An illustrated guide to building an F5

[Itsmee]

Just to clarify: I have a ZETEX ZRA6045F in the PS. I only "need" the CL-60 fron PS to chassis ground. I was hoping to finish this beast before weekend - I don't want to order one. Can I use a resistor instead?

* Not in the best mood for silly jokes. Damn, I hate chassis work.

Yes, any value between 10 & 100R, put a capacitor in parallel with it.

Some prefer to use anti-parallel diodes - use a bridge rectifier, short the + & - pins together, connect one AC pin to 0V and the other AC pin to chassis.

 

[Cassiel]

Thanks!

 

[albertob]

what type of wire did you use from the mosfets to the PCB board? My construction technique is similar to yours

I used silver wire diameter of 0.8 cm

Câble Nu Argent-Or-Cuivre - Câble Pur Argent 99.999% 0.8mm

 

[Cassiel]

Thanks for the info Alberto. Erm...just another question o), the thermal grease between the mosfet and the mica or between the mica and the heatsink?

I will post pics of the amp next week if all goes well.

 

[Zen Mod]

grease :

between mosfet and mica

and

between mica and htsnk

 

[Cassiel]

I see, everything well lubricated. Game on!

Looking forward to your fugly comment.

 

[albertob]

the feast of grease!

The thermal paste used to fill all the micropores

 

[tinitus]

if youwant to see how much(or little) grease you need, mount one up, and dismantle again, carefully
you should be able to if there are air 'pockets'
but I think the rule of 'less is more' counts

 

[Cassiel]

I will post pics of the amp next week if all goes well.

Blowing fuses left and right! Some blow themselves up, others see a bright white light before dying. No shorts and my bridges are OK, it's got to be the solid state relay. Do these things blow fuses when testing the power supply unloaded? Should I load the power supply and see what happens? HELP!

The SSR is old and can't find data but it was working allright. Input says 240VAC and 'CONTROL' says 80-280VAC. It was workimg in an amplifier fitted with a 35-0-35 torodial. Should I get rid of this and buy CL-60's? It is OK to test the amp with no inrush current limiters for a couple of weeks? HELP!

 

[AndrewT]

use a bulb tester for all mains power ups while you are still experimenting with any mains powered project.

 

[Cassiel]

a bulb tester

As a dummy load? One for each secondary?

 

[Zen Mod]

nope - as sort of fuse , in-line with mains ;

if everything is OK - it will dim lightly

if something is wrong ( drawing excessive current ) it will dim bright as sun

search forum for light bulb tester - everything is explained numerous times

 

[jacco vermeulen]

Blowing left and right!

Ah, you manly male of a man.
You have a number of the SSR ?

 

[Cassiel]

Guess this is what you were talking about. I'm pretty sure my wiring is OK so what I'm going to do is connect the power supply to the mosfets and if the fuse blows again then the SSR for whatever reason is no good for this amp.

Anyway since the trimpots are set to lower resistance not much current is going to flow.... what I really wanted to know was if SSR's pass voltage when there's little current and if they blow fuses when there's no load. Guess I'll have to post this in the power supply section of this forum.

You have a number of the SSR ?

ZRA6045F

 

[Cassiel]

OK, with a bulb limiter (60W) AND the SSR out of the circuit the fuse lives to tell and my -/+ voltages are correct. Now I'm going to power up the mosfets.
Just one more question: can I listen to the amp for a week with no current limiters? Waiting for my CL-60's.

 

[AndrewT]

what is SSR?
The CL60 are in the mains side (the primary circuit).
They are a version of soft start. Don't call them up as current limiters. That will confuse Members into thinking you have added some kind of limiting to the amplifier output.

 

[Zen Mod]

.......can I listen to the amp for a week with no current limiters? Waiting for my CL-60's.

if fuse survives , why not .

 

[Cassiel]

Thanks for the help. Yes the fuse is OK, something was wrong with the SSR (solid state relay).

They are a version of soft start. Don't call them up as current limiters.

OK, I won't.

This is my power transformer, F5 PSU schematic doesn't show how to wire up the CL-60's with this primary. Sorry, too many questions.


http://www.amplimo.nl/images/downloads/ds standardrange/78014.pdf

 

[Cassiel]

F5 PSU schematic doesn't show

No need to answer, connected in series with each transformer leg.

 

[Bksabath]

Just one more question: can I listen to the amp for a week with no current limiters? Waiting for my CL-60's.

Of course you can I have and not bothered to ad them on the PCB as well

As you mention Amplimo cek the speaker protection relay they make
NTE7100 or similar can save speakers if any bubues.