Crawls Backward (When Alarmed)

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1961 Supro 1616T Guitar Amplifier Overview

The small tube amp saga continues!  But unless I build one, this will be the last one for a while.  But it's a really great one.  In my opinion, anyway.

What we have here is a 1961 Supro 1616T.  This is a little single-ended 6V6 amp with tremolo built by Valco in Chicago.

A few years ago I was fortunate enough to have a Supro 1606 - basically the same amp minus tremolo - cross my workbench.  I serviced it for a friend's husband.  That little amp was just amazing.  Great low volume clean tone, and a fantastic blues or rock tone cranked. 

Since then I discovered that Valco made a tremolo version of the 1606 - the amp you see here.  So I've been on the lookout for one, and I finally got one!

There seem to have been two versions made with the "Supro" nameplate.  One had a larger grille which took up the entire front panel.  The second version, which may have been the second generation, is the one you see here - with a border around the grill.

The electronics are identical, and you can see the control panel here.  Inputs for 'Normal' and 'Treble,' Volume with on/off switch, Tone, Tremolo speed, tremolo footswitch jack, pilot light, and fuse.  Notice the famous "Valco Chicago 51" label.  "Chicago 51" was the post office zone that Valco was located in; this was pre-zip code postal service.

This might be the kookiest feature of this amp - a 6x9 inch speaker!  See the green arrow in the picture - it's the EIA code for the speaker.  "228" means it was made by Rola, the next "1" for 1961, and the "19" the week of the year it was made.

The famous spare fuse envelope.  All Valco-made amps (with Valco, National, Gretsch, and Supro nameplates) had one of these inside.  This one is unopened.

Here's the engine room.  This amp is very very clean and original.  This is typical construction for these amps - true point-to-point wiring with terminal strips.  A bit harder to service than a Fender, but still easy enough to following wiring.

Note all the ceramic caps (those orange/brown discs).  Ceramic caps were (and are) dirt cheap.  They sound rather grainy though - I'm going to swap out the signal caps for PIOs I think.  Having said that, the amp is so clean I'm still debating that move.

Ceramics, by the way, are extremely reliable and generally don't go 'leaky' with age the way paper caps do.

A closer view of the input side and the volume and tone controls.  Very tidy wiring.  A couple components are buried a bit, but in general everything's easy to get to.

Here's the covering on the cabinet.  I'm pretty sure this is some type of cloth.  The white trim is vinyl I think.  It's a bit dirty, but will clean up nicely.

As far as I know, no one is making a modern repro version of this covering today.  Too bad, because it's pretty unique.

Remember how I said it was very original?  Here's an example.  The tubes are original to the amp.  Here's the 5Y3 rectifier - an RCA with a 1961 date code.  Thirty ninth week.

The two 12Ax7s also have the exact same date code.  The tubes probably came in the same shipment and batch from RCA.

The fact that the silkscreening is so fresh tells me the amp probably wasn't played much.

I'm going to restuff the electrolytic cap can and maybe change some signal caps, but that will be it for this amp. 


Post a Comment 3 comments:

  • Evan C said...
    August 12, 2014 at 7:57 PM
    Hey, I recently tracked one of these down too. Unfortunately mine has an issue: it cuts out abruptly after playing it for a few seconds, but sometimes over half an hour. If I turn it off and back on a few times then the sound comes through again. I tried swapping out the tubes one by one, to no avail. My dad, who has built a few Weber kits is trying to fix it but requesting the original layout, which I can't find, instead of the schematic, which I was able to find. We're you able to find a layout to work off of?
  • Yr Fthfl Blggr said...
    August 17, 2014 at 9:47 AM
    I have the original schematic which came with the amp. I haven't scanned it, however, the Gretsch 6150T is identical to the Supro 1616T (Valco made them for Gretsch).

    The Gretsch schematic is here, among other places:

    If you plan on using the amp, you will need to recap it. If you don't, there is a very high likelihood that a component such as a power transformer will fail due to another component failure.

    Ironically, tubes are the least likely suspects with regards to amp problems. Capacitors fail over time, period. There is a good chance that recapping the amp (especially the filter caps) will cure your problem.

    Thanks for reading!
  • Anonymous said...
    April 17, 2015 at 11:38 AM
    I also found one of these amps after working on the non-trem version. Take a close look at the two schematics and notice the preamp setups for both. The non-trem version uses a grid-leak bias on the 1st stage while this amp does not. The grid-leak biased 12AX7 is harsher when driven hard but this thing stays smooth and sweet all the way! I put a 10"Weber alnico in mine and it is one of my favorite amps!

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