18W TMB tremolo JOHN!!!

[zaphod_phil]

.22uF would basically give you a treble booster

In case anybody needs an ice pick, right?

Worse than that, the amp's tone would be very weak and thin.

[JMPGuitars]

.22uF would basically give you a treble booster

In case anybody needs an ice pick, right?

Worse than that, the amp's tone would be very weak and thin.

And make your ears bleed.

[Bieworm]

My new build...it cracklepops when I turn it on. And disappears after a few minutes. Caps?
I also changed the resistor from 120 to 180 ohms and the cap from 450uf/50V to 2200uf/50V. But the crackle was before that

[zaphod_phil]

My new build...it cracklepops when I turn it on. And disappears after a few minutes.

In my experience "cracklepop" noises are usually caused by a faulty 12AX7. I'm not saying there aren't other possible reasons, but that's usually the most common one.

[zaphod_phil]

Not me... I'm Bjorn...from the hellhole (Belgium)

With a name like that, I would have thought you're a member of ABBA from Sweden, not from "the hellhole" LOL

Did you know that, according to the HitchHikers Guide to the Galaxy, "Belgium is the rudest word in the Universe, yet by a strange coincidence, also the name of a country on Earth. "and is completely banned in all parts of the Galaxy, except in one part, where they don't know what it means, and in serious screenplays." "? I've actually visited "hellhole" a number of times, myself. It wasn't actually that bad!

[Bieworm]

My new build...it cracklepops when I turn it on. And disappears after a few minutes.

In my experience "cracklepop" noises are usually caused by a faulty 12AX7. I'm not saying there aren't other possible reasons, but that's usually the most common one.

Well..it's not this time. I am not gonna worry about it. Going to finish the build of the Shell..play it for a while and build the TMB trem from josh afterwards in a brand new turret
Actually , I reflowed all the connections without result. Tried other tubes.. pfff
Just gonna try one from scratch and hope 4 the best. But one thing is for sure.. the 18w is really sensitive

[zaphod_phil]

...for the not so purists. Hey, I still have to be converted from a lifetime of fender amps..give me a break Phil;)

Yeah, F*nder amps need reverb to give some life to their otherwise dull tone. Not the case with these chimey 18 watters

I am in the same line when it comes to BF or SF fenders, but tweed , blonde and brown can kick some b*tt!!

It may surprise you to know I agree with you on those early F*nders Note, they didn't have reverb, which F*nder only brought in during the BF era. And like the Marshall 18W, most of them also didn't have global nfb (to use the correct technical term). So they had more natural chime and sparkle and didn't need reverb. The 6G3 Brown Deluxe had only a limited form of NFB, just applied to the PI tail to help compensate out its PI imbalance.

Building the Shell for the 18W right now... very anxious to finally hear it with the G12H INSIDE ..with the VK's 3x10 it sounds already amazing

Trust me, it will sound awesome with the G12H - and loud as heck!!!

[Bieworm]

⁸

...for the not so purists. Hey, I still have to be converted from a lifetime of fender amps..give me a break Phil;)

Yeah, F*nder amps need reverb to give some life to their otherwise dull tone. Not the case with these chimey 18 watters

I am in the same line when it comes to BF or SF fenders, but tweed , blonde and brown can kick some b*tt!!

It may surprise you to know I agree with you on those early F*nders Note, they didn't have reverb, which F*nder only brought in during the BF era. And like the Marshall 18W, most of them also didn't have global nfb (to use the correct technical term). So they had more natural chime and sparkle and didn't need reverb. The 6G3 Brown Deluxe had only a limited form of NFB, just applied to the PI tail to help compensate out its PI imbalance.

Building the Shell for the 18W right now... very anxious to finally hear it with the G12H INSIDE ..with the VK's 3x10 it sounds already amazing

Trust me, it will sound awesome with the G12H - and loud as heck!!!

fired it up yesterday... the combo-shell is ready to tolex , but I couldn't resist. So I built the amp and the speaker in...wow!!!
Still have that crackling tho.. I suspect the EZ81.. I can emulate the crackling and popping when I wiggle the tube. When I remove the tube it rattles in my hand.
However..I don't have a spare tube so I was thinking about adding a switchable rectifier so I can try SS. If it still crackles, then I can pull it from the list of possible errors.
I drew a lay-out for the switching ... is that a correct one?

20200226_095156.jpg

[Bieworm]

20200226_203354.jpg

New voltage chart. Everything is pretty high value, except the heaters.
The values on V3 are off spec. I don't know why..everything is wired correctly. All is within spec (resistors,..)

[Bieworm]

The logo is 3D printed!!!
Nice result!!

