Josh's 18W Tremolo TMB Builds

[JMPGuitars]

I got a lot of work done the past couple days.

First I wire up the front panel:

_JMP1250.jpg

Then I install the board and connect the front panel:

_JMP1256.jpg

Then I wire the tube sockets:

_JMP1259.jpg

Then I connect the rear panel jacks:

_JMP1264.jpg

BTW- I'm contemplating sharing my reverb circuit. If you can figure out enough/ask the right questions based on what I post in here, I'll share it.

Thanks,
Josh

[Bieworm]

Josh this is what I derived from my marble clubreverb. It has a great 1-tube reverb...
Do you reckon it could work?

16005017257843449278404995931660.jpg

I also stepped away from the 36W tremolo TMB idea.. I gigged with my 18W trem TMB last weekend and I just loved it. I don't need nearly 18 watt so I will never need 36W. Besides, I still have my vibro king when I need more volume.. played it yesterday for 30 minutes and it sounds sooooo great!! After that I played my tremolo TMB for 2 hours straight... go figure !!!

[Daviedawg]

That's a sure sign you gel with it.

Dd

[JMPGuitars]

Okay, I'm kind of surprised nobody has noticed an old flaw on my board's layout. I figured at least one person would have noticed by now.

[crgfrench]

Okay, I'm kind of surprised nobody has noticed an old flaw on my board's layout. I figured at least one person would have noticed by now.

No components?

[JMPGuitars]

No components?

Lol! Nope. They're mostly there now, I'll post more photos later. There was a flaw on the original layout that somebody pointed out to me, which happened after I made the board.

[JMPGuitars]

Here's the board completed (with the old layout flaw also corrected):

JMPGuitars-Tremolo-TMB-Reverb-Build.jpg

I will do a highlighter test before powering up on my variac tomorrow. I'll also test the amp and work out any kinks before I install the FX loop or footswitch stuff.

There's enough visible in this image for anybody interested in my version of the reverb circuit to figure out/comment enough to get me to share it.

Thanks,
Josh

[Bieworm]

Did you fire it up yet? Hope all is ok..

[JMPGuitars]

Did you fire it up yet? Hope all is ok..

Not yet, busy with other work. But I did have time to highlighter test it last night, and it was all good. Though I moved the 4th filter cap to match the layout. I don't think it really mattered where I had it, but I wanted the build to match the layout doc for testing.

If I have time, I'm going to throw in some tubes and fire it up today.

Thanks,
Josh

[JMPGuitars]

Well, unfortunately I'm going to need to drop the voltage more than expected, so it will be longer before I can test this out properly. My B+ is around 383VDC, and I only have a 10V zener after it, so I'm going to have to swap that out with a couple bigger ones.

My voltages in general so far look okay, although some are high (as expected with the high B+). But, my V1 voltages were oscillating on almost all measurements (I'm fairly certain that's not normal even if this is my first trem ). I'm going to put a standard 12AX7 in there, and retake the voltages when the B+ is dropped before I do any tweaking/troubleshooting.

Thanks,
Josh

[Bieworm]

1600916636810861553259522614254.jpg

1600916550070398776885708583747.jpg

16009165850832305563145474326806.jpg

[Bieworm]

I have a 150R after the rectifier diodes. Do you have a resistor there? I only see the diode rectifier straight to the switch...

[JMPGuitars]

I have a 150R after the rectifier diodes. Do you have a resistor there? I only see the diode rectifier straight to the switch...

That 150R you're using is a sag resistor. I'm probably not using one in this, but I'll determine that after playing it.

[JMPGuitars]

Here's a question for you Trem nerds (this is my first tube tremolo build). Do you have to disable the trem to get your V1 voltages? Switching it off is the only way I got stable voltages from the tremolo channel (I jumped pin 7 to ground).

Thanks,
Josh

[Bieworm]

Here's a question for you Trem nerds (this is my first tube tremolo build). Do you have to disable the trem to get your V1 voltages? Switching it off is the only way I got stable voltages from the tremolo channel (I jumped pin 7 to ground).

Thanks,
Josh

What exactly is the problem? Mine works flawless... you mentioned oscillations earlier.

[JMPGuitars]

What exactly is the problem? Mine works flawless... you mentioned oscillations earlier.

I'm not sure yet, I haven't actually connected a speaker yet (I have it connected to a dummy load). The signal was generally clean on my scope with the trem knobs turned down, so I'll be testing V1 section out later.

When you test your trem voltages, do any or all of them fluctuate while the tremolo is active? Or did you test with the trem disabled (via the footswitch, or by manually grounding it out)?

[Bieworm]

What exactly is the problem? Mine works flawless... you mentioned oscillations earlier.

I'm not sure yet, I haven't actually connected a speaker yet (I have it connected to a dummy load). The signal was generally clean on my scope with the trem knobs turned down, so I'll be testing V1 section out later.

When you test your trem voltages, do any or all of them fluctuate while the tremolo is active? Or did you test with the trem disabled (via the footswitch, or by manually grounding it out)?

I only tested with the trem disengaged by footswitch. I don't have the equipment to measure the fluctuating trem while enabled. It just works great.. better than the modern classic Fwiw..

[JMPGuitars]

I only tested with the trem disengaged by footswitch. I don't have the equipment to measure the fluctuating trem while enabled. It just works great.. better than the modern classic Fwiw..

Okay, cool. That's what I was asking. So that means I should be good, and only need to focus on my voltages.

Scoping was clean, and the tremolo was audible in the speaker motor, so it sounds like everything probably works.

[JMPGuitars]

Mine works flawless...

IIRC, didn't you use a 4.7K resistor between B and C because you didn't have an 8.2K?

Well, that's going to be permanent. 4.7K gives better voltages down the line, but I will likely have a couple more small changes depending on how it sounds once I connect a speaker.

EDIT: I just saw your note on your voltage charts. 4.7K is definitely a winner. I think I also suggested 82K for the V2 plates? Is that what you stuck with? That's where I'm about to head to next.

Thanks,
Josh

[Bieworm]

Mine works flawless...

IIRC, didn't you use a 4.7K resistor between B and C because you didn't have an 8.2K?

Well, that's going to be permanent. 4.7K gives better voltages down the line, but I will likely have a couple more small changes depending on how it sounds once I connect a speaker.

EDIT: I just saw your note on your voltage charts. 4.7K is definitely a winner. I think I also suggested 82K for the V2 plates? Is that what you stuck with? That's where I'm about to head to next.

Thanks,
Josh

Yes the 4k7 was required to get the voltage line corrected. It is still there
On the v2 plates the 100k is parallelled with a 470k, so yes.. that's about 82.
You do remember I also have that gain/edge pot ? And some tweaks on the cathodes of V2?