Completed FirstWatt F6 amp build

[atharva]

I haven't heard the F5.

 

[jmascreen]

I haven't heard the F5.

Oh wasnt you there at hfv meet at pune in 2011 where om showcased the f5?

 

[atharva]

I was at the meet where Om shared the B1 but don't recall the F5. Was it the same meet?

 

[Hari Iyer]

I was still under the impression that India was one of the major country exporting Aluminium ! strange Economics and its Dynamics!

I don't believe that a small fluctuations in Aluminium price would have such major impact in chassis cost. There may be something else which the vendor is not telling us.

 

[himadri]

For some time I'd wanted to try a low powered SS amp with my Maargas instead of the Lyrita 2A3. A little over a year ago I found a used Valvet E2 and it sounded very good. That gave me some confidence and I always had a FirstWatt at the back of my mind given the fan following. I thought to try a FirstWatt SIT3 but they sold out and my only option was to get an F8. The SIT were special but I wasn't sure about the F8. I had considered the DIY route but most of the designs the Toshiba JFETs (or the Semisouth In the J2) which are no longer available. I was very lucky to find someone who had all the parts for an F6 and decided to bite. The F6 is rated 25W into 8 Ohm and 50W into 4 Ohm. That was much more than I needed but I had no choice. Figured if I liked the amp that much I could use it with lower sensitivity speakers as well.

Here is the final build of the amp. It's just been a few hours so still breaking in but it is super silent and sounds wonderful. The enclosure is also DIY - sketched it in CAD and got it laser cut on 3mm Aluminium and then anodised. I'm currently playing the amp with my DIY Open Baffles and will try it with the Maargas as well. It gets very hot though especially with the ambient temp around 42C. Plan to try PC cooling fan inside the chassis. Sharing a few pics.

Thanks for reading!

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My F5 experience is that the first watt circuits sound just as they look , ie. simple, clean and direct.
Congrats.

 

[surfatwork]

I don't believe that a small fluctuations in Aluminium price would have such major impact in chassis cost. There may be something else which the vendor is not telling us.

It is always better to check facts before making an allegation.
This is bare aluminium. If you add in the impact of rising production costs, retail price of aluminium sheet has gone by a factor of 3x or more since before covid.

 

[Hari Iyer]

It is always better to check facts before making an allegation.
This is bare aluminium. If you add in the impact of rising production costs, retail price of aluminium sheet has gone by a factor of 3x or more since before covid.

If your chart is correct, then it's just double the price for a metric ton. I don't think any chassis will weigh more than 10 kg. So if 10kg of Aluminium cost pre-covid was 1222/- then post COVID it will be 2880/- which is not very high to fret upon.

Btw, the scale on your graph is not very linear and hence show a huge jump.

 

[jenson]

How does it sound in comparison to lyrita... Also, curious on how it works with maargas.

My Exp with f5 was it's very meaty and powerful. Closest to a tube sound.

Superb build btw

 

[Subbu68]

If your chart is correct, then it's just double the price for a metric ton. I don't think any chassis will weigh more than 10 kg. So if 10kg of Aluminium cost pre-covid was 1222/- then post COVID it will be 2880/- which is not very high to fret upon.

Btw, the scale on your graph is not very linear and hence show a huge jump.

This price you see is for ingots or raw metal and spot prices.

Provided your energy costs, wages, transportation, retailer's costs for his place, wages and all other allied costs including the tea you sip thrice a day remain the same, if raw metal price increases two times, chassis should cost twice. It doesn't happen and hasn't happened post covid. Everything has gone up in price.

 

[surfatwork]

The most recent preamp chassis I built is far simpler than a far more complex power amp chassis I built 3 yrs back. Yet the new one cost me more.

 

[anilva]

Well done. F6 is a brilliant amp. I have been using most of the FW DIY amps for a while. I am a big fan of them.

Cheers

 

[atharva]

Thanks @jenson. I haven't played it with the Maargas as yet. Will do so soon.

Thanks @anilva. Which others have you built and how would you compare them?

 

[anilva]

Thanks @jenson. I haven't played it with the Maargas as yet. Will do so soon.

Thanks @anilva. Which others have you built and how would you compare them?

Built F5, F5T, F6, Aleph J, J2, Sony VFET, M2 and few preamps including BA3 and JBOZ. I like all of them. They have a distinct Firstwatt sound. Currently using J2, M2 and Sony VFET in my setups. Also use BA3 preamp extensively.

 

[atharva]

@anilva, that's an impressive list! M2 is a favourite of many. May be I should try that next. I would try the J2 if it wasn't for the uber expensive/unobtainable Semisouth.

 

[anilva]

@anilva, that's an impressive list! M2 is a favourite of many. May be I should try that next. I would try the J2 if it wasn't for the uber expensive/unobtainable Semisouth.

M2 is my favourite too. It drives my Fostex Back loaded horns. Its awesome. I managed to get SemiSouths, VFETs and Toshiba Jfets way before they became extinct.

 

[drlowmu]

Nice !

First of all, CONGRATULATIONS for using zero plastic tie wraps inside the amp.

All tie wraps do ( sound - wise ) is co-mingle the differing fields around one wire lead to another wire's lead. slightly blurring and degrading the sound of both wires, wherever and every time a tie wrap is used.

Have you ever A-Bed this ??? I have !!!

Question, what is that red cylindrical device on what appears to be the red positive Output wiring off of each board, to the speaker output post ? What is it used for ????

If it is something like a ferrite bead ? If so, replace that lead with similar length and type of wire, with NO FERRITE bead, and give that a listen . Which sounds best ??

Refer please below, to the last two comments, from the late Pierre Sprey, of MapleShade Audio.

Jeff