Building my 5F2A Chassis - progress report

[tubeswell]

Other stuff

Well I tested the voltages from the HT winding (318.5VAC) to ground from each side) and the heater winding (6VAC) this morning, before inserting the Toshiba 5Y3GT (NOS) I bought and testing the Plate to ground (439VDC) and screen to ground (432VDC) without load. Then I plugged in the New Sensor "Tung-Sol" 6V6GT and a sovtek 12AX7 (I'll try some other pre-amp tubes this afternoon for sound check) and fired up the heaters with the standby switch off - and yup all the filaments appeared to be glowing (touch wood).

So I flipped the Standby on and got a wee hum (but not unexpected - I've got a second 20uF Sprague Atom arriving in a few days, so I'll biff that in and see how it goes), and a lovely quiet hiss as I turned up the vol, which altered in pitch as I fiddled with the tone control (still haven't plugged me Strat in yet - I'm drooling for this afternoon when my wife goes out).

When I flipped the Presence (NFB) switch on, there was this horridibel screeching, which turned out to be the primaries from the OT being back-to-front, so I swapped them around and now she's all good. I'll do the bench-burn later this avo to see if she smokes anywhere, but for the 2 or 3 mins I had it on before, I couldn't see anything ominous.

All up about $473NZ for all materials, and that's allowing for more than a bit of leftover Aluminium sheetmetal for my next few builds and another baffle boards worth of 3/4" ply.

Since I had a ball making it, I don't count my sweat and toil as anything negative or costly, (infact it was actually free entertainment). So I figure that's better value than paying $499NZ for a new, teency, diode-rectified Champion 600 that doesn't even have a tone control or a presence switch or a fancy-pancy dual/single speaker output system.

I gots ta finish the cab with something retro and get an engraved dashboard for the control panel (to cover the chassis faceplate).

I definitely recommend building one of these as a first build to anyone contemplating it.

[tubeswell]

Test drive results

Well the bench test didn't turn up any further problems at this stage and I test drove it a couple of times this afternoon with my Strat.

Dare I say It sounds surprizingly hum free, although there is a tiny little bit of hum (quite liveable) when the vol is maxed out, but its almost nothing. Maybe another 20uF in the first fliter cap will reduce that.

Got a fab range of sounds. The vol dial goes from nice'n'fendery clean at one end to nice'n' dirty at the other end, and the tone dial goes from nice and round at one end to nice and bright at the other end. Definitely like the NFB switch - this adds a whole nother dimension. All in all its quite bluesy, jazzy, rocky little piece.

I'm definitely going to have to build something else now. I'm hooked.

[Paul P]

Glad to see a happy ending to this story. Must have been a bit tense when
you fired the thing up for the first time.

Thanks for sharing your journey with us. So what'll it be next time 'round ?

Paul P

[Casey4s]

Well the bench test didn't turn up any further problems at this stage and I test drove it a couple of times this afternoon with my Strat.

Dare I say It sounds surprizingly hum free, although there is a tiny little bit of hum (quite liveable) when the vol is maxed out, but its almost nothing. Maybe another 20uF in the first fliter cap will reduce that.

Got a fab range of sounds. The vol dial goes from nice'n'fendery clean at one end to nice'n' dirty at the other end, and the tone dial goes from nice and round at one end to nice and bright at the other end. Definitely like the NFB switch - this adds a whole nother dimension. All in all its quite bluesy, jazzy, rocky little piece.

I'm definitely going to have to build something else now. I'm hooked.

Good for you sir, seems like you did a great job on this build, thanks for sharing your progress with everyone.

Now you have discovered the real danger of building your first amp, cronic addiction.

Looking forward to your next project.

[tubeswell]

So what'll it be next time 'round ?

Paul P

Dunno - a tweed deluxe maybe.

[tubeswell]

Casey4s - That is some piece of art! You must be a master craftsman! What sort of reverb pan did you use? (or did you make one?)

[Casey4s]

Casey4s - That is some piece of art! You must be a master craftsman! What sort of reverb pan did you use? (or did you make one?)

