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Old 11th August 2010, 04:04 PM   #2601
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Thanks Russellc,
Yes the only desire for the kit was the great enclosure.
So next question is concerning what the output impedance is for the B1 Buffer and how well it will mate with a tube Amp with an input impedance of 100K. Second question is concerning the 25K Linear pot what can be gained by using a different value and are there any solutions for remote control of the pots?
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Old 11th August 2010, 04:56 PM   #2602
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Just one doubt about the B1. Why linear and not logaritmic pots? Why two mono pots? I can't imagine a major pain in the ***!
Once you have balanced the sound according to the room and your taste, you cannot control volume without skrewing it up.
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Old 11th August 2010, 05:02 PM   #2603
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Quote:
Originally Posted by HarryOOOO View Post
...was there ever a kit for the B1 and if so how much
Thanks
Harry.
The first post of this thread tells you everything you need for a basic build:
Nelson Pass B-1 preamp kit

You'll also need to buy RCA jacks and hookup wire. If you wish to spend more money and make a "premium" version, then there are many options for the caps / resistors. However, you can probably make a basic version for less than $150.
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Old 11th August 2010, 05:14 PM   #2604
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Quote:
Originally Posted by regiregi22 View Post
Just one doubt about the B1. Why linear and not logaritmic pots? Why two mono pots? I can't imagine a major pain in the ***!
Once you have balanced the sound according to the room and your taste, you cannot control volume without skrewing it up.
Regarding 1: Some folks have a preference for the independent control of each channel. Also, some worry about drift between the channels on a stereo pot (although that is usually only a problem at the lower volume settings). There is certainly no problem with using a two-gang pot.

Regarding 2: Since there is no gain on the B1 (it is just a buffer), the initial rotation would do very little (the speaker output would range from very quiet to quiet). By using a linear pot, the initial rotation would bring you into the "usable range" more quickly. Some prefer adjustments in the 9-12 o'clock range.

-Tom
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Old 11th August 2010, 06:46 PM   #2605
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The answer to the question is the usual:

I have a big box of these pots.

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Old 11th August 2010, 06:59 PM   #2606
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Thanks Nelson
So the next question is in regards to the tube amp with an input impedance of 100k I wish to use with the B1 buffer the B1 buffers output impedance is 1k is there an optumium match between input and output impedance?
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Old 11th August 2010, 07:11 PM   #2607
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I expect that 1K would be fine. I figure the minimum
output resistance would be about 100 ohms or so -
whatever it takes to avoid parasitic oscillations in a given
application.

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Old 31st August 2010, 07:29 PM   #2608
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Default transformer help

Hello guys i am gathering parts for my b1 build and i found a transformer that reads bolulder tech plug in class 2 trans- input 120v 60hz 25w-output 18vdc 533ma will this work as i have read 18vdc seems to work, and is there a way i can test it to see if it puts out 18vdc .
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Old 31st August 2010, 10:42 PM   #2609
AndrewT is offline AndrewT  Scotland
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Hi,
measure the output voltage.
Check it is DC and not AC.
Check which side of the socket is +ve with respect to the other side.
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Old 3rd September 2010, 06:47 PM   #2610
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I put my open chassis B1 into a box yesterday...

Still sounds great and looks much better. All in all a good use of a $4 Tatuaje box.

My wife even said something complimentary about the appearance.
Attached Images
File Type: jpg IMG_3063.JPG (37.4 KB, 885 views)

Last edited by chrismercurio; 3rd September 2010 at 06:53 PM.
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