Idea for an Ecstasy Mod...can this even be done?

[DRC]

I've been toying with the idea of swapping power sections to make my 101B more versatile. I love the sound of my Blue Channel in plexi mode and my thinking was maybe a 6L6 or 6V6 would have a softer attack and a more attractive mid range in the Red Channel. I finally realized that I wouldn't want to lose my Blue Channel sound with EL34's. That in fact every time I really find the full gain tone I'm looking for, it's the Blue Channel with the Treble, Middle and Bass shifted ever so slightly. My issue is really not being able to use the Blue Channel in Plexi and Full Gain and more than that, not having dedicated tone controls for both.

Before someone chimes in with what would seem obvious, the Red Channel in Plexi does not sound the same as the Blue in Plexi. Maybe it's just my 101B, but I can hear it. Not that I don't like the Red Channel in Plexi, in fact I used it as a clean sound with "hair on it" when I use to dedicate my Blue Channel to full gain rhythm/lead. I'd actually go as far as saying I liked my Red Channel in Plexi better for my clean sound than the Green Channel. I'll get to the point.

#1) Does the Green Channel EQ have the same values as the shared Blue/Red's Treb, Mid, Bass?

#2) Can the Blue Channel gain stages be replicated on the Green Channel signal path or does the PCB not allow for that?

What I really wanna do with this amp is make the Green Channel a second Blue Channel (A Purple Channel maybe?) that would be hardwired for Plexi Mode or have the former Green Channel's boost toggle become a Plexi On/Off toggle. If I could have that in this amp, I could have:

Channel One - dedicated Treble, Mid, Bass and Gain for my Plexi Blue.
Channel Two - set the EQ and Gain for this Full Gain Blue Channel.
Channel Three - use the Pre-EQ toggle to find a good semi-clean with the Red in Plexi mode and the Gain rolled back.

My apologies if you see this thread elsewhere.

 

[jamme61]

IMHO leave it alone

 

[DRC]

I was thinking about doing that to the boost side of the green channel. it looks like a 1 meg running through a .oo1 cap, when the boost is activated. I think raising that caps value and changing that 1 meg to a 500k with a 500pf in parallel (like a marshall) would get close. I have to try it but if it worked you would still have the green clean channel unaffected and have your plexi mode in boost mode. I have not ried this so it might not work. someone else in the know might chime in.

UPDATE: replace 1meg resistor with 500k. parallel a 500pf on the 500k resistor meg resistor. Take out the 1000pf cap ( next to the 1 meg resistor you just changed) and change it with a .01 cap
these resistors and caps are on the board where V6 tube is. You can find them looking for the 10 pf cap which is right there next to everything. use your meter to find the 1 meg resistor which is right next to the 1000pf cap you need to remove and change. I have been playing it for about a half an hour and it sounds really good IMHO let me know if you check it out. good luck

Thanks for the heads up. But there is no way I'd do this myself with an amp this costly.

Though your idea handles the independent EQ issue, the signal path has to be different from the Blue Channel so it isn't going to have the same tone. If that were the case the Red Channel would sound the same as the Blue does in Plexi Mode. It dosen't. There is something going on with that channel. I'm sure I could get close, but I don't want close. I want a duplicate. The Red in Plexi is close, but not quiet the same.

I may hit Bogner up with an email. That last time I did it took a while for them to get back and I'm sure they don't wanna spend time modding an old amp when they can build new ones but at least I'll find out if I'm chasing a pipe dream.

 

[Setneck]

I don't have my amp by my side now and I don't use Plexi mode. But according to the schem both channels in Plexi mode should sound exactly the same. Look:

Red is V4-V5-V6-V7. Blue bypasses V6. Plexi mode skips V5 & V6 for both channels, it is simply V4 into V7 thru 499k//470pF treble peaker. So Plexi Mode SHOULD sound exactly the same using both channels. If You say it isn't there should be a reason for that. Maybe Charlie at Bogner could answer why.

As for You main question: IMO duplicating Blue Channel out of the Green is potentially doable, but I'm afraid that You would have to ruin Your amp. Green is 3 stages like Blue, but first of all the Green's tone stack is plate-driven out of the 1st stage (Blue is cathode-driven after 3rd stage). So You'd have to cut the traces to re-locate the TS. Besides that, it needs changing the values of the cathodes, pre-eq, CC's and voltage dividers. And You'd have to find the way to implement Plexi Mode switch... Forget it Mate IMO....

