PS: More About Dumbleator Settings

[ayan]

Gil
Sorry for the delay as I got a last minute sub job in DC and the site went out last night.

I didn't have a 15K pot on hand so it was a 50K and 25K pots. Both seemed to work OK. The only thing I noticed was there was a bit more compression when going to the lower value pots. It was pretty subtle so I don't know if you will notice this or not. The really interesting thing was the lower value pots increased the lators ability to sustain (especially the 25K) which was pretty cool!. Of course, the send pots became really sensitive but we already knew this. As much as I tried I couldn't get the CF to distort so it never ran completely out of headroom. (I've heard followers distort)
So far I prefer the 25K for now and am leaving it in there to try on the next few gigs and see how it feels
Of course YMMV depending on your setup tubes/cables and effects.
Master on 7
Lexicon LXP-15
Stock D-Lator
Amps were
High Plate Skyline
Low Plate Skyline Music Man
Let me know if you have any questions.

Tony

Tony,

I have a Dumbleator in a box waiting to be built here so i'm interested in your findings. Are your pots log or Lin? I'm going to give the 25K a shot as I like how you described the tone


M

I would presume audio/log, linear would probably be more of an on/off switch.

[talbany]

Marcus
An audio taper is what you want. In this case, I recommend and low taper audio pot like a 10 or 15% . The higher the taper the more responsive the pot.

Tony

[Rollylama]

Can someone baby-speak this concept to me?

I have a Glaswerks Zingaro. It has the active loop in it. From what I’ve read and I suppose experienced to an extent, the loop can be a “master volume” for the master volume.

What is going on here? What’s the most effective way to do this? Do whatever you want with the master (cranking it saturates the PI?), keep the send low, and use the return to control the overall level?

Does the send level even matter? I guess that’s what confuses me the most.

I have a Timeline and Suhr Alexa/Jack Rabbit in the loop and it doesn’t seem like any of them are adversely affected by the send/return settings (though I’ve never gone past noon).

I feel like I sort of understand the concept but if I actually understood how this works I may be better able to implement it.

Thanks!

[stelligan]

One of the best ways to hear what is happening with your loop is to put a short patch cable in the loop and fiddle with your send and return knobs, if the Zingaro has them. And Yes, the the send and return levels do raise and lower the overall volume of the amp. As does a level knob on any effect you have in the loop. Adjusting your send and returns will give you a feel for the gain added in the loop tube. I like to run my send high as my effect can tolerate and use the return to return to unity and use the master for overall volume. I like the smoothing it can impart to the OD channel. It can make the clean channel sing as well. But knock yourself out and use your ears. No rules other than gain staging that your loop effects will like...

PM "glasman" and ask him for guidance. Dunno if the loop is tube or SS. He built your amp

[Rollylama]

One of the best ways to hear what is happening with your loop is to put a short patch cable in the loop and fiddle with your send and return knobs, if the Zingaro has them. And Yes, the the send and return levels do raise and lower the overall volume of the amp. As does a level knob on any effect you have in the loop. Adjusting your send and returns will give you a feel for the gain added in the loop tube. I like to run my send high as my effect can tolerate and use the return to return to unity and use the master for overall volume. I like the smoothing it can impart to the OD channel. It can make the clean channel sing as well. But knock yourself out and use your ears. No rules other than gain staging that your loop effects will like...

PM "glasman" and ask him for guidance. Dunno if the loop is tube or SS. He built your amp

Thanks! It’s a tube loop. I’ve gleaned some info from him but still haven’t really nailed down how the loop actually behaves.

From what I’ve gathered it’s a little different than your description where advice seems to be run the master at X level and use the FX return to govern volume rather than set send/return and use the master to control it.

I guess having a tube stage after the master volume is still kind of a foreign concept. The closest I’ve used is boogies but even those use the channel to send and return and then have a global output to control it.

[pompeiisneaks]

PM "glasman" and ask him for guidance. Dunno if the loop is tube or SS. He built your amp

Except the PM won't email notify anymore and I can't get it fixed, so he may never see it unless he logs in to the site.

