A successful accident

[SILVERGUN]

While working on a high gain amp design I decided to quickly add on a clean channel, and decided to use the 5E3 preamp topology for simplicity and a minimum of controls.
The amp already had an active effects loop which adds some gain to the picture, so when I joined the two together the resulting channel came out as a pleasant surprise...
In the lower gain setting it stays fairly clean, but as the gain control is increased it goes through gritty to all out gainy....and by the time you max out the volume control, it produces plenty of gain with great sustain and punch.
So, if nothing else, I'm suggesting that you add Tubenit's active FX loop to your 5E3 to spruce things up a bit.
Or, if you left an empty tube socket in a recent build,,, Ed,, this might be a great use for it.

I ran this channel into a standard LTPI with mostly standard values, and IMHO it's really got something.

[Ed_Chambley]

V1A plate resistor 180K.  What is the voltage and is this designed for 12Ay7?  Probably a 12Ax7, correct?  Did you use a pot to find the best sound and ended up with 180v or did you just have a voltage you wanted here?


Do you have a 5E3 and tested this with it, or have you found it to work work well with your recent build?  I do not know how it would perform with a cathode bias, EL84.  Worth playing with, IMO not using a 12Ay7 in a tweed makes it lose the tweed tone.  If you an do it and still maintain the use of the 12aY7, it might be a nice mod for a tweed as you can still maintain the tweed tone.

[SILVERGUN]

I should probably stop using the term 5E3...it was just a jumping off point, and it looks like the only thing that remains is the tone stack 

When I was working on the board, I just laid this out separately from the high gain channel and spent very little time tweaking it....when it wound up in the amp, it sounded better than it did on the board.

What I am suggesting to you is the use of the active effects loop in the AC15, because besides giving you a loop, it will add a bit of gain along the way. I would make it switchable in and out so your gain boost will come in with the loop.  ...for me that would work, because you always seem to lose a little volume when you switch in a delay anyway.....
But, then again, your amp is a horse of a different color.
Just thinkin and throwing stuff around  ...I know you tend to be more analytical than that 

V1A plate resistor 180K.  What is the voltage and is this designed for 12Ay7?  Probably a 12Ax7, correct?  Did you use a pot to find the best sound and ended up with 180v or did you just have a voltage you wanted here?

On my build, the supply voltage at that point is 280VDC and designed for AX7
The V1A's specs were in place from the high gain channel because both channels share that triode...it was only chosen for sound, and I didn't really spend much time there.
If you look at the two channel schematic (it's up now), I basically just plugged in the tone stack and second stage of the 5E3, to make a clean/gritty channel, but it turned out much better than I expected.....nothing crystal clean about it, but in my case that works!

If you an do it and still maintain the use of the 12aY7, it might be a nice mod for a tweed as you can still maintain the tweed tone.

Now you're talkin'

[jojokeo]

SG, the first three stages appears to be like it could be a Trainwreck Express "Lite" version in that it's using a simple tone control instead of the tone stack is all. Not all the values are perfect but they don't have to be, just speaking as it's close is all.

[SILVERGUN]

SG, the first three stages appears to be like it could be a Trainwreck Express "Lite" version in that it's using a simple tone control instead of the tone stack is all. Not all the values are perfect but they don't have to be, just speaking as it's close is all.

Yup,,, and I meant to mention that it evokes a similar feel to me as my original wreck build,,,but a little different.

I really like it with either pickup, and it just wants to sustain for days and has some of the feedback effect...

I have a feeling it will sound really cool with a boost in front of it.

[SILVERGUN]

SG, the first three stages appears to be like it could be a Trainwreck Express "Lite" version.

And the more I've looked at it jojo,,,the more this makes sense....
'Cause the Twreck only uses 3 triodes, so if you use the last stage as the fx send,,,and then the unused triode as the return,,,you won't have to add a tube to get it there.....
For guys who are looking to add a loop their TW and don't want to drill a hole, this is a cool option.

