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Old 26th February 2013, 03:30 PM   #681
6L6 is offline 6L6  United States
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Quote:
Originally Posted by richluvsound View Post
I think I have a problem with the selector .... can't get any continuity with the DMM
You are measuring it incorrectly. Grayhill switches are Mil-spec, the likelihood of you having a bad switch is about the same as finding an honest politician...

If I recall, Grayhill switches have many contacts (solder lugs) on the same plane, these are the "input" connections.

You have a 2-pole switch, so there will be 2 lugs (likely opposite of each other) that are on a different plane, probably closer to the shaft. Those lugs are the output connections. (common) Set the DMM to continuity beep. Put one lead of your meter on one of the output lugs and now touch each of the input lugs until you get a beep. That will show that in and out for that particular switch position, on that half of the switch. Move the switch and repeat. After messing with that for a bit you will see which lugs on the input connect with the output lugs.
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Old 26th February 2013, 06:19 PM   #682
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Thanks 6

I have checked it and all OK ......

Going to wire it up and give it a go . Where does the common go to ? RCA L\R respectively ?

R

PS , where does the B1 board get its signal from ?

Last edited by richluvsound; 26th February 2013 at 06:45 PM.
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Old 26th February 2013, 07:22 PM   #683
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BINGO ! Finally , after 18 months gathering dust in the cupboard .

thanks all .

Rich
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Old 26th February 2013, 08:35 PM   #684
6L6 is offline 6L6  United States
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Rich - Is it working?
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Old 26th February 2013, 09:41 PM   #685
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Yes thank you Sir 6 !

Used 9v batteries . Bit of a hum ,but thats not a suprise considering its gator clipped together .

PSU ? If you remember , you helped me build it last year . The batteries do sound crisp though ,but I have the PSU board made up all ready , the IEC and the switch sitting here .

What are my options ?

Rich
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Old 26th February 2013, 09:49 PM   #686
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So you just need a transformer? 14-20v secondary voltage, 50VA or so is all you need. Let me look at Farnell for something appropriate.

A DC wall-wart at 20-24v or so would be fine, just remove the rectifier on the regulator board.

A laptop PSU would also work, they are usually 19v. You wouldn't need the regulator, however.
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Old 26th February 2013, 09:59 PM   #687
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Cool , I wait for your advice
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Old 26th February 2013, 11:19 PM   #688
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This looks good - MCTA030/18 - MULTICOMP - TRANSFORMER, 30VA, 2 X 18V | Farnell United Kingdom
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Old 27th February 2013, 11:15 AM   #689
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I see that a lot of folks have utilized standoff connectors like this Digikey part number:

1776275-2 TE Connectivity | A98036-ND | DigiKey

Can someone please post the exact ones that fit the original B1 board? I'd like to use them rather than solder the wires where possible to maximize the experimentation potential of the board.
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Old 15th June 2013, 01:17 PM   #690
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Default B1 Sound

Hi all,
Iíve recently built a B1 using a Pass DIY PCB and have been listening and experimenting with different capacitors. I have tried some audio grade MKP types from Maplin on their own and with low value (100nF) bypass caps and also some Mundorf aluminium Ė oil types from Hifi Collective wih and without the bypass capacitors. All combinations sound different with the ally Ė oil types on their own sounding nicest.
The B1 is powered using a simple linear regulator circuit with a John Linsley Hood shunt regulator across it giving about 18.6 volts. I am quite a fan of these shunt regulators and have been using a pair on the supply to a Linsley Hood discrete component shunt feedback phono stage for nearly 20 years and they made an impressive improvement to the sound (using a low output moving coil cartridge) when I added them.
Anyhow, I have to agree with KatieandDadís opinion that the sound lacks excitement. Itís as if the ďattackĒ and dynamic impact of the music is diminished. Also the stereo soundstage has somehow shrunk. I had a long listen last Sunday afternoon and eventually re-connected my 26 year old (itís older than I was when I bought it!) Audiolab 8000C preamp and WOW excitement, dynamics and attack have returned and the stereo soundstage is now huge, 3 dimensional and well out of the speakers again. Iím using 2 Pass A40 monoblocks which I finished earlier this year. I was wondering if anyone may be able to shed any light on this or if KatieandDad managed to cure their B1 and make it sound as good as it should? I have included a photo with the Mundorfs fitted.
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