Dual Recto - channel volume vs. master volume

[hydro]

I have a DR - 100 watt 3 channel (not the newer power scaling one).

I have some trouble trying to match volume levels on this amp. Seems like it floats around a little as the amp warms up, even after playing for an hour or so sometimes.

I have a couple of questions about this -

1) Is there a difference in tone or power tube distortion between cranking the master volume up and keeping the channel volume levels lower, vs. achieving the same volume level by keeping the master volume lower and raising the channel volumes up?

2) Do the channel volumes behave differently in terms of sensitivity depending on where they are? Is the pot taper linear on these controls?

I am just wondering if I can get more volume stability and/or better sounds by cranking the master rather than turning the channel volumes up higher, or if it would work better the other way around, or if it makes no difference at all.

 

[afu]

The the bias of the tubes in 6L6 is extremely cold. It increases the headroom and makes the tubes last longer, but the DR is biased so cold that the distortion it creates is not a bluesy distortion, but more of a grainy distortion. The power amp on this amp is meant to be run loud and more or less cleanly amplify the preamp distortion. Therefore, you can crank the output up and it will make the preamp distortion sound mucho good.

I have a DR - 100 watt 3 channel (not the newer power scaling one).

I have some trouble trying to match volume levels on this amp. Seems like it floats around a little as the amp warms up, even after playing for an hour or so sometimes.

It may be time to change your tubes. Alternately, if you're playing loud, your ear will fatigue and the apparent loudness of the frequencies will change. If it's really subtle, it may be your ear.

I have a couple of questions about this -

1) Is there a difference in tone or power tube distortion between cranking the master volume up and keeping the channel volume levels lower, vs. achieving the same volume level by keeping the master volume lower and raising the channel volumes up?

The areas of the amp that control signal levels are: gain -> channel volume -> FX send -> master volume. Since the amp is meant to have a relatively less distorted power amp and a heavily distorted preamp, work your way backward. The amp still sounds good with the output cranked up, but not too much.

I set my output and send level around noon. I turn the gain and channel volume up to where I want them.

If you do it the other way around, a large signal is hitting the FX loop. Even though V4a is a buffer, it's job is to change the resistance of the load for line level FX, not to make a serious difference on the sound characteristics. It'll pass most of the signal to the send level control which will overdrive V4b, which is not meant to distort. The output control comes just after V4b. If it's turned down, you don't really get the sound of the 6L6, but a more sterile sound with the a lot of buzzing preamp/fx loop on top of it.

The only time I would determine my overall volume with the channel volume is when the FX loop is bypassed. The signal is hitting the phase inverter and it can handle distortion just fine. In fact, what makes most people exclaim the virtues of bypassing the FX is the difference between two volume controls passing the signal to the PI and just hitting it directly.

2) Do the channel volumes behave differently in terms of sensitivity depending on where they are? Is the pot taper linear on these controls?

I am just wondering if I can get more volume stability and/or better sounds by cranking the master rather than turning the channel volumes up higher, or if it would work better the other way around, or if it makes no difference at all.

All the volume controls are audio pots; logarithmic. They are tapered to match the way we hear things. So half way up sounds like half way up.

 

[hydro]

The the bias of the tubes in 6L6 is extremely cold. It increases the headroom and makes the tubes last longer, but the DR is biased so cold that the distortion it creates is not a bluesy distortion, but more of a grainy distortion. The power amp on this amp is meant to be run loud and more or less cleanly amplify the preamp distortion. Therefore, you can crank the output up and it will make the preamp distortion sound mucho good.

I have a DR - 100 watt 3 channel (not the newer power scaling one).

I have some trouble trying to match volume levels on this amp. Seems like it floats around a little as the amp warms up, even after playing for an hour or so sometimes.

It may be time to change your tubes. Alternately, if you're playing loud, your ear will fatigue and the apparent loudness of the frequencies will change. If it's really subtle, it may be your ear.

My tubes are relatively new. I do have non-Mesa tubes in this one - it's kind of a hot-rod kit from Eurotubes. I am using the GZ34 rectifier tubes, in the preamp sockets, JJ ECC83S; I think these are pretty standard - but this kit has KT88/KT66 pairs in the power section; I'm using 6L6 bias mode. It sounds great but I wonder if this could contribute to the problem I am having? (sorry if this sounds dumb; I am not an electronics guy...)

And yes, I figured some of this is ear fatigue, etc., but the other guys in the band seem to notice it too at times. It is hard to tell how much is real and how much is just my perception.

I have a couple of questions about this -

1) Is there a difference in tone or power tube distortion between cranking the master volume up and keeping the channel volume levels lower, vs. achieving the same volume level by keeping the master volume lower and raising the channel volumes up?

The areas of the amp that control signal levels are: gain -> channel volume -> FX send -> master volume. Since the amp is meant to have a relatively less distorted power amp and a heavily distorted preamp, work your way backward. The amp still sounds good with the output cranked up, but not too much.

I set my output and send level around noon. I turn the gain and channel volume up to where I want them.

