First Watt F5
#16
I got the PCB's and transistors from diyAudio folk. Peter Daniels I think for PCB's. Very easy build. Hardest part was tapping the holes in the heat sink, but that's because my M3 taps are made from play-dough.
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#18
I have had real problems tapping into soft alloys, but the high spec dural (or HE30) I use is normally not too bad.
If it's not a critical application, or needing to be done up really tight, I sometimes use a gnats bigger drill (and lubricate the tap with fairy spit. )
If it's not a critical application, or needing to be done up really tight, I sometimes use a gnats bigger drill (and lubricate the tap with fairy spit. )
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#20
I've just marked out the M3 hole positions for Mosfets on my heatsinks.
I've decided to contract-out the drilling and tapping to my mate Len who reckons he can do this properly . I'm pretty sure he can do it better than me .
I've decided to contract-out the drilling and tapping to my mate Len who reckons he can do this properly . I'm pretty sure he can do it better than me .
"Once you find out ... the Circumstances ; then you can go out"
#22
i would be suprised if it was really any better in the bass than a low powered valve amp with decent valves in it paul ?Paul Barker wrote:. It is really nice. Obviously much better at bass than a low power valve amp.
Nick says he has been listening to it at home quite happily.
i was very suprised at the sound of Eds amps.. they where impressive
on a sound per £ they are much better value..
when tapping alloy.. use parafin as a cutting lube otherwise it will tear
the thread.
#23
in post 4 I made reference to the F5 and F4 being similar, it was post 750 here that I was referring to:Paul Barker wrote: Obviously much better at bass than a low power valve amp.
http://www.diyaudio.com/forums/pass-lab ... er-75.html
what I meant to say is I didn't want to risk £100 and a weeks work to find that I'd already got the same amp, If you see what I mean.
If they are the same, and I guess Nick might be the best judge cos he's heard both, then I can say that I've got a low wattage valve amp that equals the bass. My experience is that the speakers make more than a profound difference to the end result, I think due to the DFs involved. The F5 has twice the DF of the F4, and also twice the noise, so again the speakers will tell the tale. I developed a back horn(pipi) which the F4 couldn't play with at all due to DF, so I'm pretty certain it's a big factor.
the truth is out there......just gotta find the money to nail it down
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#24
I agree about DF. I took my ported speakers to Colin's (Toppsy) and they were extremely bass heavy on a valve amp (can't remember which one), but fine on my 1 Watt class A and a NAD solid state amp. When I looked on WinISD, and set an output impedance of 8 ohms - probably somewhere near, there is a 7dB peak in the output at around 80Hz. drop below 1 ohm, and it's gone.ed wrote:I developed a back horn(pipi) which the F4 couldn't play with at all due to DF, so I'm pretty certain it's a big factor.
the truth is out there......just gotta find the money to nail it down
My speakers are flat to around 40Hz, so any boost in bass is undesirable, so they are only really suited to solid state amplification, if the bass output of a speaker is falling below 100Hz, an increase in bass from low DF is desirable, so bring on the valves.
Just my simple take on this and contains sweeping generalisations, but I think the principle is right.
Brian.
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#25
Even imperial doesn't help, you need something like a 7/64th'sNick wrote:Not much choice for nats bigger with M3 though.
Or a 3 and a half 32nd's....
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#26
Well, its hard to say, the F4 is a buffer, so most of what you hear is the character of the gain stage before it. Other than that, yes I think they are very similar. And yes the f5 has more noise, but again, something needs to add a extra 15dB of gain to the F4 to make them equal. So the noise will increase in that situation. In both cases, the noise is lower than most if not all valve amps.If they are the same, and I guess Nick might be the best judge cos he's heard both, then I can say that I've got a low wattage valve amp that equals the bass. My experience is that the speakers make more than a profound difference to the end result, I think due to the DFs involved. The F5 has twice the DF of the F4, and also twice the noise, so again the speakers will tell the tale. I developed a back horn(pipi) which the F4 couldn't play with at all due to DF, so I'm pretty certain it's a big factor.
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#27
I don't hear any noise. We haven't got folk who stick their ear into speakers have we?
#28
The numbers on Nelson Pass's site lists the various amps vital statistics, and the noise of the F4 is 50µV the F5 100µV. But both are lower than we need to worry about I suggest. 100µV and 25w is a 102dB S/N ratio
Not that I think Ed is saying it is.
Not that I think Ed is saying it is.
Whenever an honest man discovers that he's mistaken, he will either cease to be mistaken or he will cease to be honest.
#29
Nick wrote:The numbers on Nelson Pass's site lists the various amps vital statistics, and the noise of the F4 is 50µV the F5 100µV. But both are lower than we need to worry about I suggest. 100µV and 25w is a 102dB S/N ratio
Not that I think Ed is saying it is.
I was just pointing out the differences in spec in order to cover all the bases when discussing whether the two amps might be the same or similar. Noise might have nothing to do with overall sound but DF certainly seems to.
its funny how 4 or 5 years ago I was defending the first watt amps against all comers, narrowly avoiding the ducking stool. Now I seem to be defending the humble SE valve amp against the first watts....
watts going on?
There's nowhere you can be that isn't where you're meant to be
#30
F F F F Fashon (turn to the left)
Using the right tool for the right job, thats my take. I think I remember liking your first F2 Ed, though that my be me altering my memory to sute
Using the right tool for the right job, thats my take. I think I remember liking your first F2 Ed, though that my be me altering my memory to sute
Whenever an honest man discovers that he's mistaken, he will either cease to be mistaken or he will cease to be honest.