Pass B1

[omishra]

Checked the local hardware stores didn't find them. Purchased some plastic ones. Will try one more market this weekend. I have a large CAT 5 cable with cut that ope,. Won't it be preferable to use shielded wire.

That is good to have shielded cable inside metal box unless radio frequencies are concerned. IMO it is over cautious for audio band frequency at line level.

At low line level voltages, for audio frequency to get radiated itself and induced in another adjacent wire is difficult. It is far possible unless proximity of any hi power equipment/wire nearby. That's why we provide metal shielding by means of enclosure. Twisted pair is more than enough inside the box. Also this is no gain circuit does not possess possibility of feedback too.

Still outside the enclosure care should be taken provide shielding.

 

[Audiodoc]

I agree that the outside interferences will be negated in a metallic enclosure however the interference from an R-core in close proximity of the preamp (even if less) may cause some noise. Your approach of using a mesh partition will definitely reduce the noise however my enclosure is a little scarce on space will still try to incorporate it.

 

[santhosh]

Om, very neat build . Thanks for sharing the listening impressions.

Sorry guys.... about the aluminium enclosures GB, I will definitely meet my friend this weekend and revert. He was away on a holiday when I was in the vicinity of his office last week.

 

[captrajesh]

I also want to get into DIY but don't know much.

Just walk to the local main road, uncover the lid of the nearest man hole and get in ... no sweat ! :thumbsup:

Wait for the next GB if there is going to be one ...

--G0bble

Hey Gobble, that Manhole is to cover up the DIY, not get into DIY.

Don't scare the daylights out of poor novices.

Hey Gans, there are a lot of DIY activities going on here. DIY speakers, Pre-amps, Phono stages and Power amps. Do check out the threads.

Don't worry about the soldering part, even I don't know much. I outsource it and since you are in Chennai, I can help you get over that.

 

[doors666]

any chance of having another round of this gb. i am interested, are there more people who are?

 

[omishra]

BTW, guys another simple method of balancing Volume Pot. No soldering required for temporary connections.

1. I removed the Pass B1 'CW' and 'W' wires (white, Blue and orange wires) connected at LDR Volume Control, Keeping CCW (Green wire) connected(this is ground).
2. I connected two 3" wires from L-IN & R-IN on LDR board to 5V.
   • In my photo of LDR Vol Control, white wires in each channel are L-IN & R-IN on LDR board.
   • Rear left first pin hole at Volume Pot while holding Volume Pot towards you is 5V.
3. Now measure Voltage at output (where I earlier connected Blue and orange wires).
   This need to be same at any point of Volume level wrt ground (green wire in my last photo).
4. Vary Volume pot little 10% at a time from. Notice both the voltages at same position. Write down them for each position till you reach 90% of volume level.
5. Observe the difference in the voltages, ideally they should match equal.
6. Set Volume pot at your preferred listening level. Match output voltage at out pins equal towards middle of voltage difference
   (e.g. mine preferred listening level is at 25% of volume total level)
7. Remove this 5V supply wire and reconnect to PASS B1 wires. You are done!

This way it is always guaranteed that for same inputs you will get equal output in both channels. Verified by providing 5V input to both channels, and at desired position equal output from Volume Control.

 

[svaze]

I'll also be interested in the group buy if one gets planned in future :licklips:

 

[omishra]

Good new!

Transformers will be ready by tomorrow or worst case by Monday evening. I will let you know price details after confirming shipping charges v/s weight. Please let me know who would like to collect it personally. I know Captrajesh and quad are collecting personally and stereorules can do it. For others shipping will be arranged.

1. Gopib - 1 Nos 22-0-22, 30VA;
2. Stereorules - 1 Nos 22-0-22, 30VA;
3. Santhosh - 1 Nos 22-0-22, 30VA;
4. jetlag - 1 Nos 22-0-22, 30VA;
5. basawamin - 1 Nos 2X9-0,15VA;
6. AudioDoc - 1 Nos 22-0-22, 30VA; 1 Nos 18-0, 30VA;
7. cmsajith - 1 Nos 22-0-22, 30VA; 2 Nos 2X7-0, 10VA; 2 Nos 2X15-0, 10VA;
8. Captrajesh - 1 Nos 22-0-22, 30VA; 1 Nos 34-0-34, 320VA;
9. gobble - 1 Nos 22-0-22, 30VA
10. quad - 1 Nos 22-0-22, 30VA;
11. Omishra - 1 Nos 22-0-22, 30VA;

Prices I will PM individually. Keeping in mind business interest of source - by request.