[jojokeo]

I like the idea SG. Now it's back to a final tweak on another pedal I've been working on while "down" known as a Harmonic Percolator. I've got an order for a ODS & another gig or two so I'll be back at it all soon enough. I have to make time for some things like this but life keeps moving along. There's a couple of family illness' all happening at once too. I keep thinking there's going to be a let-up but don't see one on the horizon. No pity party here, you just prioritize and keep going. It's been good to see you, ed, sluckey, and everyone realizing the nice fruits of your all of your labors lately.

[tubenit]

I like your design & I appreciate your sharing it!

With respect, Tubenit

[jojokeo]

tubenit I might have to rely on you to test out SG's idea here in the meanwhile? I haven't seen what you've been up to or working on lately? Or maybe just enjoying things at the moment?

[SILVERGUN]

I like your design & I appreciate your sharing it!

Well that's great news..
Cause I basically stole it from YOU   

 

I like the idea SG. Now it's back to a final tweak on another pedal I've been working on while "down" known as a Harmonic Percolator. I've got an order for a ODS & another gig or two so I'll be back at it all soon enough. I have to make time for some things like this but life keeps moving along. There's a couple of  family illness' all happening at once too. I keep thinking there's going to be a let-up but don't see one on the horizon. No pity party here, you just prioritize and keep going. It's been good to see you, ed, sluckey, and everyone realizing the nice fruits of your labor lately.

Well good luck with EVERYTHING Joe....
We'll all still be here when you get around to it, and I'm looking forward to what's next from you....

These guys have been taking great care of me and not letting my head get too big...
Where were they the first 44 years of my life?
......doesn't matter cause now I'm hooked!....and I'm hoping I've still got 44 left.

[jazbo8]

Just curious why are you using 0.1uF for the coupling caps? Wouldn't you have issues with block distortion when crank'd? And why the addition of the RC bypass on the Fx send-return path, doesn't that act as a bleed-through?

[kagliostro]

Ciao SILVERGUN

Thanks for sharing

I think this will be a great input for one of my friends who is building a 5E3 + FXLoop 

Franco

[SILVERGUN]

Ciao SILVERGUN
Thanks for sharing

Your welcome K,,,,glad I could help
 

And why the addition of the RC bypass on the Fx send-return path, doesn't that act as a bleed-through?

It acts as a parallel path for the signal, so some of the signal remains unaffected, and doesn't travel through the effect circuitry....
To me, it just sounds better that way.

It's something that tubenit brought to our attention, and we discussed here:
http://el34world.com/Forum/index.php?topic=16606.msg164197#msg164197

Just curious why are you using 0.1uF for the coupling caps?

I honestly didn't think about it that hard 
The .1uf was on the 5E3 schematic, and the parallel fx loop schematic, so it just came together that way...

But that sounds like a valid point and probably a "tweak to taste" mod....maybe just use a smaller coupling cap into the PI?
The channel has so much push and presence that I haven't cranked it.....into 2 EL34's I can barely stand in the same room with it 

[Ed_Chambley]

Are you not going to have adjustable levels on your loop?  I was wondering if you could maybe change the design to accommodate this.  I am not suggesting you change your current build, just revising what I see as a loop with gain.  I may be missing it, but wouldn't it then be able to act as a Master Volume as well?





Also, I was thinking of the tone when I jump channels in the AC15, which is very nice and allows the normal grind channel to have the effects, but will get swamped when the normal channel volume was too high.  Not rocket science since the EF86 has much more gain.


I have not gotten my thinking clear on this and need to think a little longer on it.  I think there may be a couple of nice switchable options to use it for way more than a loop.  Mid cut, Fat along with a Belton Brick verb.  ANyway, thanks.  I believe this has most of the things I like.  First, I understand it    also it has potential as a cool stompbox with a floor loop maybe.  I don't know yet, but it is one of those things that has stuck so you know I have to play with it now.

[SILVERGUN]

Are you not going to have adjustable levels on your loop?  I was wondering if you could maybe change the design to accommodate this.  I am not suggesting you change your current build, just revising what I see as a loop with gain.  I may be missing it, but wouldn't it then be able to act as a Master Volume as well?

I didn't need a send pot on mine because the loop is always active and since both channels share the loop, which is active all the time, the gain just became part of the amp.......If you wanted that control you would just change the 100K to ground right before the effects send to a 100K pot.

