15,000 seems a little overkill. Maybe inrush current is a little high. But don't those three pin regulators have overcurrent protection? I'd think a discrete shunt regulator circuit would work better.
isn't the B1 supposed to be used with a 'standard' external regulated supply
I even think a particular one is suggested in manual
with this low 'power' draw, I guess its basicly like running on batteries
unless...maybe shut down bleeders may be working against this
funny....but I think I have read that high capacity caps will be replacing much more battery functions in the future
I even think a particular one is suggested in manual
with this low 'power' draw, I guess its basicly like running on batteries
unless...maybe shut down bleeders may be working against this
funny....but I think I have read that high capacity caps will be replacing much more battery functions in the future
actually, with a 100.000uf cap I reckon a B1 would work all day, dissconnected from power source
mind you, I'm not suggesting to do that
only saying it might be possible
mind you, I'm not suggesting to do that
only saying it might be possible
The stock value of 15,000uf is there so the original PCB can be used with an unregulated supply, such as a wall-wart.
If you have a regulator, a smaller value cap could be appropriate.
If you have a regulator, a smaller value cap could be appropriate.
not useless but not as effective(?) I read somewhere the output of the regulator does not want to see a large capacitance. The large capacitance should be on the input side of the regulator. that's why I'm asking.
Mr. Pass says anywhere between 1000uF to 15,000uF so there is a good reason for the wide range. justed want to know why.
I once tried one LM3886 with a total of 200.000uF at +-35v. It stayed playing for half a minute at moderate volume with the power cord disconnected.
I thought that it was large inrush current on power-up that could kill the regs ?
If you deal with that, and stays well inside the current draw limit, what else problems could there be
If you deal with that, and stays well inside the current draw limit, what else problems could there be
Care to be more specific(Please)?
(If it helps for me to be more specific, I have a choice of the following caps: 4,700uf, 1,000uf, 330uf, 100uf, 10uf, or 1uf.) Which one? 😕
I'm planning on using what I have on-hand (a finished LM1084 adjustable series regulator, built according to the manufacturer's applications sheet).
I have little interest in undertaking construction of another regulator circuit, (especially one that approaches the B1 in complexity).
I want to be done with it so I can listen to music soon!
Thanks all!
-Chas
Clm,
the B1 has only 2 active devices in each channel.
It does not need a regulated supply.
Just follow Pass build instructions.
the B1 has only 2 active devices in each channel.
It does not need a regulated supply.
Just follow Pass build instructions.
Yes, no real worries about values. It's not that critical. With the items you mentioned, I would use 4700uf in each position - the 2 filter caps on the regulator board (but remember to use the film caps as specified the the 317 datasheet, and 4700uf on the B1 board. (in lieu of the 15000uf)
That said, you could save a bit of money and use 4700 before the regulator, and 1000 downstream, as well as 1000 on each of the board positions.
Remember to look at lead spacing ( to be sure they fit on the pCB) before you buy filter caps.
I used 6800 on my build mainly because that was available at the surplus store. It works fine and is dead quiet.
That said, you could save a bit of money and use 4700 before the regulator, and 1000 downstream, as well as 1000 on each of the board positions.
Remember to look at lead spacing ( to be sure they fit on the pCB) before you buy filter caps.
I used 6800 on my build mainly because that was available at the surplus store. It works fine and is dead quiet.
Does this mean there are no advantages to regulating the DC voltage?
I read that NP supplied a laptop-type 18v supply to Dick Olsher for his review.
What about ripple and noise on the rails? Can it be worse to utilize the precision series regulator(with high quality bypass caps) than just a bridge driving generic 15,000uf caps??
-Chas
Hi Chas,
I have used a voltage regulator using a LM1084 like this one:
LV30 Variable Voltage Regulator 1.5-30V (5A) Kit_Power Supply Kit_Analog Metric Limited - DIY Audio Kit
It works perfectly...
Cheers
,Eric
Exactly. You are most certainly not going to make anything worse (in fact, probably the opposite...) with a regulated PSU. Plus, you will like it more, and it has the added satisfaction of your project being made the way you want it. Which is very important -- it's why many of us do the DIY thing. 🙂
😀
Arick,
Pray tell: what cap values did you use on the B1 PCB (after the regulator that worked perfectly)?
TIA
-Chas
A B1 working as intended by NP using the build guide is far better than a non-working modified B1 everytime.
You must accept your limitations or learn to advance.
You must accept your limitations or learn to advance.
When we all started building these a lot of us used wallwarts. Yeah, I said it.. wallwarts. Then a few guys started using Lm317 and other adjustable regulators. That's how they found that some voltages sounded better than others. I don't think anyone left out the big cap. Why not do both?
Arick,
Pray tell: what cap values did you use on the B1 PCB (after the regulator that worked perfectly)?
TIA
-Chas
I used the 15000uf caps prescribed by Mr. Pass. I will try to post a few pictures latter.
Eric
"Going with da big cap"
Hi all.
Thanks for all the input. I'll go with my largest caps: 4,700uf caps(Nichicon KG type, bypassed with a B.G.NX/HQ 0.47uf) on the B1 board. Then I'll be using a B.G. FK 100uf(bypassed w/ B.G. 0.1) on the output of the LV30 regulator board. ok4me.
Andrew(no disrespect): I refuse to accept my "limitations", that's why I'm building a Pass preamp and doing it from "scratch". It's what makes the hobby interesting and exciting for me. I'm just glad I have some of the finest brains here to "pick" (yours included)!
Time to get out the soldering iron...
Thanks again.
-Chas
p.s. Anybody here experiment with different volume pots? Care to comment?
Hi all.
Thanks for all the input. I'll go with my largest caps: 4,700uf caps(Nichicon KG type, bypassed with a B.G.NX/HQ 0.47uf) on the B1 board. Then I'll be using a B.G. FK 100uf(bypassed w/ B.G. 0.1) on the output of the LV30 regulator board. ok4me.
Andrew(no disrespect): I refuse to accept my "limitations", that's why I'm building a Pass preamp and doing it from "scratch". It's what makes the hobby interesting and exciting for me. I'm just glad I have some of the finest brains here to "pick" (yours included)!
Time to get out the soldering iron...
Thanks again.
-Chas
p.s. Anybody here experiment with different volume pots? Care to comment?