~Phil

[ayan]

One of the best ways to hear what is happening with your loop is to put a short patch cable in the loop and fiddle with your send and return knobs, if the Zingaro has them. And Yes, the the send and return levels do raise and lower the overall volume of the amp. As does a level knob on any effect you have in the loop. Adjusting your send and returns will give you a feel for the gain added in the loop tube. I like to run my send high as my effect can tolerate and use the return to return to unity and use the master for overall volume. I like the smoothing it can impart to the OD channel. It can make the clean channel sing as well. But knock yourself out and use your ears. No rules other than gain staging that your loop effects will like...

PM "glasman" and ask him for guidance. Dunno if the loop is tube or SS. He built your amp

I would add that in the case of Gary's Zingaro, you'll be better off using whatever length cables you will be using when you use the amp (whether it be at a coliseum or your basement). If I recall correctly, Gary's told me that he uses 250K pots in his FX loop. That being the case, the SEND pot setting may set the Zout of the FX loop anywhere between 0 (with the pot set at 0) and about 63K with the pot set at 125K. I'm repeating myself here, since I've already written this before, but couple that with an 18 ft, with a 40 pF/ft capacitance cable connecting to a pedalboard and you have a LPF with its 3 dB point will be at f = 1/(2*pi()*Zout*C) = 1/(2*3.14*63e3*18*40*1e-12) = 3,500 Hz. If you use a short patch cable, 3 ft long, the 3 dB point will shift to 35 KHz and you would never hear the effect.

Bottomline, although an infinite number of combinations of amp Master and FX loop Send settings are capable of sending the same signal level to the FX, ther tonal variation among all those settings can be mind boggling. If on top of that a bright cap is added to the amp's Master volume -- which I believe Gary does not usually include in the Zingaro -- you have yourself a greater balancing act.

Gil

[Rollylama]

One of the best ways to hear what is happening with your loop is to put a short patch cable in the loop and fiddle with your send and return knobs, if the Zingaro has them. And Yes, the the send and return levels do raise and lower the overall volume of the amp. As does a level knob on any effect you have in the loop. Adjusting your send and returns will give you a feel for the gain added in the loop tube. I like to run my send high as my effect can tolerate and use the return to return to unity and use the master for overall volume. I like the smoothing it can impart to the OD channel. It can make the clean channel sing as well. But knock yourself out and use your ears. No rules other than gain staging that your loop effects will like...

PM "glasman" and ask him for guidance. Dunno if the loop is tube or SS. He built your amp

I would add that in the case of Gary's Zingaro, you'll be better off using whatever length cables you will be using when you use the amp (whether it be at a coliseum or your basement). If I recall correctly, Gary's told me that he uses 250K pots in his FX loop. That being the case, the SEND pot setting may set the Zout of the FX loop anywhere between 0 (with the pot set at 0) and about 63K with the pot set at 125K. I'm repeating myself here, since I've already written this before, but couple that with an 18 ft, with a 40 pF/ft capacitance cable connecting to a pedalboard and you have a LPF with its 3 dB point will be at f = 1/(2*pi()*Zout*C) = 1/(2*3.14*63e3*18*40*1e-12) = 3,500 Hz. If you use a short patch cable, 3 ft long, the 3 dB point will shift to 35 KHz and you would never hear the effect.

Bottomline, although an infinite number of combinations of amp Master and FX loop Send settings are capable of sending the same signal level to the FX, ther tonal variation among all those settings can be mind boggling. If on top of that a bright cap is added to the amp's Master volume -- which I believe Gary does not usually include in the Zingaro -- you have yourself a greater balancing act.

Gil

Thanks Gil! The math is over my head because I’m not a builder or anything close to that. I just have (2) 10’ canare cables and a couple of 4” patch cables in the loop

I’m used to FX loops like on Mesa where the channel level is the send and the global is the return.

On this style loop, it sounds like the master volume is sending the signal and the send is somehow changing the impedance in the loop so it’s more of a tonal thing...do I have that right?

Does the send have anything to do with the strength of signal being sent to the effects in the loop?

