Mesa Boogie Mark IV effect loop question?

[Dimebucker]

Hey


Does someone know is that Mark IV effect loop true bypass when that loop is not engage? And i mean that way ,if i put in effect loop some buffered pedal. Like some Boss digital delay witch is buffered pedal and that eat some tone ,and i do not push my boogie own footswitch effect loop engage button like boogie effect loop is off. Will that Boss digital delay eat there some tone ,because that is buffered pedal and i do not want that pedal eat boogie tone? And i mean that boss digital delay is on all the time ,but boogie effect loop is off. Do then boogie sounds 100% same ,like there is nothing in effect loop?

 

[Markedman]

No.

 

[Dimebucker]

No.

Hey


What no you mean?

 

[cho]

When the effects loop is not engaged, the effect is not in the signal path.

 

[Dimebucker]

When the effects loop is not engaged, the effect is not in the signal path.

Hey

Okey thanks.

 

[Dimebucker]

Hey


Okey now i came back home ,i was playing in my band today. And i have a problem whit that mesa effect loop. Some here say that it will not ,eat boogie tone if effect loop is not engage. And i have tc electronic flasback delay witch is true bypass pedal. That was in boogie effect loop ,it was only device in my loop. And i was lost my orginal tone ,there was missing punch and that pedal in loop was give little midi boost too. And i was try pedal off and pedal on in effect loop ,and boogie footswitch effect loop was off only that delay device was in to loop. And when i unpluged my cables in effect loop ,that amazing boogie tone was there right away. And now i have one question ,if i plug cables or pedal in the loop of boogie. Will that boogie do something there when effect loop send and return have cables on. Comparable to there is not plugged any cables?

 

[cho]

Dimebucker,
Sorry, I am having a little trouble understanding you. I don't have a Mark IV anymore, but I am pretty sure that if the effects loop on the Boogie footswitch is OFF, then it shouldn't matter if you have cables plugged in or not. If it does make a difference, perhaps there is a problem with your amp.
Anyone with a Mark IV wiling to test this on their amp?

 

[Golden1984]

Check your cables connecting effct to amp. If you have very long or cheap cables, there may be significant difference, even with you true bypassed effect, because avoiding effect`s circuit with it`s internal switch doesn`t mean avoiding cables.
There is also a difference between A nad B model MKIV. In B you can simply switch the loop off, so cables into and from effect will be also cut off. In A model there are two fx loops. Standard loop can be turn on/off only with a switch situated on amp (not footswitch), switchable loop can be controlled by footswitch. According to schematic, in A model, NORMAL loop`s return is always active, even when you switch it off with amp`s (no fottswitch`s) switch.
So if you want to have a true bypass in A model, you have to set switch on the amp to "SWITCHABLE", leave normal loop`s jack sockets empty, connect your effect to SWITCHABLE loop and use footswitch.

 

[Dimebucker]

Check your cables connecting effct to amp. If you have very long or cheap cables, there may be significant difference, even with you true bypassed effect, because avoiding effect`s circuit with it`s internal switch doesn`t mean avoiding cables.
There is also a difference between A nad B model MKIV. In B you can simply switch the loop off, so cables into and from effect will be also cut off. In A model there are two fx loops. Standard loop can be turn on/off only with a switch situated on amp (not footswitch), switchable loop can be controlled by footswitch. According to schematic, in A model, NORMAL loop`s return is always active, even when you switch it off with amp`s (no fottswitch`s) switch.
So if you want to have a true bypass in A model, you have to set switch on the amp to "SWITCHABLE", leave normal loop`s jack sockets empty, connect your effect to SWITCHABLE loop and use footswitch.

Hey

I have B-model Mark IV ,and im using very short cables two 30cm long good cables. And today i was call one amplifier wizard dude. And he was looking for those mark iv schematic in paper. And he say that problem is this ,because mark IV loop have so much impedance values that dude was suprise how much there is. And when i plug cables in effect loop those impedance values will come in singal chain. And that is thing why it eat my sound ,not matter if there is loop off or pedal is off same results. And when i was testing that effect loop ,i was playing some riffs. And my friend was disconnect to cables off in effect loop and putting again cables in effect loop. When cables was in effect loop ,sound was chance and when he was unplugged cables in effect loop sound was what it should be perfect. And effect loop was off all the time ,when we was testing that .Have someone find a cure ,how those impedance values can be fixed?

