Yet Another Tweed Deluxe Build

[p2pAmps]

For those interested 5E3s here is Doug's rendition of the infamous 5E3 Tweed Deluxe. I am almost done with her as I am still waiting on my Belton tube sockets (I thought I had enough)... The cab will be here from Mather in mid Nov. I haven't made my mind up yet on a speaker so.....

[Fresh_Start]

Nice!


I've been daydreaming about a modified 5E3 but think building one dead stock first makes good sense. I'll save your pics if I decide to use one of Doug's boards.



Chip

[eleventeen]

You shoulda been a dentist or a surgeon!

[p2pAmps]

Opinion question:  Do you think I should substitute the unused ground switch for a standby?

[SILVERGUN]

Opinion question:  Do you think I should substitute the unused ground switch for a standby?

Read this before making your decision or implementing:
http://www.valvewizard.co.uk/standby.html

It's a great spot for another fuse.

Really nice work on everything you've posted.

[p2pAmps]

Opinion question:  Do you think I should substitute the unused ground switch for a standby?

Read this before making your decision or implementing:
http://www.valvewizard.co.uk/standby.html

It's a great spot for another fuse.

Really nice work on everything you've posted.

That was an interesting read, thank you, and thanks for the nice comment

[sluckey]

I'd keep it original. Just get a Class Y cap. The amp does look nice.

[Platefire]

Wow! Neat and colorful--I like it. A 5E3 is just plain fun 

[HotBluePlates]

Note that the Hoffman 5E3 layout doesn't include 100Ω resistors for a virtual center-tap on the board, and it looks like your chosen PT doesn't have a heater center-tap.

When I built a Hoffman 5E3, I noticed this after finishing assembly; I added the 100Ω resistors at the input tube. I had a resistor each for 4/5 & 9, joined the free ends together in a ring terminal, crimped/soldered, and then secured the ring terminal under a mounting bolt for the input tube socket.

[plaidzebra]

Why stick with only carbon comp resistors?

[p2pAmps]

Note that the Hoffman 5E3 layout doesn't include 100Ω resistors for a virtual center-tap on the board, and it looks like your chosen PT doesn't have a heater center-tap.

When I built a Hoffman 5E3, I noticed this after finishing assembly; I added the 100Ω resistors at the input tube. I had a resistor each for 4/5 & 9, joined the free ends together in a ring terminal, crimped/soldered, and then secured the ring terminal under a mounting bolt for the input tube socket.

Hi, yeah those 2 100Ω are there, just hard to see in the current pics.  Look real close under the pilot light...  I tucked the green/yellow wire inside the PT...

[p2pAmps]

Why stick with only carbon comp resistors?

Well, I guess I don't have a solid answer other than so far everything I have built with CC sound great and I have not had any issues (so far)... 

[HotBluePlates]

Hi, yeah those 2 100Ω are there, just hard to see in the current pics.  Look real close under the pilot light...  I tucked the green/yellow wire inside the PT...

Gotcha! I see those 100Ω's now.

It's probably personal preference, but I'd have used the PT's center-tap given it was available. Separately, unless you're trying to replicate the 5E3, I've found soldering to the pilot-light assembly is needlessly-hard. Those resistors work the same wherever you place them along the heater string.

That said, nice, neat installation!!

[Fresh_Start]

Opinion question:  Do you think I should substitute the unused ground switch for a standby?

How do your voltages compare with "true" vintage voltages?  Given the physical location of the Ground switch, adding some form of sag switch might be in order?  Don't know whether you want to add resistance between the supply cap and the screen alone, add a sag resistor between the rectifier and the reservoir (plate node cap) dropping voltage on entire power rail, or increase the resistance between the plate and screen grids from 4.7K to drop screen and preamp voltages.


Or you could try Geezer's cathode bypass attenuator switch as shown on Sluckey's website:  http://home.comcast.net/~seluckey/amps/misc/Amp_Scrapbook.pdf


My first thought was a master volume in place of the 1 meg grid leak for the PI stage, but I think that switch is just a bad spot for that due to high voltage all around.

Chip

[p2pAmps]

Opinion question:  Do you think I should substitute the unused ground switch for a standby?