Edit:
Shipping charges will be approx Rs 70 + 20 (or at actual) packing/handling for all small transformer (except that huge 320VA).
For multiple items it will combined to save your money. So my brother will calculate last figure according to weight and destination.

 

[baswamin]

Hello all,

I see few people from Bangalore in this group buy. Is it better to ship all the stuff to one person and then distribute it here locally? Folks from Bangalore ok with that?

If yes, then we can ask Om to ship it to one of the people in group buy

Thanks
Balaji

 

[sachu888]

any chance of having another round of this gb. i am interested, are there more people who are?

Hi,
I can help you on boards,if there are 10 or more people.Total cost would be 750+shipping(approx) for all three PCbs(B1+LDR+PS).There are few AK members interested for boards.Post your interest here if anyone need boards.
I have received request from following members:
1.Doors
2.Magma
3.Svaze

Regards,
Sachin

 

[gopib]

Hello all,

I see few people from Bangalore in this group buy. Is it better to ship all the stuff to one person and then distribute it here locally? Folks from Bangalore ok with that?

If yes, then we can ask Om to ship it to one of the people in group buy

Thanks
Balaji

Balaji,

Considering that the shipping estimate/piece is coming up to only 90/- I feel it is convenient to get it directly unless we are all located in the neighborhood.

Gopi

 

[ravi_d]

Hi,
I can help you on boards,if there are 10 or more people.Total cost would be 750+shipping(approx) for all three PCbs(B1+LDR+PS).There are few AK members interested for boards.Post your interest here if anyone need boards.
I have received request from following members:
1.Doors
2.Magma
3.Svaze

Regards,
Sachin

Sachin,
Add me for 1 set of PCB's.

 

[baswamin]

Ok, we go with individual shipping.

Thanks

Balaji,

Considering that the shipping estimate/piece is coming up to only 90/- I feel it is convenient to get it directly unless we are all located in the neighborhood.

Gopi

 

[magma]

just for my info

what is the general consensus of the size of cab needed for the pass b1

i have some matl left from my previous build - if i leave it lying around for too long the factory just uses it up for something unimportant
maybe i can put it to good use

im restricted in height though -60mm internal MAX ( probably 65)

 

[captrajesh]

just for my info

what is the general consensus of the size of cab needed for the pass b1

i have some matl left from my previous build - if i leave it lying around for too long the factory just uses it up for something unimportant
maybe i can put it to good use

im restricted in height though -60mm internal MAX ( probably 65)

Good idea, over to Mishra, Sachin & Audiodoc for expert opinion.

 

[sachu888]

Good idea, over to Mishra, Sachin & Audiodoc for expert opinion.

60 MM would be low IMO.

Regards,
Sachin

 

[magma]

i think the 2 large caps are the only issue probably
audio doc has done some "juggad" i think though

if thats possible - then someone can make use of what ive got

otherwise - didnt hurt to ask

 

[sachu888]

i think the 2 large caps are the only issue probably
audio doc has done some "juggad" i think though

if thats possible - then someone can make use of what ive got

otherwise - didnt hurt to ask

Hi Magma,
I just checked the specifications of those big caps.They are 50MM tall.
CORNELL DUBILIER|SLPX153M025A9P3|CAPACITOR ALUM ELEC 15000UF 25V | element14 India so 65 MM would be sufficient.

Regards,
Sachin

 

[magma]

internal width and depth reqd for the cab
would 10 * 10 be sufficient ?

 

[sachu888]

internal width and depth reqd for the cab
would 10 * 10 be sufficient ?

B1 board is 7.5 inches in width+ Trafo 3inch(approx) so 10 would be very tight,so 13 inches width would be recommended.