B1 Buffer Preamp

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nightrush

nightrush

Member
Joined 2010
sawdusttt said:
Frustration is starting to sink in. Is it just me or is trying to search at Digikey difficult?

NP mentioned using a 5ohm 3w for R1.
Is there such a thing or have I missed something? Do you have a source for said resistor.

This is my first build where I'm sourcing the parts (an earlier effort stopped when the aggravation to fun ratio went upside down. I'm trying to prevent this from happening again.


Thanks,

Fred Griffith
Click to expand...

Hi,

I've found thirty different resistors!? Maybe you did something wrong:
Click this link--> Select 5ohm and 3W --> "Apply Filters" --> "Show Page"

:rolleyes:

~ nightrush
 
H

Harolda

Member
Joined 2005
output caps on B1

I have a question on the output caps for the B1. I am using a B1 with a symmetrical PSU. Now i am using PIO (russian) 1uF and 10uF as output caps.
I want to try now russian silver-mica which seem to be very good, but i have to go down to .1uF to .2uF. would this be possible.

I am using the B1's in a active crossover. I use 1uF as the HP output caps and 10uF on the LP. I would then replace 1uF with 0.1uF and 10uF with .2uF! The crossover will drive a LM3886 on both low and high (audiosector kits).

thanks for response
 
6L6

6L6

Moderator
Joined 2010
Paid Member
Hello all!

I have a very PassDIY specific question -

I have recently inherited a set of Original Pearl Phono boards with the transistors. Would the B1 be an appropriate line level circuit to make this into a full-unction (Phono and Line) preamp? I.E., is the Pearl a good match for the B1?? And vice-versa?

Is there any good way to cheat a power supply for the B1 using the original Pearl circuit and PSU suggestions?

In a perfect world I will be able to use the Pass B1 circuit board. However I am not opposed to building the B1 circuit on perfboard if I have to.

Thank you in advance!
 
M

MechanicalAnimal

Member
Joined 2009
Hai guys,

just ordered my B1 PCB @ passdiy, should be here in hopefully 3 weeks, so plenty of time to ask dumb questions.

i got one at the ready just now :D

as a novice in this area i have a little trouble understanding the following found in the B1-manual:

"With the exception of R1, all the resistors are ¼ watt"

okay..so R1 is a 3watt resistor..but what is the value of R1 in Ohms? Is it 1K but is the "k" missing? Or is it 0.1 Ohms

I enclosed a picture of the schematics to see what makes me confused.

my apologies for my novice-level on this subject, i hope you guys can help me out.

Greetings from The Netherlands.

Maarten
 

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Last edited:
nightrush

nightrush

Member
Joined 2010
MechanicalAnimal said:
Hai guys,

just ordered my B1 PCB @ passdiy, should be here in hopefully 3 weeks, so plenty of time to ask dumb questions.

i got one at the ready just now :D

as a novice in this area i have a little trouble understanding the following found in the B1-manual:

"With the exception of R1, all the resistors are ¼ watt"

okay..so R1 is a 3watt resistor..but what is the value of R1 in Ohms?

I enclosed a picture of the schematics to see what makes me confused.

my apologies for my novice-level on this subject, i hope you guys can help me out.

Greetings from The Netherlands.

Maarten
Click to expand...

It's 1 Ohm. That's what the small 1 left of the 3W stands for. ;)

Nice project, I'm looking forward to build a B1 too, but a symmetric version.

~ nightrush
 
D

daniloreyes

Member
Joined 2010
Just get the parts list and order them together.