Regards, Andy

 

[DRC]

I don't have my amp by my side now and I don't use Plexi mode. But according to the schem both channels in Plexi mode should sound exactly the same. Look:

Red is V4-V5-V6-V7. Blue bypasses V6. Plexi mode skips V5 & V6 for both channels, it is simply V4 into V7 thru 499k//470pF treble peaker. So Plexi Mode SHOULD sound exactly the same using both channels. If You say it isn't there should be a reason for that. Maybe Charlie at Bogner could answer why.

Just last night I was again trying to dial in the Red Channel to sound like my Blue in Plexi. I had the Pre Eq both set to B2, then matched the gain as close as I could and I used the same excursion and presence. I went back and forth between the two scaling the gain and volume back and forth to try and make a match. The Blue Channel just sounds so open. The mid range is richer to me. It sounds more defined. The Red sounds more compressed. I used to think they were the same as well, but after really getting into the Plexi Mode a few years back I came to realize there is a difference. Maybe it's just my 101B.

As for You main question: IMO duplicating Blue Channel out of the Green is potentially doable, but I'm afraid that You would have to ruin Your amp. Green is 3 stages like Blue, but first of all the Green's tone stack is plate-driven out of the 1st stage (Blue is cathode-driven after 3rd stage). So You'd have to cut the traces to re-locate the TS. Besides that, it needs changing the values of the cathodes, pre-eq, CC's and voltage dividers. And You'd have to find the way to implement Plexi Mode switch... Forget it Mate IMO....

Regards, Andy

I had a feeling it would be a huge overhaul. I'm not even sure if the EQ values for the Clean Channel are the same as they are for the Blue/Red. To me it wouldn't ruin the amp to have two Blue Channels. In fact, I wish I could make all three channels Blue and just set them different. To give you an idea...

My favorite, open, low-gain dirty sound: Plexi Blue.
B2
Exc. Loose
Pres @ 2:30
Treb @ 12:30
Mid @ 11:30
Bass @ 1:00
Gain @ 2:30

My Punchy Rhythm sound: Blue.
B2
Exc. Med
Pres @ 1:00
Treb @ 12:00
Mid @ 10:30 to 11:00
Bass @ 2:00
Gain @ 2:00

My Lead sound is the same except I set my Pre EQ to N and back the gain down to 12:30 and juice it with a subtle overdrive. I could honestly switch between three Blue Channels and only need a pedal for solos. Oh, well. Pipe dream over. Probably just leave it on Plexi Blue and use another amp for my higher gain dirt.

 

[_actual time_]

I don't have my amp by my side now and I don't use Plexi mode. But according to the schem :

thread hijack:

do you have the part of the XTC schematic that shows R66 and C224? i'm thinking about doing the C224 mod to the un-boosted Blue and Red, like that guy posted on the Bogner forum years ago:

http://bognerampforum.informe.com/just- ... t2224.html

thanks!

 

[EarthRoosterUK]

Hi,Just in case you haven't already been down this route...
I also like the Blue Plexi;but preferred the 'normal' mode more.
(and yes ,I absolutely did feel a difference,even at low volume, to
Red's Plexi -squashed!- ;
it could be down to individual pre-tube sides mis-match?anyhow...)

So,tried out a BLUE-Pedal XTC; ok it isn't quite the same,but
.it is cheaper(than a complete re-wire).
.more convenient(than lugging around yet another amp).
I've got the pedal set at:
Variac -off- does 'squidge' too much for me
Mode -Plexi- (of course )
pre eq -b2-
structure -20th-
treble@ 12 O'clock ,mid@ 2 O'c,bass@ 10 O'c.
Gain@ 3 O'c vol@ 11 O'c & boost off.
(This is going into a 20thXTC /6L6 & open-back 412 cab).

The 'normal' blue mode on the fx pedal may be an acceptable compromise for your set-up?

I was also curious to the 101B-Blue Pedal sound.A bit too 'weighty' for me',
even w/ Bass rolled right down....
Curiosity satisfied.
To round off,it's one of the VERY few (set at unity-gain) drives that did not
sound like compressed-cardboard-boxyness-crap ,into the Amp's Blue-Channel.
So,I've got 3&1/2 channels.Not Bad!
Kind Regards,David.

 

[DRC]

Hi,Just in case you haven't already been down this route...
I also like the Blue Plexi;but preferred the 'normal' mode more.
(and yes ,I absolutely did feel a difference,even at low volume, to
Red's Plexi -squashed!- ;
it could be down to individual pre-tube sides mis-match?anyhow...)