The Master Volume in that schematic is actually the effects return level control as well....and again, in my case, I didn't feel like I had to have a separate Master...but you could  ....just depends on how many pots you want to buy and how many holes you have room to drill....in my case, I was short on real estate 

[jojokeo]

The Master Volume in that schematic is actually the effects return level control as well....and again, in my case, I didn't feel like I had to have a separate Master...but you could  ....just depends on how many pots you want to buy and how many holes you have room to drill....in my case, I was short on real estate 

So you're saying that you originally had a 250K return pot and measured it to be at about the 180:51 position on the dial? (which turns out to be 22% overall preamp signal output at that point)

[SILVERGUN]

The Master Volume in that schematic is actually the effects return level control as well....and again, in my case, I didn't feel like I had to have a separate Master...but you could  ....just depends on how many pots you want to buy and how many holes you have room to drill....in my case, I was short on real estate 

So you're saying that you originally had a 250K return pot and measured it to be at about the 180:51 position on the dial? (which turns out to be 22% overall preamp signal output at that point)

No,,, I meant that the effects return control could be after the recovery triode for the loop, and in my case it's just my master volume control...
In one of T's original schematics, he put it there.
It's this 250K pot:

[jojokeo]

Disclaimer: this response feels to have a negative vibe to it but it's not meant that way in the least. It's playing devils' advocate with the concept is all creating discussion to learn more about it if it's not what it appears to be?

It's hard to see the need or want for a "recovery" triode on a return. First of all they aren't used nearly as often as one might think in the big picture for most people. Second, think about what's being put into it. If it's for effects return, there are many various signal boosters, compressors, buffers, overdrives, and gain-galore distortion devices driving power o' plenty of their own ramping and/or jacking up the signal usually hotter than when it's left the amp's preamp at that point and it's usually always returning back in HOT. This is mostly the end result when using pedals, racks, & boards and they certainly aren't lacking in signal drive. Therefore you don't need to "recover" anything. If anything you would want limiting control for protection from those high powered signals especially if another amp's preamp is being inserted here rendering this current amp to then just be a slave amp. And in fact that's basically what's there on the return with that 180K:51K voltage divider that's limiting the signal down to 22%. (I'm thinking why arbitrarily 22%?) Anyway, so then why knock down the signal coming back in in the first place to the point it needs to be brought back up - and then back down again with another control pot after all of this? This all seems over complicated, unnecessary, and counter productive from a theoretical and a design perspective?

Now if you want another gain stage for a particular amp design, then why not just do that and make better use for the triode and put it where it belongs in the first place so that it doesn't have the possibility to be affected by anything or affect something further that's not necessary? The painstaking effort in getting things just right for when there's nothing plugged into the loop there. But then IF something's plugged in there, then everything changes and the efforts likely are where? So now there's double signal coloring going on as well as multiple voltage dividers. I'm scratching my head trying to find reason that after creating supposedly the preamp signal, tone, and amount of drive you supposedly want, then hitting that precious signal to change it and color it with effects (which can enhance and be nice for sure), but then wanting to color all that by knocking it down and bringing it up again and then back down again all over again? (did I say "again" enough times to get the point across?) So, is there really effects to be ran through here full time or not? Is it an effects loop in "sheeps clothing"?? What is this game of signal voltage calisthenics? 

[SILVERGUN]

Disclaimer: this response feels to have a negative vibe to it but it's not meant that way in the least. It's playing devils' advocate with the concept is all creating discussion to learn more about it if it's not what it appears to be?

Thanks for that!....typed words can have different meanings to different people and sometimes, without a disclaimer, it can read like guys are just pushing buttons....luckily for me,  I know you, and that's not the case....and I appreciate the open dialogue for discussion purposes....I wish I had more to add ......
I take a little bit of this and a little bit of that, and try to stay within certain parameters,,,and if it works and sounds/feels good, than that's as technical as I need to get with an answer.

