F5m kit

[zman01]

9050lx,

What is the size of the heat-sinks for your build?

 

[9050lx]

6 inches tall, 10 inches wide, approx 1 1/4 thick. Old Astron 50 amp DC power supply.

 

[zman01]

Good DIY work in repurposing the power supply enclosure with heatsinks for an amplifier project.

 

[coffee-fan]

Hello,

I would like to ask if the soft start and speaker protection board is recommanded to be included? Or do you all run your projects without it?

 

[rolandong]

Unless you have expensive speakers or one could short your output, but if you know what you're doing - i've been enjoing lots of diy amps without it.

 

[william2001]

I have always just relied on the TH in series with the transformer primary to limit inrush current at turn-on. I haven't used DC protection and have not had a problem....yet (20+ years in the hobby).

 

[mkrawcz]

If we were talking chip amps, I’d say speaker protection is a must, but the first watt designs are as reliable as it gets as long as they’re built and set up correct.

 

[6L6]

The PSU already has a soft starting function, so the soft start PCB isn’t not necessary.

If you wish to add the DC protection you may, however, I suggest doing this after you have your amp built and functioning properly.

 

[Russellc]

Never used it (DC protection) here with the many Pass clone amps Ive had. All but the F6 are still running. I used its case and power supply
for Aleph J. Most of my builds have the CL-60 setup for inrush. I did follow 6l6's build guide instructions and used the store delay in my BA3 amp.. Both work fine.

 

[coffee-fan]

Thank you for all the answers

 

[broennimannrainer]

Hi coffee-fan
I have built the F5 several years ago. Sound was amazing. No noises when I switched it on or off. What, when it blows? Then you have 28V DC going directly to your loudspakers. In the end I returned to my Yamaha MX-2 which sounds quite good and has a very good protection circuit (tested it involuntary).

One of my next projects will be a F5M. I will add a Ls-protection circuit - for peace of mind. They are much cheaper than any loudspeaker in case of failure. Yes I am a coward. I can happily live with this.

 

[Extreme_Boky]

And... why did it blow?

 

[9050lx]

6 inches tall, 10 inches wide, approx 1 1/4 thick. Old Astron 50 amp DC power supply.

I must apologize. I did not disclose the fact that a top cover was not included in the purchase of my enclosure, and my temps are achieved while going topless.

 

[Nelson Pass]

The next batch of F5m Essentials will be listed in the store very shortly.

Important to note that I have made a minor improvement in the power supply boards detailed here.

 

[Mark Johnson]

Is this a mistake?

_

 

[Zen Mod]

what's missing wire between friends?

 

[seventenths]

I must apologize. I did not disclose the fact that a top cover was not included in the purchase of my enclosure, and my temps are achieved while going topless.

Have you tried a second test with a solid panel (cookie sheet, cardboard, whatever) place over the top for comparison. It seems to me that Imperfect as it is, simply sliding the panel over to allow a 5%, 10% etc opening may be helpful in laying out/buying a permanent lid. Cheers

 

[9050lx]

Tried and watched the bias go to about 1.5 amps per side. I will probably buy a bigger pair of sinks and fab an expanded metal of some kind for a lid.

 

[Demonkleaner]

These can work is you have a way to cut them. There are different sizes. Search Amazon:

Excellante 18" X 13" Half Size Aluminum Sheet Pan, Perforated​

 

[9050lx]

Nice idea on the sheet pan. I cut aluminum by using a jig saw, then some clamps and a 2x4 for sanding a straight edge . I then use a belt sander (3x21or 3x24 is a good size) makes almost perfect results.Need to file the sharp edge with a file of course. I suppose a table saw with a metal blade would also work well. I assume one could use a masonite or plywood backer for thin gauges.