High Voltages After Headfirst Origin 50 Mod

syscokid said:
That's just Robert showing his appreciation for the help in getting this amp to fly with some added mods based on common sense by humorously calling the extra mods the "Greg Mod"... or the "Iverg Mod"... or even the "Ivanberg Mod"! BTW, I'm Greg.

But the extra mods is simply composed of bringing the high voltages to V2 down quite a bit. And instead of replacing the two V1 cathode bypass caps with .68uF's, we felt that 1uF's was more appropriate. Even installing the new fx loop board had to be adjusted accordingly. You got to remember that Jason Tong modded and documented an Origin 20. The Origin 50 is a lot more different than Jason acknowledges.
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syscokid said:
With my PC, I print out the blank voltage chart. Then I hand draw the added info with a pencil or a red marker onto the chart. Then I scan the chart and save the new pic as a jpeg or pdf copy back to the PC. I could also add all the text, the lines, the circles, and colors, using my PC's Paint program.
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Thanks once again, so C43 & C37 are replaced with 1uf along with the R8/9/10 changes & having just read Roberts reply it looks like the Amp sounds better again ?, wow it sounds pretty bloody good now & i'm using what could well be the original valves(sorry Tubes :) ) & it's a very early ORI50C which i bought cheap just to try it out.
So You are Greg (aka syscokid) & you're changes to the HF mod are called the "Greg Mod" or "Iverg Mod" or Ivanberg Mod" ?, i'm getting there slowly :D'
Cheers, Graham.
 
Robert Herndon said:
Impressions:

The amp after the Ivanberg mod is at least twice as loud as it was before the mod. Volume dial '3' is now giving you '6' and 6 is absolutely unattainable.

It's crystal clear at 6, bit the sheer volume at that setting is incredibly loud.

The EQ knobs are much more sensitive.

Gain NEVER gets muddy...ever.

The amp has a tone that's hard to explain. The best way I can explain it is that it seems as though a noise gate is connected. When you let go of the strings, it gets quiet immediately.

The guitar responds to pick attack and you can "clean up" just by picking more lightly.

Here's a shot of my settings from a February 4, 2021 performance

View attachment 73708

And the settings we dialed in at Greg's lab yesterday:

View attachment 73709

The tone from the bare amp sounds studio produced. Totally balanced across the tonal spectrum. Almost like it has a compressor running.

The gain production is very similar to George Lynch's tone on 'Breaking The Chains.' (Which we know was an extra gain stage Marshall hit with a Tube Screamer.)

The voicing of the amp is night and day different. It's got a sort of Friedman quality to it. It's not quite like any Marshall I have heard.

Maybe Greg can describe it better. Gonna be at least Saturday before I can get soundclips recorded...

Here's a shot of the rig from a 2021 performance.

View attachment 73707

More to follow...
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Thanks Robert, well if the "Greg Mod" improves the Amp even further, it must sound not just "really good"(my description), but "really really good" & a big thanks to you, i only found out about the "HF/Jose mod" after reading your thread on the MF.
By the way i've done 3 gigs with my Modded amp using the "johnH M2" attenuator from the MF forum but i'm using it in a way which john advised me on, so instead of the standard -7db(then switchable down from there) which starts with a Maximum watts of about 10w & then down from there to just under 1w(so really home use, i'm using the M2 as a "load box" which cuts the ORI50 down to about 25w & it just about retains all it's 50w goodness , sounds great, the best stage(pub gigs) sound i've had for years :D , i'm running with my gain on "8"(boost on with my Tele & off with my Humbuckers) & my volume on "6" without Jose switch & "7" with the least clipping on the Jose switch, can't wait to get the "Greg Mod" done
:electric:Cheers Graham.
 
old rocker said:
Thanks Robert, well if the "Greg Mod" improves the Amp even further, it must sound not just "really good"(my description), but "really really good" & a big thanks to you, i only found out about the "HF/Jose mod" after reading your thread on the MF.
By the way i've done 3 gigs with my Modded amp using the "johnH M2" attenuator from the MF forum but i'm using it in a way which john advised me on, so instead of the standard -7db(then switchable down from there) which starts with a Maximum watts of about 10w & then down from there to just under 1w(so really home use, i'm using the M2 as a "load box" which cuts the ORI50 down to about 25w & it just about retains all it's 50w goodness , sounds great, the best stage(pub gigs) sound i've had for years :D , i'm running with my gain on "8"(boost on with my Tele & off with my Humbuckers) & my volume on "6" without Jose switch & "7" with the least clipping on the Jose switch, can't wait to get the "Greg Mod" done
:electric:Cheers Graham.
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It's really a remarkable tone from this amp!!!

