B1 builders thread

[AndrewT]

Hi,
if you already have the speakers and the amp then adding a B1 is cheap. You can breadboard it as an experiment.

To check gain, just use a passive pot, it will have the same maximum volume as a pot + B1

 

[endrik35]

Me and Les wants to impart a Zen spirit to this pre-amp. I bought a rubber wood the other day, painted it with maple varnish and burned some portions to achieve a "bird's eye" maple effect.Then I attached it to the sides of the B1.

 

[IZHAKKATZ]

No Andrew T

I don't have the amp
Just the speakers
I wanted to build the combo (B1 + F5)

ik

 

[AndrewT]

Borrow a 25W to 30W amplifier and listen to your speakers at home at the levels you like.

 

[6L6]

endrik35 -- Your build is beautiful! Very well done!

May we see some photos of the inside?

Question - what did you do to make the "Pass" logo on the front? It looks nice.

 

[endrik35]

Thanks Sir 6L6. Here are photos of the innards:

Re: Pass logo, there's a sticker shop here in the Philippines which uses laser to cut acrylic plates.

 

[Arick]

Finally my turn to post pictures of my complete B-1. It is a balanced version (or RCA) and it uses 2 DRV-134 (Per Anders PCB) to convert the RCA signal to XLR. A word of caution: I had to use 2 separate transformers to get the DRV-134 to work with the B1.
Cheers to all,
Eric

 

[exojam]

6L6,

I apologize if I missed in this thread or your build thread but where did you get that chassis from for your B1? Thanks.

James

 

[6L6]

I got it from a friend, who in turn bought it from a now-defunct supplier called (I think...) DIY hifi enclosures.

Look to Par-Metal or Modushop for nice enclosures.

 

[exojam]

Thank you.

James

 

[exojam]

6L6,

One last question, do you have the dimensions of it?

I like the way you incorporated the power supply within the same chassis and when I modify mine I would like to do the same (get mine off a wall wart).

James

 

[shanx]

Hey Arick..nice build on the preamp!! CLEANN

 

[harrydg]

I have a question too... on the B1, i see that the switch for the 2 inputs each have a 1MOhm attached to the input. Why do you need R100/R101 and R200/R201? why not just use 1 resistor and use that one for both inputs?

In other words: what is the advantage of having 2 resistors instead of just 1 connected "higher" up?

 

[Atilla]

Those are just there so that the device that's currently not connected doesn't have its output left open.

And you really don't want to connect the 2 inputs together, that's what the switch is there in the first place

 

[harrydg]

hm.... i didn't know there was a difference in:
input - resistor 1M - nothing ("8onitsside impedance")
input - nothing
And connecting them together... well du'uh

Thanks for the explanation!

 

[Roscoe Primrose]

It depends. Some sources may develop a small DC offset when left unterminated, which can give you a significant pop when changing inputs. The separate resistors for each input should help eliminate that problem....

Roscoe

 

[Arick]

Hey Arick..nice build on the preamp!! CLEANN

Thank's
ShanX

 

[richluvsound]

Balanced B1

Hi Gents ,

I have the boards and the caps ready to start my balanced B1 build . Can anyone help me with a schematic and any other info that will help me get off in the right direction . I have seen a mention of a balanced version ,but I can't find anything concrete enough to get me started . Not asking to be spoon fed ,but I do need some help .

I have built a couple of power amps after a lot of mistakes and corrections , so I have a little experience ,but not enough to go off on this project without some guidance .

If there is anyone out there that can keep an eye me I would be truly grateful .

Thanks , Rich

 

[6L6]

If there is anyone out there that can keep an eye me I would be truly grateful

Just post lots of pictures and ask specific questions in this thread and you will get lots of assistance from many people who love to help!

Looking forward to seeing your progress.

 

[Arick]

Hi Gents ,

I have the boards and the caps ready to start my balanced B1 build . Can anyone help me with a schematic and any other info that will help me get off in the right direction . I have seen a mention of a balanced version ,but I can't find anything concrete enough to get me started . Not asking to be spoon fed ,but I do need some help .

I have built a couple of power amps after a lot of mistakes and corrections , so I have a little experience ,but not enough to go off on this project without some guidance .

If there is anyone out there that can keep an eye me I would be truly grateful .

Thanks , Rich

Hi Rich,
You can go to post #2547 of the thread "B1 Buffer Preamp" on page 255. There is a basic wiring diagram there, It should help. I finished mine, works great. Feel free to ask more questions
Eric