Pass B1

Luxman 507z Integrated Amplifier
Swapnil, Sachin, Om,

Received my package today. Excellent packing, and love the kits.
Great work. Thanks!
 
For all of those who received Group Buy batch-2 kits.
Here are two documents which I assembled sometime back.
1. Power Supply
Only ignore the section "Setting up output voltage". You need to set output to 24V and +15, -15 as marked on the PCB. You have Panasonic coils (shining outside) which will not drop extra voltage. [Earlier batch was having KOA coils (non shiny, mat black finish) which dropped 5-10 volts. That's why document mentions to set 19V in 15V line and 28V in 24V line.]

if you have batch 1 KOA coils (non shiny, mat black finish) -> follow document section "Setting up output voltage"
if you have batch 2 Panasonic coils (shining outside) -> follow PCB marking for setting output voltage.

In place of 3 X 240 ohm resistors you are provided 2 X 240 ohm and 1 X 200 ohm resistor. Use 200 ohms in 24V line and remaining 240E into 15V lines.

2. LSA document
Do not go for balancing LEFT-RIGHT channels if you do not listen the difference because your LDRs are closely matched.

image608t.jpg

BTW, 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.
  3. In my photo of LDR Vol Control, white wires in each channel are L-IN & R-IN on LDR board.
  4. Rear left first pin hole at Volume Pot while holding Volume Pot towards you is 5V.
  5. Now measure Voltage at output (where I earlier connected Blue and orange wires, i.e. in above pic from left, screw no 3 and 7).
  6. This need to be same at any point of Volume level wrt ground (green wire in my last photo).
  7. 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.
  8. Observe the difference in the voltages, ideally they should match equal.
  9. 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)
  10. 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.
Regards,
 
Last edited:
All new diyers please read 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
 
Hi Sachin,
I very lately saw this GB. I believe this group buy is closed. Is it possible to start another group buy?

Thanks
Badri
 
Actually, the reason people are missing this GB is due to a very simlple reason, the thread title doesnt say GB. Nor is it in the GB section, atleast thats why I missed the first one.
Maybe some mod can rename this thread to include the keyword GB.
 
Which post tells about the inter-connectivity of various components (i have only 1 input source)).

I saw Post 303 in Page 31... is that the one ?

Then i have few :-) questions

---If i have only 1 input then i need to short L1 & R1 (Yellow Wires). Right/Wrong?

---How do i connect the LDR to power supply? The diagram in post 303 show +ve coming from the inductors. Can i not use the 15,0 from the 15-0-15 supply (maybe after regulating it to 12V).

---I one of the posts there was some talk about adding a 330E resistor for heat dissipation. Is that still true?

---In all configs i see that I/P->B1->LDR->B1->O/P....can i not use I/P->LDR->B1->O/P. If yes can somebody please guide me about the connectivity.
 
kroyin said:
Which post tells about the inter-connectivity of various components (i have only 1 input source)).

I saw Post 303 in Page 31... is that the one ?

Then i have few :-) questions

---If i have only 1 input then i need to short L1 & R1 (Yellow Wires). Right/Wrong?
Click to expand...

That's correct at that page.

kroyin said:
---How do i connect the LDR to power supply? The diagram in post 303 show +ve coming from the inductors. Can i not use the 15,0 from the 15-0-15 supply (maybe after regulating it to 12V).

---I one of the posts there was some talk about adding a 330E resistor for heat dissipation. Is that still true?
Click to expand...
If are not connecting anything to +15,0,-15 then be happy to use +15V output. Resistors of 330E are not required for you (GB-2 purchase)

kroyin said:
---In all configs i see that I/P->B1->LDR->B1->O/P....can i not use I/P->LDR->B1->O/P. If yes can somebody please guide me about the connectivity.
Click to expand...

I/P->B1->LDR->B1->O/P

^^ This is the way there. Don't avoid anything as there are 1Mohm terminations at input and LDRs comes at correct place as depicted in diagram.
 
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