Pass B1 BOM

Thanks! I think I follow most of that. What is "VC"? Are you saying that the LDR PCB has a trimmer pot to allow for channel matching? I'll have to go back and look at the schematic.

The tolerances in all my system components add up such that the right channel is a little "louder" than the left, so I guess that I could use that to achieve a balanced sound. Would have to recalibrate each time I change cartridges on the TT.
.

VC => Volume Control.

This is volume control at the input of buffer just like stereo pot. Both channels are fed same voltage and tolerances in LDR resistances are made equal by trimmers. Irrespective of source, once both channel are made equal that need not be calibrated again. It gives same treatment to input channels.

Sachin,
This thread was quiet for a long time so I'll bring it back to the top.
I saw that your transformer was a 22-0-22, do the rectifiers run hot having to dissipate that much voltage?

Have you changed anything since you finished that build?

Ron

Renron said:

Sachin,
This thread was quiet for a long time so I'll bring it back to the top.
I saw that your transformer was a 22-0-22, do the rectifiers run hot having to dissipate that much voltage?

Have you changed anything since you finished that build?

Ron

Click to expand...

Hi Ron,
Yes I have replaced 100 Mh inductors with 10MH Panasonic.Regulators were very hot earlier and I had to put 330 Ohms 2V resisters for heat,but after changing with 10 MH they are on warmer side.

Regards,
Sachin

sachu888 said:

Hi Ron,
Yes I have replaced 100 Mh inductors with 10MH Panasonic.It was very hot earlier and I had to put 330 Ohms 2V resisters for heat,but after changing with 10 MH they are on warmer side.

Regards,
Sachin

Click to expand...

Sachin what is running hot?I think rectifiers should not run hot, I also have transformer from same batch and values. Rectifiers run cool no warmer, regulators run warm with smaller heatsinks, 2W resistors used to drop voltage for LSA and source selectors are running hot as expected.

omishra said:

Sachin what is running hot?I think rectifiers should not run hot, I also have transformer from same batch and values. Rectifiers run cool no warmer, regulators run warm with smaller heatsinks, 2W resistors used to drop voltage which we derived for LSA and source selectors are running hot as expected.

Click to expand...

Sorry Om I meant regulators.edited

Regards,
Sachin

sachu888 said:

Sorry Om I meant regulators.edited

Click to expand...

Offsss.. I thought something went wrong or short circuit which is heating the rectifier.

No issues!

Thanks guys,
My fault, I started it. Sorry. I too meant regulators.
And English IS my first language. (sad)
Ron

B1 update

I have received Russian PIO caps today.George aka 1mor on AK sent me these.I thank you George for this.This made a great improvement over stock Axon caps.
Few pics :

By sachu888 at 2012-08-29


By sachu888 at 2012-08-29

Regards,
Sachin

I have those same caps but have not yet replaced the axeons. I should do this! Continue saving the beautiful tigers. I was recently reading (National Geographic) where one was in captivity, but poachers came in killed and slaughtered it in the night. Such fools...

Russellc

Russellc said:

I have those same caps but have not yet replaced the axeons. I should do this! Continue saving the beautiful tigers. I was recently reading (National Geographic) where one was in captivity, but poachers came in killed and slaughtered it in the night. Such fools...

Russellc

Click to expand...

Yes they are worth trying,please try them.There are very few Tigers alive in the wild.I feel very sad when I here such news.We must save them.

Regards,
Sachin

sachu888 said:

I have received Russian PIO caps today.George aka 1mor on AK sent me these.I thank you George for this.This made a great improvement over stock Axon caps.
Few pics :

By sachu888 at 2012-08-29

By sachu888 at 2012-08-29

Regards,
Sachin

Click to expand...

Thanks Sachin, caps went from Florida to India by first class mail in 9 days. I was worried that the package would never make it to you. They add somewhat of an industrial look to the B1 Board. I found them to be a little edgy at first listen but after some burn in time, they became superbly smooth.

Damn it. Now you two have me thinking.........:scratch2:

Pardon the Necropost here........:drool:
Still building my SSP/DCB1, yeah, I'm slow like a turtle , I've got a question about the 100K Ohm pot for the LDR Volume control.
I'm building mine with the LDR after the SSP which is after the DCB1.
I wanted to be able to switch in/out the SSP in the circuit. From the output of the SSP to the input of the LDR is no problem. I'm having trouble understanding the 100K Pot connections. I'm not using a pot that snaps/solders onto the board because of the layout of my casework. I'll post pictures when I'm finished. So of the 6 solder / wire tabs on the LDR board, are the center 2 the wiper?
Any help would be appreciated.
Ron

Renron said:

So of the 6 solder / wire tabs on the LDR board, are the center 2 the wiper?
Ron

Click to expand...

