Pass B1

[sachu888]

I want the preamplifier and LDR circuit and DONT need the phono. Will start the transfer as soon as you are ready.

Where is the phono?

Regards,
Sachin

 

[quad]

I want the preamplifier and LDR circuit and DONT need the phono.

The third board in the pic in the power supply board. Quite nice
and versatile. It is general purpose symmetric (positive, negative
rails) PSU, and good to stock up a few for future use too, as
the output voltage is adjustable.

 

[captrajesh]

I visited SV Troniks today for the R-core trafo. They seem to supply only EI and Toroid trafos. Since Quad stays close to the the R-core trafo maker at Hyderabad, it would be great if a group buy can be arranged for trafo too.

 

[sachu888]

I visited SV Troniks today for the R-core trafo. They seem to supply only EI and Toroid trafos. Since Quad stays close to the the R-core trafo maker at Hyderabad, it would be great if a group buy can be arranged for trafo too.

Hi capt.
Omishra has a source for R core trafo in Hydarabad.I have also opted for one Rcore.

Regards,
Sachin

 

[Audiodoc]

Was referring to the post by omishra where he had added a phono in the end. I understand than the third board us a 317 337 based power board. I already have 5 simpler versions of the same in my various projects.

I already am in the process of completing a jfet based pass preamplifier which has the supply on the same board. Will compare the two when both are ready. Not much difference in the design though. By the way ordered the Axon 11 MFD caps the same day you posted. Had I known I would troubled you in providing them.

Summary

PASS B1 Preamp -

Some links (it includes part list):
Andy_H's Pass B1 Build - AudioKarma.org Home Audio Stereo Discussion Forums
Nelson Pass B-1 preamp kit
B1 Buffer Preamp - diyAudio
DIY Order Form

Parts
Ordered 24 X 11uf Axon caps from Parts ConneXion - The authority on hi-fi DIY parts and components
ordered 12 pairs of matched JFETs from Spencer(DIY audio member,Hong Kong).
Remaining parts from in.element14.com

PCB Size: 82.5X190.5mm double sided

Estimated cost PCB + Parts = 2000 Rs


LDR Volume Ctl

LDR based volume control referrence:

The Poor Serbian Man's Optical Attenuator - diyAudio

Poor Serbian Man Optical Volume Control - diyAudio

Our PCB:



Size : 2.2" X 2.2" Single sided.

Part list:

4 X 100E, 1/4W 1%, MFR X 12
2 X 1K Trimmer, M64W (9mm width) X 12
1 X 100K Stereo Pot, PCB mount X 12

1 X 1.0uF, 35V electrolyte Capacitor X 12
1 X 10.0uF, 35V electrolyte Capacitor X 12

1 X 7805 TA220 Voltage Regulator X 12
5 X 1X2MTA amp-connector X 12

Source: All part are locally purchased except Silonex NSL32SR2 LDR.
LDR are bought from Uriah Bought 60 to match 48 closed in 12 groups.

Estimated cost with PCB+Part = 1100Rs

PreAmp-Power Supply

Features:
Input transformer secondary voltage 20-0-20, 500mA or 22-0-22, 500mA
Rectifier diodes MUR8xx fast switching diode.
One single PS for Pass B1 and Lightspeed Volume Control
One dual PS for CNC Phono.
Input C-R-C ripple filter at 31Hz
Output L-C-L noise filter at 1590 Hz
Output voltage tunable from 1.5V to 25V output
Size: 4" X 3" single sided PCB
We reffered Elliot Preamp power supply and LM317/LM337 datasheet, application notes for hints. Also we put some of experiences into this.
This power supply based on low noise linear voltage regulators LM317 (2 numbers for +24V and +15V) and LM337 (1 number for -15V).
It take input voltage from transformer, any from (18-0-18) to (32-0-32). (minimum 500mA for PASS B1, LDR Volume Control and CNC phono stage). More current is not an issue as regulators can provide upto 1.5A but heatsink will be required for regulators and output filter coils need to be rechecked.
Output is designed to provide (+24, 0) and (+15, 0, -15). Output voltage it set using trimmers in each power line which could be adjusted with small screw driver. You can settle at any preferred value but need DMM for this voltage reading.
If you plan to power up CNC phono stage then please use r-core or EI transformer without overlapped winding. This will couple less noise from ac mains power line. (as it is understood that toroidal transformer have more capacitance between primary and secondary, hence more noise coupled through it)

Our PCB; Single sided 4" X 3"
This image has been resized. Click this bar to view the full image. The original image is sized 800x610.