(THIS A REPOST)
Bill of Materials

Board

Blank Page


Digikey

(6) 1M
Digi-Key - CMF1.00MHFCT-ND (Manufacturer - CMF551M0000FHEB)

(4)1k
Digi-Key - CMF1.00KHFCT-ND (Manufacturer - CMF551K0000FHEB)

(2) 221k
Digi-Key - CMF221KHFCT-ND (Manufacturer - CMF55221K00FHEB)

(2) 10k
Digi-Key - CMF10.0KHFCT-ND (Manufacturer - CMF5510K000FHEB)

(1) 15k
Digi-Key - CMF15.0KHFCT-ND (Manufacturer - CMF5515K000FHEB)

(1) 1ohm 3 Watt
Digi-Key - P1.0W-3BK-ND (Manufacturer - ERX-3SJ1R0)

(1) 1uf bypass cap
Digi-Key - BC2076-ND (Manufacturer - BFC241671005)

(2) 15000uf caps
Digi-Key - P6890-ND (Manufacturer - ECO-S1EP153BA)

(1) 1n914 diode
Digi-Key - 1N914BCT-ND (Manufacturer - 1N914BTR)

power jack
Digi-Key - CP-037A-ND (Manufacturer - PJ-037A)
alternate
Size M Panel-mount Coaxial DC Power Jack - RadioShack.com

wall wart
Digi-Key - T987-P5P-ND (Manufacturer - EPS240025-P5P)

(2) 1uf Polyprop Cap
Jantzen 1.0uF 400V Crosscap Capacitor | Parts-Express.com

(2) 10uf PP Cap
Jantzen 10uF 400V Crosscap Capacitor | Parts-Express.com

20 - 25k Volume pots (there are tons out there, these are just some inexpensive but good quality
options)

Mono

Digi-Key - RV4N253C-ND (Manufacturer - RV4NAYSD253A)

Stereo

Alps pots, and more.

controls_pot_alps


Ebay DACT-Type Stepped Attenuator - $15 shipped
Even better AND cheaper
You can find values for 20k and higher. These are frickin' great for the money.


http://cgi.ebay.com/DACT-Type-21-St...ltDomain_0?hash=item2eab0205e4#ht_1476wt_1202

DPDT Toggle Switch for Input

Mini (1/4" hole)

DPDT Mini Toggle Center Off | Parts-Express.com

(1/2" hole)

Digi-Key - 360-1829-ND (Manufacturer - M2022B2B1W01)


Optional for zee thrifty audiophile connoisseurs:

May I recommend zee PRP:

Precsion Resistive Products PR9372 audio series reesistor

and zee Dayton film/foil (parallel 2 to make 1uf, so get 4):

Dayton DFFC-0.47 0.47uF 400V By-Pass Capacitor | Parts-Express.com

Enclosures

Ebay seller: fan_computer
Aluminum 8"x5.7"x2.7"

Ebay seller: gkphotonics
Alumimum, different colors/sizes

Par-metal.com
Aluminum, Desktop 20 series
http://par-metal.com/product-ttp-20series.php


Solder
(you can $4 10-50ft rolls of the primo stuff)

Cardas Quad (melts like butter at low temps)
GET IT FROM A CARDAS DEALER)

And do not forget to request your free labels from Nelson Pass (really nice)


http://www.diyaudio.com/forums/pass-labs/83022-pass-diy-stickers.html


hope this helps
 
D

daniloreyes

Member
Joined 2010
Just get the parts list and order them together.

(THIS A REPOST)
Bill of Materials

Board

Blank Page


Digikey

(6) 1M
Digi-Key - CMF1.00MHFCT-ND (Manufacturer - CMF551M0000FHEB)

(4)1k
Digi-Key - CMF1.00KHFCT-ND (Manufacturer - CMF551K0000FHEB)

(2) 221k
Digi-Key - CMF221KHFCT-ND (Manufacturer - CMF55221K00FHEB)

(2) 10k
Digi-Key - CMF10.0KHFCT-ND (Manufacturer - CMF5510K000FHEB)

(1) 15k
Digi-Key - CMF15.0KHFCT-ND (Manufacturer - CMF5515K000FHEB)

(1) 1ohm 3 Watt
Digi-Key - P1.0W-3BK-ND (Manufacturer - ERX-3SJ1R0)

(1) 1uf bypass cap
Digi-Key - BC2076-ND (Manufacturer - BFC241671005)

(2) 15000uf caps
Digi-Key - P6890-ND (Manufacturer - ECO-S1EP153BA)