So,tried out a BLUE-Pedal XTC; ok it isn't quite the same,but
.it is cheaper(than a complete re-wire).
.more convenient(than lugging around yet another amp).
I've got the pedal set at:
Variac -off- does 'squidge' too much for me
Mode -Plexi- (of course )
pre eq -b2-
structure -20th-
treble@ 12 O'clock ,mid@ 2 O'c,bass@ 10 O'c.
Gain@ 3 O'c vol@ 11 O'c & boost off.
(This is going into a 20thXTC /6L6 & open-back 412 cab).

The 'normal' blue mode on the fx pedal may be an acceptable compromise for your set-up?

I was also curious to the 101B-Blue Pedal sound.A bit too 'weighty' for me',
even w/ Bass rolled right down....
Curiosity satisfied.
To round off,it's one of the VERY few (set at unity-gain) drives that did not
sound like compressed-cardboard-boxyness-crap ,into the Amp's Blue-Channel.
So,I've got 3&1/2 channels.Not Bad!
Kind Regards,David.

That has certainly crossed my mind David. I might stop by Makenmusic and try this. By the way, what are your clean channel settings for running the Blue pedal into?

Thanks for the info.

 

[Setneck]

Just last night I was again trying to dial in the Red Channel to sound like my Blue in Plexi. I had the Pre Eq both set to B2, then matched the gain as close as I could and I used the same excursion and presence. I went back and forth between the two scaling the gain and volume back and forth to try and make a match. The Blue Channel just sounds so open. The mid range is richer to me. It sounds more defined. The Red sounds more compressed. I used to think they were the same as well, but after really getting into the Plexi Mode a few years back I came to realize there is a difference. Maybe it's just my 101B.

Tried that in my amp amp and indeed, Plexi mode sounds different in both channels. Red is indeed more compressed and darker. So that's something in amps design that the circuits which use same tube topology sound different.

I had a feeling it would be a huge overhaul. I'm not even sure if the EQ values for the Clean Channel are the same as they are for the Blue/Red. To me it wouldn't ruin the amp to have two Blue Channels. In fact, I wish I could make all three channels Blue and just set them different. To give you an idea...

As for the EQ's, bass pot is different, clean is 250K and dirty is 1MEG audio. As I said, it is potentially doable to transform Green to Blue. I get the idea what You are after, I like Your settings. You might have "full" Blue on Green and Plexi Blue on regular Blue. Relocating the Green tone stack would be quite messy though.

Regards, Andy

 

[Setneck]

do you have the part of the XTC schematic that shows R66 and C224? i'm thinking about doing the C224 mod to the un-boosted Blue and Red, like that guy posted on the Bogner forum years ago:

http://bognerampforum.informe.com/just- ... t2224.html

On a schem I posted R66 is R20 and C224 is C20. The capacitor in a boost circuit is totally redundant indeed. The value of a dropping resistor R66 is the game to play.

regards, Andy

 

[_actual time_]

http://bognerampforum.informe.com/just-did-a-mod-to-my-101b-very-happy-with-it-dt2224.html

On a schem I posted R66 is R20 and C224 is C20. The capacitor in a boost circuit is totally redundant indeed. The value of a dropping resistor R66 is the game to play.

thanks man!

i did the 'test' version of that mod today, like that guy describes, and i really dig it. the un-boosted is now nicely brighter.

now i'm going to design it so that it will be switchable. i have a question about capacitors for you. i will PM you.

 

[Setneck]

The cap in boost circuit is to me another part of Reinhold's idea to darken the XTC's tone insanely. I keep the boost always on, but if I'd use it I'd remove the cap completely .

Regards, Andy

 

[EarthRoosterUK]

DRC: ''Amp's clean channel settings? ''(w/ Blue pedal)

Hi,on the Amp Green/Clean,it's just the tone controls @ 12 O'clock;pointing straight up.
Pre-EQ is on 'B1'.
The Excursion is on 'Loose' (same for the amp's Blue-Channel)
Vol.1 is @ 10.30 O'c,or aligned to a slope of the 'pyramid-design' on the panel.
Gain is @ 1.30 O'c, aligned to the other slope if it's pyramid-design.(VERY clean!)
Presence is @ 10.30;same as Vol.1

(ps, Red is: presenceB-right down to off, 'Med' Excursion ,'normal' pre-EQ. & 'vintage'...would be good to have a seperate mode-switch for the ampBlue-channel;'modern' is good fun!
Tone control for Treb is @ 10.30 O'c,other two @ 12 O'c.)

