Pass B1

[sachu888]

Hi,
Sent one kit today to T.Antony

Regards,
Sachin

 

[sachu888]

Hi all,
Please follow this guide for DIY B1
http://www.passdiy.com/pdf/B1 Buffer Preamp.pdf

Some imp points:

Capacitors, Electrolytic capacitors in this case are polarized. The positive lead must go in the hole next to the positve symbol.The white stripe = Negative So do not have the white stripe facing the '+' on the PCB
Diode the striped side of your diode should matches the stripe on the pcb
JFETS be sure to place them so the cutout end matches that on the PCB.
Touch something grounded before handling them.

Regards,
Sachin

 

[Audiodoc]

It was such a small and straightforward circuit. Had ordered a DAC too was soldering that too. Completed a few minutes ago. Unfortunately the seller had missed a important SMD component so couldn't finish.

Will be ordering the toroids for both my pass preamplifiers tomorrow. What will be ideal voltage and current requirements.

 

[Audiodoc]

Secondary voltage should be 0-18V. Should I get a 500mA or 1A one. And what about the same toroid supplying the volume control.

 

[sachu888]

Hi Audiodoc,
B1 can be powered by two 9v batteries,they offer better sound.
Nelson Pass B-1 preamp kit

Regards,
Sachin

 

[omishra]

Secondary voltage should be 0-18V. Should I get a 500mA or 1A one. And what about the same toroid supplying the volume control.

For out PS, use 22-0-22, 1A, R-Core preferred. Shielded non overlapping primary-secondary type EI will also do. Toroidal transformers has noise issue to high capacitive coupling between primary and secondary.

This voltage is given because we will be using 270+270ohm inductors in series with PS line which will drop ~9V @ 20mA there itself. So LM317 will give 27V, after coil we will get 18V while loaded with B1.

 

[captrajesh]

Input transformer secondary voltage 20-0-20, 500mA or 22-0-22, 500mA

use 22-0-22, 1A

Hi Mishraji,

Which one of these is correct?

 

[Audiodoc]

Can we arrange a group buy for the R-core transformers too. I would need two of them. One for this project and another 0-18V secondary for my second pass preamplifier.

 

[santhosh]

Sachin, I have made the payment today, should come through today/tomm.

@Bangalore members part of this groupbuy:
Not sure if it is too late.... since I am away from Bangalore, can Sachin/Omishra ship my kit to your place along with your kit? I can collect it when I am back. TIA .

 

[sachu888]

Sachin, I have made the payment today, should come through today/tomm.

@Bangalore members part of this groupbuy:
Not sure if it is too late.... since I am away from Bangalore, can Sachin/Omishra ship my kit to your place along with your kit? I can collect it when I am back. TIA .

Hi Santhosh,
I have shipped all B1 kits.Sajith kit is ready to ship today.Can I ship your kit with it?


Regards,
Sachin

 

[omishra]

Hi Mishraji,

Which one of these is correct?

Considering 9V dropped by coils on loaded 20mA.

We need aprrox 18V+9=27V min at regulator So anything above 20-0-20 and below 25-0-25 is adequate. You can go upto 32-0-32 provided output caps 100uF/35V & adjustment cap 10uF/35V are replaced to higher voltage.
I felt safe for 22-0-22, 1A which would draw ~ .09 A (90mA) through load and some through regulators.

 

[gobble]

Sachin, I have made the payment today, should come through today/tomm.

@Bangalore members part of this groupbuy:
Not sure if it is too late.... since I am away from Bangalore, can Sachin/Omishra ship my kit to your place along with your kit? I can collect it when I am back. TIA .

You can get it shipped to me.

--G0bble

 

[captrajesh]

Considering 9V dropped by coils on loaded 20mA.

We need aprrox 18V+9=27V min at regulator So anything above 20-0-20 and below 25-0-25 is adequate. You can go upto 32-0-32 provided output caps 100uF/35V & adjustment cap 10uF/35V are replaced to higher voltage.
I felt safe for 22-0-22, 1A which would draw ~ .09 A (90mA) through load and some through regulators.

OK so 22-0-22 1VA would suffice I guess or should we go for higher amperage considering likelihood of sub optimal performance of the trafo; have some cushion and go for, say 1.2VA?

 

[omishra]

OK so 22-0-22 1VA would suffice I guess or should we go for higher amperage considering likelihood of sub optimal performance of the trafo; have some cushion and go for, say 1.2VA?

22-0-22 1A ( approx 22V X 1A = ~ 22VA, 30VA in price calculation) here we have 1A = 1000mA available, out of which we will use 0.015A = 150mA only

 

[Audiodoc]

Have reserved an enclosure for this kit. The only problem is the height of the 15000 microfarad filter caps. Will have to search stouter ones. Can someone provide the exact dimensions of the volume control and power supply boards so that I could calculate the transformer dimensions and order accordingly.

 

[captrajesh]

I felt safe for 22-0-22, 1A which would draw ~ .09 A (90mA) through load and some through regulators.

22-0-22 1A ( approx 22V X 1A = ~ 22VA, 30VA in price calculation) here we have 1A = 1000mA available, out of which we will use 0.015A = 150mA only

Mishraji, you must kindly excuse my noob questions. If you provide me so many technical options, I'll get thoroughly confused.

Just mention what voltage and what capacity and I'll procure that. Best would be a group buy.

AFA this thread is concerned, you are the Captain and I'm the soldier.hyeah:

 

[santhosh]

Folks, include me in a transformer group buy as well. I plan to combine the CNC Phonostage and the Pass B1 in one cabinet. So need your suggestions. TIA.

Hi Santhosh,
I have shipped all B1 kits.Sajith kit is ready to ship today.Can I ship your kit with it?

Sachin, please ship it to Gobble, he stays close to my office.

You can get it shipped to me.

Thanks buddy

 

[omishra]

Have reserved an enclosure for this kit. The only problem is the height of the 15000 microfarad filter caps. Will have to search stouter ones. Can someone provide the exact dimensions of the volume control and power supply boards so that I could calculate the transformer dimensions and order accordingly.

LDR board is 2.2" X 2.2"
Power Supply board is 4" X 3", I need to look into height of big cap ~ 2"

 

[captrajesh]

I plan to combine the CNC Phonostage and the Pass B1 in one cabinet.

You are forgetting the LDR.

 

[omishra]

mishraji, you must kindly excuse my noob questions. If you provide me so many technical options, i'll get thoroughly confused.

22-0-22 1a (30va)

Afa this thread is concerned, you are the captain and i'm the soldier.hyeah:

:lol: