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Re: Completed my 5E3x2 - now modding too

4/2/2005 12:14 AM
Thorny	Re: Completed my 5E3x2 - now modding too 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 www.webervst.com (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. http://members.sigecom.net/jthornburg/5E3mod.jpg 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 AM

Thorny

Re: Completed my 5E3x2 - now modding too

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 www.webervst.com (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.

http://members.sigecom.net/jthornburg/5E3mod.jpg

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.

Replies:

Thorny I forgot to mention, although it is... -- 4/2/2005 12:14 PM