High Voltages After Headfirst Origin 50 Mod

ivan H said:
Thankyou @67plexi for correctly answering the question.

Please stop referring to the EHX 6CA7 as a "fake" 6CA7. We have been through this twice before, where I went into detail explaining to you that the fat bottle 6CA7 (beam tetrode) was originally designed by Sylvania to be a suitable EL34 (pentode) substitute, while avoiding paying Philips "pentode" royalties,,,, as such, the EHX 6CA7 is the only current production 6CA7 that is a "true" big bottle beam tetrode 6CA7, as "originally designed" by Sylvania.
Regarding the EH 6CA7's plate current looking much higher than a normal "real" 6CA7, I am imaging that you are comparing the figures shown on the EH 6CA7 boxes that @Robert Herndon posted a pic of, being;
Ip: 66 (plate current in mA)
GM: 6,800 (transconductance in umhos)
to figures for EL34's.

Firstly, plate current test figures can vary depending on exactly which type tester the tubes are tested on (various testers supply different voltages to plate, screen & control grid).
Secondly, these are the plate current & transconductance figures for NOS/NIB Blackburn Mullard xf2 EL34's (as "real" as EL34's get)View attachment 71864GE branded tubes;
Ip: 82mA/80mA
GM: 11,300/11,200 umhos

Amperex "globe" branded tubes;
Ip: 81mA/79mA
GM: 11,200/11,000 umhos

As you can see, the plate current (& transconductance) figures are quite noticeably higher than those of the EH 6CA7's. I have other NOS Blackburn Mullard EL34 duets & quads & all have Ip & Gm figures in this range. Cheers
Edit:
As originally designed, the USA produced fat bottle beam tetrode 6CA7's had electrical characteristics almost exactly matching those of the British made EL34's (Mullard, Brimar etc etc). Cheers
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You know what's funny to me is I usually go with the EH's. Not with my ORI 50H. I prefer the JJ6CA7'S with this amp. Along with the 12AY7 in V1 the JJ's really add fatness yet are as articulate as you'd want a vintage Marshall.

Into an EVH 412. Guitar loaded with DiMarzio SD's or Fishman Fluence Classic Core pups.

My 900 DR clone sounds better with the EH's.
 
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Pissed Plexi said:
You know what's funny to me is I usually go with the EH's. Not with my ORI 50H. I prefer the JJ6CA7'S with this amp. Along with the 12AY7 in V1 the JJ's really add fatness yet are as articulate as you'd want a vintage Marshall.

Into an EVH 412. Guitar loaded with DiMarzio SD's or Fishman Fluence Classic Core pups.

My 900 DR clone sounds better with the EH's.
Click to expand...
While I haven't seen one first hand, I have heard/read that the JJ 6CA7 is actually a beam tetrode type tube, though not made to the spec of the original fat bottle 6CA7. Rather, it's likely an adaptation of a type previously produced, such as they did with their 6V6. While on the subject, the Shuguang EL34B is also a beam tetrode type tube, rather than being a pentode type that an EL34 "should" be.
Cheers
 
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I'm not sure what the Headfirst/Jose Mod does, other than add the extra gain stage by reassiging tube V3 and substituting the Metro FX Loop for the tube driven loop.

The "Jose" Diode mode adds switchable diodes that produce some pretty cool tones.

Here's where we are going...

 
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Robert Herndon said:
I'm not sure what the Headfirst/Jose Mod does, other than add the extra gain stage by reassiging tube V3 and substituting the Metro FX Loop for the tube driven loop.

The "Jose" Diode mode adds switchable diodes that produce some pretty cool tones.

Here's where we are going...

Click to expand...
You should post some of this in the My Origin thread on MF started by Solarburn DSL50
AKA ( Pissed Plexi ) over here.
Thanks
 
ivan H said:
While I haven't seen one first hand, I have heard/read that the JJ 6CA7 is actually a beam tetrode type tube, though not made to the spec of the original fat bottle 6CA7. Rather, it's likely an adaptation of a type previously produced, such as they did with their 6V6. While on the subject, the Shuguang EL34B is also a beam tetrode type tube, rather than being a pentode type that an EL34 "should" be.
Cheers
Click to expand...

I've put them in a few of my Marshalls. They definitely effect bottom end yet lean to a more articulate translation. Kinda like the JJ 34L's.

I find both EH & JJ more articulate while soloing than most EL34's. I use the EH's most. Instead of EL34's. I like 6CA7'S response to my playing. Plexi like. Singingly clear and dynamic.

Course none of this matters under overly saturated amps. If I kick you in the ballz dynamics go unnoticed. Brutz don't care.
 
Pissed Plexi said:
I've put them in a few of my Marshalls. They definitely effect bottom end yet lean to a more articulate translation. Kinda like the JJ 34L's.

I find both EH & JJ more articulate while soloing than most EL34's. I use the EH's most. Instead of EL34's. I like 6CA7'S response to my playing. Plexi like. Singingly clear and dynamic.

