Silvertone Model 1263

Silvertone Model 1263

4 input, 2 channel, tube head

[ Photos ] [ Silvertone Model 1263 ] [ Louden Up! ] [ Music/Guitars/Amps ]

I can't find a manufacturer name on this. We have had it apart - no luck. But someone on alt.guitar.amps identified it as a Silvertone like theirs. And in fact I had wondered. It just has that Silvertone look and feel. On the other hand, I have never seen another Silvertone without a logo. I have been told by someone else it was a dead ringer for their Univox. Lately I'm beginning to think it was just a no-name. Now it's something else entirely (details to come).
The more we played with this amp, the more we liked it. It produces about 12 watts (right on the edge of Class A), but it'll rattle the living room windows and the tone was excellent. Unfortunately the tone drifted south like a dead fish. The trem circuit was disconnected (unclear whether the wire was broken at the pot on purpose or not), but it's fixed now. The trem was pretty wimpy at first, but a cap job helped. It could still use more depth, but it's about a 6 out of 10 as tremolos go. We were playing it through the 2-12 cabinet of my Peavey Heritage VTX, which sounded great, but I've loaned that cab out. So now we use an old 2x12 Silvertone cabinet with some (IIRC) Vintage 30 clones I bought off Lee Jackson when he thought he was done with the amp business. Killer cab.
The only designation is "Model 1263". Power requirements are "2 AMP 117V-60~". It had a two conducter line plug with no ground indication (both lugs are the same size). Naturally this has been replaced with a 3-wire, grounded power cable.

Click on any of the images to see a larger, full color image. Larger images are close to 700KB each.

Front of amp with funky grill installed. Front left foot is missing, leather handle had rotted and had to be cut off to avoid breaking and dropped amp. Face is a bit scuffed up, but the chrome's mostly still all there. I razored off the control labels on the trem channel; this photo was taken in the process of turning this amp into something else. Front of amp without with funky grill installed. The original tubes were junk, but the transformers are fine and the big cap is still fine! Shown containing EH power tubes, and Sovtek 12AX7LPS preamps and PI. I want to get a clear or smoked plexiglass front to replace the grayish grill in the first photo. Back of amp. The jacks on either side are for speakers. There's a vent in the bottom of the head (originally covered with wood) that will let air flow through and out the back to cool the tubes. With the bottom plate in, the amp got seriously hot.
Why are these photos in black and white? This amp was built in the 1960s. The world was mostly still black and white so the amp was built black and white. Even today, the amp just sucks the color right out of the surrounding area. But I couldn't see making you download larger images in black and white; they might permanently destroy your monitor's or printer's abaility to produce color, or even burn out the color cells in your eyes. So when you click on the images, you'll see enlarged, colorized versions. Ted Turner needed the work, so he did it cheap. I'm hoping he can do the same for the real world cacti in the background; they can use the chlorophyl.

The Sound
The clean sound is very clean. Excellent pick dynamics, and notes articulate as well within chords as the pickups allow. With modern, high output pickups, distortion arrives fairly early on the volume knob, progressing to a serious crunch reminiscent of the best 60s overdriven sounds. The pots in this amp are linear taper, which makes for some fairly odd settings.
Despite having only a single tone control per channel, the amp is quite versatile. With the highs rolled off (tone control closer to 0 than to 10), a good single-coil guitar can be made to sound fairly close to a Les Paul (no humbucking, of course!) With the highs left in (tone control closer to 10 than to 0) it's quite bright. With the trem controls both set to 5, the trem isn't very noticeable, but the highs have a nice shimmer to them.
You can run the channels bridged, but only with the instrument plugged into jack #1 or #2, because the other two jacks each have their own triode channel. However, using the tremolo with this setup is not a good idea. This results in serious amplification of the low frequency generated by the tremolo oscillator, to the point that you can see the speaker extend fully in time with the oscillator. The sound is pretty bizarre but not very interesting. And it's way too close to DC to do the speakers any good.
The tremolo channel has plenty of bottom end, but the "bass" and "normal" inputs are all high end! The bass and normal channels are identical. The tremolo channel brings the tremolo signal in at the channel's preamp stage grid, which means highs can shunt to ground via the caps in that circuit. I have some plans for both these issues.
Appearance, Layout, Etc
The box is covered in black cloth rather like cloth electricians tape (but not sticky 8^). It has a silverish "grill cloth" on the front - which is stapled onto a board (IOW, no air flow through it). The bottom air channel has a black-painted piece of wood glued over it - looks like original, but I can't tell. It had (it rotted) a leather handle. The faceplate is chrome with white lettering (all caps) and a "cute" border around the top and sides, comprised of outlined, longish boxed shapes.
The "grill" comes out the front after two round-headed wood screws are removed from each side. Removing two more wood screws from the ends of the faceplate allows the chassis to slide out (it's made to fit snugly).
Everything that doesn't normally attach via a nut (pots, jacks) is held on with bolts - even the tube sockets. Almost all of the tube bolts were loose, and three were missing (on the power tubes, of course!)
The grounds are usually made with braided ground straps, soldered directly to the chassis and to nuts and bolts.
There are two speaker jacks on the back, one at either end. They are connected to the electronics via an RCA plug with brown zipcord, and to each other with black zipcord. There's also an RCA phono jack on the underside of the chassis near the front of the unit, almost impossible to reach. It's near the tremolo circuit, and almost certainly originally went to one of the jacks on the back for a footswitch, in which case someone added that zipcord between the jacks.
The 1/4" jacks are labeled by number (1-4), and somewhat with words. Jacks 1 and 2 are aligned vertically, and the word "Tremlo" (sic) appears beneath them. Jacks 3 and 4 are also aligned vertically; one is labeled "Normal" and one is labeled "Bass". The "Bass" designation of jack #3 is purely arbitrary as there is no difference in its circuitry from the #3 (normal guitar) jack.
I've made rough drawings of the faceplate and chassis layouts. Click on the image below to obtain a JPEG file (112KB) or you can download a PostScript file (10KB) created with xcircuit.

