Final parts for fest amps.

[angelod307]

Hey guys and gals, as i have looked and it is getting by me, who knows the final parts that the baby amps got. There are some black circular looking devices right after the iec plug that i think is a current rush limiter. Then the other tweaks that i may not be aware of. Thank you for the help.

[radioeng2]

If it's a current inrush limiter Angelo, I think it'll have a part number of CL sumpin sumpin on it. Like CL##.

On a inrush limiter, when voltage is first applied and it's cold, it has some small resistance. It drops some volts in other words. As current passes and it warms, the resistance drops...but it still has some loss thru it. This resistance cold and less when warm, BTW, is the opposite of a filimentary light bulb. A bulb when they first have voltage applied, are about a short and as they warm, start to have a resistance.

So if you have a big cap bank and SS diodes, you may pull enough charging the caps up to pull the fuse. You could up the fuse value, but if you do then you're not very well protected under normal operation when current draw is less than startup. Caps on initial charge are about like a short circuit they pull so much.

In this case, the idea in the fest amp was to use the long term warmed up state of the inrush limiter, to drop a few volts and lower B+ some not so much any need for inrush limiting. The long term dropping of a few volts as resistance is why they run hot as hell during normal operation. That is why they need to be placed carefully to allow convection cooling and best to keep them away from electrolytics. The idea in the fest amp is to drop a few volts on the primary side....which when multiplied to the higher voltage on the secondary, was even more volts. This mattered with the B+ right up against the limit of the caps and where the finals were running at their very top end.

That's todays story for those with hot irons on the kitchen table. Not only will a hot iron burn your fingers, the inrush limiter will to if you touch it too quick after unplugging. Yes, unplug it first Ray.

Mark

[mbskeam]

sorry got busy and forgot to respond....



Mouser #: 667-ECW-FA2J224J4
Mfr. #: ECW-FA2J224J4
Desc.: Film Capacitors 630volts 0.22uF 5% Ammo Pack L/S 7.5mm
12 $0.57 $6.84
this goes on the +/- of the main cap


Mouser #: 871-B57153S330M51
Mfr. #: B57153S330M51
Desc.: Inrush Current Limiters 33 Ohms 1.3amp 3000k
12 $0.39 $4.68
thermistor


Mouser #: 863-1N5352BG
Mfr. #: 1N5352BG
Desc.: Zener Diodes 15V 5W
25 $0.27 $6.75
bias circuit


Mouser #: 863-1N5360BG
Mfr. #: 1N5360BG
Desc.: Zener Diodes 25V 5W
36 $0.27 $9.72
voltage drop net work


Mouser #: 286-6.8K-RC
Mfr. #: 286-6.8K-RC
Desc.: Metal Oxide Resistors 6.8Kohms 5% Tol
12 $0.56 $6.72
voltage drop net work


Mouser #: 660-MO2CT631R681J
Mfr. #: MO2CT631R681J
Desc.: Metal Oxide Resistors 2W 680 5%
voltage drop net work

[Zoot Horn]

Thanks for posting that Mike!

[angelod307]

Slumber party for sure now!

[Magnaryder]

Slumber party for sure now!

Knocking IS required when entering your cabin,,,boys

ray

[Zoot Horn]

OK-- if I get the parts will someone be kind enoughto bring my 2 up to par at this years CF--- Harry? Mikey?Marky?--Seriously,, my eyes are not what they used to be.

Thank you kindly.

[hewlew1]

George,The only items you are missing are the first two mike listed, the thermistor and the capacitor . If you want to get them bring them to the fest I will do it for you.

[Magnaryder]

OK-- if I get the parts will someone be kind enoughto bring my 2 up to par at this years CF--- Harry? Mikey?Marky?--Seriously,, my eyes are not what they used to be.

Thank you kindly.

George how are they sounding? I'm interested in the Russian caps.

ray

[Zoot Horn]

George,The only items you are missing are the first two mike listed, the thermistor and the capacitor . If you want to get them bring them to the fest I will do it for you.

Thank you sir

[Zoot Horn]

OK-- if I get the parts will someone be kind enoughto bring my 2 up to par at this years CF--- Harry? Mikey?Marky?--Seriously,, my eyes are not what they used to be.

Thank you kindly.

George how are they sounding? I'm interested in the Russian caps.

ray

Ray. They sound good. I just need some efficient speakers. If you want the runs sky's. I will give them to you. I like the auric amps better

[angelod307]

So i now ordered all the remaining parts. Anyone interested in a amp perhaps?

[BrianT]

So i now ordered all the remaining parts. Anyone interested in a amp perhaps?

Angelo

Did you order any spare parts, as I could do with a set to do the upgrades
but as you know, shipping to Canada kills me.

Brian

[hewlew1]

Brian , you are in the same boat as George your amp I believe only needs the thermistor and the cap as well. If you whisper nice things in George's ear maybe he will buy some additional parts for you.

[angelod307]

Maybe. I think brian. I tried to anyway. We shall see . I spent like 60 or so on the parts, alot of them.