It may seem a bit daft to have a Bogner pedal with an actual Bogner amp,but the way the FX pedal Gelled so seamlessly with the valve sounds & feel(and PARTICULARLY with the ampBlue-channel,pre-EQ'B1';possibly one of the most 'truthful' channels around?) ;well worth it,folks!

My own experience is with a 20thXTC w/6L6 & OPEN-back 4 x 12,(V30 & anniG12H).
Hope the pedal option is good for you,too. Regards, David.

 

[DRC]

DRC: ''Amp's clean channel settings? ''(w/ Blue pedal)

Hi,on the Amp Green/Clean,it's just the tone controls @ 12 O'clock;pointing straight up.
Pre-EQ is on 'B1'.
The Excursion is on 'Loose' (same for the amp's Blue-Channel)
Vol.1 is @ 10.30 O'c,or aligned to a slope of the 'pyramid-design' on the panel.
Gain is @ 1.30 O'c, aligned to the other slope if it's pyramid-design.(VERY clean!)
Presence is @ 10.30;same as Vol.1

My own experience is with a 20thXTC w/6L6 & OPEN-back 4 x 12,(V30 & anniG12H). Hope the pedal option is good for you,too. Regards, David.

Thanks for the info. I'm sure my clean channel will be a bit more mid forward being a 101B vs. your 6L6's but it's a good starting point. I'll let you know how it works out when I get my hands on one.

 

[DRC]

Tried that in my amp amp and indeed, Plexi mode sounds different in both channels. Red is indeed more compressed and darker. So that's something in amps design that the circuits which use same tube topology sound different.

I'm glad someone else hears this as well. I've gotten a few IM's from people saying "they are the exact same in Plexi Mode."

As for the EQ's, bass pot is different, clean is 250K and dirty is 1MEG audio. As I said, it is potentially doable to transform Green to Blue. I get the idea what You are after, I like Your settings. You might have "full" Blue on Green and Plexi Blue on regular Blue. Relocating the Green tone stack would be quite messy though.

I had a feeling the tone values would be different. Though changing the bass value is probably much easier than cloning the whole blue channel. I would only do this if Bogner would do the mod so I would be covered under warranty with them.

I was playing around tonight with both channels in Plexi Mode using the same tone settings. If I keep the bass where I like it on the Blue Channel w/Loose Exc, I can get a great base sound on the Red in Plexi for boosting with light overdrive but with the Exc on M or T. It makes me wonder if the Plexi Mode might be switchable? I'd gladly swap my Clean Boost pin to be wired up as a PLEXI MODE switch.

Now if I had this mod done and Channel One was my full gain Blue, that's where I'd want my boost. If I was using both Channels 2 & 3 in Plexi, I wouldn't have the boost anyway. So making the 2/3 Boost a PLEXI MODE switch would be more fitting. Ever wonder if Reinhold reads these forums?

 

[Setneck]

Tried that in my amp amp and indeed, Plexi mode sounds different in both channels. Red is indeed more compressed and darker. So that's something in amps design that the circuits which use same tube topology sound different.

I'm glad someone else hears this as well. I've gotten a few IM's from people saying "they are the exact same in Plexi Mode."

The difference is subtle, but my amp responses a bit different in Plexi Mode while on Blue and Red. Slightly more compression is hearable on Red. If I'd use it I would do it using Blue only.

As for the EQ's, bass pot is different, clean is 250K and dirty is 1MEG audio. As I said, it is potentially doable to transform Green to Blue. I get the idea what You are after, I like Your settings. You might have "full" Blue on Green and Plexi Blue on regular Blue. Relocating the Green tone stack would be quite messy though.

I had a feeling the tone values would be different. Though changing the bass value is probably much easier than cloning the whole blue channel. I would only do this if Bogner would do the mod so I would be covered under warranty with them.

Replacing bass pot only wouldn't turn Green into Blue, as tone stacks are localised in different places. The amp responses different depending on whether TS is plate or cathode driven.

Ever wonder if Reinhold reads these forums?

I doubt it. No one from Bogner hq reads any forum I'm afraid. It's a shame, there are many amp builders online, Peter Diezel, Santiago Alvarez, Dave Friedman, Jon Wilder, Mike Fortin... Wish at least Charlie would be available here sometimes....

Regards, Andy

 

[se7en]

I can't blame them for not reading these forums...I wouldn't if I was a builder...lots of drama to stay out of.