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Re: Completed my 5E3x2 - now modding too

3/29/2005 1:45 PM
Erwin Re: Completed my 5E3x2 - now modding too
Very good thread and very nice looking amp! The brown knobs are a nice touch.  
I just scored a box of old RCA, Mullard and JAN GE 12au, av, at and ax7s. The 12AV7s are a little lower gain than the AY so that might be intersting.  
I'm thinking of adding a third tube to my amp and split the inputs between a AX and an AY.  
I'm ready for a long plug and play session with my 5e3x2!  
Shoot me an email about the tone control mod you did if you don't mind.  
And now, a word from our sponsors:

4/1/2005 6:58 PM

I am about to get started on a 5E3 style project and wanted to ask you some questions about your modded design. I play mostly Jazz with a Big Jazz box (Gibson - Johnny Smith) - and want a clean sounding amp. I like the simplicity and portability of the 5E3 designs, with one tone control in a giggable amp and volume (thats all I need!).  
Sometimes I get bored with my Jazz stuff, and get my strat out to pretend I am stevie Ray Vaughn. So overdrive dirt would be a nice feature, but it isnt a requirement.  
So here are my basic questions:  
1. Do you have some sound clips of your amp, both clean and dirty.  
2. How clean is clean on your amp ? Some amps that are clean sound dirty anyway. I really want clean to be clean. I dont mind modding the amp to add a "dirt" bypass switch if necessary.  
3. Have you measured your power output - how many watts are you pumping out.  
4. Do you have a schematic of your amp ?  
5. What kind of speaker are you using ?  
6. What is the deal with the "backwards" volume pot wiring ? and what is the tone stack mod you are referring to?  
Feel free to email me directly.  
4/2/2005 12:14 AM

