The new dumble modded bassman build video series... begins!

[pompeiisneaks]

Thanks all, I've got to record a demo, keep forgetting.

I have a cradle but it's down in the garage and I built this up on a new work area I setup in my office... I should have brought that up but forgot like a dumbass... and paid the price.

~Phil

[aab0mb]

Thanks all, I've got to record a demo, keep forgetting.

I have a cradle but it's down in the garage and I built this up on a new work area I setup in my office... I should have brought that up but forgot like a dumbass... and paid the price.

~Phil

Awesome looking build! I'm really looking forward to hearing it.

My one question about this circuit is about the treble peaking circuit and the coupling cap after the second stage on the lead channel. The JCM800 topology has coupling cap > treble peaking resistor/cap combo > volume control. The second stage usually has coupling cap > voltage divider with a treble peaking cap which is omitted in the Dumble circuit.

In the schematic for this circuit the order after the first gain stage is treble peaking circuit > coupling cap > and then another resistor into the Volume control. As well, the second stage coupling cap position is swapped with the inline resistor which usually makes up the top half of the voltage divider. How does this effect the response and tone of what is basically a JCM800 circuit?

[Lothy]

Thanks all, I've got to record a demo, keep forgetting.

I have a cradle but it's down in the garage and I built this up on a new work area I setup in my office... I should have brought that up but forgot like a dumbass... and paid the price.

~Phil

A slightly bigger dog house would be a good cradle substitute
Well done!
Cheers
Gerhard

[pompeiisneaks]

Thanks all, I've got to record a demo, keep forgetting.

I have a cradle but it's down in the garage and I built this up on a new work area I setup in my office... I should have brought that up but forgot like a dumbass... and paid the price.

~Phil

Awesome looking build! I'm really looking forward to hearing it.

My one question about this circuit is about the treble peaking circuit and the coupling cap after the second stage on the lead channel. The JCM800 topology has coupling cap > treble peaking resistor/cap combo > volume control. The second stage usually has coupling cap > voltage divider with a treble peaking cap which is omitted in the Dumble circuit.

In the schematic for this circuit the order after the first gain stage is treble peaking circuit > coupling cap > and then another resistor into the Volume control. As well, the second stage coupling cap position is swapped with the inline resistor which usually makes up the top half of the voltage divider. How does this effect the response and tone of what is basically a JCM800 circuit?

I can only guess, but my understanding of a peaker circuit is it would do it's job so long as it is in the signal path. Not sure why you'd need it twice. Where it sits shouldn't matter a ton either, because so long as you do the treble peaker, you'd get that same output at the coupling cap or after it. So long as the coupling cap was large enough to be outside the impacted frequency range of the treble peaker.

Not sure if that makes sense?

~Phil

[aab0mb]

Thanks all, I've got to record a demo, keep forgetting.

I have a cradle but it's down in the garage and I built this up on a new work area I setup in my office... I should have brought that up but forgot like a dumbass... and paid the price.

~Phil

Awesome looking build! I'm really looking forward to hearing it.

My one question about this circuit is about the treble peaking circuit and the coupling cap after the second stage on the lead channel. The JCM800 topology has coupling cap > treble peaking resistor/cap combo > volume control. The second stage usually has coupling cap > voltage divider with a treble peaking cap which is omitted in the Dumble circuit.

In the schematic for this circuit the order after the first gain stage is treble peaking circuit > coupling cap > and then another resistor into the Volume control. As well, the second stage coupling cap position is swapped with the inline resistor which usually makes up the top half of the voltage divider. How does this effect the response and tone of what is basically a JCM800 circuit?

I can only guess, but my understanding of a peaker circuit is it would do it's job so long as it is in the signal path. Not sure why you'd need it twice. Where it sits shouldn't matter a ton either, because so long as you do the treble peaker, you'd get that same output at the coupling cap or after it. So long as the coupling cap was large enough to be outside the impacted frequency range of the treble peaker.

Not sure if that makes sense?

~Phil

I think you're right and there might be something else happening. The peaking circuit, being first, does it's normal shelving action. Then the coupling cap in conjunction with the 100k/1M voltage divider and gain control creates a high pass as well as shaving some of the highs off depending on the 100k plus the Volume pot setting. This seems like a cool way to tweak that part of the circuit that I haven't seen anywhere else. I'm thinking this configuration is the middle ground between the JCM800 with no treble peaking or bright cap and the full on boosted highs of the stock circuit. Maybe i'm missing the mark but this seems to make sense. Maybe someone with more experience or sim capabilities will chime in here.

How does it sound? Like a gain boosted jcm800 with less sharp high mids and high frequencies? Have you calculated the high end rolloff from the cold clipper plate bypass cap?

[pompeiisneaks]

I've not calculated it, I've played it a bit and it definitely sounds marshally. I've not had extensive playing on many different amps except those I've built, but I have built sluckey's dual marshall and it's in that definite ballpark for sure.

~Phil

[aab0mb]

I've not calculated it, I've played it a bit and it definitely sounds marshally. I've not had extensive playing on many different amps except those I've built, but I have built sluckey's dual marshall and it's in that definite ballpark for sure.