If you do it the other way around, a large signal is hitting the FX loop. Even though V4a is a buffer, it's job is to change the resistance of the load for line level FX, not to make a serious difference on the sound characteristics. It'll pass most of the signal to the send level control which will overdrive V4b, which is not meant to distort. The output control comes just after V4b. If it's turned down, you don't really get the sound of the 6L6, but a more sterile sound with the a lot of buzzing preamp/fx loop on top of it.

The only time I would determine my overall volume with the channel volume is when the FX loop is bypassed. The signal is hitting the phase inverter and it can handle distortion just fine. In fact, what makes most people exclaim the virtues of bypassing the FX is the difference between two volume controls passing the signal to the PI and just hitting it directly.

Ok, so this answers some questions I had and raises some others - if I understand correctly, the signal from the individual channels goes into the FX loop which has the V4 position tube, and then out to the power section which is controlled by the master volume and solo controls.

I do not use my FX loop; that is, I don't have any effects plugged into it. But I do have it on (set to Loop On) though, because I like the master volume and solo features which only work if it's on. I was never sure what I should set the send and mix to, given that I am not actually using it. I think I have the Send all the way up, actually. It sounds like maybe I should set it at noon instead.

2) Do the channel volumes behave differently in terms of sensitivity depending on where they are? Is the pot taper linear on these controls?
I am just wondering if I can get more volume stability and/or better sounds by cranking the master rather than turning the channel volumes up higher, or if it would work better the other way around, or if it makes no difference at all.

All the volume controls are audio pots; logarithmic. They are tapered to match the way we hear things. So half way up sounds like half way up.

Thank you very much for the information and your suggestions. I will try them out.

 

[Authorized Boogie]

The the bias of the tubes in 6L6 is extremely cold. It increases the headroom and makes the tubes last longer, but the DR is biased so cold that the distortion it creates is not a bluesy distortion, but more of a grainy distortion. The power amp on this amp is meant to be run loud and more or less cleanly amplify the preamp distortion. Therefore, you can crank the output up and it will make the preamp distortion sound mucho good.

I have a DR - 100 watt 3 channel (not the newer power scaling one).

I have some trouble trying to match volume levels on this amp. Seems like it floats around a little as the amp warms up, even after playing for an hour or so sometimes.

It may be time to change your tubes. Alternately, if you're playing loud, your ear will fatigue and the apparent loudness of the frequencies will change. If it's really subtle, it may be your ear.

My tubes are relatively new. I do have non-Mesa tubes in this one - it's kind of a hot-rod kit from Eurotubes. I am using the GZ34 rectifier tubes, in the preamp sockets, JJ ECC83S; I think these are pretty standard - but this kit has KT88/KT66 pairs in the power section; I'm using 6L6 bias mode. It sounds great but I wonder if this could contribute to the problem I am having? (sorry if this sounds dumb; I am not an electronics guy...)

And yes, I figured some of this is ear fatigue, etc., but the other guys in the band seem to notice it too at times. It is hard to tell how much is real and how much is just my perception.

I have a couple of questions about this -

1) Is there a difference in tone or power tube distortion between cranking the master volume up and keeping the channel volume levels lower, vs. achieving the same volume level by keeping the master volume lower and raising the channel volumes up?

The areas of the amp that control signal levels are: gain -> channel volume -> FX send -> master volume. Since the amp is meant to have a relatively less distorted power amp and a heavily distorted preamp, work your way backward. The amp still sounds good with the output cranked up, but not too much.

I set my output and send level around noon. I turn the gain and channel volume up to where I want them.

If you do it the other way around, a large signal is hitting the FX loop. Even though V4a is a buffer, it's job is to change the resistance of the load for line level FX, not to make a serious difference on the sound characteristics. It'll pass most of the signal to the send level control which will overdrive V4b, which is not meant to distort. The output control comes just after V4b. If it's turned down, you don't really get the sound of the 6L6, but a more sterile sound with the a lot of buzzing preamp/fx loop on top of it.

The only time I would determine my overall volume with the channel volume is when the FX loop is bypassed. The signal is hitting the phase inverter and it can handle distortion just fine. In fact, what makes most people exclaim the virtues of bypassing the FX is the difference between two volume controls passing the signal to the PI and just hitting it directly.

Ok, so this answers some questions I had and raises some others - if I understand correctly, the signal from the individual channels goes into the FX loop which has the V4 position tube, and then out to the power section which is controlled by the master volume and solo controls.

I do not use my FX loop; that is, I don't have any effects plugged into it. But I do have it on (set to Loop On) though, because I like the master volume and solo features which only work if it's on. I was never sure what I should set the send and mix to, given that I am not actually using it. I think I have the Send all the way up, actually. It sounds like maybe I should set it at noon instead.

2) Do the channel volumes behave differently in terms of sensitivity depending on where they are? Is the pot taper linear on these controls?
I am just wondering if I can get more volume stability and/or better sounds by cranking the master rather than turning the channel volumes up higher, or if it would work better the other way around, or if it makes no difference at all.

All the volume controls are audio pots; logarithmic. They are tapered to match the way we hear things. So half way up sounds like half way up.

Thank you very much for the information and your suggestions. I will try them out.