[ayan]

One of the best ways to hear what is happening with your loop is to put a short patch cable in the loop and fiddle with your send and return knobs, if the Zingaro has them. And Yes, the the send and return levels do raise and lower the overall volume of the amp. As does a level knob on any effect you have in the loop. Adjusting your send and returns will give you a feel for the gain added in the loop tube. I like to run my send high as my effect can tolerate and use the return to return to unity and use the master for overall volume. I like the smoothing it can impart to the OD channel. It can make the clean channel sing as well. But knock yourself out and use your ears. No rules other than gain staging that your loop effects will like...

PM "glasman" and ask him for guidance. Dunno if the loop is tube or SS. He built your amp

I would add that in the case of Gary's Zingaro, you'll be better off using whatever length cables you will be using when you use the amp (whether it be at a coliseum or your basement). If I recall correctly, Gary's told me that he uses 250K pots in his FX loop. That being the case, the SEND pot setting may set the Zout of the FX loop anywhere between 0 (with the pot set at 0) and about 63K with the pot set at 125K. I'm repeating myself here, since I've already written this before, but couple that with an 18 ft, with a 40 pF/ft capacitance cable connecting to a pedalboard and you have a LPF with its 3 dB point will be at f = 1/(2*pi()*Zout*C) = 1/(2*3.14*63e3*18*40*1e-12) = 3,500 Hz. If you use a short patch cable, 3 ft long, the 3 dB point will shift to 35 KHz and you would never hear the effect.

Bottomline, although an infinite number of combinations of amp Master and FX loop Send settings are capable of sending the same signal level to the FX, ther tonal variation among all those settings can be mind boggling. If on top of that a bright cap is added to the amp's Master volume -- which I believe Gary does not usually include in the Zingaro -- you have yourself a greater balancing act.

Gil

Thanks Gil! The math is over my head because I’m not a builder or anything close to that. I just have (2) 10’ canare cables and a couple of 4” patch cables in the loop

I’m used to FX loops like on Mesa where the channel level is the send and the global is the return.

On this style loop, it sounds like the master volume is sending the signal and the send is somehow changing the impedance in the loop so it’s more of a tonal thing...do I have that right?

Does the send have anything to do with the strength of signal being sent to the effects in the loop?

Gotcha. If you have short cables, there are less variables. It might help you to look at it this way: the amp’s master volume sets the signal level that feeds the input of the FX loop. The Send control from the FX loop sets the level that is sent to the FX. The loop Return level sets the signal that will feed the power amp and therefore becomes the control that will set the overall loudness. So you could set the amps’s Master high and the loop Send low, or vice versa, or anything in between, such that you feed the FX the same signal level. Now, the signal level can be set the same using different combinations, but the tonal characteristics may not be the same because of other considerations. You need to experiment and see what you like the best. The easy part is to set the loop Return control, since the desired loudness for the occasion will dictate that. I hope this is clearer.

The case of most other amps is different, because many eliminate the redundancy described above. The reason for the redundancy in Dumble’s case is that the Dumbleator was optional and external, so it had to interface with a system (the amp) that was already designed and fixed. Some people building D style amps and incorporating the active loop leave in this redundancy to give the user the same capability that a Dumble user would have when adding an external Dumbleator to their rig.

Gil

[Rollylama]

I would add that in the case of Gary's Zingaro, you'll be better off using whatever length cables you will be using when you use the amp (whether it be at a coliseum or your basement). If I recall correctly, Gary's told me that he uses 250K pots in his FX loop. That being the case, the SEND pot setting may set the Zout of the FX loop anywhere between 0 (with the pot set at 0) and about 63K with the pot set at 125K. I'm repeating myself here, since I've already written this before, but couple that with an 18 ft, with a 40 pF/ft capacitance cable connecting to a pedalboard and you have a LPF with its 3 dB point will be at f = 1/(2*pi()*Zout*C) = 1/(2*3.14*63e3*18*40*1e-12) = 3,500 Hz. If you use a short patch cable, 3 ft long, the 3 dB point will shift to 35 KHz and you would never hear the effect.

Bottomline, although an infinite number of combinations of amp Master and FX loop Send settings are capable of sending the same signal level to the FX, ther tonal variation among all those settings can be mind boggling. If on top of that a bright cap is added to the amp's Master volume -- which I believe Gary does not usually include in the Zingaro -- you have yourself a greater balancing act.