~Phil

Thanks for documenting the process and offering your thoughts. Really looking forward to the sound clips! Great work, Phil!

[pompeiisneaks]

Okay FINALLY got time to record a video demo.



~Phil

[Guy77]

Okay FINALLY got time to record a video demo.



~Phil

Sounds great Phil. Congrats! Love the nice rich deep bass tones the amp gets

Cheers
Guy

[pompeiisneaks]

Thanks! My plucking was never amazing and it's getting worse due to lack of playing because of arthritis. Either way I really like the tone of this thing. That drive sound comes with the main volume of the channel at like 5 or 6 bit it's still loud lol. I am sure I couldn't pay it to the full fifty watts and survive

~Phil

[Mark]

Thanks! My plucking was never amazing and it's getting worse due to lack of playing because of arthritis. Either way I really like the tone of this thing. That drive sound comes with the main volume of the channel at like 5 or 6 bit it's still loud lol. I am sure I couldn't pay it to the full fifty watts and survive

~Phil

What can you do about the arthritis in your hands?

Good stuff on the build.

[10thTx]

What can you do about the arthritis in your hands?

Nothing much to help lessen the arthritis beyond staying active. However, you can adapt a new playing style.

Not use a guitar pick. Or use a thumb pick.

Play more triads and comp chords. Example https://soundclick.com/r/s86j2x

Play more slide guitar.

Take Advil prior to playing jazz.

With respect, 10thtx

[WhopperPlate]

What can you do about the arthritis in your hands?

Nothing much to help lessen the arthritis beyond staying active. However, you can adapt a new playing style.

Not use a guitar pick. Or use a thumb pick.

Play more triads and comp chords. Example https://soundclick.com/r/s86j2x

Play more slide guitar.

Take Advil prior to playing jazz.

With respect, 10thtx

There was a point I literally was contemplating quitting guitar from pain caused by poor technique , sports injuries (dislocated right shoulder AC socket, sprained wrists , perepetual cracking sore wrists) and the subsequent tendinitis that resulted from my increased tension .

I work using my hands for any of my occupations , and the pain was preventing me from executing my duties and interfering with my income .

Everything changed when I began to use high strength cannabis salves. It was night and day . I could actually play better after several months of consistent application and conscientious care and attention, and that remains true today . This method, combined with understanding how my poor technique was increasing tension and relearning how to play relaxed , is how I can still pickup a guitar without wincing in pain.

I have turned on a lot of my older friends practice ( musicians and non musicians alike) and I am grateful and happy to share that people return elated with their improvement .

I had one friend of mine , coincidentally the original owner of Lang’s Fang , who actually came to me trying to sell off his gear because he was losing feeling in his hands and wrists and couldn’t play guitar anymore. I told him about the protocol and gave him all the extra product I had . After 3 months of me trying to find some buyers he came back and asked for his gear back because he could play music again , I shit you not .

There’s probably nothing more frustrating than when the artists can’t perform the way the artist wants, especially to not be able to perform at all. Don’t take my word for it , but this was the light at the end of my tunnel . Might not be the silver bullet treatment for all , but it holds great potential .

[Stephen1966]

...
There was a point I literally was contemplating quitting guitar from pain caused by poor technique , sports injuries (dislocated right shoulder AC socket, sprained wrists , perepetual cracking sore wrists) and the subsequent tendinitis that resulted from my increased tension .

I work using my hands for any of my occupations , and the pain was preventing me from executing my duties and interfering with my income .

Everything changed when I began to use high strength cannabis salves. It was night and day . I could actually play better after several months of consistent application and conscientious care and attention, and that remains true today . This method, combined with understanding how my poor technique was increasing tension and relearning how to play relaxed , is how I can still pickup a guitar without wincing in pain.

I have turned on a lot of my older friends practice ( musicians and non musicians alike) and I am grateful and happy to share that people return elated with their improvement .

I had one friend of mine , coincidentally the original owner of Lang’s Fang , who actually came to me trying to sell off his gear because he was losing feeling in his hands and wrists and couldn’t play guitar anymore. I told him about the protocol and gave him all the extra product I had . After 3 months of me trying to find some buyers he came back and asked for his gear back because he could play music again , I shit you not .

There’s probably nothing more frustrating than when the artists can’t perform the way the artist wants, especially to not be able to perform at all. Don’t take my word for it , but this was the light at the end of my tunnel . Might not be the silver bullet treatment for all , but it holds great potential .

Just before Christmas, I sent my wife off to a spa for her back pain and there were a couple of cannabis therapies included which helped her a lot. She's been using these salves and unguents ever since and it's transformed her life. She can be herself again. So, a big +1.

[WhopperPlate]

Just before Christmas, I sent my wife off to a spa for her back pain and there were a couple of cannabis therapies included which helped her a lot. She's been using these salves and unguents ever since and it's transformed her life. She can be herself again. So, a big +1.

You know it works if the wife says so ! Lol Hallelujah