Solved the transformer buzz / hum in my F4

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Manolo47

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Joined 2006
#1
My F4 is factory assembled and had recently aware of a low transformer hum or buzz which was not ameliorated by disconnecting interconnects, power ground, etc. So, I decided to braid the input wiring to the transformer and problem solved quiet as a baby sleeping!

Got the idea from Rick Schultz's site where he recommends this as a tweak for First Watt amps, albeit a cure for transformer hum is not mentioned it attained an improvement.
 
#2
just took quick look at First Watt Mods

1. Remove the indicator LEDs.
2. Remove distorted limiters on the incoming AC power.
3. Bypass the binding posts. This could be done by eliminating the binding posts and simply have wire sticking out the amp or drilling some holes in the chassis underneath/besides the binding posts and running the output wires through these holes and wrapping around the outside of the binding posts....essentially making the binding post a clamp.
4. Change all steel hardware to non magnetic stainless steel or brass hardware.
5. Remove the steel cover and screw from the main power transformer and lift the transformer off the chassis using plywood and use tie wraps or brass hardware and wood to hold down the transformer
6. Better input jacks.
7. Better input and output wiring.
8. Bypassing the power supply rails with modified Wima Polyprop caps.
9. Tightly twist the AC wires to and from the power transformer.
10. Damp various parts including the heatsinks.
11. Use Audiophile fuse.
12. Upgrade resistors and capacitors.
Click to expand...

with #9 I agree 100% ( never enough twisting) , with #12 I agree just partially , rest is ...... well - rest .......

it's morning here and I'm usually unusually polite in the morning ..... :devilr:

whatever , money is made to flow ......

though - can you specify - buzz was comming from xformer itself ( mechanical ) or from spks , or both ?
 
#3
on second thought .........

regarding #5 - I'm using spongy rubber for that , strictly as anti-zzzzzz procedure



IMG_9261.jpg



while for #7 there is sole proper solution 0.1mm dia silvered copper , nude or tefon isolated twisted :

IMG_9269.jpg



Papa’s Koan (M)2 , an amp for living room | Zen Mod Blog

😉
 
#4
What does Distorted limiters in 2) mean? thanks.



Zen Mod said:
just took quick look at First Watt Mods



with #9 I agree 100% ( never enough twisting) , with #12 I agree just partially , rest is ...... well - rest .......

it's morning here and I'm usually unusually polite in the morning ..... :devilr:

whatever , money is made to flow ......

though - can you specify - buzz was comming from xformer itself ( mechanical ) or from spks , or both ?
Click to expand...
 
#7
Braiding is not a good way to reduce LOOP area.
Close coupling and twisting are the recognised good methods of reducing LOOP area.

In addition, twisting swaps the phase of interference between each half loop of the twist. This achieve MUCH better attenuation of interference.
 
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#10
Just clicked the link and checked out Tweakaudio's mod list for Firstwatt amps.
What a hack..... He is trashing out these fine amps.

I can only imagine opening one of his "modded" amps and seeing plywood and tie wraps holding down the transformer! Not to mention the extra drilled holes with speaker wires running through them utilizing the original binding posts as anchors.

Are people actually paying this company to deface and devalue their equipment?
 
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