Engl Fireball - keeping the basic stuff

[Leka]

Here's a clip from sending ideas back and forth with my brother, sounds to much like Diamond head though. I used a set of bright sounding C12N's. Could use a little less treble, I grabbed the Gibson V with emg's and forgot to adjust for the treble bite they have. It's a quick take with a flat EQ.

http://home.comcast.net/~jayjay67/headache.mp3

Amazing how much speakers change the sound. Weber Michigans sound good too, more mids with a huge bottom end. Thinking about going for a set of G12T-75 or Eminence Man O War. I love to compare notes with you Leka. I could go into more details about my experience and what I have learned with this type of amp. Got to go for now, wife is feeling ill.

Cheers
Jay

Hi Jay!

Hope your wife's feeling better now!
Thank you for sharing the info, I have also an Hammond choke in my build.
Your sound clip was really nice!! Really respectable sound!
Here are two small clips of my build, played with a -87 Tokai with its original humbucker / one Celestion Vintage 30 speaker, recorded with one shure 58 beta.
These are also quick takes with just a small distortion to make some rock music.

demo1.mp3
demo2.mp3

Cheers,

-Leka

[SysCrusher]

Hi Jay!

Hope your wife's feeling better now!
Thank you for sharing the info, I have also an Hammond choke in my build.
Your sound clip was really nice!! Really respectable sound!
Here are two small clips of my build, played with a -87 Tokai with its original humbucker / one Celestion Vintage 30 speaker, recorded with one shure 58 beta.
These are also quick takes with just a small distortion to make some rock music.

demo1.mp3
demo2.mp3

Cheers,

-Leka

Wow, that sounds really good Leka! Sounds more defined then the last time I heard your amp. That Vintage 30 really gives it a thick tone. I think I'll have to reconsider the Vintage 30 for my build. How well did the cleans come out for you? I had an extra triode left so i dedicated that to my clean channel so the clean channel is completely separate from my distorted channel. Thank you for you condolence, my Wife is doing fine. Seems to be just the normal allergies. When she is quiet, not bothering me to do something, then I need to worry.

[Leka]

Wow, that sounds really good Leka! Sounds more defined then the last time I heard your amp. That Vintage 30 really gives it a thick tone. I think I'll have to reconsider the Vintage 30 for my build. How well did the cleans come out for you? I had an extra triode left so i dedicated that to my clean channel so the clean channel is completely separate from my distorted channel. Thank you for you condolence, my Wife is doing fine. Seems to be just the normal allergies. When she is quiet, not bothering me to do something, then I need to worry.

Hi Jay!

I'm glad you liked it! The clean side isn't _that_ good. It did get better by using separate coupling caps on clean / dist channel. (bigger cap for the clean channel)
However I still have a lot to learn and one thing I have noticed is that you should _always_ keep track on what changes you do to your amp. I don't have any idea (maybe some) of what was the setup in these two sound samples as I have done numerous of different experimentations to this amp during the last year...
It's sad because now when I heard these samples again, my amp sounded better then than now...
I am very pleased with the Vintage 30 speaker, you should try one!

I do have a problem with getting away from annoying mids which make it sound too "nosy".
Is it the best way to drop the middle-band in the eq-section?
Or shoud I try to expand the bass and treble before / after the eq?

Now when I'm having a "good" tone the mids knob is at nearly zero, bass at 10 and treble knob at about 3, from 0-10.

All the best,
-Leka

[R ski]

The diagrams look simular at the output section. The transformer
resistance will detirmined the bias of the output current The zener diode
is shunted out from what I assume as relay contacts

The power transformer multitap isn't clearly on the secondary taps.
The B+ is stepped up by a German multiplier circuitry.

A lot of build, kinda resembles MESA Boogie Mark 4 in some way.

[Joe N]

The diagrams look simular at the output section. The transformer
resistance will detirmined the bias of the output current The zener diode
is shunted out from what I assume as relay contacts

The power transformer multitap isn't clearly on the secondary taps.
The B+ is stepped up by a German multiplier circuitry.

A lot of build, kinda resembles MESA Boogie Mark 4 in some way.

from what I hear, they are not built that well, or at least in the cheaper models.

[SysCrusher]

Hi Jay!

I'm glad you liked it! The clean side isn't _that_ good. It did get better by using separate coupling caps on clean / dist channel. (bigger cap for the clean channel)
However I still have a lot to learn and one thing I have noticed is that you should _always_ keep track on what changes you do to your amp. I don't have any idea (maybe some) of what was the setup in these two sound samples as I have done numerous of different experimentations to this amp during the last year...
It's sad because now when I heard these samples again, my amp sounded better then than now...
I am very pleased with the Vintage 30 speaker, you should try one!

I do have a problem with getting away from annoying mids which make it sound too "nosy".
Is it the best way to drop the middle-band in the eq-section?
Or shoud I try to expand the bass and treble before / after the eq?

Now when I'm having a "good" tone the mids knob is at nearly zero, bass at 10 and treble knob at about 3, from 0-10.