We DO NOT recommend GZ34's or KT88's in a Dual Rectifier! The amp was not designed for it - and we've seen amps here for repair damaged by both GZ34's and KT88s. The KT66's are fine as they are a 6L6 equivalent, as long as they are rated for the correct current draw.

 

[screamingdaisy]

If you're not using the effects loop set the send knob to the centre position.

Channel 2 is optimized for Raw/Vintage and channel 3 is optimized for Modern.

The way I do it is I dial in modern mode with the channel master set to 10:00, then adjust the master output to taste.

Dial in the other two channels so that they balance channel 3, but avoid adjusting channel 3 since it's your baseline.

 

[hydro]

We DO NOT recommend GZ34's or KT88's in a Dual Rectifier! The amp was not designed for it - and we've seen amps here for repair damaged by both GZ34's and KT88s. The KT66's are fine as they are a 6L6 equivalent, as long as they are rated for the correct current draw.

I had gone with the GZ34s to get less rectifier sag & squishyness but not going all the way to the diode rectifier. From what I understand, Mesa sells a tube that does this, which is branded as a 5AR4/GZ34.

http://mesa.stores.yahoo.net/5archin.html

Is this tube OK to use in a Dual Recto?

I hear you about the KT88s. I like the way my amp sounds but I admit I was a little worried about running those in the power section. I expect I'll switch back to 6L6 across the board once I can get a new set shipped.


Thanks again to everyone for the advice -

 

[hydro]

If you're not using the effects loop set the send knob to the centre position.

Channel 2 is optimized for Raw/Vintage and channel 3 is optimized for Modern.

The way I do it is I dial in modern mode with the channel master set to 10:00, then adjust the master output to taste.

Dial in the other two channels so that they balance channel 3, but avoid adjusting channel 3 since it's your baseline.

Cool. The FX loop was throwing me off, and I was using green as my baseline. I'll give this a try.

 

[hydro]

If you're not using the effects loop set the send knob to the centre position.

Channel 2 is optimized for Raw/Vintage and channel 3 is optimized for Modern.

The way I do it is I dial in modern mode with the channel master set to 10:00, then adjust the master output to taste.

Dial in the other two channels so that they balance channel 3, but avoid adjusting channel 3 since it's your baseline.

Cool. The FX loop was throwing me off, and I was using green as my baseline. I'll give this a try.

Also, if you are not using the loop and have the send set to 12 o'clock, does it matter where the "mix" knob is set? I would think it does not make any difference, right?

 

[screamingdaisy]

Also, if you are not using the loop and have the send set to 12 o'clock, does it matter where the "mix" knob is set? I would think it does not make any difference, right?

None of mine have a mix knob so I can't say for sure, but I think it only matters when something's in the loop.

 

[afu]

The bypass makes the FX loop non-functional. The send will not matter. The the send, output, and solo are all part of that circuit.

 

[Jorn218]

The bypass makes the FX loop non-functional. The send will not matter. The the send, output, and solo are all part of that circuit.

Do you think there are variances in the loop circuit through the years? I ask because even when have loop disengaged vvia selector switch, I get no signal through rest of amp unless send knob is turned up. I usually leave it at 12 regardless if loop on or off.

 

[siggy14]

There is a hard bypass on the back of the amp to remove the loop from the circuit, that is what has to be selected.

The bypass makes the FX loop non-functional. The send will not matter. The the send, output, and solo are all part of that circuit.

Do you think there are variances in the loop circuit through the years? I ask because even when have loop disengaged vvia selector switch, I get no signal through rest of amp unless send knob is turned up. I usually leave it at 12 regardless if loop on or off.

 

[afu]

Thanks, Siggy. I wasn't very clear. I've been playing the last week with the loop disengaged. With Ch1 Pushed, Ch2 Raw and Ch3 Vintage, I'm getting some nice results.

 

[SonVolt]

With the loop engaged (but nothing plugged into the loop) the send and mix knobs are still active. Turn the mix knob off (10%) to have the best tone.

 

[Third Age Amps]

Re: Master volume settings ...

Per Slipperman, to get the best overall tone from a dual/triple is to engage the master and turn it up until you see the speakers moving (excursing). At that level you are getting a warm powertube tone mixed with a hint of speaker distortion. All of which helps to create the classic Recto magic.

He wrote that nothing sounds as good as a triple into a recto cab turned up loud.

 

[Jorn218]

There is a hard bypass on the back of the amp to remove the loop from the circuit, that is what has to be selected.

The bypass makes the FX loop non-functional. The send will not matter. The the send, output, and solo are all part of that circuit.

Do you think there are variances in the loop circuit through the years? I ask because even when have loop disengaged vvia selector switch, I get no signal through rest of amp unless send knob is turned up. I usually leave it at 12 regardless if loop on or off.

I get what afu was saying. That is why I asked what I did because on my amp bypassing the loop still requires me to have the send pot turned up to pass signal through the amp. If this is not supposed to happen, what/where to look in the amp to check for faulty part? Aside from this the amp is working properly.

 

[afu]

I think I have an answer. If you turn the loop to "off" it still needs the send turned up, because the output and solo is still active. Selecting "bypass" will completely remove the FX loop, output, and solo.