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View Full Version : FS: First Watt F5 DIY Clone



no_lo_fy
11-04-2015, 09:10
Hi,

Time has come to sell my DIY FirstWatt F5 clone, running 28Wpc into 8Ω. Built by my own “fair” hand around 3 years ago. But I fancy giving the Hypex route a go, so I have to sell.

(I’m conscious of the ‘ethical’ nature of making any money from someone else’s design - so the asking price is less than it cost me in components. I’m not trying to make money off the back of Nelson Pass’ generosity)

The amp sounds (genuinely) fantastic - it is not really surprising that it is so popular amongst DIYers. I have no way to know how it sounds compared to an original Nelson Pass built one, but I have had a lot of very satisfied listening - I didn’t deviate from the original design, so I can’t imagine it is much different.

The amp is set up as per an original and will work like any other amp with no need to fiddle if you don’t want to! (It is biased to ~1.3A idle current, as per specs, and DC offset never exceeded 4mV on either channel when I checked over a ~10 minute period last night). I am very happy with my build standard (see pics), and have never had any reliability issues - worked perfectly from first switch on and never any failures. What I am trying to say is this should be just as reliable and easy to use as a commercial amp - BUT at the end of the day was built in my study and any buyer must understand that. There are no marks or scratches that I can see.

The bad:
It has some mechanical hum from the transformer. I have it bolted down on semi-rigid foam which means it becomes inaudible at about a foot or so away, but the amp is best not thrown around in this setup. Bolted down hard to the case it is heard at 2-3 feet in a silent room.
It also has some ground hum, audible again a foot or so away on my 88dB speakers.
All this is inaudible from a listening seat.

I don’t want to test it against the rigours of the postal system, so I offer to deliver it locally (Northumberland, Newcastle, Sunderland, Durham, Carlisle etc) within the price. Further afield, hopefully we can sort something out.

Price is £400

Thanks for looking!
(sorry - I only seem to be able to attach 4 images)

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hughandella
11-04-2015, 09:29
Hi Jonathan

Looks nice and tidy and i may be interested although I am further afield --- but what is the price ? ( or am I blind ha ha )

Ali Tait
11-04-2015, 09:30
Price?

struth
11-04-2015, 09:32
Hi,

Time has come to sell my DIY FirstWatt F5 clone, running 28Wpc into 8Ω. Built by my own “fair” hand around 3 years ago. But I fancy giving the Hypex route a go, so I have to sell.

(I’m conscious of the ‘ethical’ nature of making any money from someone else’s design - so the asking price is less than it cost me in components. I’m not trying to make money off the back of Nelson Pass’ generosity)

The amp sounds (genuinely) fantastic - it is not really surprising that it is so popular amongst DIYers. I have no way to know how it sounds compared to an original Nelson Pass built one, but I have had a lot of very satisfied listening - I didn’t deviate from the original design, so I can’t imagine it is much different.

The amp is set up as per an original and will work like any other amp with no need to fiddle if you don’t want to! (It is biased to ~1.3A idle current, as per specs, and DC offset never exceeded 4mV on either channel when I checked over a ~10 minute period last night). I am very happy with my build standard (see pics), and have never had any reliability issues - worked perfectly from first switch on and never any failures. What I am trying to say is this should be just as reliable and easy to use as a commercial amp - BUT at the end of the day was built in my study and any buyer must understand that. There are no marks or scratches that I can see.

The bad:
It has some mechanical hum from the transformer. I have it bolted down on semi-rigid foam which means it becomes inaudible at about a foot or so away, but the amp is best not thrown around in this setup. Bolted down hard to the case it is heard at 2-3 feet in a silent room.
It also has some ground hum, audible again a foot or so away on my 88dB speakers.
All this is inaudible from a listening seat.

I don’t want to test it against the rigours of the postal system, so I offer to deliver it locally (Northumberland, Newcastle, Sunderland, Durham, Carlisle etc) within the price. Further afield, hopefully we can sort something out.

Thanks for looking!
(sorry - I only seem to be able to attach 4 images)

14432
14429
14430
14434

you need to put a price down Johnathan. bigger pics would also helpas these are rather small

hornucopia
11-04-2015, 09:46
Pics open OK for me......
Nice amp..http://www.6moons.com/audioreviews/firstwatt7/f5.html

My F3 works very well.



Thinks....the ground hum might be the toroid radiating to the speaker terminals -which are close by. I had this with an amp I had-using 'flying leads' eliminated it. Seems the hum was being picked up via the tiny bit of wire showing at the terminals!

no_lo_fy
11-04-2015, 10:01
Oh man... the price... of course, the price!

How does £400 sound?

disarmamant
11-04-2015, 10:08
Is the transformer from Canterbury Windings? I built an F5 with one of those and could not get rid of the mechanical hum.

petrat
11-04-2015, 10:38
Interesting amp, with a good reputation for sound quality.
Good luck with the sale, Jonathan ... shouldn't hang around long!

hughandella
11-04-2015, 10:40
PM sent ( not claiming first dibs )

no_lo_fy
11-04-2015, 16:02
The transformer was from Airlink I seem to remember. A lot of DIYers seem to comment on mechanical hum from a range of suppliers. I recall someone saying they had the traffo potted which fixed it.

I have looked at it again - packed well and with the transformer foam removed it should courier OK. I work in electronics manufacture though, and have seen some horrors!!

no_lo_fy
13-04-2015, 17:36
A little bump for Monday perhaps?