The very first mod should be: Install a power cord with a grounding plug, connect the chassis to a real ground (as on newer amps), and get rid of the ground switch and cap. Those pose a shock hazard. You can also bridge the new mid boost switch and the cap side of the NFB switch with relatively high valued resistors. This will help to avoid pops due to the caps (dis)charging when the switches are flipped.
About lifting the tone stack: If tone stack is driven by a cathode follower, lifting it (from ground) works just fine. But if the tone stack is driven by a normal triode stage plate circuit, the output impedance of that stage is so much bigger than (of CF) that the extra capacitance (to ground) of that tone stack and the wiring (depending how it is done of course, shielded or not etc.) in fact cuts the high end frequencies. So if you really want to lift the tone stack not driven by CF, and nail it without any treble and transient loss, you have to bypass the whole tone stack and its wiring. Well TBH, the difference is usually barely audible but it can be measured very easily by measuring the high end 3dB frq. Even a very little extra capacitance at triode plate output circuit narrows the bandwith of the audio signal. Of course, sometimes reducing the bandwidth is quite OK and makes the amp less prone to parasitic oscillations, but IMHO reducing bandwith is best done increasing grid stoppers to the circuit not uncontrolled capacitance.
In the original amp design (5e3 normal channel) there is no tone control connected. So lifting the tonestack does nothing but revert the design back to how it was originally made and then used for almost 70 years
I’m saying the guy may be accurate But it doesn’t apply to this particular circuit Because in this stock circuit there is no tonestack / so it’s already lifted No need for a technical explanation
Great Video Kley!! Rob Robinette's website rocks for all the mods you can do to your 5E3!! I have the 3 position neg feedback done to mine and love it. Why not have the option if you can. Also did the diode/rectifier switch option on mine. Tempted to do your tone stack mod! Have you built his Blackvibe amp? I did and love it, filled it with tones of Rob's mods, did a raw switch on that one. Keep the amp vids coming! 🤓
i finished my 5E3 build but haven't tested it yet. it was my first time soldering and i'm pretty sure i messed up some pins with the abuse I put them through. it looks beautiful though, and my soldering improved especially after buying better quality solder. I'm thinking of starting over. I want to get better caps and maybe some mercury magnetic transformers. I am digging the work though. I even bought some hammond ao, that I want to convert and I'm tempted to start the 5E3 over doing p2p. I wish I knew what was inside your TD. Hopefully I will see what you put in it. So far the vids of yours Ive watched are great, informative and your a great player making great gear.
This is amazing. Considering a 5E3 kit from Mojotone is only around $550, I think I might have found a new project. I can't believe how many different tones you got out of it. Would it be possible to add a footswitch to control the NFB on/off and bypass the tonestack at the same time? Or better yet, turn it on... that would effectively be a lead channel switch. crazy...
Thanks! It is one of my most played amps to this day. The tone stack bypass would be quite easy. Run the ground connection through a switch. The nfb would require a relay. You don't want to run the nfb signal through the switch.
i was wondering if you could add a 25k pot in the tone stack as a midrange control knob instead of a fixed resistor. that or a 20k potentiometer in series with a 5k resistor so you always have 5k resistance and you can dial it up to 25k ohms. also the same to the nfb, wath a smaller fixed resistor and a potentiometer to control the resistance to the speakers.
I'm not a big fan of the smaller tweeds- they are a bit too compressed for my taste- The Vibrolux and up seem to play better with me. I do love the blackface smaller amps though.. PR is one of the best amps for home playing.
Hey Kley ! I've got an AO29 chassis, and I'd love to build some thing like a trainwreck in it. Ive built a few bassman plexi type things. And 5e3, 5f2a etc. But im still pretty green. Im going to check out your bandmaster/trainwreck video but i wondered if you had any suggestions. Thanks
Got a lil Dawg 5e3 build and it’s mercury mags and was told it’s 12w but looking it up those mags are 18w so I was bummed cause I wanted the lower watt power amp gain. Also, I have a “Paul c mod” but mine is just 2 way toggle not three way. Idk what it is but to The left it’s a lot more bass and low mid heavy. Maybe more headroom?
I have a pre phase inverter master in place of the 1M grid leak resistor just prior to the final 12AX7 phase inverter stage. Honestly I mostly always leave it on max full volume. I play this amp for fun in my basement. It isn't a high headroom amp anyways, so I find it actually works great to crank it up for fun in my basement without it getting stupidly loud. It doesn't generate a ton of preamp gain, but I do appreciate the option to turn it down. I may try making a video to explore my feelings more about it. For now I'd say I don't regret having it - but I don't use it a ton. I find the NFB switch and the tone stack mod I made to be quite a bit more useful.
How much would you charge to build me a clone of this bad ass amp? Only thing different I want is a slightly more throaty low end & some spacing between all the pots on the control panel. What would the damage be
The very first mod should be: Install a power cord with a grounding plug, connect the chassis to a real ground (as on newer amps), and get rid of the ground switch and cap. Those pose a shock hazard.
You can also bridge the new mid boost switch and the cap side of the NFB switch with relatively high valued resistors. This will help to avoid pops due to the caps (dis)charging when the switches are flipped.
Fantastic demo Kley.
Still the best guitar mouth on you tube.
You built a killer amp my guy!
Thanks!
About lifting the tone stack:
If tone stack is driven by a cathode follower, lifting it (from ground) works just fine. But if the tone stack is driven by a normal triode stage plate circuit, the output impedance of that stage is so much bigger than (of CF) that the extra capacitance (to ground) of that tone stack and the wiring (depending how it is done of course, shielded or not etc.) in fact cuts the high end frequencies. So if you really want to lift the tone stack not driven by CF, and nail it without any treble and transient loss, you have to bypass the whole tone stack and its wiring. Well TBH, the difference is usually barely audible but it can be measured very easily by measuring the high end 3dB frq. Even a very little extra capacitance at triode plate output circuit narrows the bandwith of the audio signal.
