B1 Buffer Preamp

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#2,741
sawdusttt said:
Line one from The Rules:

"diyAudio is a place for all members of the DIY audio community to learn, share knowledge, and enjoy interacting with others interested in the design and construction of audio components. This privately owned forum reserves the right to limit the behavior of its members. The rules will be enforced in good faith to maintain discussion quality and peer respect."



I have come late to the party. Electronics is a new hobby for me and I am on the steep part of the learning curve. I am going to ask stupid questions. We all start out here.

The B1 is an simple project for those with experience, perhaps not so simple if it is your first build. It seems like an appropriate place to ask simple even stupid questions. It also seems to be a good place to welcome and encourage newcomers. I'm not seeing that here.

Perhaps a B1 101 thread could be started where newcomers are encouraged. Maybe an B1 Advanced thread could be started at the same time. This B1 thread has run it's course perhaps it's time to retire it.

Fred
Click to expand...

The introductory headlines to the rules are not rules themselves. They are stating the spirit that the founder and administration liked to introduce for the forums. Threads are vast and participants multi level. Normally all questions are taken in a good stride no matter their level is our experience, much common attitude in Pass section threads. Nobody is demanded to contribute or reply, its intuitive. There are also NOTES to the rules like note 1. ''Trolling is posting inflammatory, extraneous, or off-topic messages in an online community with the intent of provoking other users into an emotional response or of otherwise disrupting normal on-topic discussion. Threadjacking is the practice of taking over a thread by posting off-topic replies such that the original topic becomes diluted or lost. Off-topic posts, and replies to off-topic posts, can be a positive outcome of discussion, but must either be brief or be moved to another thread. If something interesting does arise that warrants extensive discussion -- then start a new thread and link to it.''
:captain:
 
#2,742
sawdusttt said:
Line one from The Rules:

"diyAudio is a place for all members of the DIY audio community to learn, share knowledge, and enjoy interacting with others interested in the design and construction of audio components. This privately owned forum reserves the right to limit the behavior of its members. The rules will be enforced in good faith to maintain discussion quality and peer respect."



I have come late to the party. Electronics is a new hobby for me and I am on the steep part of the learning curve. I am going to ask stupid questions. We all start out here.

The B1 is an simple project for those with experience, perhaps not so simple if it is your first build. It seems like an appropriate place to ask simple even stupid questions. It also seems to be a good place to welcome and encourage newcomers. I'm not seeing that here.

Perhaps a B1 101 thread could be started where newcomers are encouraged. Maybe an B1 Advanced thread could be started at the same time. This B1 thread has run it's course perhaps it's time to retire it.

Fred
Click to expand...
I don't understand your attitude. Have you already read the whople one hundred and thirty seven (at least in my post-per-page config) pages of the thread?

Atilla has sooo kindly replied to you, what are your reasons to critizice the forum?
 
#2,743
Yes, I have read every page of this thread, and every page of the F5 thread plus the B1 and F5 threads at AK and other sites. I had a hip replaced five weeks ago so I have had plenty of time to read. I have taken extensive notes and learned a great deal but due to my lack of practical knowledge some questions remain.

This morning before I posted here I Emailed Night Rush (Florian) thanking him for being helpful. I didn't feel the need to post it here. Who is Attila?

The LED question regarding specs is still on the table.
Also, does the LED serve a function when the B1 is powered down or is it strictly an indicator light.

Thanks,
Fred
 
#2,747
I fearlessly created a rat's nest in a box a while ago, which buzzes like an angry swarm of bees. But I also fearlessly have 2 more B1s, standard and DC-coupled which sound grrrreat.

Keep on building stuff. I mean - how bad can it go 🙂

The LED is just a led. It's there to shine. Sure, caps will also discharge trough it, but you've got your class-A buffers to draw that down as well. Use whatever color/forward-drop you like. Mine are white, with that eery blue tint.
 
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#2,748
Atilla said:
I fearlessly created a rat's nest in a box a while ago, which buzzes like an angry swarm of bees. But I also fearlessly have 2 more B1s, standard and DC-coupled which sound grrrreat.

Keep on building stuff. I mean - how bad can it go 🙂

The LED is just a led. It's there to shine. Sure, caps will also discharge trough it, but you've got your class-A buffers to draw that down as well. Use whatever color/forward-drop you like. Mine are white, with that eery blue tint.
Click to expand...
I run my 3mm leds through 470K Rs so they barely glow. Lately I have used UV leds, acqua and blue.
 
#2,749
sawdusttt said:
I was wondering about the headphones myself.

The only references to what type of LED to use were non specific. NP called it "common" someone else said to use a 5mm.
What voltage should it be?
It serves a function when the unit is powered down so does the amount
of draw it has matter? I am going to run off batteries and prefer it to be
not too bright so I would like it to have as little draw and output as necessary.

Thanks,
Fred

Newbies Unite!
Click to expand...

Since D2 is just a generic type of LED you could just buy one in whatever color you like that will fit the board. Raising the value of R4 will reduce the current through the LED.
 
#2,751

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#2,752
I have a vision of ZM dying at the age of 100 (I wish you even more!), lying in his deathbed and singing this old Harrison song:

Fab - long time ago when we was fab
Fab - but It's All Over Now Baby Blue
Fab - long time ago when we was fab
Fab - like this pullover* you sent to me

😀

* or Pass Labs polo shirt
 
#2,754
Relay in output of B1

Hi,
I integrated my B1 into a Marantz chassis and managed to reuse the power relay of the original Marantz, thinking that the delay would gives things time to settle before the power-amp gets to see the signal. However what happens is that the relay closes with an audible click coming through the speakers, which kind of defeats the objective of protecting the amp / speakers. I have not had this experience before and I am wondering of it indicates some excessive voltage on the output of the B1 or just a standard switching effect.

If the latter, can anyone advise on a cure.. for example connecting a small value (what value?) capacitor across the relay contacts?

Apart from this, the B1 has performed faultlessly. Embedding it in the Marantz chassis allowed me to reuse the switching and so on of the Marantz and, finally, to get a decent front panel... this time for free!
As ever, thanks for the help.

George
 
#2,758
The CLICK

Hi,

well that is very interesting... Marantz must have put a lot of thought in to preserve a click like that!
If that is the case I am going to experiment with a low value cap to see if it suppresses it.
I have searched various documents that describe relay switching circuits; so far none have found it necessary to show a paralleled cap across the relay.... that makes me very suspicious.

George
 
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