Can't wait to hear the updates!!!
 
syscokid said:
Ha ha... You British truly are too proper and polite! Ask away my friend... :cheers:
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Hi syscokid, after reading another post(different thread) by Robert, i see he has used different valves to the standard EL34/12AX7 valves, will the voltage changes still apply to the standard valves ?, i will be changing the valves, but i will probably stick to the standard set.
Sorry to be a pain(my wife says i'm good at it :D ).
Cheers, Graham.
 
old rocker said:
Hi syscokid, after reading another post(different thread) by Robert, i see he has used different valves to the standard EL34/12AX7 valves, will the voltage changes still apply to the standard valves ?, i will be changing the valves, but i will probably stick to the standard set.
Sorry to be a pain(my wife says i'm good at it :D ).
Cheers, Graham.
Click to expand...

The Genelex Gold Lion B759 preamp tubes are a direct replacement for the standard 12AX7 (ECC83) but they produce the highest level of gain of all the 12AX7s. It's been my favorite tube for years.

The 'Milk Bottle' 6CA7's are said to be like an EL34 on steroids. The construction and voltage having capabilities are very robust. They are said to have much more clean headroom than the EL34.

These are a 'drop-in' replacement, requiring only cursory bias adjustment.
 
Robert Herndon said:
Impressions:

The amp after the Ivanberg mod is at least twice as loud as it was before the mod. Volume dial '3' is now giving you '6' and 6 is absolutely unattainable.

It's crystal clear at 6, bit the sheer volume at that setting is incredibly loud.

The EQ knobs are much more sensitive.

Gain NEVER gets muddy...ever.

The amp has a tone that's hard to explain. The best way I can explain it is that it seems as though a noise gate is connected. When you let go of the strings, it gets quiet immediately.

The guitar responds to pick attack and you can "clean up" just by picking more lightly.

Here's a shot of my settings from a February 4, 2021 performance

View attachment 73708

And the settings we dialed in at Greg's lab yesterday:

View attachment 73709

The tone from the bare amp sounds studio produced. Totally balanced across the tonal spectrum. Almost like it has a compressor running.

The gain production is very similar to George Lynch's tone on 'Breaking The Chains.' (Which we know was an extra gain stage Marshall hit with a Tube Screamer.)

The voicing of the amp is night and day different. It's got a sort of Friedman quality to it. It's not quite like any Marshall I have heard.

Maybe Greg can describe it better. Gonna be at least Saturday before I can get soundclips recorded...

Here's a shot of the rig from a 2021 performance.

View attachment 73707

More to follow...
Click to expand...
Going from essentially dimed out to lots of room to spare on the controls... That is indeed something!! Looking forward to listening to those new recordings! I'd love to listen to an A/B comparison to the previous sound, for sure.
 
SIx String Chef said:
Going from essentially dimed out to lots of room to spare on the controls... That is indeed something!! Looking forward to listening to those new recordings! I'd love to listen to an A/B comparison to the previous sound, for sure.
Click to expand...

I've been thinking about maybe re-recording the guitar parts on one of my existing recordings so it could be a very 'A' vs. 'B' type of scenario???
 
Another interesting point. The 70/80's don't sound much different from the combination of the two Jensen Neodymium's, or the combination of one Jensen Jet Neodymium 80watt Stealth and one 50watt WGS Reaper 55Hz.

All combination of speakers listed above sounded good and had very, very slight differences in tonal character. So slight, it was difficult to tell the difference between them at times.

Unlike the highly lauded Vintage 30, that has a pronounced midrange spike and a kind of flat/muffled bottom end, or the Creamback, that goes loose and flabby when subjected to heavy palm-muted F#'s @ high gain levels, these speakers that I have on hand all tend to replicate whatever the amp is set too, without "colouring" the tone.

I prefer this type of "speaker neutrality," because it allows me to keep my EQ's more neutral and when I decide to crank one of the tone knobs, the result is useful tone all the way too '10' without any muddiness or loss of definition.

I won't even get into the half-blown out Greenbacks that people rave about as "breaking up," when in reality, they are distorting the signal, which may help those who have amps that can't produce enough gain on their own, but it is a nails-on-the-chalkboard sound to me.

What I am discovering is that many players seem to seek out a speaker that can give them more of what their amp cannot.

Now, as far as Celestion goes, all is not lost. There are two I played through that deserve honorable mention.

The Celestion G12H-150watt Redback and the Celestion Neo 250watt Copperback. Both are incredible speakers. Super loud and clear without coloring the tone.

The Redbacks weigh 10 pounds each and the Copperbacks weigh only 5 pounds each.

 
Took me a while to read through this thread....

Congrats @Robert Herndon, glad you like the end result!!
I really respect and appreciate the effort by @syscokid and @ivan H to bring this together, and again to Greg for the hands on work.

@syscokid - any chance you could make that blank voltage chart available here?
I cant seem to find one. I use Duck Duck Go but tried Google as well.
 
jtcnj said:
@syscokid - any chance you could make that blank voltage chart available here?
I cant seem to find one. I use Duck Duck Go but tried Google as well.
Click to expand...
Try this attached pdf file. You should be able to print out any single chart page that you see fit for your purposes. Hope this helps.
 

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