How do your voltages compare with "true" vintage voltages?  Given the physical ocation of the Ground switch, adding some form of sag switch might be in order?  Don't know whether you want to add resistance between the supply cap and the screen alone, add a sag resistor between the rectifier and the reservoir (plate node cap) dropping voltage on entire power rail, or increase the resistance between the plate and screen grids from 4.7K to drop screen and preamp voltages.

Chip

I wish I knew what you were talking about LOL... Dude, I am a total rookie but I have fun just the same

[Ed_Chambley]

Opinion question:  Do you think I should substitute the unused ground switch for a standby?

I have read many times about not needing a standby and I must say I always keep mine in the operate position.  I built a replica of a 63 Vibroverb for a fellow player and used the standby for a dwell.  Well the guy had a squealing worm extrude from his rear end.  I put him a standby switch in and left the dwell a 1 meg resistor.

So I usually waste a nice Carling Switch so someone can flip on their DC.

On my 5E3 I have a couple of extras like a switch to change the first Bypass to a 4.7 and reduced the bypass cap values to get headroom since they distort so quickly.  BTW, in the schematic library there is a schematic of the reissue that has the voltages.

Nice work.  BTW, I have been on your youtube site and I believe you have a tad more knowledge than you claim.

Here are a few images for mods on the 5e3.  The gain switch is nice.

[lego4040]

Incredible build and I cant believe you dressed each component leg . I read that same article on standby swtiches some time back and thought the same thing about a waste of a switch.

[Stevewdewitt]

Very nice build. I miss my 5E3. Your looks great!

The only thing I didn't like about it was the fact that it didn't seem to have much in the way of volume control. Anything past about 2 or 3 seemed to be almost full volume.

Steve

[p2pAmps]

Very nice build. I miss my 5E3. Your looks great!

The only thing I didn't like about it was the fact that it didn't seem to have much in the way of volume control. Anything past about 2 or 3 seemed to be almost full volume.

Steve

Yeah Steve I get what you are saying.  What I am looking forward to is playing with the circuit and some different mods.  There is so much info out there it will be neat to try some different things.  Ed Chambley has a lot of great info on 5e3s as do many other guys here on the forum. 

[lego4040]

 

So, for the 1st preamp gain stage, I made up a couple of brackets from some parts I had laying around to mount a couple of rotary switches. They both are movable so I can use them on other gain stages too. I did test and mark the outside foil on the CC's. (They don't look real pretty but they work fine.) 

I saw how to that with the caps but can't remember anymore, could you explain please

[Willabe]

Ummmm, how did you get my quote from a different thread in this thread?   

I mean, I know how but why?

[lego4040]

  I did cross threads, sorry. But I'm still interested in knowing how to find the positive end of a cap

[Willabe]

The positive end of the cap? 

Is this what your looking for?

http://el34world.com/Forum/index.php?topic=11427.0
 

[lego4040]

That's exactly what I was looking for, thanks.

[Willabe]

 

[lego4040]

Since this is a Tweed build have you thought about a speaker yet? I stuck the WGS 12" in my 5G9 just to test and it sounds great but to clean at higher volumes. I assuming this is because it's a 60 watt speaker. I did bid on a 50's era(53to be exact) Jensen P12R alnico to get me in the correct period. It's from a reputable source and has been tested, for the same price as a new one

[p2pAmps]

Ok, so I finally fired this guy up an hour ago and OMG!  It sounds amazing!  Seriously.  Now, once i get the cab and speaker I will re-evaluate but if it sounds the same or better I will be one happy dude...

Deluxe Reverb next on the list 

[Willabe]

So what did you end up going with, stock circuit, any mods?

[lego4040]

Sluckys Tweed Deluxe Reverb would be a great project.

[p2pAmps]

So what did you end up going with, stock circuit, any mods?

Well, no mods yet...  I am waiting to get the cab and speaker first then re-look at things

[p2pAmps]

Sluckys Tweed Deluxe would be a great project.

I would be very interested in seeing Steve's build and changes...  Sluckey?

[Fresh_Start]

Sluckeys Tweed Deluxe Reverb:
http://home.comcast.net/~seluckey/amps/tdr/tdr.htm

Note that it's an AB763 circuit with a single channel which has reverb.  No tremolo.  The "Tweed" aspect is the chassis and cab, not really the circuit if I understand correctly.  It's a really neat project - a Blackface in Tweed clothing.  What's so cool about the project is physically fitting the Blackface AB763 circuit into that chassis...
 

