Finally something to give back after all my years reading this excellent forum!
Well that was the plan but senility seems to have gotten in the way. Can't find any snaps of the build process so there is only the finished product to share.
Anyway improvising on the Ron Worsley layout and using a pre-cut chassis and board material from Modulus Amplification it's done and powered up without fire or explosion. The tubes are running a little hot for my liking at 12.9W each so some tweeking may be in order.
On the plus side hum and noise are low. Not sure when I'll get to 'let rip' given I'm surrounded on four sides by old ladies and mum's with babies. But I'll find a way.
The face and back plates are again from Modulus Amplification. I tried to go for wooden but having made a solid walnut cabinet about 7 years ago (on another continent!) it was already pretty non standard.
Initially tried to stick walnut veneer behind perspex to get a sort of glossy sports car dashboard for the panels but it seems you need to be an actual maker of cars to do this sort of thing. So ended up with Dr Z style white on black plastic.
Anyway better late than never!
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Nicely done. Very tidy, even by TAG OCD standards. Nice walnut too, and the closely matching perf board. The PS board in particular looks to be a design improvement. Wondering about the wisdom of putting the resistor chain on the underside, which presumably is where they hide. Any reasoning behind that?
Thanks! I think mine used the JTM45 blank from Modulus as well. I vaguely remember cutting cutting a board down to fit the TW format - can't recall which one it was. Good luck with your build!
didit wrote:Nicely done. Very tidy, even by TAG OCD standards. Nice walnut too, and the closely matching perf board. The PS board in particular looks to be a design improvement. Wondering about the wisdom of putting the resistor chain on the underside, which presumably is where they hide. Any reasoning behind that?
Best .. Ian
Thanks! I figured the resistors aren't dissipating much so won't fry anything. If I recall they're 5 watt green wire wound ones from Hungary via RS components.
Just checked and the highest dissipation is R28a and R28b with 1/4 watt between them over 10 watts of resistor - so wouldn't expect the fire brigade.
nickt wrote:I figured the resistors aren't dissipating much so won't fry anything.
Yep, OK. Having repaired amps over the years my concern would be if something goes wrong elsewhere and current there jumps. Repair/replace or even a visual check might mean lifting that board. It's just a nit. Very nice work overall as I said.
nickt wrote:I figured the resistors aren't dissipating much so won't fry anything.
Yep, OK. Having repaired amps over the years my concern would be if something goes wrong elsewhere and current there jumps. Repair/replace or even a visual check might mean lifting that board. It's just a nit. Very nice work overall as I said.
Agree - if I were to do it again I'd do a bunch of things differently. You make a good point about repairability. I worked as a techo back in the 1980's - guess I've gone over to the dark side in the intervening years
The cabinet finish is something called 'Furniture Oil' - Basically Danish Oil I think but without any stain. The best Homebase UK could do
The shots are from my phone and it looks better in real life however I'm not super happy. Main issue is it needed grain filler. So its not glassy smooth .
I'm considering stripping it back and starting again (being totally OCD) to get the full 'awesome'.
Given my build pace it'll probably be done just as the undertaker arrives...
You can try block sanding it with 400 to level the finish before applying more.
Then once dry and hard enough, try 0000 steel wool to buff it followed by burnishing the finish with a piece of denim from a pair of 1949 Levi's jeans.
No seriously, take a piece of denim and rub it on the finish.
This will leave a semi gloss to satin look.
@stretch: hadn't heard the plain white paper thing before. Thanks for the tip!
I've built guitars in the past and always used wet-n-dry up to 2000 or so then rubbing compound for gloss. Mostly I haven't used polyurethane unless its satin and then left it 'as sprayed' but with light sanding between coats.
Still think I'll have to strip it all off eventually and apply grain filler to get the finish OCD grade perfect. But your suggestion sounds like the quickest way forward - will post pics when done.
I think mine used the JTM45 blank from Modulus as well. I vaguely remember cutting cutting a board down to fit the TW format - can't recall which one it was. Good luck with your build!