To Brett and Erwin:  
So here are the answers to your basic questions:  
1. Do you have some sound clips of your amp, both clean and dirty.  
Not at the moment. Maybe sometime later when setup to do that.  
2. How clean is clean on your amp ? Some amps that are clean sound dirty anyway. I really want clean to be clean. I dont mind modding the amp to add a "dirt" bypass switch if necessary.  
It is a cleaner sounding than the stock 5E3 sound, but it still gets dirty. It cleans up better when you back off on it. The stock 5E3 is a very distorted amp and sounds like it on 12 when it is on 3. The mods I did give it more flexibility in that the volume control will have a more gradual taper and the output will be overall cleaner (maybe the 270K mixing resistor helped reduce the output some – you could even try a higher value if you wished). I suspect if you want jazz clean and wanted to use my mods you might also want to:  
- use the normal channel and the 2nd input jack – it gives you less input and is not overly bright for Jazz players  
- use “cleaner” output tubes – use the JJ6V6s or the 6V6EHs (I use the JJs)  
- use a cleaner V1 preamp tube such as a 5751, 12AT7, 12AY7, or 12AU7 (in order from more powerful to the cleaner).  
- be careful of your speaker choice – choose one that won’t distort too early for you – a Weber 12F150 or possibly a California might give more clean tone.  
- consider some of the other mods such as a choke mod, fixed bias mod, output tube rewire (making it more like a blackface era amp) to give you more headroom. This will probably eliminate some of the compression of the amp when it is pushed, so I am not sure if that is what you are after or not.  
3. Have you measured your power output - how many watts are you pumping out.  
Have not measured it, probably around 25w or so. It will not have likely changed from the stock 5E3x2 amp. The 5E3x2 amp is Bruce’s design so he would really know. But it is probably around the 25w range. You can expect around half of that from a 5E3.  
4. Do you have a schematic of your amp ?  
No. It started out as the Weber 5E3x2 schematic from the amp kits section of (layout and schematic are included there for free). I isolated both of my channels and tone controls and Chris posted a schematic of this in the volume taper thread. As long as he does not object I will post it with my notes on it.  
It included most all of the significant mods. I did the paulc mod in the phase inverter area. That was detailed in the 5E3 forum and a guy had links to a great picture of it. The only other mods I did was to add treble bypass caps on the volume controls for the back of the volume pots – consider 47, 100, or 120pf silver mica and listen to each. For the normal channel you may not want any treble bypass cap. Looking on back of the vol pot it connects between the non-grounded terminals.  
5. What kind of speaker are you using ?  
Right now I have a pair of vintage 70s Celestion G12H 30w speakers. They have great low end and are not overly middy nor crunchy until you push them. They are very efficient too so they can sound quite loud per watt you push into them. But if you push them hard they do distort and sound fantastic. The amp can really sound like a marshall when pushed but it has a wee bit more compression. I only now just got the weber speakers in, so I will try them too. I expect them to be more mids, a little less efficient, and possibly more crunchy as well, but I need to try them to find out.  
6. What is the deal with the "backwards" volume pot wiring? and what is the tone stack mod you are referring to?  
It is detailed in Chris’ schematic he posted to the volume pot taper thread – the same thing listed above. I did this in baby steps because I am still learning. If you look at the deluxe compared to other tweed amps the signal output from the volume pot comes out of the middle wiper. The 5E3 has the input on the middle wiper – that is the “backwards” part. Once I changed that like the other amps the volume controls taper was better but they became more interactive (one shut off the other). So I took some more advice and put in isolation resistors. Then where do I put the single tone control? It now had to be isolated along with the volume pots, or it had to be shared after the isolated channels. Well, I ran into difficulty putting it after the isolation resistorst wired as it was because it would cause the volumes not to shut completely off.  
Chris chimed in and suggested wiring the tone controls separately on each channel using a dual ganged pot. I knew I could have two tone pots, but never thought about using a dual ganged 1M audio pot for the tone control. It was a simple and GREAT idea. He posted a schematic, and I have added to it some names and values. It is very similar to other tweed amps now in that each channel is isolated. I didn’t realize the original no longer posted. I will post it unless Chris objects. Another alternative is to come up with a shared tone pot, but this was easy and solved my problem before I had a solution for the single tone control – and just plain made a lot of sense. It sounded great – and that is the important part.  
Parts needed for the mod are:  
- (2) 270K resistors  
- 1M Dual Ganged Audio Pot  
- Any additional caps you need for the 2nd tone pot used for the normal channel  
- Any caps needed for treble bypass  
- Moving few wires, and some shrink wrap over the isolation resistors so they don’t short.  
If you don’t like it, just put the old parts back. 5E3s are great amps in stock form – I just thought this made it more flexible and liked this better. You won’t know if you like it unless you try it yourself.
4/2/2005 12:14 PM