For me,,,I do see a pattern of this,,,,"building up pressure to knock it back down" approach, and I'm not sure what it is I like about it...
And it works, for me.....the completed amp sounds like I've got a fire hose with 100psi and I'm controlling it all through a garden hose...
(to mix in the water analogy for the sake of a visual picture)

Good post....thought provoking and questioning my reasoning....I like it!....hey, but I thought you were leaving the thread earlier 
...how dare you jump back in and question me (said through the voice of The Great OZ)

I guess my only real "dumbed down" answer is....."cuz it sownds kewl"  (Ed)

Here's a snip of the loop that's in my Mesa Rectoverb.....I compared it to tubenit's loop and it confirmed I was on a good path...once on the breadboard, I tweak it, and if it sounds good it stays. 
I had used the MIX control in an earlier attempt, but didn't feel the need to include it here,,,and some of tubenit's research just confirmed that.....it's a simple addition if needed.

I do believe that we are not taking every single effect type in to account, and do run the risk of overloading the return.....but that would be up to the player/user to recognize.  .....and in some situations it probably would make sense to just have a return level control........but then again, the player/user would have to know how to use it. 

[Ed_Chambley]

Disclaimer: this response feels to have a negative vibe to it but it's not meant that way in the least. It's playing devils' advocate with the concept is all creating discussion to learn more about it if it's not what it appears to be?

It's hard to see the need or want for a "recovery" triode on a return. First of all they aren't used nearly as often as one might think in the big picture for most people. Second, think about what's being put into it. If it's for effects return, there are many various signal boosters, compressors, buffers, overdrives, and gain-galore distortion devices driving power o' plenty of their own ramping and/or jacking up the signal usually hotter than when it's left the amp's preamp at that point and it's usually always returning back in HOT.   

This how you use a effects loop?  I use modulation pedals and rack units that normally have unity gain.  Anything that boost the signal hits the front or it does not work as well to me.

[SILVERGUN]

This how you use a effects loop?  I use modulation pedals and rack units that normally have unity gain.  Anything that boost the signal hits the front or it does not work as well to me.

Yeah, what he said!

Ed, that sounded a little hostile/confrontational,,,I'm gonna need you to include a disclaimer next time....

I'm goin' golfin'.......

[Ed_Chambley]

This how you use a effects loop?  I use modulation pedals and rack units that normally have unity gain.  Anything that boost the signal hits the front or it does not work as well to me.

Yeah, what he said!

Ed, that sounded a little hostile/confrontational,,,I'm gonna need you to include a disclaimer next time....

I'm goin' golfin'.......

No way, I guess I need to put these things in.


Joe, what do you propose to keep the signal as pure as possible.  I like to discus loops, but only have one amp with one and it is simple just to add delay in a princeton type amp.  Sort of grab and go playing.


I really prefer a separate amp for modulation, or sometimes I use my Marshall 50/50 with Modulation panned to the left and original signal with overdrive options to the right.  Neither is 100% and always the original signal stays center mostly.


That is big gigs, smaller I simply use a solid state peavey bandit for modulation with whatever amp fits the size needed.  I would like to hear a loop that sounds as good as a separate amp, but I have not yet.


Yes, it is a pain to have to carry one more amp, least that is what I am told but I don't spend half the night on the floor twiddling knobs either.


No disclaimer needed.  Put on your big girl panties.

[Ed_Chambley]

This how you use a effects loop?  I use modulation pedals and rack units that normally have unity gain.  Anything that boost the signal hits the front or it does not work as well to me.

Yeah, what he said!

Ed, that sounded a little hostile/confrontational,,,I'm gonna need you to include a disclaimer next time....

I'm goin' golfin'.......

When you git to old to run women, you start running those balls across the golf pasture.

[Ed_Chambley]

Now we are talking loops.  What have you found to work best all around?  I have used, don't gasp, the Mojotone board and no I did not build it nor does it have a tube.  I put one in a Fargen Ole 800 and loved it, so I put one in mine.


I do use a EQ in front of pedals in a loop to EQ them as well as boost or reduce them as needed.  Very easy to install but it does kill all the tube tone of my tubeless pedals.

[Tone Junkie]

Sorry to bump thois up was looking for it Im at work so had to do this,.
Thanks Bill