Ron, that's right - the center pins are the wiper.

Quadtech,
Thank you for the quick reply.
I'm a bit confused by having 4 LDRs, and how their function(s) are determined by pot.
I'll post a picture of my project later today when the garage warms above 35*.
I'm used to working in the past with a "standard" pot for volume control.
Thanks again Quad.
Ron

Ron,

This is probably explained in a much better and comprehensive
way elsewhere - such as diyaudio. Anyways -

The pot in a LDR volume control is not in the signal path, but used
to control the series and shunt LDRs.

To control a signal, you could either use -

a resistance in series with the signal and decrease this resistance to get
a higher output signal,
or
a resistance in between the signal and the ground (shunt) and increase this to get
a higher output signal.

(My attempt at ASCII art...doesn't seem to render well here.)


For best effect, the LDR volume control uses a combination of both
of these methods, one LDR in series and another in shunt config, for each channel.

The ganged pot is actually two potentiometers on a single shaft.

One pot is wired such that it controls the series LDRs of each channel, decreasing
the series resistance when you turn it clockwise.

The other pot controls the shunt LDRs of each channel, increasing the
shunt resistance as you turn it clockwise.

Hope that was clear

Quad,
That was AWESOME!!!!!!!!!
Very simply explained, which means you understand this very well to be able to distill it down to laymens terms. Very nicely done.

I now understand what I'm looking at, when looking at the traces on the board. I was trying to follow a Left / Right channel and was confusing myself.
Thank you so very much for the explanation. (even the ASCII :thmbsp

I'm building a DCB1 which IS a Shunt voltage regulator design. It would have been easier to leave out all the extraneous parts in my preamp, but where would the fun be in that? The front panel is already drilled and powder coated in black, it's waiting at the engravers for the lettering. It will have corresponding LEDs to the selector position. I've thought a lot about this build, but I couldn't wrap my head around the LDR board. Back to making solder fumes!
Thanks,
Ron

Renron said:

Quad,
That was AWESOME!!!!!!!!!
Very simply explained, which means you understand this very well to be able to distill it down to laymens terms. Very nicely done.

I now understand what I'm looking at, when looking at the traces on the board. I was trying to follow a Left / Right channel and was confusing myself.
Thank you so very much for the explanation. (even the ASCII :thmbsp

I'm building a DCB1 which IS a Shunt voltage regulator design. It would have been easier to leave out all the extraneous parts in my preamp, but where would the fun be in that? The front panel is already drilled and powder coated in black, it's waiting at the engravers for the lettering. It will have corresponding LEDs to the selector position. I've thought a lot about this build, but I couldn't wrap my head around the LDR board. Back to making solder fumes!
Thanks,
Ron

Click to expand...

Hi Ron,
Quad is one the designer of our LDR board.The new LDR board is little simplified than older one.

He has also design a 5-1 input selector


BTW your enclosure looks cool.Did you make it yourself?

Regards,
Sachin

Sachin,
(A nice man to know) ............ BTW. how's that other project coming along? Do you have enough information?

Yes, I made the enclosure myself out of spare aluminum I have from other completed projects. My son gave me his perforated shelf from a computer desk that fell apart from moving it too many times. I enjoy making the chassis for my projects almost as much as soldering all the boards. IN this project there are 6 different boards, count 'em 6. The DCB1 has all very high quality parts, come to think of it they all do. By the time I'm finished wiring up this mess it will be a miracle if there is no hum to track down.......It's going to look like a pot of spaghetti when I'm finished. Talked to the engraver yesterday (he's had the front panel for 2 weeks) he's just now getting started on the layout for black powder coated front. Not like the picture, but reversed. It will match my F5 Amp very well when completed. Maybe before next year?
Thanks for the help.
I really like this website. Nice people.
Quad, Yes I'm a working member of the other DiyAu..o.com website. Burning Amp in San Francisco was very fun this year. I've been able to meet some of the "SuperStars" of audio design, all genuinely nice people.
Ron