Yet another F5 building log

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I hope you don t mind another vanila F5 building log thread :)

My goal is to eventually build 4 channels to drive my speakers in biamping topology.

For now I have received the F5 and the generic PSU boards from the DIY store, and I am now working on the component list.

So far I have located the F5 parts. I would appreciate it if you had a look at my list
http://www.mouser.com:80/ProjectManager/ProjectDetail.aspx?AccessID=967a424ecd

Thanks a lot. I hope I have some more news very soon

Dimitri
 
It s good to see people following on such projects:)

Hopefully next week I will order some more stuff... for now, it s just planning (I love to hate that phase... reading and more reading...)

Still trying to decide on transformer size (thinking of 1KVA) and find a relevant good vendor.

For now, I have decided to get the 5U 400mm Dissipante from HIFI2000 (to accomodate for possible turbing of the project :) ).
 
Dont mind at all new F5 tread go for it

About traffos I got 1 KvA on mine with 20 and 24 V taps now I wish I had a few more volts

I had a bit of trubles with traffos as poor construction caused same hum
I sent one back and it was resin dipped and most probably the tape over it was retightened no more hum from that.

At the time this is what mighty Zen sugested on MY F5 tread

Quote:
exactly

when I tell to my supplier - " Iwanna300VAdonutwithstaticshield2x18Vacindependent notcentretapped36VacanditwillworkinclassAampwith10 0VAconstantjuice" , he answer : "yeahcorewillbedoublebakednextsizeandwirewillbesom ewhatthickerbutI'llchargejust10%morethanforusuall3 00VAdonutmadeforhalogenbl/i/o/nding"

simple , isn't it ?
at least 'till first time he forget to pass that info to winder


Hope it helps.
 
Oh my god my head almost exploded trying to read this... :D

1KVA overkill for two channels? I am running a 100mA phono with dual 160VA toroids... And yes there is audible difference from smaller ones...

To be honest I was thinking 1KVA per channel.... Perhaps I will also get a 600VA one and compare. I still have to find some decent built ones though...
 
Each channel of an F5 draws a continuous 1.3Adc from the PSU.
That requires an absolute minimum rating for a single channel transformer of 2.6Aac.

To ensure cool running I recommend a single channel transformer rating of ~5Aac.
using 18+18Vac transformer that equates to a single channel requirement of ~180VA, two channel rating of ~360VA and 4 channel rating of ~750VA.
 
Here it is 1000Va 24 v sec F5
the picture 1 is just main suply
the rest is in 2 towers with another 100 mU of caps
it sounds prety good with 2.6 A bias and is ready to go balanced
Just have to put in another 100 mU worh of caps and bolt in 2 extra boards.

Yes got head and hart hake reading Zen Mod post but he is prety decent chap
I wrote once
quote >
if it came from Zen it must be fertiliser...

Wel worth to take your time and put spaces on tha post

Can say same for same that never built a thing or heard F5;)
 

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My dual mono F-5 uses two Antek transformers, 300VA each....there is no reason for more. The same could be said for an even smaller one. If I recall, the commercial F-5 used a single 250VA? I may be mistaken. My current F-5 build is using a single 500VA.

Russellc
 
Guys just a question.
Your suggestions are based on experience between 1KVA and smaller ones, or is it just that you are content with the smaller ones?

The reason why I am asking is that I see you saying that the small ones should be "sufficient" or "enough" or other adjectives that tend to describe something that is just working without problems.

Does anyone have actual experience indicating that the 1KVA has no sonic difference over for example the 300VA?

The results I have so far form my phono indicate that the difference is huge with a bigger transformer.

Please have a look at this blog entry by Richard RJM
http://www.diyaudio.com/forums/blog...ower-transformer-than-you-think-you-need.html

You will see that the rectifier-diode/filter combination does not need current on a continuous basis, but rather in a spike-like manner. And the spikes can reach easily 10 times the nominal current draw. Which can easily be translated according to Andrew's calculations (minus the cooling compensation) to 2,6x10=26A or and for 2x18 secondaries to 18x2x26=936VA

I have tried/verified Richard's theory on my phono and there is a huge difference in the sound.

I see no reason why the bigger PSU should behave any differently. Especially with the huge filter caps that practically act like shorts
 
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