Building a symmetrical psu B1 buffer - Page 61

merlin2069er · 1st December 2009, 12:39 AM

Quote:

Originally Posted by Salas

Its a good rig the one you used so to check Vf at enough mA, as they will work on the real boards.

Just use 4 of them 1.95V and in a Led position put 2 little diodes (1N4004) in series instead then. 1.95X4=7.8+DiodeDropX2+Vbe=about 10V. Those diodes are checked once by a member and measured very low noise.
Just tie the 2 diodes on air and insert them as a single component in one of the led positions. There are solutions so not to wait and wait.
See the picture, and don't forget, in the negative reg cathodes are facing the other way around.

There's a string of 3 and 5 leds - where does this apply?

Thanks,
JG

udailey · 1st December 2009, 12:46 AM

Hey JG,
Dont use 2 fuses. Put one on the primary. You dont want one of your two fuses on your secondary frying and the other surviving. Sacrifice the fuses

Put only one on the primary.
Uriah

merlin2069er · 1st December 2009, 01:07 AM

Ok, I'll use 1 fuse. There are 2 fuses on the BOM & 2 on the schematic.
I just was a bit confused as to why.

Salas · 1st December 2009, 01:20 AM

Quote:

Originally Posted by merlin2069er

There's a string of 3 and 5 leds - where does this apply?

Thanks,
JG

5

woodturner-fran · 1st December 2009, 09:54 AM

Merlin, 1 fuse is specc'd for 230V mains and the other for (US) 110V mains.

Fran

woodturner-fran · 1st December 2009, 01:22 PM

I added in the new transformer last night, 15V secondaries. So it powers up fine and I get basically the same voltages out of the shunt. So all is well. The other thing I did was do a bit of fiddling with the 68R//68R. I followed AndrewTs advice and started by adding a 3rd 68R in parallel to drop the resistance in stages. Anyway, right now I have 68R//68R//10R in parallel (just didn't want to take out the 2 68R yet until I was sure there was no heat issues). So anyways, I haven;t really got to listen yet, but the 140/9140 still barely get warm, I'd guess 30degC, no more (I'm used to the F5 !!). So next step now is to swap them out for the 10R on its own.

BTW, I also did the mod using the coax instead of the regular silver in teflon and it made absolutely no difference at all. I was really surprised that there wasn't some change! I know the runs are short (about 50mm-80mm), but I expected something!!

So the plan tonight is to listen, swap the shunt resistors, listen, and then maybe put in the lightspeed if time allows.

Fran

Salas · 1st December 2009, 01:36 PM

Measure the resistance of the combination you got right now for Rset and the voltage across so we know you really got high current. 30c sounds fishy. No difference with coax, means you had no real noise picked up by the open weave. Checked.

P.S. The regs outputs are supposed not to change, its just that sufficient input margin lets them perform as intended.

merlin2069er · 1st December 2009, 02:37 PM

Quote:

Originally Posted by woodturner-fran

Merlin, 1 fuse is specc'd for 230V mains and the other for (US) 110V mains.

Fran

Ok, but there is something wrong with DCB1 BOM V4.2 (it says 2 each for Hypnotize & Mezmerize)

Salas · 1st December 2009, 03:21 PM

For having a spare I guess.

merlin2069er · 1st December 2009, 03:24 PM

Hi,

I got 100x 2sk170BL in from China the other day. I wont be needing them all. (Unless I can think of something else to build.)

I initially placed an order with Mouser - but they were on backorder for months.

So, if anyone wants 50 pieces email me. I'll set the price to 1/2 of what I paid for them.

$20 USD (free shipping too.)

Thanks,
JG

1st December 2009, 12:46 AM	#602
udailey Passive Aggressive diyAudio Member Join Date: Mar 2008	Hey JG, Dont use 2 fuses. Put one on the primary. You dont want one of your two fuses on your secondary frying and the other surviving. Sacrifice the fuses Put only one on the primary. Uriah __________________ You can purchase LDRs anytime to build a standard LDR attenuator or to build my new LDR Attenuator "A Lighter Note". Email me. diyldr@gmail.com

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1st December 2009, 01:07 AM	#603
merlin2069er diyAudio Member Join Date: Sep 2008 Location: Toronto	Ok, I'll use 1 fuse. There are 2 fuses on the BOM & 2 on the schematic. I just was a bit confused as to why.

1st December 2009, 09:54 AM	#605
woodturner-fran diyAudio Member Join Date: Jan 2006 Location: Ireland	Merlin, 1 fuse is specc'd for 230V mains and the other for (US) 110V mains. Fran

1st December 2009, 01:22 PM	#606
woodturner-fran diyAudio Member Join Date: Jan 2006 Location: Ireland	I added in the new transformer last night, 15V secondaries. So it powers up fine and I get basically the same voltages out of the shunt. So all is well. The other thing I did was do a bit of fiddling with the 68R//68R. I followed AndrewTs advice and started by adding a 3rd 68R in parallel to drop the resistance in stages. Anyway, right now I have 68R//68R//10R in parallel (just didn't want to take out the 2 68R yet until I was sure there was no heat issues). So anyways, I haven;t really got to listen yet, but the 140/9140 still barely get warm, I'd guess 30degC, no more (I'm used to the F5 !!). So next step now is to swap them out for the 10R on its own. BTW, I also did the mod using the coax instead of the regular silver in teflon and it made absolutely no difference at all. I was really surprised that there wasn't some change! I know the runs are short (about 50mm-80mm), but I expected something!! So the plan tonight is to listen, swap the shunt resistors, listen, and then maybe put in the lightspeed if time allows. Fran

1st December 2009, 01:36 PM	#607
Salas diyAudio Chief Moderator Join Date: Oct 2002 Location: Athens-Greece	Measure the resistance of the combination you got right now for Rset and the voltage across so we know you really got high current. 30c sounds fishy. No difference with coax, means you had no real noise picked up by the open weave. Checked. P.S. The regs outputs are supposed not to change, its just that sufficient input margin lets them perform as intended.

1st December 2009, 03:21 PM	#609
Salas diyAudio Chief Moderator Join Date: Oct 2002 Location: Athens-Greece	For having a spare I guess.

1st December 2009, 03:24 PM	#610
merlin2069er diyAudio Member Join Date: Sep 2008 Location: Toronto	Hi, I got 100x 2sk170BL in from China the other day. I wont be needing them all. (Unless I can think of something else to build.) I initially placed an order with Mouser - but they were on backorder for months. So, if anyone wants 50 pieces email me. I'll set the price to 1/2 of what I paid for them. $20 USD (free shipping too.) Thanks, JG