Part list:

3 X 1E, 2W Metal Film 5% - 10% X 12
3 X 240E, 1/4W 1%, MFR X 12
3 X 5K Trimmer, M64W (9mm width) X 12

9 X 0.1uF, 50V Ceramic Capacitor X 12
5 X 4700uF, 50V Electrolyte Capacitor X 12

6 X 10-100mH 10% 70mA radial inductor (5mm lead spacing)

4 X MUR810 Ultra fast Diodes X 12
9 X 1N4007 rectifier Diodes X 12
2 X LM317TS TA220 Voltage Regulator X 12
1 X LM337TS TA220 Voltage Regulator X 12

2 X 1X3MTA amp-connector X 12
1 X 1X2MTA amp-connector X 12

Part Source: All parts are sourced locally except Inductor coils

Estimated cost with PCB+Part = 750 Rs

--------------

CNC Phono

Estimated cost with PCB+Part = 2000 Rs

These kits does not contains RCA jacks, wires, chassis, transformers, knobs. source selector etc.

That is your choice.

 

[sachu888]

Sorry Doc.
I should have read Omishra's post properly,just saw the phonostage part.

Regards,
Sachin

 

[captrajesh]

@Audiodoc, I do not understand why you have reproduced Omishra's post in your last post. I initially thought that you are also offering a group buy. Then somehow, I went through all posts and realised that you have just reproduced Mishra's post. The whole thing is confusing.

 

[omishra]

@Audiodoc, I do not understand why you have reproduced Omishra's post in your last post. I initially thought that you are also offering a group buy. Then somehow, I went through all posts and realised that you have just reproduced Mishra's post. The whole thing is confusing.

I think its my mistake to include CNC phono in the list. I wanted to only point out that thread. That's not part of current group buy. I am sorry for creating confusion.

This group buy is only PASS B1, LightSpeed LDR based Volume Control and Power Supply (which will be useful for CNC also).

I hope I stand clear.

BTW all parts are here except LDRs, I will prepare final list and cost tomorrow. Now going to bed early. Thanks to traffic chaos and headache.

Today I got MUR860 which are nice and original; dual pots and this CCR 5% 1 W 1 ohm resistors. More details tomorrow.

 

[captrajesh]

Omishra has a source for R core trafo in Hydarabad.I have also opted for one Rcore.

Hi Sachin / Omishra, Prasad (Quad) has given me the info and he stays about 2kms away from this Hyd based manufacturer and hence suggested his name. Let us also go in for a group buy for the transformer. In addition to a trafo for the Pre-amp, I also intend to buy a 35-035 R core trafo of rating 400VA for my Class D Power amp.

I'm in for the trafo for the pre as well as the one mentioned above.

 

[Tanoj]

Need help to fix my pyle pro pre amp

Hi friends,

i bought a pyle pro PP444, pre amp, it worked for a day, then felt as if there was a loose connection at the power socket, so i opend it and soldered the power input to the circuit board to avoid the loose connection, but since then it stoped working

no sound coming out , only little hum

Thanks in Advance

Regards

Tanoj

 

[quad]

Hi Sachin / Omishra, Prasad (Quad) has given me the info and he stays about 2kms away from this Hyd based manufacturer and hence suggested his name. Let us also go in for a group buy for the transformer. In addition to a trafo for the Pre-amp, I also intend to buy a 35-035 R core trafo of rating 400VA for my Class D Power amp.

I'm in for the trafo for the pre as well as the one mentioned above.