I forgot to mention, although it is mentioned earlier that the .1 caps can be changed to .047 or .022 caps like in many other amps. This will brighten up the amp. I changed mine to .047 currently, but also liked .022. Many people have mentioned this and it is a good mod. Most newer amps use .022 mfd. I left mine at .047 because it was a compromise between the .1 and .022 and it sounded good to me.  
The main changes are the ones in Chris' schematic and the cap changes, matched JJ 6V6S power tubes, and the vintage celestion G12H30 speakers. I also did the paulc mod and it was detailed earlier but you can find it at this guy's excellent 5E3 Build Website:  
You will have to scroll down to find the paulc mod.  
I need to devote more time to learning how to make web pages and post this stuff, maybe put it all into a schematic, but this is just what I did. I think you can get nearly identical results modding a 5E3 as I did modding a 5E3x2. I also look into similar amps and try to learn from them - some amp schematics can be found on the schematic heaven website.  
One that comes to mind is the TopHat Club Deluxe - it is a tweaked 5E3 - and they sound fantastic. I think it uses .022 caps in it, it has only one channel (but has a boost function), and some versions have a master volume on them. That amp does not have a lot of clean headroom, but the volume pot taper works a lot better. The one I owned had a celestion greenback in it. I think my 5E3x2 modded amp has a lot more clean headroom than the club deluxe (comparing the two amps).  
The schematics posted there for some of the matchless amps are a pretty similar design too but they use EL84s instead of 6V6s.  
There are a lot of ways to get where you all want to go. I thought about Bruce's power section mods but it distorted so early and so much that I thought my problem was in the preamp - because the power section of the amp should not normally be overdriven so much so early. This channel isolation mod cleaned it up a lot and I like the usability of the controls. I suppose I still can always chain them together if I need more gain, but I really don't need more gain. If I didn't like the compression I am currently getting I would do Bruce's choke, fixed bias, and other power section mods. But it turns out I really like the comression. I knew I didn't want to stray from 6V6s - I didn't want this amp to be a twin.  
Some things I considered but never tried. You could opt for only one channel and not need mixing resistors and also have another gain stage to work with and do what you wanted with it. You could use a push/pull control to switch that channel between a bright and normal channel like other fenders do with a bright switch. You could use that to drive a tone control, to add gain in series, or to experiment with a parallel gain stage. You could use the 2nd volume control as a master volume if you wanted in that scenario. You could put different resistors and/or caps on inputs to give them different voicings like some older amps have done. There are a lot of options!  
I have learned and lot and am having a hellova lot of fun. I already have someone that is asking to buy my amp, and two or three others are also interested in it. This potential buyer has a small studio and has a music store, and probably would sell a few more for me if he can make a bit too. The price was raised quite a bit on the kit though in the last couple weeks, so I can't build another for what i have in this one. I need to figure out how much I have into this anyway since I have not been keeping good tabs on things. If I am building several of these I need to drive to Kokomo and meet Ted and company and pick them up!  
If I decide to sell it I will use the funds to build another or two. I don't think I will change much if I do build another one of these beyond what I have already done - I will move from the kit jacks to switchcraft jacks, and probably use a few carbon comps to see how that changes the sound. So I am not sure what I want to do here.  
I am very happy with the tone of the amp and all the help everyone has given me. I did not buy the wrong amp at all. Anyone that would listen to the end result would probably agree. I know I have said it before but thanks a lot everyone.
4/5/2005 12:40 PM
My mod results
Hey Thorny -  
I just wanted to update on where I'm at on my 5e3X2. I originaly had the amp done as follows: Choke mod, power tube rewire like blackface twin, Chris's tone stack dual-ganged pot mod w/rewired volumes like other tweeds, and .02 caps feeding the volumes. I took out the choke mod and power tube rewire - it tended to take away some of the tweed compression and actually cleaned the amp up a little too much. I also changed the caps to .047's because the .02 took out a lot the tweed Deluxe style midrange. I kept Chris's tone mod and the volume rewire - that's a keeper for sure.
4/5/2005 5:20 PM

Wow -  
You are exactly where I am at now then. I still have the celestion G12Hs in it and have not tried my signature 12s yet (been too lazy and have had to work on other things. I don't recall what speakers you are using. But I even have the .047s. I think you have the EHs instead of the JJ 6V6s. I have the GT mullard clone 12AX7M in V1, and probably the chinese 12AX7 in V2. It really would be hard to improve this thing. I am very pleased.  
Now if I can just fix the other amps on the bench so I can start working on tweaking my 5E7. It is too crunchy and distorted to me right now - I think the tone should be sweeter than it is. It might just need the weber alnico signature 10s to break in - sometimes they can sound harsh until they are broken in. I have very good tubes in it. I am going to try carbon comps in it but I don't really expect anything dramatic (I can hope). I may also break down and try a mercury magnetic output tranny. If I buy 3 more I can start to get their discount.  
4/5/2005 8:47 PM

It's a pretty cool amp since it sounds as good as my Victoria Bassman (yes, I had to buy one), but in a tweed Deluxe way. The Bassman is cleaner at low to moderate volume, while the 5E3X2 breaks up a lot quicker like a Deluxe, only louder and more controlable. It's cool to have both sounds at my disposal. I've still got the 12AY7 in V1 so I can get pretty good clean tone out of the Double-D up until about 4 or 5. I'm using a Reverend All-Tone and a Greenback run in parallel, but I'm going to take the Greenback out and replace it with Weber's P12Q. The Reverend has a good solid low end and a pretty bright top, but I'm thinking that combining it with the 20 watt alnico Weber will give me the smooth compression in the upper mids too. To me, the Greenback sounds good right at the volume where the club owner shuts down the power and tells you not to come back.

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