Doug has a complete project for a single-channel Deluxe Reverb with tremolo:
http://el34world.com/Hoffman/files/Hoffman_AB763_1.pdf

An interesting question would be "Can you fit this board into a Princeton Reverb chassis?"  Take out the tremolo since it uses a 12AX7 you don't have space for.  If the board fits, you could use it "as is", but all of the circuitry for the tremolo and V4 (that tube you don't have space for) is together.  Maybe you could cut that section out of the board, leaving you with two boards and shorter combined length.  Control pots: Volume, Treble, Middle, Bass, Dwell and Reverb.  That would be a wolf in sheep's clothing too although many would prefer a 12" speaker.  I've read about guys stuffing a 12" into a PR cab though...

Chip

[p2pAmps]

She is all but finished now.  I have a few small changes to do while I tweak it in.  Fun amp and sound pretty cool with my PR in stereo! 

[Paul1453]

Your work is always top notch!

I appreciate your attention to every little detail.  Like how you made sure to give your speaker jacks some clearance from the AC heater wires.
Many would just run those in tight to the chassis, practically on top of those jacks, and then wonder why they have hum.
Like Ed, I also think you have far more experience than you admit to.

 

[p2pAmps]

Your work is always top notch!

I appreciate your attention to every little detail.  Like how you made sure to give your speaker jacks some clearance from the AC heater wires.
Many would just run those in tight to the chassis, practically on top of those jacks, and then wonder why they have hum.
Like Ed, I also think you have far more experience than you admit to.

 

Thank you so much but guess what?  I do have some hum :(  I need to go through this thing from top to bottom.  I have already checked all the obvious stuff.  Next I will go through the ground routing which I will make perfect if its not.  This is a side project while I work on a PR and a Twin Reverb frame off resto.  Oh yeah, I have a day job too LOL

[p2pAmps]

I do have some hum

I don't see a real center tap for the filament winding. Nor do I see an artificial center tap ( 2 x 100Ω resistors). The whole purpose of referencing the filament circuit to ground through use of a center tap is to reduce hum.

Look at page 2 of this pdf to see how Doug connected the artificial ceter tap resistors...

     http://el34world.com/Hoffman/files/Hoffman_5E3.pdf

Yeah Steve, the 2 100Ω CT are hung off the pilot, hard to see in my pics but they are there.  I'm going to tear all the grounds out tonight and re-solder them all to one PT bolt on the power side. 

[sluckey]

Ah. I found them.

[p2pAmps]

Ah. I found them.

I think I may have my grounds separated too much.  Sooooo, I brought the CT off the pilot, the AC ground, the cap ground, and the red/yellow off the OT all the the same lug on the PT.  That may have helped a little but I still hear a hum.  This amp is grounded exact to Doug's layout.  Yes, I did swap tubes for known good ones, no change so far

[Fresh_Start]

Mike - I'd add a separate grounding bolt close to the power tubes and not use a PT bolt. Just my approach.

Can you use vertical separation to get heater wires farther away from preamp caps, etc?

You might try tacking the virtual center tap to one of the power tube sockets and "grounding" at top of shared cathode resistor. More typical to elevate the heater ground in a single-ended amp or one with a cathode follower, but it might help here.

Cab looks great BTW!

Chip

[p2pAmps]

Mike - I'd add a separate grounding bolt close to the power tunes and not use a PT bolt. Just my approach.

Can you use vertical separation to get heater wires farther away from preamp caps, etc?

You might try tacking the virtual center tap to one of the power tube sockets and "grounding" at top of shared cathode resistor. More typical to elevate the heater ground in a single-ended amp or one with a cathode follower, but it might help here.

Cab looks great BTW!

Chip

"Mike - I'd add a separate grounding bolt close to the power tunes and not use a PT bolt. Just my approach. "
I usually do that on Bassmans and most BF/SF Fenders

Can you use vertical separation to get heater wires farther away from preamp caps, etc?
Well I did pull the heater wires away from the caps while running with my chop stick, no change in hum at all.

[p2pAmps]

I think I may experiment around a little and try this ground scheme to see what happens...

[dude]

Maybe ground the first two E caps to the PT bolt and the Pre-amp E cap to the input jack ground or near it ...? Separate the HT grounds from  the Pre-amp grounds.