 

[Golden1984]

Are you sure you`re using FX send (not satellite send) and right (mono) return? Are you sure you have all of the loop-to-channel assigning switches in neutral positions? The loop in MKIV is just a gap between preamp and poweramp, when you plug the jack in, you`re just putting another wire there, and impedance change cannot take place. I have MKIV a and MKIV b, and there`s no such problems. When the loop is bypassed, there is a wire preamp to pwr amp too; sound from preamp gets poweramp anyway. It is the simplest fx loop you can imagine. If the mono loop in B model is off, it CANNOT affect your tone, even if there is a broken or cut in two cable plugged in, unless you have A version of MKIV, where normal loop`s return is always active.

 

[Dimebucker]

Are you sure you`re using FX send (not satellite send) and right (mono) return? Are you sure you have all of the loop-to-channel assigning switches in neutral positions? The loop in MKIV is just a gap between preamp and poweramp, when you plug the jack in, you`re just putting another wire there, and impedance change cannot take place. I have MKIV a and MKIV b, and there`s no such problems. When the loop is bypassed, there is a wire preamp to pwr amp too; sound from preamp gets poweramp anyway. It is the simplest fx loop you can imagine. If the mono loop in B model is off, it CANNOT affect your tone, even if there is a broken or cut in two cable plugged in, unless you have A version of MKIV, where normal loop`s return is always active.

Hey

I use normal fxloop send and return ,not that satellite loop. I have fxloop mode switching on ,not that fxloop on. And i have those rhy2 and lead switches center positions. I do not use those external switching jacks ,those jacks are empty i only use that boogie big own footswitch. And my mode selection is Ft.SW. And Mark IV B-version head i have. That amp dude say me that some buffer pedal would help that impedance problem ,because boogie have that high impedance in effect loop jacks. What i must do then?

 

[Golden1984]

I have additional FX/PREAMP/VOL switcher in my FX loop. The loop is always enabled. The switcher allows me to switch between channels and effects or three volume pots. When I turn the additional vol pot to max and bypass all fx in switcher, there`s no difference in tone either I turn loop on or off. When I crank MKIV output volume, a little hum is barely visible if the loop is on. No tonal loss. I built the switcher and I know by the way how the loop is built. I spent weeks on comparing sound with or without switcher. Not only by the ear, I recorded my tone with sm57, e609, etc... Technically the loop in mkiv is always enabled, the only thing changing is signal route. So I advice you to check cables and jack sockets in amp. If your amp is stock and your cables are good, there shouldn`t be such tonal loss.

According to what you write, your loop is modded somehow or it`s broken, it is always on. It looks like your loop is on even when you hard bypass it with switch on amp. Connecting short cable into send and return should not affect your tone anyway. I don`t have any tonal problems even when I have active effect in loop. I suggest you to bring your amp to some decent technician. If you need schematic for B version, contact MESA [email protected] - they should send it to you you as they sent it to me, but they forbidden me giving it to anyone. Don`t forget to describe your problem to them. In web you can only find schematic for A version, so I doubd your technician could have schematics for B version.

 

[Dimebucker]

I have additional FX/PREAMP/VOL switcher in my FX loop. The loop is always enabled. The switcher allows me to switch between channels and effects or three volume pots. When I turn the additional vol pot to max and bypass all fx in switcher, there`s no difference in tone either I turn loop on or off. When I crank MKIV output volume, a little hum is barely visible if the loop is on. No tonal loss. I built the switcher and I know by the way how the loop is built. I spent weeks on comparing sound with or without switcher. Not only by the ear, I recorded my tone with sm57, e609, etc... Technically the loop in mkiv is always enabled, the only thing changing is signal route. So I advice you to check cables and jack sockets in amp. If your amp is stock and your cables are good, there shouldn`t be such tonal loss.

According to what you write, your loop is modded somehow or it`s broken, it is always on. It looks like your loop is on even when you hard bypass it with switch on amp. Connecting short cable into send and return should not affect your tone anyway. I don`t have any tonal problems even when I have active effect in loop. I suggest you to bring your amp to some decent technician. If you need schematic for B version, contact MESA [email protected] - they should send it to you you as they sent it to me, but they forbidden me giving it to anyone. Don`t forget to describe your problem to them. In web you can only find schematic for A version, so I doubd your technician could have schematics for B version.

Hey


Thanks man that email address. I just send them email ,and asking that problem can they help me. My loop is not modded ,and amp is like a new one it is last of line what they have build in 2008. And i have very short cables there in fxloop ,problem is something else. If some another trick will come in mind ,give me directions to test that loop again. Cables i have try and another pedal i have try ,same results. And you speak that volume of boogie. I use lead channell master to 3/10 and output master to 4,5/10 ,i hear that those knobs navigate that effect loop somehow. But i don`t want touch those two knobs ,because they are perfect now ,and i get that amazing heavy punchy tone now. When effect loop do not have any pedals plugged. But would be nice to have that delay working ,what im looking for.