Gb: F5 Pcb

[bobodioulasso]

My F5 (Cviller board) is as i described, dual mono and quiet dead.

In general bi-amping or monoblocks for L and R seem more problematic in my experience in dealing with ground loops. Keeps one thinking.

That's the opposite, the more channels on one common PSU the more problems with ground loops.

 

[samoloko]

thank you guys

 

[specialidiot]

My power supply board is up and running. I'm just missing a couple of parts for my F5 boards and I'm done.

I have + and - 29vdc from my PSU with no load. Is this OK?

 

[cviller]

My F5 (Cviller board) is as i described, dual mono and quiet dead.
That's the opposite, the more channels on one common PSU the more problems with ground loops.

True unless you have gnd directly connected to chassis and use safety gnd...

My power supply board is up and running. I'm just missing a couple of parts for my F5 boards and I'm done.

I have + and - 29vdc from my PSU with no load. Is this OK?

Sounds a bit high, but it might be ok. Is the toroid 2x18VAC?

 

[specialidiot]

Sounds a bit high, but it might be ok. Is the toroid 2x18VAC?

Yes, it's an Antek 4218. I have 120vac at the mains.

 

[cviller]

Yes, it's an Antek 4218. I have 120vac at the mains.

What is the rating on your capacitors? The voltage will go down substantially when you drive the F5 boards.

 

[bobodioulasso]

True unless you have gnd directly connected to chassis and use safety gnd... quote:

I cannot say as i never use safety ground.

 

[Lee35210]

PSU schematic

Samoloko, You need to watch that lower bridge. As drawn will result in a large mess when lower cap bank explodes! You have polarities of lower bridge reversed.

 

[samoloko]

Re: PSU schematic

Samoloko, You need to watch that lower bridge. As drawn will result in a large mess when lower cap bank explodes! You have polarities of lower bridge reversed.

you are right - the lower bridge Is with reversed polarities

 

[specialidiot]

What is the rating on your capacitors? The voltage will go down substantially when you drive the F5 boards.

I am using 15000uf and 50v.

Thanks for the reply.

 

[cviller]

I am using 15000uf and 50v.

Thanks for the reply.

Then you should be safe.

 

[samoloko]

anyone got measured rails with load and no load
I got 25 Vdc no load and 22 Vdc with 2 F5 amps at 0.5 V bias

 

[specialidiot]

Then you should be safe.

Thank you cviller, I appreciate the reply. I knew I'd bring it down a bit under load, but 29vdc seems high to me.

What is the correct gauge of wire to use for the power connections? I have 16 ga on hand.

 

[labjr]

Thank you cviller, I appreciate the reply. I knew I'd bring it down a bit under load, but 29vdc seems high to me.

What is the correct gauge of wire to use for the power connections? I have 16 ga on hand.

"00" gauge !

Seriously, the transformer secondaries look like 16-18 gauge I would think that's enough.

 

[Tea-Bag]

anyone got measured rails with load and no load
I got 25 Vdc no load and 22 Vdc with 2 F5 amps at 0.5 V bias

Mine are ~ 22-22.5v loaded.

 

[samoloko]

The posted drawings from http://www.diyaudio.com/forums/showthread.php?postid=1814765#post1814765 and http://www.diyaudio.com/forums/showthread.php?postid=1814874#post1814874 are wrong - reversed polarity of the lower bridge

here corrected drawing

 

[bobodioulasso]

I just found this nice thread about star grounding.
Hoping it can help.
http://www.diyaudio.com/forums/showthread.php?s=&postid=1403793#post1403793

 

[na]

Hello CViller,

Just bought 2 F5 boards, and one PSU board by paypal.

Couldnt not send you email because i am newbie here..

Best regards,

-Niko from finland.

 

[cviller]

Hello CViller,

Just bought 2 F5 boards, and one PSU board by paypal.

Couldnt not send you email because i am newbie here..

Best regards,

-Niko from finland.

I got your order and paypal - thanks. My weekend is busy, but I'll send the boards on monday.

 

[alazira]

initial rail reading

Thank you cviller, I appreciate the reply. I knew I'd bring it down a bit under load, but 29vdc seems high to me.

What is the correct gauge of wire to use for the power connections? I have 16 ga on hand.

Hi,
This was my 1st amp build (thanks N. Pass, C. Viller for boards, and U.Dailey for step-by-step power supply pictorial) and I bought my 1st multimeter and variac. I put everything together, plugged it in and slowly turned up the voltage to 125. I was very happy to see the little led lights glow. When I first measured the rails they were 29vcd!
Some things I thought were perhaps my toroid was incorrectly labled (antek 300va 18x18) or my variac was defective. I had to turn it down to 105 volts to achieve 24vdc rails. My initial reading across r11 was 0. After p1/p2 adjustment my rails were 25 at 120volts and generally I have measured 22 to 23.5 average off the mains.