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Old 3rd April 2009, 04:40 PM   #1
Malka07 is offline Malka07  England
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Join Date: Mar 2009
Default B1 Buffer and some help please!!!!

Well on the weekend I attempted to build the b1 buffer to compare with my passive pre, and this is the result...please excuse the burn marks on the boards...damn butane refill soldering iron!!!! lol





Well all looks well, but the problem is....It doesn't work Sound does come out...but is very distorted. The blue led light seems to only light up when the volume is turned up a little and seem to flash in time to the music being played!!!

Ok so i checked again to see that everything was wired up correctly and found that i had forgotton to link the two 10k resistors in series...so i did that but the sound is still distorted!!!
I have also noticed that i have wired up the jfets on one channel incorrectly but correctly on the other channel...funny thing is both channels sound distorted.

I have some spare jfets and im wondering if i should swap them in(the correct way round!!!) or wether i should be looking for another problem?

Any help i could get would be greatly appreciated...as im dying to hear this buffer in action.


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Old 3rd April 2009, 04:49 PM   #2
adason is offline adason  United States
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Location: Maryland
start all over again
its a simple circuit, it will work if wired correctly
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Old 3rd April 2009, 07:28 PM   #3
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Location: uk
hi Malka07

Your matrix boards bear a very strong resemblance to the photos posted on my web site. If you used my photos as a reference then from your photos it would appear that on one side your jfets are wired backwards.....

if that's the case then thats your problem...just turn them round, or better still, put the new ones in the right way round.


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Old 4th April 2009, 09:31 AM   #4
Malka07 is offline Malka07  England
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Join Date: Mar 2009
Hi Ed,

Yes i did indeed use your pics as reference, infact it was your comments on the b1 buffer that got me interested in building it
And as this was my first build apart from a passive pre and re-wiring and modding my wad kat34 it was invaluable to have your pics as a reference...thanks

You will be glad to know i have solved the problem and it is all working now....i had the generic diode wired to the wrong end of the 15k resistor!!! strange thing is the on one channel as you rightly pointed out the jfets are wired incorrectly but it still works!!!

As for the sound, well i am seriously happy...the whole thing cost me about 20 (no premium parts here) apart from some left over silver wire i had. It beats my passive pre with a vishay dale stepped attenuator, shunted with 2w audionotes, silver wire and solid silver phono connectors!!!

The soundstage is huge now, instruments so much more real and in there place...the bass goes lower and tighter and the clarity is amazing im hearings things ive never heard before...and perhaps one of the most improved aspects is the music is now ALIVE

Thank you Mr Nelson Pass, and thank you Ed for your help and pics for reference.

Now i just have to get it in a box and maybe change some of the parts. I will post pics when i have done it.


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Old 28th May 2012, 07:18 PM   #5
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Join Date: May 2010
Location: Texas
Default my B1

Hi Alon,
I have noticed a big improvement in sound over other good buffers,also has kindled a fire to build F5's one is almost ready to fire up and adjust and listen,also means I have to build more as I have a active system with 7 amps ,but I like DIY,lol. The new updated f5 turbo will fill that nicely just add more FETS and a BEEFY power supply and your done ,well for a little while,lol.
I built Nelsons Slot loaded woofer,I doubled them got 12 speakers in each slot ,I got NICE bass,THANKS Nelson
GOD BLESS our Troops
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