Of course, sometimes reducing the bandwidth is quite OK and makes the amp less prone to parasitic oscillations, but IMHO reducing bandwith is best done increasing grid stoppers to the circuit not uncontrolled capacitance.
In the original amp design (5e3 normal channel) there is no tone control connected. So lifting the tonestack does nothing but revert the design back to how it was originally made and then used for almost 70 years
What was that, that just flew over my head damn it was fast
I’m saying the guy may be accurate
But it doesn’t apply to this particular circuit
Because in this stock circuit there is no tonestack / so it’s already lifted
No need for a technical explanation
Great Video Kley!! Rob Robinette's website rocks for all the mods you can do to your 5E3!! I have the 3 position neg feedback done to mine and love it. Why not have the option if you can. Also did the diode/rectifier switch option on mine. Tempted to do your tone stack mod!
Have you built his Blackvibe amp? I did and love it, filled it with tones of Rob's mods, did a raw switch on that one.
Keep the amp vids coming! 🤓
Thanks!
I have not built a Blackvibe, but I did built a Super Reverb clone a few years back and its my #1 amp.
i finished my 5E3 build but haven't tested it yet. it was my first time soldering and i'm pretty sure i messed up some pins with the abuse I put them through.
it looks beautiful though, and my soldering improved especially after buying better quality solder. I'm thinking of starting over. I want to get better caps and maybe some mercury magnetic transformers. I am digging the work though. I even bought some hammond ao, that I want to convert and I'm tempted to start the 5E3 over doing p2p. I wish I knew what was inside your TD. Hopefully I will see what you put in it. So far the vids of yours Ive watched are great, informative and your a great player making great gear.
I just found your channel and I dig it I'm subscribing thanks man !
im about to build my first 5e3 in the coming months and am going to try many of these mods and what not
Dude that is sick.
Hi Kley, Great work here, and on your other vids too! One question: What speakers do you like with your 5e3 amp, and also for Blackface types?
This is amazing. Considering a 5E3 kit from Mojotone is only around $550, I think I might have found a new project. I can't believe how many different tones you got out of it. Would it be possible to add a footswitch to control the NFB on/off and bypass the tonestack at the same time? Or better yet, turn it on... that would effectively be a lead channel switch. crazy...
Thanks! It is one of my most played amps to this day.
The tone stack bypass would be quite easy. Run the ground connection through a switch.
The nfb would require a relay. You don't want to run the nfb signal through the switch.
i was wondering if you could add a 25k pot in the tone stack as a midrange control knob instead of a fixed resistor. that or a 20k potentiometer in series with a 5k resistor so you always have 5k resistance and you can dial it up to 25k ohms.
also the same to the nfb, wath a smaller fixed resistor and a potentiometer to control the resistance to the speakers.
Yes absolutely
I'm not a big fan of the smaller tweeds- they are a bit too compressed for my taste- The Vibrolux and up seem to play better with me. I do love the blackface smaller amps though.. PR is one of the best amps for home playing.
Hey Kley ! I've got an AO29 chassis, and I'd love to build some thing like a trainwreck in it. Ive built a few bassman plexi type things. And 5e3, 5f2a etc. But im still pretty green. Im going to check out your bandmaster/trainwreck video but i wondered if you had any suggestions. Thanks
Got a lil Dawg 5e3 build and it’s mercury mags and was told it’s 12w but looking it up those mags are 18w so I was bummed cause I wanted the lower watt power amp gain. Also, I have a “Paul c mod” but mine is just 2 way toggle not three way. Idk what it is but to
The left it’s a lot more bass and low mid heavy. Maybe more headroom?
Would it be possible to make some of those changes footswitchable?
What speaker did you put in it?
I bet a Jensen Blackbird would absolutely soar in there.
I'm using it as a head. Mostly with a wgs g12c.
Considering a master volume for my 5e3. Wondering what your thoughts are? I know Rob approves but on the forum I see a lot of people don't.
I have a pre phase inverter master in place of the 1M grid leak resistor just prior to the final 12AX7 phase inverter stage. Honestly I mostly always leave it on max full volume. I play this amp for fun in my basement. It isn't a high headroom amp anyways, so I find it actually works great to crank it up for fun in my basement without it getting stupidly loud. It doesn't generate a ton of preamp gain, but I do appreciate the option to turn it down. I may try making a video to explore my feelings more about it. For now I'd say I don't regret having it - but I don't use it a ton. I find the NFB switch and the tone stack mod I made to be quite a bit more useful.
@@KleyDeJong Hi Kley. Thanks for the reply. I would like to see something like that. Your experience seems to match a lot of what I've read.
How much would you charge to build me a clone of this bad ass amp? Only thing different I want is a slightly more throaty low end & some spacing between all the pots on the control panel. What would the damage be
Send me an email at kleydejong@gmail.com
what is that red mustang on the wall?
what speaker do ya use with it?
Wgs g12c
Is it possible to send a schematic for you to analyze and suggest modifications? It's a tube amp made in Brazil.
Sure my email is kleysquestions@gmail.com
@@KleyDeJong Okay, thank you
Finished my first build--a Tweed Princeton. The low volume sound is kinda terrible. Boxy and gassy. Anything I can do?
No. This is the life with 5f1 and 5f2 amps :|
Actually you can do something. Try a reverb pedal , an eq pedal or somekind of preamp processor.
Or running it as a head into a bigger cabinet