First Watt F5

For the three and more legged things
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ed
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#31

Post by ed »

Nick wrote:F F F F Fashon (turn to the left)

:-)
not so much about fashion as me learning a bit more about DF and how it affects synergy....also I didn't have much experience of DHTs to do the comparisons in those days...these things have changed slightly and I think I have a better feel for the different flavours......

F2, ah memories, I have great affection for that amp, and I'm still creeping up on the F2J which will see the light of day sometime in the next 6 months.....

back to Paul's black and white statement that I highlighted, and which caused me to respond......I had to question it because I think there are other factors to consider, called shades of grey, only one of which is synergy. Plus,(I used plus to avoid starting a sentence with 'and') I have a 3 watt SE valve amp which I consider does as good a job as the F4 in the bass.
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#32

Post by Nick »

I had to question it because I think there are other factors to consider, called shades of grey
There always are, we live in a analog world.
Whenever an honest man discovers that he's mistaken, he will either cease to be mistaken or he will cease to be honest.
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#33

Post by Nick »

Nick wrote:
I had to question it because I think there are other factors to consider, called shades of grey
There always are, we live in a analog world.
Though, thats only partially true.
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#34

Post by colin.hepburn »

So what is meant by DF and how it affects synergy could you explain what DF is as it may help to understand what you are talking about :)
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#35

Post by brig001 »

Damping Factor.
I found this explained the effects quite well: http://www.audioholics.com/education/am ... m-response
For me, the synergy comes from having a starting point and either matching the loudspeaker to a given amplifier or the amplifier to a given loudspeaker. My own loudspeakers are unsuitable for use with anything with a high output impedance - I designed them with a solid state amplifier in mind, but I could re-design them to suit just about any amplifier as long as I knew what output impedance it has.

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#36

Post by colin.hepburn »

Ah DF Damping Factor yes of course :oops: thanks for the link Brian. :)
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#37

Post by Mike H »

I keep forgetting as well!
 
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#38

Post by colin.hepburn »

Hi Nick All
Well I have been considering building the nelson Pass F5 for some time know if I can get all the genuine matched Transistors not to easy now I believe
Also the heat sinks used in this build were that from the Australia Company Conrad heatsink range if so I am guessing but it looks like the MF30-100 can you confirm this
Thanks
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#39

Post by IslandPink »

Colin, Have you been on the DIY Audio 'Pass Labs' section ?
You should with a bit of searching through the F5 threads still be able to find suitable links to people offering matched parts for the F5 .
Are the heatsinks for F5 the same size as for the F4 ?
I can trawl through some posts I made 2-3 years ago on the F4, in that case .

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#40

Post by Nick »

That case and heatsinks are from

http://www.modushop.biz/ecommerce/cat143_l2.php?n=1

The 3U heatsinks are just about right for the F5, though a bit small for the F4

I got the semiconductors and PCB's as Mark suggested from DiyAudio
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#41

Post by colin.hepburn »

Thanks Mark/Nick
Yep i did have a quick troll through diy audio but I will have another look could look at eBay for the transistors but most will be fake at a guess the heat sink looks like ether the MF35-100 or 151 would do
http://www.conradheatsinks.com/products ... 0_350.html
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#42

Post by colin.hepburn »

Is it absolutely necessary to use match transistor in the Nelson Pass F5
What are likely to be the consequences if unmatched transistors are used?
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#43

Post by Cressy Snr »

colin.hepburn wrote:Is it absolutely necessary to use match transistor in the Nelson Pass F5
What are likely to be the consequences if unmatched transistors are used?
BANG ? :) (sorry)
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#44

Post by Paul Barker »

ed wrote: back to Paul's black and white statement that I highlighted, and which caused me to respond.....
I had to look hard for this black and white statement, and found you must have dug up my opinion statement on the new amp as it was then on first impressions, comparing it with what I had otherwise experienced.

You want to call opinions black and white?

Shall I not bother with my opinion any more based on my experience?

If you prefer to discuss the way things might be with fense sitters be my guest. I am bored with the forum anyway.
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#45

Post by Nick »

colin.hepburn wrote:Is it absolutely necessary to use match transistor in the Nelson Pass F5
What are likely to be the consequences if unmatched transistors are used?
Most likely higher distortion. The setup equals the idle current through them so its mainly gain that needs to me matched.
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