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Old 16th March 2009, 05:16 AM   #1481
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Default Integrated?

Has anyone built a B1 into an Fx amplifier for a simple integrated?

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Chris

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Old 16th March 2009, 08:47 AM   #1482
AndrewT is offline AndrewT  Scotland
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The B1 is not there to help improve the performance of the amp that follows.

The purpose of the buffer is to help the drive ability of the preceding stage/source cope with the load presented by the interconnect cables and the Zin of the next stage/receiver.

The B1 should be located at the outlet of the source, not at the inlet of the receiver.
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Old 16th March 2009, 11:56 AM   #1483
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Default Re: Integrated?

Quote:
Originally posted by chrismercurio
Has anyone built a B1 into an Fx amplifier for a simple integrated?

Regards,
Chris

I'm in the process of building one into a MyRef.
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Old 16th March 2009, 12:11 PM   #1484
AndrewT is offline AndrewT  Scotland
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Default Re: Re: Integrated?

Quote:
Originally posted by marc brown
I'm in the process of building one into a MyRef.
why?
What are you expecting to achieve?
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Old 16th March 2009, 12:23 PM   #1485
labjr is offline labjr  United States
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Default Re: Integrated?

Quote:
Originally posted by chrismercurio
Has anyone built a B1 into an Fx amplifier for a simple integrated?

Regards,

Chris


This was just discussed in the F5 thread.

http://www.diyaudio.com/forums/showt...34#post1771634
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Old 16th March 2009, 12:25 PM   #1486
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Default Re: Re: Re: Integrated?

Quote:
Originally posted by AndrewT
why?
What are you expecting to achieve?
Ummm . . . an integrated amplifier?



One less set of interconnects, one less chassis. My source control, buffer, volume control and amplifier in one box.

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Old 16th March 2009, 12:41 PM   #1487
udailey is offline udailey  United States
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I think that what Andrew is getting at is that the B1 is more buffer than preamp. The pots are the preamp and the circuitry is a buffer, so if your MyRef will perform well with just the pots then there is no need for the buffer and you can still cut out all the interconnects and integrate them into the same chassis. When I got my B1 I was psyched and built it right away. Then the MyRef board arrived and I built that quickly as well. Put a 10k pot on it and 'voila' it worked. Which depressed me cuz I wanted a reason to use my B1. So right now the B1 sits on the shop table waiting for a source that needs help driving a poorly matched amp through some particularly capacitative interconnects and in your case you probably do not need to help the source drive the MyRef. The 10k pot will probably do the trick fine. However, nothing is hurt by trying the B1 with the MyRef. It shouldnt change the sound and this is good but it might be unnecessary to use it in this setup.
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Old 16th March 2009, 12:52 PM   #1488
labjr is offline labjr  United States
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Default Re: Re: Re: Re: Integrated?

Quote:
Originally posted by marc brown


Ummm . . . an integrated amplifier?



One less set of interconnects, one less chassis. My source control, buffer, volume control and amplifier in one box.

The Myref has like a 100K input impedence. It doesn't need a buffer. It has a ton of gain too so I can't imagine you would ever need a preamp.
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Old 16th March 2009, 01:12 PM   #1489
BFNY is offline BFNY  United States
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Quote:
Originally posted by merlin2069er
I was in the process of hooking up my 2nd b1 buffer, and was expecting the LED to light up when hooking up the power.

It didn't, I checked the power coming into the b1 and it was ~ 35 vdc ( I have a walwart that's rated for 24v dc).

Anyways, I've unplugged the transformer and started checking the circuit. I retested the transformer and get ~2 volts out of it now.

I'm not sure if it was a bad walwart or faulty hookup.

Any suggestions? What would cause such odd results.
1) As you said, a bad wallwart to start.

2) A short to ground somewhere on the 18V power rail circuit would likely take out the protection built into the wallwart. Usually there is some sort of fuse in there, sometimes embedded in the transformer windings. Test the resistance of the 18 volt rail to gnd at the where the wallwart input hooks up. It could also maybe be a bad power cap, or a cap in backwards.
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Old 16th March 2009, 02:07 PM   #1490
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Default Re: Re: Re: Re: Re: Integrated?

Quote:
Originally posted by labjr


The Myref has like a 100K input impedence. It doesn't need a buffer.
Yeah, I know the MyRef doesn't need it -- even moreso now that I'm building a DIY.Lightspeed.VCCS. But, after I joined the MyRef group buy I needed to get some sort of line control stage. I've always loved Pass gear and building the B1 is the only way I could afford to get even a small piece of something designed by Nelson Pass. Eventually I may build an amplifier that needs a buffer stage so I can put the B1 in front of it.
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