All the best,
-Leka

I don't get that unless I want it too sound that way. My standard setting is, bass 10, mids 4, treble 7.5, presence at 3 - 6 depending on my mood. I have a depth control added to the nfb loop too and I set that at around 3. Sounds like you got alot of extra high mids and treble there.

If you build using the schematic, think about that 680pf treble cap. Also think about the mid and bass caps in the tone stack. The engl from what I see from the schematics, is that they use an extra 47nf coupling cap before the tonestack. That means the caps in the tone stack will be in series with that 47nf coupling cap. That means, the tone stack caps are really half that value. 47nf and 47nf in series is about 23.5nf. So your bass and mid cap is 23.5nf. If you want to get closer to a more Fender values, I would change that 47nf coupling cap to a 100nf and then change the bass cap to 1uf, mid cap to 100nf. Your going to get alot high mids and highs with that 680pf treble cap. I have that on a pull switch for a decent mid and high boost.

Personally I don't understand the 47nf snubber cap across the plate resistor for the effects loop send. That 47nf cap is 47,000pF killing all the high end. Can't be right. The powerball and the rest of the schematics have the same thing. Remove that cap if you got it. Add a 1nf cap across the 330k plate resistor for that cold clipping triode. That will sweeten up your treble and high mid response. I also added a .5nf cap from plate to cathode on each triode except that cold clipping triode. I think they sound better than passing highs to ground. A trick I coppied from Rivera. Those are my personal secrets that I think are a must have for these engl type circuits. The rest is just playing with the coupling caps, grid resistor and grid leak resistors in the preamp. Duncan Amps site has a decent excell spread sheet for the frequency cutoffs if you don't like the doing the math. A 47nf cap and a 220 grid leak resistor is around 15 Hz. Something to think about.

My opinion is to do all your frequency shaping or control before the eq section. Atleast leaving a decent enough frequency band to manipulate with the tone stack. Then the power amp and the effects loop can be configured for a nice wide band of frequencies.

Im with you about the clean side, not the beat but usable. I guess I love that Fender clean to much. Oh, look for ExpressSCH on the net. Cool little program for free. I use that to draw out my circuits and then update them every time I get that modding bug. Got to leave for now. Wife has a nice dinner going.

Cheers
Jay

[Leka]

I don't get that unless I want it too sound that way. My standard setting is, bass 10, mids 4, treble 7.5, presence at 3 - 6 depending on my mood. I have a depth control added to the nfb loop too and I set that at around 3. Sounds like you got alot of extra high mids and treble there.

If you build using the schematic, think about that 680pf treble cap. Also think about the mid and bass caps in the tone stack. The engl from what I see from the schematics, is that they use an extra 47nf coupling cap before the tonestack. That means the caps in the tone stack will be in series with that 47nf coupling cap. That means, the tone stack caps are really half that value. 47nf and 47nf in series is about 23.5nf. So your bass and mid cap is 23.5nf. If you want to get closer to a more Fender values, I would change that 47nf coupling cap to a 100nf and then change the bass cap to 1uf, mid cap to 100nf. Your going to get alot high mids and highs with that 680pf treble cap. I have that on a pull switch for a decent mid and high boost.

Personally I don't understand the 47nf snubber cap across the plate resistor for the effects loop send. That 47nf cap is 47,000pF killing all the high end. Can't be right. The powerball and the rest of the schematics have the same thing. Remove that cap if you got it. Add a 1nf cap across the 330k plate resistor for that cold clipping triode. That will sweeten up your treble and high mid response. I also added a .5nf cap from plate to cathode on each triode except that cold clipping triode. I think they sound better than passing highs to ground. A trick I coppied from Rivera. Those are my personal secrets that I think are a must have for these engl type circuits. The rest is just playing with the coupling caps, grid resistor and grid leak resistors in the preamp. Duncan Amps site has a decent excell spread sheet for the frequency cutoffs if you don't like the doing the math. A 47nf cap and a 220 grid leak resistor is around 15 Hz. Something to think about.

My opinion is to do all your frequency shaping or control before the eq section. Atleast leaving a decent enough frequency band to manipulate with the tone stack. Then the power amp and the effects loop can be configured for a nice wide band of frequencies.

Im with you about the clean side, not the beat but usable. I guess I love that Fender clean to much. Oh, look for ExpressSCH on the net. Cool little program for free. I use that to draw out my circuits and then update them every time I get that modding bug. Got to leave for now. Wife has a nice dinner going.

Cheers
Jay

Hi Jay!

Thank you a lot for the tips! Now I know what to do next and which part will be modified again...
I did have the large snubber cap already replaced. The Rivera trick I have to try! Rivera is a nice looking amp but I've never seen one here in Finland...
I've been using Orcad for drawing the schematics but I've been too lazy to update it. I will do it next before I mess up further the circuit...
I got permission from my friend to tear down his Engl and see how it's done. (If I get it back again... )
I certainly will do it to see how they are done in real life.
I think the Engl-amps have quite nice sound, but could be also better with some mods...

Cheers,
Leka