Sadly, Quad has moved nearly 30km away to the concrete jungle,
and goes back to the "ancestral home" only on Sundays.
Hence, my own DIY activity has nearly halted too and I opted out of this group buy too.
So I may not be able to follow up in person with ElectroMagnetic Devices.

For my one or two piece order, they delayed it a lot.
If there is a good number in the group order, hopefully they will
be more responsive. The quality of the transformer is very good.

Another option is the Mumbai based vendor, Toroid Engineers,
which Joshua has used for his MyRef build. They seem be very
competitively priced and transformers look good in the pics.

 

[GeorgeO]

I picked up a nice 500VA R Core from Electro Magnetic Devices, last year for my 5 channel Class D build am quite happy with it and recommend them.

 

[GeorgeO]

The only negative was that though the tranny was good, the lead wires looked totally inadequate. No issues so far in actual usage though.

 

[omishra]

I picked up a nice 500VA R Core from Electro Magnetic Devices, last year for my 5 channel Class D build am quite happy with it and recommend them.

I ordered 30VA 22-0-22, 1A for ~625Rs + shipping. It included ~30% tax.

My younger brother lives near that facility ~2KM distance. He will be collecting that for me and getting it delivered to me through his visiting friend.

 

[captrajesh]

I ordered 30VA 22-0-22, 1A for ~625Rs + shipping. It included ~30% tax.

My younger brother lives near that facility ~2KM distance. He will be collecting that for me and getting it delivered to me through his visiting friend.

Hi Mishra, is it possible for him to negotiate a price for a group of participants of this thread?

 

[sachu888]

Total cost

Hi all,
We have calculated total cost for this GB(prices inclusive of shipping,Custom and Octroi):
JFEts : 2980 (no Custom and Octroi)
Element14: 8684(Rs 360 Octroi)
Part Connexion : 8610 (866 Custom and Octroi)
PCBs(B1+LDR+Powersupply) :9460 (460 OCtroi)

Om has bought components for power supply and LDR = 15800

Total INR = 45534
Total participants =12
Per person cost = 3794+200 Rs courier charges
Courier charges includes courier from my side(B1)and Om will courier LDR+Power supply

I will start shipping kits from Monday.


Regards,
Sachin

 

[Audiodoc]

Can you pm the account details for netbanking transfers.

 

[gobble]

I picked up a nice 500VA R Core from Electro Magnetic Devices, last year for my 5 channel Class D build am quite happy with it and recommend them.

Agreed, I use the EMD R-Core with the myRef and it is so dead quiet, me and linuxguru were puzzled why the amp was not switching on when placing our ears right next to the tweeter (almost brushing it with our ears)!! The noise floor is non-existant with this one - compared to the trafo used the RevE modded MyRef which I am burning-in for Linuxguru right now.

The only negative was that though the tranny was good, the lead wires looked totally inadequate. No issues so far in actual usage though.

I thought so too but ultimately the low noise floor made very happy. I will go for their R-Core only for this Pass B1.

The other option is :: Shilchar Technologies Limited ::

Can somebody contact them and get tentative pricing for single vs group buy pricing? They export their r-cores to International vendors I believe.

--G0bble

 

[omishra]

Hi Mishra, is it possible for him to negotiate a price for a group of participants of this thread?

Sure! I will try.

 

[omishra]

Re: Total cost

Hi all,
We have calculated total cost for this GB(prices inclusive of shipping,Custom and Octroi):

Om has bought components for power supply and LDR = 15800

Courier charges includes courier from my side(B1)and Om will courier LDR+Power supply

I will start shipping kits from Monday.

Break up from my side is this (prices rounded to nearest 10Rs) -

Component (local): 3980 (caps, resistors, regulators etc)
Diodes MUR 860: 740
Stereo Pots: 450
LDRs (online) : 7430
16mA Coils (online): 3200
-------------------------
Total 15,800/-

I till take another week to receive LDR and matching for pairs. Then shipping will be done from me. Mostly a week later from now.

Thanks.