(1) 1n914 diode
Digi-Key - 1N914BCT-ND (Manufacturer - 1N914BTR)

power jack
Digi-Key - CP-037A-ND (Manufacturer - PJ-037A)
alternate
Size M Panel-mount Coaxial DC Power Jack - RadioShack.com

wall wart
Digi-Key - T987-P5P-ND (Manufacturer - EPS240025-P5P)

(2) 1uf Polyprop Cap
Jantzen 1.0uF 400V Crosscap Capacitor | Parts-Express.com

(2) 10uf PP Cap
Jantzen 10uF 400V Crosscap Capacitor | Parts-Express.com

20 - 25k Volume pots (there are tons out there, these are just some inexpensive but good quality
options)

Mono

Digi-Key - RV4N253C-ND (Manufacturer - RV4NAYSD253A)

Stereo

Alps pots, and more.

controls_pot_alps


Ebay DACT-Type Stepped Attenuator - $15 shipped
Even better AND cheaper
You can find values for 20k and higher. These are frickin' great for the money.


http://cgi.ebay.com/DACT-Type-21-St...ltDomain_0?hash=item2eab0205e4#ht_1476wt_1202

DPDT Toggle Switch for Input

Mini (1/4" hole)

DPDT Mini Toggle Center Off | Parts-Express.com

(1/2" hole)

Digi-Key - 360-1829-ND (Manufacturer - M2022B2B1W01)


Optional for zee thrifty audiophile connoisseurs:

May I recommend zee PRP:

Precsion Resistive Products PR9372 audio series reesistor

and zee Dayton film/foil (parallel 2 to make 1uf, so get 4):

Dayton DFFC-0.47 0.47uF 400V By-Pass Capacitor | Parts-Express.com

Enclosures

Ebay seller: fan_computer
Aluminum 8"x5.7"x2.7"

Ebay seller: gkphotonics
Alumimum, different colors/sizes

Par-metal.com
Aluminum, Desktop 20 series
http://par-metal.com/product-ttp-20series.php


Solder
(you can $4 10-50ft rolls of the primo stuff)

Cardas Quad (melts like butter at low temps)
GET IT FROM A CARDAS DEALER)

And do not forget to request your free labels from Nelson Pass (really nice)


http://www.diyaudio.com/forums/pass-labs/83022-pass-diy-stickers.html

hope this helps
Dan
 
M

MechanicalAnimal

Member
Joined 2009
nightrush said:
It's 1 Ohm. That's what the small 1 left of the 3W stands for. ;)

Nice project, I'm looking forward to build a B1 too, but a symmetric version.

~ nightrush
Click to expand...

Thanks Nightrush,

i assumed it should have said 1K in Ohms with the K missing but you explanation is clear, thanks a bunch!

If the B1 goes well i'll go for a UcD of the F5.

Looking forward to see you build as well


@daniloreyes

thanks for the BOM! I'll see if i can use it to get the parts overhere! It might be a big help to me.
 
Last edited:
G

goody75

Member
Joined 2010
I feel compelled to use a teflon cap for c100 but the largest values that i've found are .22uF & .47uF.

Does anyone have comments about:
1) using a teflon cap with a value (.22uF or .47uF) < the 1uF in Nelson's original design and using an adjusted value for r102

2) using multiple teflon caps in parallel to get close to 1uF.
 
S

sawdusttt

Member
Joined 2010
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!
 
G

giulio

Member
Joined 2004
giulio said:
I know that it would be happier drive a load at least double that, but I was just wondering.
Click to expand...

Forget the newbie nonsense. I was mistaking the output impedance at the source pin (50 Ohms) with the OUTPUT IMPEDANCE (1K). I finally took the plunge and read the thread. Even lowering the output resistors to 100 Ohms (Nelson's suggested minimum) we are still talking 150 Ohms output impedance.

Oh well...
 
A

Atilla

Member
Joined 2008
150ohm output impedance could be alright for headphone use, depending on what you're trying to drive. The amount of current the JFETs can deliver in this configuration will most definitely be an issue. Not to mention you'd need a different output cap altogether. There's tons of things you can build to drive headphones properly. The B1 isn't one of them, however.
 
S

sawdusttt

Member
Joined 2010
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
 
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