Tube amp build (s)

[DrNomis_44]

Excellent! In that case the amp is a total success, and I was worrying for nothing, ha ha. Thanks doc.

Now to tolex the box and then start on the next one.

I thought I'd have the box done by yesterday, but somehow managed to order the wrong feet, handles and corners. I have no idea what I was doing, but clearly not concentrating.

Have you tried plugging a guitar into the amp chassis with a speaker connected to see if the amp passes good sound?

[JohnH]

Yeah, it sounds great. I was playing it when I noticed the red glow and assumed I'd wired something wrong

[DrNomis_44]

Yeah, it sounds great. I was playing it when I noticed the red glow and assumed I'd wired something wrong

Was there a loud hum with the red glow?, if so, that would indicate red-plating, red-plating is usually caused by a leaky coupling capacitor on the grid of the power tube, or a loss of the -V bias supply, or sometimes by the power tube itself if it has an internal fault.


https://www.ampvalves.co.uk/red-plat...lifier-valves/


But, if the amp is sounding really good especially if you crank it up, it should be fine.


Note that some high-power radio transmitter tubes are deliberately designed to be operated in a condition where they are red-plating.

[JohnH]

Nah, no hum. A little bit when the tone is all the way up and the volume was up but otherwise its really quiet.

[DrNomis_44]

Nah, no hum. A little bit when the tone is all the way up and the volume was up but otherwise its really quiet.

Sounds like your amp is working like it's supposed to.

[JohnH]

Well, that's a relief! It's very cool to be able to play one I've built myself. It seemed impossible a year or two ago.

I think the next one will be an 18w build, but I think I'll buy a pre built head cabinet for it. It's satisfying making your own but I'm a bit too time poor at the minute

[JohnH]

An update on the cost tally. I realised I left off the transformers before, which is a huge chunk of the cost!

$120 for the chassis
$41 for wire and resistors
$80 for capacitors
$47 for turret board, stand offs, assorted hardware, and an iec socket
$163 for tubes
$200 OT
$90 PT
$30 for timber for the head
$60 for tolex
$40 for handles, feet and corners

$871 Total

I didn't include the cost of faceplates because I actually can't remember how much they were, but say another $50 or so. The next build I'll get a chassis that comes with faceplates so it's one less thing to think about.

Also didn't include the cost of the variac, etc (because tools don't count!) and didn't include the satisfaction of the build (because it's priceless!)

[JohnH]

Even though I still haven't really finished this build yet, I've started planning the next.

The next build will almost certainly be an 18W, but I came across this site today and now have a future goal to work to: http://c3amps.com/

It is way beyond me at the minute, but good to have something to aim for!

[JohnH]

I realised I forgot a gut shot!

It's a bit embarassing sharing chassis shots after some of the amazing wiring jobs I've seen online. Definitely need to be neater next time...

[McCreed]

I realised I forgot a gut shot!

It's a bit embarassing sharing chassis shots after some of the amazing wiring jobs I've seen online. Definitely need to be neater next time...

Never mind a guts shot, I don't think we've seen the outside yet! (or haven't you got the cabinet for it yet?)

As for the soldering, I know what you mean. There are some out there that have taken soldering to an artform (I'm not one of them!).
I don't see anything that resembles wads of chewing gum in your work, so that gets points from me!