IMG-20200226-WA0003.jpg

[zaphod_phil]

Trust me, it will sound awesome with the G12H - and loud as heck!!!

fired it up yesterday... the combo-shell is ready to tolex , but I couldn't resist. So I built the amp and the speaker in...wow!!!

Still have that crackling tho.. I suspect the EZ81.. I can emulate the crackling and popping when I wiggle the tube. When I remove the tube it rattles in my hand.
However..I don't have a spare tube so I was thinking about adding a switchable rectifier so I can try SS. If it still crackles, then I can pull it from the list of possible errors.

Congratulations on the wow!
I have also found that popping and crackling noises can be caused by corrosion on the pins. So try cleaning your valve pins and socket pins.

I drew a lay-out for the switching ... is that a correct one?

It will be easier for others to check your switched rectifier idea if you can post it as a schematic. Two more comments:
1- To make it simpler, just use SS rectifers on their own and switch in a 220 ohm 3W (or 5W) resistor to emulate the internal impedance of an EZ81. It will sound and feel the same as a real EZ81, and won't be violating any of Messy Booger's patents.

2 - Use UF4007 fast recovery rectifiers to reduce buzz.

[Bieworm]

Trust me, it will sound awesome with the G12H - and loud as heck!!!

fired it up yesterday... the combo-shell is ready to tolex , but I couldn't resist. So I built the amp and the speaker in...wow!!!

Still have that crackling tho.. I suspect the EZ81.. I can emulate the crackling and popping when I wiggle the tube. When I remove the tube it rattles in my hand.
However..I don't have a spare tube so I was thinking about adding a switchable rectifier so I can try SS. If it still crackles, then I can pull it from the list of possible errors.

Congratulations on the wow!
I have also found that popping and crackling noises can be caused by corrosion on the pins. So try cleaning your valve pins and socket pins.

I drew a lay-out for the switching ... is that a correct one?

It will be easier for others to check your switched rectifier idea if you can post it as a schematic. Two more comments:
1- To make it simpler, just use SS rectifers on their own and switch in a 220 ohm 3W (or 5W) resistor to emulate the internal impedance of an EZ81. It will sound and feel the same as a real EZ81, and won't be violating any of Messy Booger's patents.

2 - Use UF4007 fast recovery rectifiers to reduce buzz.

Yup! It appears to be the EZ81 after all. Made the SS switch and crackling is gone.
What do you think about the voltage chart? any ideas what I can do to get things more on spec?

20200226_203354.jpg

[Bieworm]

20200227_222746.jpg

Cab is getting there
Just the top sheet of tolex, the frontplate and the backplates need to be applied.
The grillcloth and piping is on the way (mailorder)
...the parts for the TMB tremolo Josh designed are on the same order. We don't wanna go out of work once this baby is assembled
I ordered a new turretboard and turrets too, so I can work on it AND play the amp in the meantime.
Question: since I don't dig the vent on top I want to cool down the tubes with a ventilator.
The chassis is the top version , not the combo...so the tubes are like a vox, horizontally in the back, facing to the front.
Should I go for wallvoltage one, or a 12V ?
A 12V would require a transformer..or can I hook it up somewhere in the amps circuit? Or and other suggestions?

[JMPGuitars]

What do you think about the voltage chart? any ideas what I can do to get things more on spec?

Didn't you build a TMB? That's the tremolo chart, if you built a TMB, you need the TMB chart. files/JMPGuitars_18_Watt_TMB_Voltage_Test_Chart.pdf

That said, you should start by focusing on dropping your B+ and then maybe figuring out why your heater voltages are low.

[Bieworm]

What do you think about the voltage chart? any ideas what I can do to get things more on spec?

Didn't you build a TMB? That's the tremolo chart, if you built a TMB, you need the TMB chart. files/JMPGuitars_18_Watt_TMB_Voltage_Test_Chart.pdf
--> nope, the original idea was a TMB with trem instead of the normal channel. But due to the lack of a schematic for that (at that time ) I went for the classis 18w.
But with the components on the way, that will change because I am going to build your TMB tremolo design

That said, you should start by focusing on dropping your B+ and then maybe figuring out why your heater voltages are low.

Since I found out I have a crappy EZ81, I wired a SS rectifier with 4x 1N4007 diodes with a 220ohm 10W resistor in series from the 290V wires to the standby switch. I have a 180 ohm 10W Bias resistor + a 2200uf cap. Still the plate voltage on both EL84 is 345V and there is 348V on the grids at lug 9.
I don't know how to alter that?
And the low heater voltages...don't know where to look for the problem.
And all the weird values on V3? Where do I begin?