Parallel loop - ampgarage users only - Ultimate Simplicity!

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bluesfendermanblues
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Parallel loop - ampgarage users only - Ultimate Simplicity!

Post by bluesfendermanblues »

Simplicity is supposed to be the ultimate sophistication:

Dumblelator + 25k linear pot!!

After trying a lot of different parallel loop designs and checking out a lot of schematics, I stumbles on the latest MESA iteration of the effects loop. They used this idea (a simple 25k pot) in the rectifier series 20 years ago, and they still used it in current amps like e.g. the NOMAD series.

I really think the parallel loop below, is the best solution if you want

- Original Dumblelator with
- Effects added in parallel (and in phase with the direct signal)

No effects unit connected:
The 25k pot is totally out of the equation.

With effect unit in the loop:
Turn the pot all the way down, you get 10% wet signal and 90% direct
Turn the pot all the way up to 10, you get almost 100% wet signal, like a traditional Dumblelator.

If you cant stand the idea of the pot being in the loop, you can simply add a switch to take it out of the circuit.

Very simple addition to the Dumblelator and IMO it works like a charm.
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stelligan
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Re: Parallel loop - ampgarage users only - Ultimate Simplicity!

Post by stelligan »

Thanks for this! - and all previous work on parallel loop implementation as well. I have followed them all and this looks like a snap to implement. No more MiniMix, Tru-Loop, X-Blender, etc..
vibratoking
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Re: Parallel loop - ampgarage users only - Ultimate Simplicity!

Post by vibratoking »

I'll have to give that a try. Looks like a good solution that is cheap and easy to implement. There could be more options which I need like a hole in the head. I could see another set of jacks for a series loop. Then make that 25k a digital pot. All under midi control. Damn you! :P
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Structo
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Re: Parallel loop - ampgarage users only - Ultimate Simplicity!

Post by Structo »

Interesting Claus.

The 25K pot is like a wet/ dry or balance pot.
Tom

Don't let that smoke out!
bluesfendermanblues
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Re: Parallel loop - ampgarage users only - Ultimate Simplicity!

Post by bluesfendermanblues »

Structo wrote:Interesting Claus.

The 25K pot is like a wet/ dry or balance pot.
Exactly, and if you wire the jacks as proposed, you bypass the pot completely when no effect is connected.
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hans-jörg
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Re: Parallel loop - ampgarage users only - Ultimate Simplicity!

Post by hans-jörg »

Hello Claus,

I wired my D-Lator same as the schem above and it works right as you write - except one point what I dont understand:
I have - when i.e. a delay is connected - the 100% delay signal in the middle of the 25k pot (around 12k). At the full left or right side of the pot is a mixed signal (maybe 70:30 to 90:10 / dry signal : delay signal).
What I don`t understand is why the pure signal comeing through the effect (delay) is in the mid position.
You wrote above the mix is with full left to full right.

I checked my wireing - thats ok, same like schemata.
Any idea?
From the principe I dont care because the parallel mix is fine and there - but at unexpected position :)

Best

Hans-Jörg

Edit: I implemented a Belton digi Rev. after the return too (same like Aaron) and it works perfect. Bypass via relay. Use only the mix pot (dwell) of it. The D-Lator itself is sitchable to bypass too (second relay).
A perfect world!
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hans-jörg
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Re: Parallel loop - ampgarage users only - Ultimate Simplicity!

Post by hans-jörg »

Hi,
I realised that it depeds fully on what effect you hang between. It works best with my delay (home brewed) but others are very soon overdriven. Maybe because the privious return pot is now a fix resistor (220k) and thats too much.
For my needs it`s better to put back the seriell/parallel loop with return pot as it was before.
But the circuit above has his validity too.

Best
Hans-Jörg
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Curranproducer
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Re: Parallel loop - ampgarage users only - Ultimate Simplicity!

Post by Curranproducer »

what should the voltages be for the Plate "C" and "D"? I am trying to pop an FX loop in a twin and was thinking of using the voltages reserved for the tremolo tube since I removed the tremolo circuit

also looking at the merlin, weber, and this schematic if I got the same B= running to both of the plate pins(1,6) can I just jumper that instead of running to HV wires to each pin or is this no good?
Last edited by Curranproducer on Wed Mar 18, 2015 1:47 pm, edited 1 time in total.
Curran

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Curranproducer
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Re: Parallel loop - ampgarage users only - Ultimate Simplicity!

Post by Curranproducer »

also looking at the merlin, weber, and this schematic if I got the same B= running to both of the plate pins(1,6) can I just jumper that instead of running to HV wires to each pin or is this no good?
Curran

Owner of Custom Audio Mutation Recording Studio, Guitar/Amp/Pedal Repair, and Mod center in Akron Ohio
Devout Distortion Worshipper and fan of warm hugs
234-788-6141
Garthhog
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Re: Parallel loop - ampgarage users only - Ultimate Simplicity!

Post by Garthhog »

Nice. I think I may "borrow" this idea and do a variation of it in my HayMaker Loop. I am currently using a design similar to the Dumblelator but with a few more features. This would be the icing on the cake.
Ryan Brown
Brown Amplification LLC
larsvictor
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Re: Parallel loop - ampgarage users only - Ultimate Simplicity!

Post by larsvictor »

what should the voltages be for the Plate "C" and "D"? I am trying to pop an FX loop in a twin and was thinking of using the voltages reserved for the tremolo tube since I removed the tremolo circuit

also looking at the merlin, weber, and this schematic if I got the same B= running to both of the plate pins(1,6) can I just jumper that instead of running to HV wires to each pin or is this no good?
The voltage "C" should be around +340 VDC and "D" should be + 280 VDC. Notice the voltage drop across the 100k Ra in the recovery gain stage. That reduces the voltage "C" to approximately +210 VDC for the plate (pin 6) at idle.
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