Fender Tweed Deluxe

20 June 2009

The Tweed Deluxe (5E3) is one of Fender’s classic amps. The Tweed Deluxe’s simple circuit packaged with ergonomic cabinet design have made it very popular over it’s 60+ year life time.

The Tweed Deluxe’s simple design has also made it a popular amp to build among hobbyists. Though simple in design the Tweed Deluxe is not simple sounding or lacking in tone. I find often the simplest amps are the best sounding ones. With less circuitry between your guitar and the speaker there is less processing/manipulation done to your guitar signal and as a result your tone is richer and more pleasing sounding (read better!).

Many great players of various styles have used the Tweed Deluxe over the years so it defiantly has a wide appeal. As a result of the aura of the Tweed Deluxe I set out to build one of my own. The chassis, transformers and cabinet are coming from Trinity Amps. The other parts (passive components, tubes, speaker, etc.) I sourced myself.

Parts:

  • 1W carbon film resistors for the signal path
  • 1W carbon composition resistors for the plates
  • SBE 716P Orange Drop capacitors
  • Sprague Atom electrolytic capacitors
  • PEC 2W potentiometers
  • Switchcraft jacks
  • Belton tube sockets
  • Carling switches
  • Cloth covered wire
  • Trinity Amps designed Heyboer made power and output transformer

Build:

Though the amp is fairly simple in design building it can be a little troublesome. When Fender built these amps back in the 50’s they wanted small packaging of their Tweed combo amplifiers. As a result the chassis they used to build their Tweed amps were quite small and compact. Now this probably wasn’t an issue for the women working in Fullerton, CA back then but for a guy with big hands these chassis are tight!

All that said the build went smoothly and the amp fired up first time with no issues.

Below you can see some pictures of the build in various stages.

Design:

The Tweed Deluxe is approximately 15W and runs two 6V6GT output tubes in Class AB1 push-pull configuration. The preamp uses a 12AY7 tube for the input stage and a 12AX7 tube for the cathodyne phase inverter. The amp also uses a 5Y3 tube rectifier. The amp has two simple channels Normal and Bright; controls are Normal Volume, Bright Volume and a global Tone control. Each channel has a high and low input. The Tweed Deluxe is built into a combo cabinet and uses a single 12” speaker housed in a compact tweed covered pine cabinet.

The 5E3 Tweed Deluxe was one of Fender’s early primitive amp designs. As a result the amps were built fairly simple and with budget in mind. Much can be done to the simple 5E3 circuit. There are many modifications and tweaks that can be done to the amp. Before I started the build I compiled a list of ideas I would like to try to “improve” the amp.

  • Increase filtering for tighter low end
  • Add a choke to the power supply
  • Decrease coupling caps for less low end “flub”
  • Split cathodes on V1
  • Add screen grid resistors
  • Add negative feedback
  • Try to improve response of volume controls (remove interactivity)
  • Increase headroom

All of these mods made sense and seemed reasonably prior to building the amp. Like all builds though I like to build the best stock amp I can. After I have built the amp I let it settle in, play it for an extended time then tweak it.

Building the amp with the best components I had, tweaking the voltages so they were correct, selecting the right speaker and tube set made a big difference in this amp. I can see where some people may not like the stock amp with the semi loose low end and low headroom for example but if you build like I did (listed above) the “issues” some people have can be mitigated.

A lot of the times people complain about their gear when they don’t know how to use it. In the Tweed Deluxe the volume controls are interactive and as a result the Normal Volume has an effect on the Bright Volume and vice versa. Learning the simple nuances and oddities of an amp (or even your guitar and other gear) can really make the most of your tone. More on that later though…

All that said my Tweed Deluxe ended up being built almost completely stock. The only mod I did was adding a 470KΩ resistor to the input of the cathodyne phase inverter. This simple mod does not affect the clean tone but when the amp is pushed into distortion it helps to smooth out the somewhat dissonant buzzy tone. Part of the Tweed Deluxe’s character is its rudeness or raggedness so this mod does not take it away but merely limits the amount of grid current which can cause unwanted ugliness in the tone.

The grid stopper on the phase inverter came from Merlin at Valve Wizard, more information on it can be found here.

Schematic:

tweed-deluxe-schematic

 

 

Results:

Though I started the build with the idea of really improving the amp the amp is great in it’s own right. If I did follow through and make a bunch of mods to the amp the end result would have been an amp that didn’t really sound like a true Tweed Deluxe.

The amp has a really nice warm harmonically rich tone, very fat sounding. With its low headroom it is pretty easy to get the amp distorting. The distortion from the amp is can range from very smooth sounding to very ragging and heavy. There is a surprising amount of tones avaible from the simple controls.

Tubes:
I did try out various tubes for the amp and ended up settling on a NOS Sylvania 12AY7, EHX Gold Pin 12AX7, Tung Sol 6V6GTs and a NOS RCA 5Y3. I really found the Tung Sol 6V6GT tubes sounded great in this tweed circuit. They had a bit more edge to them and just seemed to suit this amp very well.

It is important the 5Y3 used in the amp must be vintage correct. Many new production 5Y3s are not actually 5Y3s but rebranded GZ34/5AR4 that did not meet spec (avoid Sovtek!). As a result many of these new production 5Y3s put out way more voltage than a real 5Y3. Excess voltage coming from the rectifier leads to incorrect voltages on the tubes and the tone changes as a result. The change is tone is subjective as to if it’s better or not but it should be noted the tone is not that of a true Tweed Deluxe with a new production 5Y3.

Speaker:
After completing the amp I auditioned two 12” speakers to try in the cabinet. The first was an old AlNiCo Roma speaker from the late 60’s. The second was a new Ceramic Jensen MOD speaker.

After going back and forth and trying both speakers in the cabinet I settled on the Jensen MOD. Though I did like the Roma I felt it sounded a bit flat and dead sounding in the amp. It also made the low end a bit undefined sounding. The Jensen MOD on the other hand sounded tighter and livelier. It had a bit more sparkle to the tone which I liked. Overall the Jensen seemed to offer better tone.

The Tweed Deluxe does have an extension speaker jack so an external speaker cabinet can also be used as well.

Controls:
As mentioned earlier the Tweed Deluxe does have interactive volume controls. What this means is when you are on one channel the other channels unused volume control still has an effect. The unused volume control affects the active channels midrange content. This happens because the Tweed Deluxe’s volume controls are not setup in the typical variable voltage divider arrangement. Instead they are set up to load down the signal coming from the plates to attenuate the signal.

The unique volume control setup causes the interactivity. Maximum midrange occurs while the unsused volume control is set to the middle position. Maximum midrange scoop occurs when the unused volume control is set to the maximum position. As we know more midrange causes an amp to distort more so one can see how using the interactive volume controls you can set up the Tweed Deluxe for a quasi-clean and dirty channel.

Set one channel (say the Normal channel) to max on the volume control and the other (Bright channel) to mid position on the volume control. When you select the Bright channel, you should get nice clean tones and when you select the Normal channel, you will get nicely distorted tones.

On top of all this you have a global tone control to sculpt the tone. The tone control has a nice sweep going from warm and loose to bright and spanky sounding. For only three controls there is a surprising amount of tones and versatility.

{ 0 comments… add one now }

Leave a Comment

Previous post:

Next post: