Firstwatt Amps

[maLx]

Ok, noob here doing amp research. Been reading a lot on Firstwatt Amps. Would like to get my hands on one, preferably an F5. FIRST WATT F5

Anyone know where I can buy them? I've googled and have come up with nothing? Are they limited production or something?

I do understand that Pass does some DIY kits a few times a year, and I think the SIT-3 is coming out soon? But I'm still unclear as to how all of this stuff works with this company.

Someone please give me the rundown.

Thanks!

 

[coolnose]

FIRST WATT DISTRIBUTION

As far as I could see Reno Hifi is a reputated pass labs & firstwatt dealer in the US of A

Reno Hi-Fi

 

[maLx]

Thank you! That’s the only place I found as well. Will look into it.

 

[coolnose]

That said, I suppose the F5 production to be ended. But you ae at the riht place, other members will chime in as well Ithink.

 

[maLx]

I hope so. I want to find a solid good deal because I want to take one apart and reskin it. I do want a great amp so if anyone has other recommendations that would be great as well.

 

[coolnose]

Re-skin it? Would younmind elaborating for myninsane curiosiy?

Sounds like yiu would be better of juste buying a full DIY kit ...

 

[maLx]

Re-skin it? Would younmind elaborating for myninsane curiosiy?



Sounds like yiu would be better of juste buying a full DIY kit ...

Yeah I thought of that but couldn’t find one. Know where to look? I’m so lost with this haha.

 

[Blk Dynamite]

If you want to reskin it, why not build one from scratch? From what I hear it’s a relatively beginner build.

 

[maLx]

If you want to reskin it, why not build one from scratch? From what I hear it’s a relatively beginner build.

Yeah do you know where to get the kit?

 

[Blk Dynamite]

Yeah do you know where to get the kit?

Read this to start to get acclimated to the build

An illustrated guide to building an F5

And here’s the store

The diyAudio Store - DIY amplifier kits, chassis, and parts

There’s different versions of the F5 but this should get you started

 

[maLx]

Thank you! Will jump on this tomorrow.

 

[Zen Mod]

Sissy amps

 

[maLx]

Sissy amps

What do you mean?

 

[rayma]

What do you mean?

He's kidding, they are highly regarded. Complete kits are not available all in one package,
so you'll have to round up the parts from several places.

Pass usually builds 100 pieces of a First Watt model, and then releases the design to the public domain.

 

[Dennis Hui]

The Mighty Zen Mod is one of the great contributors of this forum and that's just
his humour. That said, the first watt amps are low power (F5 is around
25W into 8 ohms) and you must work within that limit.

As Rayma mentioned, there is no single kit, but you can still keep your
ordering to a minimum.

I assume you already have something in mind for the chassis since you had mentioned
re-skinning a production F5.

From the diyaudio store, you can get an F5 parts kit minus the input jfets, the F5 pcbs,
and power supply pcb. Antek is a good source for power transformer.

The store is out of the linear LSK/LSj jfets. Fortunately genuine NOS Toshibas 2sj74/2sk170
are still available, but only from selected known good sellers.
(Most of what you see on ebay are fakes) Some sources are in this thread:

Replacement For Toshiba 2SK170/2SJ74

The other electronics parts (ps caps, fuses, etc) is probably a single order from mouser or digikey.

In addition to the F5 manual ( http://www.firstwatt.com/pdf/prod_f5_man.pdf )
you should also look at the F5 turbo article:

http://www.firstwatt.com/pdf/art_f5_turbo.pdf

The most up-to-date F5 schematics is that in page 2 of this article
and the store PCB corresponds to this schematics.

 

[maLx]

Thanks Dennis.

I think for my purposes, the F5 is fine as I'm using 4ohm speakers and my speakers are around 90db at 1w and I'll be listening from 1m, and as per NPs site they do 40w so at most I'll need to increase that to 100 or 105db

My calculations are
2w = 93dB
4w = 96dB
8w = 99dB
16w = 102dB
32w = 105dB

Won't push it to 40.

From there do you think I need to consider the Turbo?

Also, getting a bit of mixed info on the parts.

Here's what I planned on buying so far to build. I contacted Jim, the person who gave me some links to look at, he has an F5 build thread.

AS-3218 - 300VA 18V Transformer - AnTek Products Corp

Back panel parts kit plus PCB / Transistor / Diode mounting parts kit – diyAudio Store

F5 parts Kit – diyAudio Store

F5 – diyAudio Store

Universal PSU – diyAudio Store

He also said get these:
https://www.ebay.com/itm/Toshiba-2S...371917?hash=item3b0bf05b8d:g:aJwAAOSw7I5TvEmk

How many do I need? Also, do you think those are fake and should I follow the link you provided?

Let me know!

 

[Itsmee]

Jim's a top bloke, all the links are good.

After you've built the F5 and got the bug, have a look at the rest.....

 

[maLx]

Sounds good @itsme. Next step is to figure out what I am amping the subwoofer with.

 

[Itsmee]

Depending on SPL, F5 is good for that too.

 

[maLx]

Depending on SPL, F5 is good for that too.

Do you think it would be possible to build like an F5 x 1.5? Basically one full amp, and one additional for the Sub but combine them into the same housing? I plan on making custom housing.

Also, where do I do my volume control? I'm using a turn table so can't be at the source. Sorry if this is a noob question.