I drew up a complete schematic, available in JPEG (560KB) format, or PostScript format (34KB) by clicking the image below.

This was done from scratch by inspecting the amp, with the help of my son, Josiah.
A few points of interest from the schematic...

The trem oscillator circuit is very much like that of a Magnatone, but without the varistors.
Channels 3 and 4 have a larger cap after the preamp, but are much brighter (very little low end).
The trem waveform is injected on the preamp grid, which leads to a very wimpy tremolo.
The tone circuit is the same as that of a Fender Tweed Deluxe.
The output section is as simple as it gets.

My Mods
So far I've kept mods to a minimum. The two-wire power cord is long gone, replaced by a 3-wire, grounded cord. I removed that wooden slab that blocked the bottom airflow cutout, and will replace it with a heavy duty screen. The grill will be replaced with either a heavy steel mesh, or possibly with colored plexiglass. At some point I will play with the component values in the trem circuit to give the tremolo effect more depth and a higher speed. I'm thinking of adding a channel switch, possibly using an opto-isolator to keep noise down. I replaced the input leads with shielded cable, grounded at the jacks, to cut down on noise.
Long term, I may try a Baxandall tone circuit (bass and treble), probably with concentric pots and knobs to avoid having to hack the front panel.
I've been trying to think of something to do with the old ground polarity switch; I may use it to switch in and out a new resistor in the power supply to lower the voltage for reduced volume playing...
Vital Statistics

Manufacturer: Silvertone?
Model: 1263
Serial number: none found
Year manufactured: 196x?
Power: ~15 watts
Controls: (left to right)

Depth (trem)
Speed (trem)
inputs 1 and 2 (labeled tremolo)
volume & tone for inputs 1 & 2
inputs 3 ("normal") and 4 ("bass")
volume & tone for inputs 3 & 4
on/off
standby switch
ground switch
blue lamp cover

Tubes:

6CA4 (rectifier)
3 ea GE 7025 (one in shield can)
2 ea 6V6 (output)

Outputs:

two 1/4" phone jacks on back for speakers, one was originally for a footswitch.

Links
Yeah, right!!!

Benjamin F for identifying this as a Silvertone, and info on the footswitch, etc.

[ Photos ] [ Silvertone Model 1263 ] [ Louden Up! ] [ Music/Guitars/Amps ]
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Copyright 1999, Y2K, 2006 Miles O'Neal, Austin, TX. All rights reserved.
Miles O'Neal <roadkills.r.us@XYZZY.gmail.com> [remove the "XYZZY." to make things work!] c/o RNN / 1705 Oak Forest Dr / Round Rock, TX / 78681-1514

Click on any of the images to see a larger, full color image. Larger images are close to 700KB each.

Front of amp with funky grill installed. Front left foot is missing, leather handle had rotted and had to be cut off to avoid breaking and dropped amp. Face is a bit scuffed up, but the chrome's mostly still all there. I razored off the control labels on the trem channel; this photo was taken in the process of turning this amp into something else.	Front of amp without with funky grill installed. The original tubes were junk, but the transformers are fine and the big cap is still fine! Shown containing EH power tubes, and Sovtek 12AX7LPS preamps and PI. I want to get a clear or smoked plexiglass front to replace the grayish grill in the first photo.	Back of amp. The jacks on either side are for speakers. There's a vent in the bottom of the head (originally covered with wood) that will let air flow through and out the back to cool the tubes. With the bottom plate in, the amp got seriously hot.
Why are these photos in black and white? This amp was built in the 1960s. The world was mostly still black and white so the amp was built black and white. Even today, the amp just sucks the color right out of the surrounding area. But I couldn't see making you download larger images in black and white; they might permanently destroy your monitor's or printer's abaility to produce color, or even burn out the color cells in your eyes. So when you click on the images, you'll see enlarged, colorized versions. Ted Turner needed the work, so he did it cheap. I'm hoping he can do the same for the real world cacti in the background; they can use the chlorophyl.