As far as a stock 5E3 most think too much mud and bassy, most change the coupling caps from .1 to .047 in the pre-amp. Maybe change the cathode caps on the first stage from 22uf to around 5uf. This will tight'n up the amp, take away the mud at higher volumes.

Very clean build,

al

[p2pAmps]

Maybe ground the first two E caps to the PT bolt and the Pre-amp E cap to the input jack ground or near it ...? Separate the HT grounds from  the Pre-amp grounds.

As far as a stock 5E3 most think too much mud and bassy, most change the coupling caps from .1 to .047 in the pre-amp. Maybe change the cathode caps on the first stage from 22uf to around 5uf. This will tight'n up the amp, take away the mud at higher volumes.

Very clean build,

al

Hi and thanks.  I already change the 1st bypass cap to a 4.7uF and all the .1s to .022.  Tone is great just have to track down the hum issue

[Willabe]

HBP has talked about Fenders reasoning in how they dressed the heater wires in the tweed amps and the brown/black face amps.

In the tweed amps they tucked the heater wires up in the chassis fold to get distance from the the eyelet boards sensitive part leads. The black/brown face amps the chassis is laid out differently so they were able to leave the heater wires up in the air above the tube sockets and still have them away from the eyelet board.

[Willabe]

What is the green wire that the green arrow is pointing to?

And I can't see where the B+ CT, red arrow, is connected to the 1st B+ filter caps ground?

[p2pAmps]

What is the green wire that the green arrow is pointing to?

And I can't see where the B+ CT, red arrow, is connected to the 1st B+ filter caps ground?

Ok, so right now the heaters are as in the pictures which I may change.

The CT from the pilot is on a ground lug on the PT
The AC ground, same lug
The PT, same lug, and the board, same lug

On the preamp side I have it grounded exactly like Doug's layout...  Using the brass plate, all pots are bussed together and connected to inputs

[Willabe]

Ok, so your 1st filter cap ground from the eyelet board is the black wire that runs from the board under the fuse and to that PT ground lug with the heater faux CT?

I'd try moving the PT B+ CT from where you have it now over to the black wire and heater faux CT.

[HotBluePlates]

I do have some hum :(  I need to go through this thing from top to bottom.  I have already checked all the obvious stuff. 

Does hum change or go away when you pull preamp tubes? Do you have any high-value (like 100uF+) cathode bypass caps laying around?

Overall, I have confidence in your work that solder joints and ground connections are good. You also noted chopsticking heater wires didn't help hum, so I'd tentatively eliminate that (yes, I've talked before about how Fender tucked the heater wiring into the chassis lip on tweed models, but if moving what you have doesn't give noticeable improvement I'm doubtful about rerouting the wiring).

My overall hunch is tube heater-to-cathode leakage. Freshstart's suggestion to "ground" the 100Ω resistors to the cathode-side of the output tube cathode resistor would help alleviate this, as would a massive (100-330uF) cathode bypass cap on the input tube (if that tube has leakage). I've convinced myself that Fender put the 250uF bypass on the Bassman not to get gain to very low frequencies, but as insurance against preamp tube leakage.

[p2pAmps]

I do have some hum :(  I need to go through this thing from top to bottom.  I have already checked all the obvious stuff. 

Does hum change or go away when you pull preamp tubes? Do you have any high-value (like 100uF+) cathode bypass caps laying around?

Pulling the V1 tube does not change the hum

Overall, I have confidence in your work that solder joints and ground connections are good. You also noted chopsticking heater wires didn't help hum, so I'd tentatively eliminate that (yes, I've talked before about how Fender tucked the heater wiring into the chassis lip on tweed models, but if moving what you have doesn't give noticeable improvement I'm doubtful about rerouting the wiring).

My overall hunch is tube heater-to-cathode leakage. Freshstart's suggestion to "ground" the 100Ω resistors to the cathode-side of the output tube cathode resistor would help alleviate this, as would a massive (100-330uF) cathode bypass cap on the input tube (if that tube has leakage). I've convinced myself that Fender put the 250uF bypass on the Bassman not to get gain to very low frequencies, but as insurance against preamp tube leakage.

I'm going to give grounding the 100Ω resistors to the cathode-side of the output tube cathode resistor is whirl and see what happens.  I have a 300Ω 10watt cathode resistor in place now as I thought she was running a little hot.  I was out of 330Ω so I used a 300 for now.

[HotBluePlates]

Got it, how about V2?