Course none of this matters under overly saturated amps. If I kick you in the ballz dynamics go unnoticed. Brutz don't care.
Click to expand...
I kinda like the JJs as well, simple but effective. Might not get as many miles as youd like but they hold up. Svetlana 34s are nice too for affordable but great
 
Clockworkmike said:
I kinda like the JJs as well, simple but effective. Might not get as many miles as youd like but they hold up. Svetlana 34s are nice too for affordable but great
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I tried the SVET's years ago in my old DSL50 and they were significantly upper mid top end power tubes. Harsh. I see quite a few players like em now. Wonder if they have changed since?

Only reason I say that is the pair I used lost a significant amount of bottom. Course we're talking a DSL and V30's(412). And I always play at volume. So I get a solid idea whether the power tube matters. Some players don't have the sonic freedom of volume I do.

There is an EL34 I love in a few of my Marshallz. Makes them upper Kerrangy without the harshness. The GT34M's. suppose to be based on the old Mullard XF2'S which I've never used. I've read(lore)that ACDC Angus loved them. You know how info like that can be inaccurate as hell.
 
Pissed Plexi said:
I've put them in a few of my Marshalls. They definitely effect bottom end yet lean to a more articulate translation. Kinda like the JJ 34L's.

I find both EH & JJ more articulate while soloing than most EL34's. I use the EH's most. Instead of EL34's. I like 6CA7'S response to my playing. Plexi like. Singingly clear and dynamic.

Course none of this matters under overly saturated amps. If I kick you in the ballz dynamics go unnoticed. Brutz don't care.
Click to expand...

We are putting EHX 6CA7 in along with Genelex B759 preamp tubes.
 
Robert Herndon said:
We are putting EHX 6CA7 in along with Genelex B759 preamp tubes.
Click to expand...

I hate guitarist reviews of tubes. Ears. They're not the same.

You're playing a Marshall. Let me know what you think of the Gold Lion's. Please. I spent over a hundy for 2 power tubes. I can check how well they are matched. I learned that my fav tube distributor guys were labeled sent to them as matched. They were 10mv off. When you only have one bias pot? How confident are you yer getting the best out of said bulbs?

they offered to take them back. Put them in the DSL40 C with 2 bias pots and found them good. Honestly? With my ears? The GT34M's the same.
 
Pissed Plexi said:
I hate guitarist reviews of tubes. Ears. They're not the same.

You're playing a Marshall. Let me know what you think of the Gold Lion's. Please. I spent over a hundy for 2 power tubes. I can check how well they are matched. I learned that my fav tube distributor guys were labeled sent to them as matched. They were 10mv off. When you only have one bias pot? How confident are you yer getting the best out of said bulbs?

they offered to take them back. Put them in the DSL40 C with 2 bias pots and found them good. Honestly? With my ears? The GT34M's the same.
Click to expand...

The Genelex B759 has been my preamp tube of choice for years in all my amps.

The Gold Lion B759 (to me) have more clarity and midrange and they tighten the bottom end significantly. They are subtle, but I notice the amp is also more responsive to pick attack with the B759's than with a lower gain 12AX7.

Ears are indeed subjective...
 
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So today, I'm finally get this process started with Rob's amp. Some pics of the setup and a short clip of the amp cranked before any mods are done.

Olympus LS-10 pocket recorder + Rivera RockCrusher attenuator + Orgy 50:
IMG_3019.JPG

IMG_3020.JPG

Mojotone Slammins with Scumback M75-LD's:
IMG_3021.JPG

My settings on Rob's amp:
IMG_3022.JPG
Rob's settings are a bit more extreme, and he plays with a lot more volume. The Master volume is on 6, and the amp is pumping hard. Thank God for attenuators. The Rivera attenuator was set for -16dB reduction (The pic shows -12dB).

And the guitar used for the clip is my '04 Hamer Studio Custom and a SD '59 Custom Hybrid in the bridge (Medium output, 10.8K):
IMG_3023.JPG

The amp's boost was on, too:
https://soundcloud.com/id%3Dgreg-grinberg-210583720%252Frobsorigin-b4-mods-9-5-21wav%3Btrack_id%3D1119310357
 
syscokid said:
So today, I'm finally get this process started with Rob's amp. Some pics of the setup and a short clip of the amp cranked before any mods are done.

Olympus LS-10 pocket recorder + Rivera RockCrusher attenuator + Orgy 50:
View attachment 72883

View attachment 72884

Mojotone Slammins with Scumback M75-LD's:
View attachment 72885

My settings on Rob's amp:
View attachment 72886
Rob's settings are a bit more extreme, and he plays with a lot more volume. The Master volume is on 6, and the amp is pumping hard. Thank God for attenuators. The Rivera attenuator was set for -16dB reduction (The pic shows -12dB).

And the guitar used for the clip is my '04 Hamer Studio Custom and a SD '59 Custom Hybrid in the bridge (Medium output, 10.8K):
View attachment 72887

The amp's boost was on, too:
https://soundcloud.com/id%3Dgreg-grinberg-210583720%252Frobsorigin-b4-mods-9-5-21wav%3Btrack_id%3D1119310357
Click to expand...

Awesome, Greg!!!! Great clip!!!!

People don't realize just how little gain these Origins actually produce!!!
 
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