Gil

Thanks Gil! The math is over my head because I’m not a builder or anything close to that. I just have (2) 10’ canare cables and a couple of 4” patch cables in the loop

I’m used to FX loops like on Mesa where the channel level is the send and the global is the return.

On this style loop, it sounds like the master volume is sending the signal and the send is somehow changing the impedance in the loop so it’s more of a tonal thing...do I have that right?

Does the send have anything to do with the strength of signal being sent to the effects in the loop?

Gotcha. If you have short cables, there are less variables. It might help you to look at it this way: the amp’s master volume sets the signal level that feeds the input of the FX loop. The Send control from the FX loop sets the level that is sent to the FX. The loop Return level sets the signal that will feed the power amp and therefore becomes the control that will set the overall loudness. So you could set the amps’s Master high and the loop Send low, or vice versa, or anything in between, such that you feed the FX the same signal level. Now, the signal level can be set the same using different combinations, but the tonal characteristics may not be the same because of other considerations. You need to experiment and see what you like the best. The easy part is to set the loop Return control, since the desired loudness for the occasion will dictate that. I hope this is clearer.

The case of most other amps is different, because many eliminate the redundancy described above. The reason for the redundancy in Dumble’s case is that the Dumbleator was optional and external, so it had to interface with a system (the amp) that was already designed and fixed. Some people building D style amps and incorporating the active loop leave in this redundancy to give the user the same capability that a Dumble user would have when adding an external Dumbleator to their rig.

Gil

Yes, I think that’s exactly what I’ve been trying to figure out...the relationship between the master and send. Thank you!

[Rollylama]

It’ll be fine if you keep the master volume down low enough. I’ve just never really warmed to the idea of the knob on the front panel becoming essentially useless when the D’lator is in the loop.

I have to say that given the small amount about this that I do think I understand, I agree with this.

As I understand it, you’re able to crank the master (without a loop it’s driving the power section) but with the loop you’re knocking it back down via send and then using the return to raise it back up. This is essentially putting the master volume in the preamp section?

[martin manning]

In the standard arrangement the amp's master controls the signal at the send jack, and it is usually set around noon (~90% attenuation of the preamp output). The D'lator's recover pots are now controlling the signal being fed back into the power amp at the return jack, so they replace the master. The D'lator recover out is last in line, in the same position (signal-wise) as the amp's master was. As Gil says, there is a lot of flexibility. You can use the amp master to drive the D'lator's send buffer hard and get some tonal variation out of that, and still dial down the signal fed into the first effect as needed with the Drive control.

[Rollylama]

In the standard arrangement the amp's master controls the signal at the send jack, and it is usually set around noon (~90% attenuation of the preamp output). The D'lator's recover pots are now controlling the signal being fed back into the power amp at the return jack, so they replace the master. The D'lator recover out is last in line, in the same position (signal-wise) as the amp's master was. As Gil says, there is a lot of flexibility. You can use the amp master to drive the D'lator's send buffer hard and get some tonal variation out of that, and still dial down the signal fed into the first effect as needed with the Drive control.

Are you saying it’s ideal to set the MV at noon? If so, what’s the reasoning behind that?

Use the send control to make sure effects aren’t clipping and then return as overall volume?

[martin manning]

You only need 2V or less going out to your FX, and the D’lators CF send buffer has gain a bit less than 1. Setting the master at noon might put around 10V at the amp’s send jack, and about the same at the top of the D’lator’s send pot. More than enough. I don’t know about ideal, but noon on the master is a place to start. You can get tonal variation by driving the D’lator’s CF, so you can play around with that.

[Rollylama]

You only need 2V or less going out to your FX, and the D’lators CF send buffer has gain a bit less than 1. Setting the master at noon might put around 10V at the amp’s send jack, and about the same at the top of the D’lator’s send pot. More than enough. I don’t know about ideal, but noon on the master is a place to start. You can get tonal variation by driving the D’lator’s CF, so you can play around with that.

I’m pretty clueless on the techie aspects. I assume driving the CF (cathode follower?) is a good thing?

I gave it a Go with the MV at noon and had pretty good results. It seems to balance out the clean and OD channels a little better.

I have a timeline in the zingaro loop and just adjusted the send until the pedal wasn’t clipping. Return to volume I wanted.

Thanks for all the advice and answering my questions.