B1 Buffer Preamp

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#2,281
Keith Lockwood said:
I have an off topic question for you. What was the name of the gentleman who was your national sales manager for Threshold during the mid eighties? I was the manager at one of your dealerships and we saw him quite often and remember that he was a pleasant fellow. Seems he moved on to a pro sound company called Myers Sound or something like that?
Click to expand...

During the mid-80's we did have Gary Hudson for a couple
of years, and he did work for Myer Sound Labs for a short time.

He was also one of the founders of ESS, and after that had an
amplifier company called QED.

He was rehired at Threshold prior to my departure, and died
a couple years later.

😎
 
#2,282
Nelson,

Thank you kindly for your reply. I am truly sorry to hear that Gary has passed. I knew Jim Thiel as well. I hate to see some of the people I enjoyed so much in this business starting to depart. The real jerks seem to live on forever though.

Please take good care of your self. You are such an asset to the industry and you were always friendly and fun when we did meet. Frankly we, as a dealer, were better at buying demo gear than selling the line but you still treated me with respect and I appreciate that. You and I only met a couple of times in Las Vegas at CES. Neither one of us had all this gray hair back then.

I did work for one of your original dealers back in about 1978.

By the way I love my B1. It is just what my system needed. I am trying to install a Bent Audio remote kit in it right now. That should be fun but not as easy as I though it would be but I did plan for it from the beginning so no issues with making it fit.

Thanks again,
Keith Lockwood
 
#2,284
Hi Maxlorenz,
I turn on my system properly and everything well ... but my wife does not. I leave the preamp prepared for any forgotten.

I will try to assemble a delay circuit for a relay.
What should the connections between the output of B1, the relay and the signal output connectors?
Br
Al
 
#2,285
If you hear a "snap" when turning off equipment, it likely
means that you do not have some capacitance across the
AC line or the switch to suppress the transient when you
interrupt current which is flowing. My prefer method is to
have AC LINE RATED filter caps across the line before and
after the switch - values like .01uF to .1uF.

😎
 
#2,287
Dear Nelson wrote:

If you hear a "snap" when turning off equipment, it likely
means that you do not have some capacitance across the
AC line or the switch to suppress the transient when you
interrupt current which is flowing. My prefer method is to
have AC LINE RATED filter caps across the line before and
after the switch - values like .01uF to .1uF.
Click to expand...

That's what I meant before 😀 though with the wrong concepts...

Thanks. I have some "Xs" and "Ys" caps around. I used them for some filters then I discarded them when I swore that they were detrimental for the sound... 🙁 that was on a period where I was still more an audiophile than a DIYer 😀 I bet that now they do not "sound" at all, he, he...

Cheers,
M.
 
#2,288
Hi,i have just finish my B1 buffer today,i bought my pcb from JIMS AUDIO,i had some problem with the selector switch.i had to mod it and now everything is ok,
i had three hours listening and will continue tomorrow,i use it with hk citation 16, now it replace my carver pre ,cannot make a jugement now but i think it`s better,one thing i`am having13.3 volts instead of 18 volts is it ok ,what is the difference
Thanks Mr PASS,
God bless you
Abes
 
#2,291
I have been reading all the posts over the last couple of days and am seriously thinking of building a B1. Do people think it would offer any improvement over a TVC and would it work with an Aleph 5 clone? Or should I just build one and see?
 
#2,293
Over at my friend's house together with is dual Promitheus reference C-Core more clarity/definition was perceived with the buffer but at the price of a minute lost of gain. But over at my house compared to my set-up with the B1 a standard Promitheus was not even a contest.
 
#2,295
For a few weeks I had the pleasure of using an active Experience Music preamp at my house that used a Sowter TVC. (This isn't what is used anymore as Sowter is no longer available.) It was quite a bit better than the B1, though for a very small investment the B1 is impossible to beat. A pair of AVC/TVC/IVC's from Sowter (not available)/Tribute/Silk or Intact will cost more than an entire B1 build with great parts.

All that being said, I sold my Transcendent Sound preamp after building the B1 and am slowly acquiring parts for a DHT buffer pre with inductive volume control. I like the B1. A lot.

Chris
 
#2,297
chrismercurio said:
For a few weeks I had the pleasure of using an active Experience Music preamp at my house that used a Sowter TVC. (This isn't what is used anymore as Sowter is no longer available.) It was quite a bit better than the B1, though for a very small investment the B1 is impossible to beat. A pair of AVC/TVC/IVC's from Sowter (not available)/Tribute/Silk or Intact will cost more than an entire B1 build with great parts.

All that being said, I sold my Transcendent Sound preamp after building the B1 and am slowly acquiring parts for a DHT buffer pre with inductive volume control. I like the B1. A lot.

Chris
Click to expand...

Good to know, i got some parts to build a lightspeed volume pot, im going to try that passivly with my mini a's and also try a B1. I bought 2 alps black beauty pots im also going to try too, with the b1 and with out. ( like passive pre-amps ) so ill have a few things to try.

I also have all my parts now to build my b1, i have a very nice idea for my case 🙂

Jase
 
#2,300
the B1 may well provide more current.
The two devices in the B1 are selected for same Idss.
The upper device is a source follower with a bias setting that roughly equals it's Idss.
Say you selected a pair of 10mA BL jFETs.
The quiescent current (bias) is ~10mA.
This is a single ended ClassA stage.
The maximum output is roughly +-9.5mA. It can flow slightly more than 19.5mA but it cannot flow less than 0.5mA (it will suffer severe distortion if you ask it to).
That +-9.5mA of maximum output current could be more or less than what the original source could deliver.

if V grade devices were selected then more output current is available. If GR devices are selected then less output current is available.

Would you like to follow and learn the advices/topics/links that this poster inquired about?
http://www.diyaudio.com/forums/solid-state/164987-understanding-amplifiers.html#post2151742
 
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