Tweed Deluxe Details
Build notes specific to this amp from Mitch.

This combo is based on the classic 5E3 circuit except updates have been done to reduce the noise and improve the grounding. I cheated a bit here again and got the chassis, the parts, the board and the cabinet from Trinity Amps. I ordered the cabinet unfinished and did the lacquering myself. I also did all the electronic assembly.

It has a push/pull power amp using two 6V6 tubes made by JJ in the Slovak Republic. Power output is about 15 watts.

The preamp has two channels, normal and bright. Each have their own volume control and they interact just like the originals. Also like the originals, it has a single tone control. The preamp uses a couple of 12AX7 tubes made by JJ.

The power supply uses a 5Y3 rectifier tube made by JJ.

The amp has Alpha pots, Switchcraft jacks, Sprague Orange Drop coupling capacitors and Heyboer transformers.

It has a 16 gauge steel chassis with a chrome plated front.

I began by installing all the tube sockets, pots, switches and jacks on the chassis. Then I wired up the AC, the power transformer, the heaters, the output transformer secondary, the jacks and the pots.

Tweed Deluxe

Tweed Deluxe

Tweed Deluxe

Tweed Deluxe

Tweed Deluxe

Tweed Deluxe

Now that the power supply was wired I could give the amp its first test. No tubes were in yet, of course. I double checked all the wiring I had done so far. Then I plugged in the AC cord and flipped on the power switch. The pilot light lit up. I measured about 6.3 VAC across the heater pins at each preamp and power amp tube socket. I also checked that there was about 3.15 VAC from each heater pin to ground. I measured 5 VAC across the heater pins for the rectifier tube. I also carefully measured the high voltage coming out of the power transformer at the rectifier tube's socket. Each leg read about 350 VAC with respect to ground.

I started working on the eyelet board next. I installed all the wiring on the bottom side, then I started working from left to right installing the resistors and capacitors on the top side. I also attached all the flyoff leads using 6" or 8" lengths. This is more than enough to later connect to the pots and tube sockets.

Once all the wires or components that go into an eyelet were in place I soldered the eyelet. Before that the wires were just passed through the eyelet and bent over to hold them in place. In the following photo you can see the second eyelet from the left at the bottom isn't soldered yet. That's where the output transformer's center tap and the B+ will connect later.

Tweed Deluxe

Tweed Deluxe

All that was left now was to attach the flyoff wires coming from the eyelet board to the tube sockets, pots and jacks.

Tweed Deluxe

Tweed Deluxe

The amp was now finished and ready for final testing. I checked my wiring very carefully. First visually, then I used an ohmmeter and the schematic to make sure everything that's supposed to be connected actually was connected. I did one more check to make sure there weren't any shorts and the polarity was right on all the electrolytic capacitors. All was good, so I plugged in the rectifier tube and applied power.

It passed the smoke test. It also passed all the voltage checks. I powered it down, waited for the capacitors to discharge, then I plugged in the preamp tubes. I powered it up again and they all glowed normally, there was still no smoke and all the voltages were still good.

I powered it down, waited for the capacitors to discharge, then I plugged in the power tubes and a dummy load. I applied power again. All the tubes glowed normally. There was still no smoke, no signs of red plating on the 6V6's and all the voltages were good. I powered it down again and plugged in a speaker and a guitar for the first time. I fired it up and it worked like a charm!

Tweed Deluxe

Tweed Deluxe

Time now to work on the cabinet. It's made from 3/4" pine and covered with real tweed fabric, just like the originals.

I applied a couple of coats of shellac to the tweed. I used Zinser Amber shellac mixed about 50/50 with Zinser clear shellac. I didn't want the cabinet to be too dark. I didn't want it to be really yellow either, the way the tweed looks naturally. This mix worked pretty well. It sealed the tweed and darkened it the amount I wanted. I applied it with a brush and sanded with 220 grit paper after each coat. Then I sprayed on four coats of clear lacquer inside and out to give the cabinet a tough durable finish.

I installed the handle, feet and speaker panel. The grill cloth is Oxblood, just like the originals. I mounted the chassis and a speaker in the cabinet. I used a 12" Jensen P12Q, also like the originals had.

Tweed Deluxe

Tweed Deluxe

Tweed Deluxe

I put on the back panel and the project was done!

Tweed Deluxe

Tweed Deluxe

Tweed Deluxe

Tweed Deluxe

It was a lot of fun to build this amp. The wiring isn't as neat as some of my other amps, the chassis is too cramped for that. It's neater than the originals, though! The small chassis is faithful to the originals and helps keep the amp light and compact. The cabinet is faithful to the originals, too, with it's tweed finish and oxblood grill cloth.

I've had a chance to use the amp for a few months now including a couple of live gigs. It sounds great and it's a lot of fun to play.

For more information please contact: message@markinamps.com

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