aha! Well done!!

 

[Manolo47]

listening to it. Hum changes with the position of the wiper in the attenuator -Goldpoint 50k stereo- listening at 12 o’clock now, no hum, if I vary the volume there is a tracking noise and might hum again at different points. Read somewhere here about grounding the attenuator to chassis?

 

[Manolo47]

grounded the attenuator to chassis from -attenuator ground post to chassis- Hum gone but still tracking noise when turned. Strange, this attenuator worked fine, So there must be something else....Must be missing some ground connection or too many....

 

[mpmarino]

Do you have DC at the attenuator? This can cause noise while turning.