Thanks for the nice comments, but no I am not a master anything LOL, Just a hobby level builder. Building a complete amp, as you discovered, is more than just one discipline, from woodworking and metal work to electronics, it takes me a while from start to finish but I really have a lot of fun.

I don't remember the model number, but the reverb pan is a stock accutronics Fender replacement unit I got from AES. http://www.tubesandmore.com/

[tubeswell]

Front profile upgrade

Got a bit carried away with a bit of cheap brown Hessian today ($5.99NZ/metre).

So I thought its a bit better than the bare plywood baffle. Whaddaya reckon?

[Casey4s]

Got a bit carried away with a bit of cheap brown Hessian today ($5.99NZ/metre).

So I thought its a bit better than the bare plywood baffle. Whaddaya reckon?

Looks like you did a good job with the grille cloth but it is hard to tell much about the cloth itself in the photo.

What do you plan to do with the rest of the cabinet? Stain it or Tolex or....?

[scole]

now you just have to learn how to do finger joints.

http://www.flickr.com/photos/1045148...7601675424588/

[Casey4s]

now you just have to learn how to do finger joints.

http://www.flickr.com/photos/1045148...7601675424588/

Nice looking Champ Sir, you seem to be an expierienced woodworker too.

[tubeswell]

now you just have to learn how to do finger joints.

http://www.flickr.com/photos/1045148...7601675424588/

Yep that's the scary next phase. I don't have the proper equipment. If I have to do them by hand, it'll take me years and probably waste heaps of pine.

But I must say, that a nice champ Scole. What're all those knobs for? (Vol. Tone and ?? (and the little switch mounted in the wood?)

[tubeswell]

Looks like you did a good job with the grille cloth but it is hard to tell much about the cloth itself in the photo.

What do you plan to do with the rest of the cabinet? Stain it or Tolex or....?

Hessian is basically sack-cloth, made from quite stringy thread with quite a loose weave, so there's plenty of holes for it to breathe. This stuff has been dyed a tan colour. I glued and tacked it over the back of the baffle. I might get back in there with a wall staple-gun today.

I don't know yet whether to tolex the rest or stain it or varnish it, or do a suit job. I found some cheap tweedy plaidy fabric which would look good with the hessian, but its not your traditional diagonal tweed, and its not brown, its more like little black and off-white and grey squares.

On the other hand, the woodgrain's got a nice natural theme going for it. The cab's got little screw-holes on the sides, (which could be a varnish feature?? ha ha).

I was thinking of getting a tan-coloured formica dashboard made up for the instrument panel, - the sort with fine routing-engraving in a white or cream colour that tells you elegantly that it is a Tubeswell Tweed and what all the fiddly bits are. - More on that later.

[Casey4s]

Hessian is basically sack-cloth, made from quite stringy thread with quite a loose weave, so there's plenty of holes for it to breathe. This stuff has been dyed a tan colour. I glued and tacked it over the back of the baffle. I might get back in there with a wall staple-gun today.

I don't know yet whether to tolex the rest or stain it or varnish it, or do a suit job. I found some cheap tweedy plaidy fabric which would look good with the hessian, but its not your traditional diagonal tweed, and its not brown, its more like little black and off-white and grey squares.

On the other hand, the woodgrain's got a nice natural theme going for it. The cab's got little screw-holes on the sides, (which could be a varnish feature?? ha ha).

I was thinking of getting a tan-coloured formica dashboard made up for the instrument panel, - the sort with fine routing-engraving in a white or cream colour that tells you elegantly that it is a Tubeswell Tweed and what all the fiddly bits are. - More on that later.

On several of my builds (5F1/F2, 5E3, 5F6A Ampeg SB12) I used a piece of brushed brass stock and had a local engraver cut the lettering in for me, it's not really expensive and has a nice look to it. Usually engravers have that brass stuff in the shop. ( I provided my own)

Here is the faceplate from my 5F6A Variation to give you an Idea of how it might lool.

[tubeswell]

Very nice Casey4s - thanks. How do you make sure they get everything (holes etc) lined up with your chassis?