DC-Coupled B1 Buffer Build

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walkern

  • Full Member
  • Posts: 459
Re: DC-Coupled B1 Buffer Build
« Reply #60 on: 23 Feb 2012, 06:43 pm »
Hi Fred,

I was hoping someone with more know how would chime in here... but nothing yet, so I'll offer my suggestions.  I did my B1 quite a while ago, and have subsequently sold it, so relying on memory here.

1) Twist together the two red wires and connect them both to either the hot or neutral AC lead coming in.  Twist together the two black wires and connect them both to the other AC lead coming in (hot or neutral).  Some folks at DIY Audio suggested running a wire from the AC ground lead to the chassis, but I did not do that, and encountered no issues (hum).

2) If you track the green and blue wires coming off the trafo you'll notice there is an outlying green, and outlying blue, and a green and blue right next to one another.  Connect the outlying green to one of the outside connections on the Molex connector (on the board), connect the outlying blue to the other outside connection on the Molex connector,  and twist together the two adjacent wires (one blue, one green) and attach both to the center connector on the Molex connector.

Since I had the hypnotize board (which had no input switching) I can't help you with your inquiry regarding the input selector.  Sorry.

And yes, you can just run a second set of outputs (one for your main amp, and one for a sub amp) by just tapping off one to the next.  Worked like a champ for me.

Best of luck!

Neil

Fredly

Re: DC-Coupled B1 Buffer Build
« Reply #61 on: 23 Feb 2012, 06:52 pm »
Thanx for the quick reply back Neil, I understand the tran wiring clearly with your explantion. :thumb:

Now if someone could clarify how the Switch Selector hooks up to the Mezmerize, that would be awesome!

Cheers, Fred in Canada

Pboden

Re: DC-Coupled B1 Buffer Build
« Reply #62 on: 27 Feb 2012, 08:33 pm »



Just finished mine, but the leds are not giving me the complete lightshow. V- is ok, but the V+ is around 7vdc

Any idea where to start looking ?

laptopboy

  • Newbie
  • Posts: 1
Re: DC-Coupled B1 Buffer Build
« Reply #63 on: 24 Jan 2014, 03:28 pm »

The LEDs probably don't light because one or more have been reversed in the chain.

BTW: I don't know if this was mentioned before, but the build document shows that the 0.22 uF capacitors were installed incorrectly.  The +/- pads on the board are not oriented in the same way for both caps, which were installed assuming they were.




Mbain

  • Jr. Member
  • Posts: 29
Re: DC-Coupled B1 Buffer Build
« Reply #64 on: 22 Feb 2014, 08:26 pm »


BTW: I don't know if this was mentioned before, but the build document shows that the 0.22 uF capacitors were installed incorrectly.  The +/- pads on the board are not oriented in the same way for both caps, which were installed assuming they were.




What? More specifics please.

SONDEKNZ

  • Jr. Member
  • Posts: 7
DC-Coupled B1 Buffer Build: Still available?
« Reply #65 on: 1 Sep 2014, 06:25 am »
Guys


A brand newby here from clean, green, beautiful New Zealand.

Just today I stumbled upon this wonderful forum for the first time, so this is my first post.

QUESTION:  Is the DC-Coupled (Pass) B1 Buffer Build board and BOM still an available option?  If so, where do I go for ordering and help please?  Appreciated.

 :green:
SONDEKNZ


PS:  Wonderful forum, but pretty tricky figuring out how to begin a new topic, insert signature, avatar, etc...

Nick77

Re: DC-Coupled B1 Buffer Build
« Reply #66 on: 1 Sep 2014, 11:57 am »
Here is the build thread and Tea-Bag is the gentleman to contact for boards.

http://www.diyaudio.com/forums/pass-labs/176723-mezmerize-dcb1-building-thread.html


WireNut

Re: DC-Coupled B1 Buffer Build
« Reply #67 on: 29 Jan 2019, 09:58 pm »

MATCHED/UNMATCHED FETS

You will need 4x matched 2SK170BLs per the BOM.
Or you can order bulk from someplace like Ampslab and use the DMM measurement setup
to match Idss.
You will want 6mA or higher.

This will be explained later.

Hi Wushuliu, Great Thread, Thank you.

I just received some 2SK170BL's and need to match them.
You mentioned that you would explain later how to match them but I can't find it in this thread.

Can you explain how to match them and can it be done with a basic DMM?

Thanks,
Steve





 

wushuliu

Re: DC-Coupled B1 Buffer Build
« Reply #68 on: 2 Feb 2019, 09:44 pm »
Hi Wushuliu, Great Thread, Thank you.

I just received some 2SK170BL's and need to match them.
You mentioned that you would explain later how to match them but I can't find it in this thread.

Can you explain how to match them and can it be done with a basic DMM?

Thanks,
Steve


Hm, could have sworn I did, but here's a succint explanation I found on how to do it:

Quote
hook up a simple jig with a 9v battery and a 100R resistor in series with the jfet and measure the voltage drop across the 100R resistor to find out the idss. do it with the rest to get your match.





tubesguy2

Re: DC-Coupled B1 Buffer Build
« Reply #69 on: 4 Feb 2019, 07:23 pm »
Hmm, the text and the diagram seem to be two different setups. The resistor drawn on the diagram appears to be 1K (or possibly 4K -  the person who drew the diagram was not taught how to write (draw?) by a Catholic nun, btw) and the voltage source, while it appears to have a "9" associated with it, has some other baffling squiggle preceding that 9.

But yes, a voltage and a resistance, and then some type of Law.

wushuliu

Re: DC-Coupled B1 Buffer Build
« Reply #70 on: 4 Feb 2019, 10:02 pm »
Hmm, the text and the diagram seem to be two different setups. The resistor drawn on the diagram appears to be 1K (or possibly 4K -  the person who drew the diagram was not taught how to write (draw?) by a Catholic nun, btw) and the voltage source, while it appears to have a "9" associated with it, has some other baffling squiggle preceding that 9.

But yes, a voltage and a resistance, and then some type of Law.

Yes, two examples with a 9v. One with 100R, the other 1K. I believe 1k was the one I used.