Page 2 of 2
Posted: Mon Mar 03, 2008 1:32 am
by Justin J
Posted: Mon Mar 03, 2008 8:25 am
by Mike
filtercap wrote:Here's the insides of the thundering Twin-o-Lux. The wiring is actually tidier than I found it. The chassis decided to Get Bent! during some previous owner's tenure. I've unbent it a little.
At top left is the push-pull Master Volume knob, which used to engage a hideous distortion feature when pulled out. I changed things around so it's in "normal" gain mode when pulled out, and engages a pretty decent fat/boost of my own devising when pushed in. You can see the disconnected high-bypass cap just off to the left of the pot; I left it in place in case I change my mind.
The 7 Vibrato channel controls do their usual thing. On the other side of the Vibrato input jacks are the "Normal" channel controls. The tone stack in this channel is as close to a '61 "blonde" Twin as I could get with available parts, hence the capacitors sticking out in odd places. The Bass knob on this channel is push-pull too (pulled out in the pic). Now that I have two different input/tone-stack sets, the push-pull knob determines which set gets routed through the Vibrato channel (vib, rev, additional gain stage, and optional fat/boost) and which set gets routed through the good old dry "Normal" channel.
Just to the right of the big power transformer is the rebuilt solid-state rectifier on a rectangle of plain circuit-board. It's bracketed vertically to a couple of the transformer mounting bolts, so you're looking at it edge-on. This opens up some floor space for the small nuclear reactor you see there. It's really a plate-voltage control for the power-amp tubes.
Along the back of the chassis (bottom of the pic), starting at the left, you have the business end of the power cord, then an AC socket, ground switch, fuse, power switch, standby switch, two unusual series-wired speaker jacks that connect two separate transformer taps, variable negative-feedback control, bias balance pot, bias level pot with a "range" pot soldered back-to-back, tip-ring-sleeve vib/rev footswitch jack, reverb out, reverb in, and heater hum-balance pot.
So freakin' awesome. I expected nothing less.
Posted: Mon Mar 03, 2008 8:26 am
by Mike
bubbles_horwitz wrote:
Nice and clean, very impressive. I'm chuffed it inspired your SPOOKY avatar too.
Posted: Mon Mar 03, 2008 10:08 am
by Sublimedo
bubbles_horwitz wrote:right now i'm making one of these:
i've been running all over town trying to find parts. sorting through bins at electronic surplus stores. i even went to this cool electronic swap meet in redondo beach where a bunch of old ham radio guys get together and sell all their old crap. there's a guy there who just sells tubes. he's gonna get the hard-to-find 6k6gt tube for me $3 a piece, nos.
anyway, here's what i've got so far:
so far i'm about $10-$15 into this project. the tough part is gonna be finding the transformers. i'm toying with the idea of winding my own power transformer, but i don't know how feasible that's gonna be.
and there I was thinking you were going to wire up a basic tranducer type spring reverb unit. I was questioning why you brought up "high voltage" at the shop, but there it is. and all is clear. MAKE A NEW THREAD ABOUT THIS PROJECT!! looks awesome.
Posted: Mon Mar 03, 2008 10:46 am
by euan
It's a pity noone here owns a 60s HiWatt amp. The wiring in those things give me boners.
This is from the Flickr guy who collects Travis Bean stuff and a shit load of effects and amps. It's a HiWatt SA412 made in the 70s.
Posted: Mon Mar 03, 2008 10:59 am
by Sublimedo
Actually well before I got a Twin Reverb I really really REALLY wanted a HiWatt. I'd definitely get one if I had the coinage.
Posted: Mon Mar 03, 2008 11:00 am
by Mike
HiWatt makes good Solid State stuff, I've played a bunch of it at Denmark St when they obviously thought I was too scruffy for a TSL100.
Posted: Mon Mar 03, 2008 3:12 pm
by Bacchus
This thread should be stickied, and whenever someone gets their hands on something, they should stick it up here.
There seems to be sufficient interest, and it's certainly the sort of thing I would sit and browse through on a quiet day.
Posted: Mon Mar 03, 2008 3:47 pm
by Justin J
Sublimedo wrote:Actually well before I got a Twin Reverb I really really REALLY wanted a HiWatt. I'd definitely get one if I had the coinage.
aren't sound city amps almost the same thing? i know they're
way cheaper.
Sublimedo wrote:MAKE A NEW THREAD ABOUT THIS PROJECT!! looks awesome.
i will once i get all the parts. i'll take a bunch of pictures of the build. and then some of me looking scared as i try to make the cabinet.
Mike wrote:I'm chuffed it inspired your SPOOKY avatar too.
haha, i think the green looks best on blackfaces. just like blue looks best on silverfaces and amber looks best on brownfaces. what was fender thinking just using red across the board? red means stop. that's the last thing i wanna do when i turn on my amp.
Posted: Mon Mar 03, 2008 4:29 pm
by Doog
bubbles_horwitz wrote:what was fender thinking just using red across the board? red means stop. that's the last thing i wanna do when i turn on my amp.
On traffic lights, yellow means "yield", green means "go". But on a banana, it's the other way around- green means "wait" and yellow means "go ahead". And red means "where the hell did you get that banana". -Mitch Hedberg
Couldn't resist, sorry.
Posted: Mon Mar 03, 2008 5:13 pm
by filtercap
euan wrote:This is from the Flickr guy who collects Travis Bean stuff and a shit load of effects and amps. It's a HiWatt SA412 made in the 70s.
Where's the part that explodes when The Who kicks one of these over? Not even a detonator. Clearly this must be one of the "studio" models.
The wiring harness is the complete antithesis of Fender's embrace-the-chaos approach in the 70's.
