2. version - Parallel Loop for amp garage users only - LOL

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bluesfendermanblues
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2. version - Parallel Loop for amp garage users only - LOL

Post by bluesfendermanblues »

Hey fellow forumites,

Its been a year since posting the first attempt at a Parallel Loop.

The original design goal was
1) In serial mode - as close to the 'original' schematic as possible
2) In Parallel mode - as transperent as possible AND unity gain.

I've done a lot of back and forth and have worn out a couple of wall-to-wall carpets :lol: And if you compare the old and updated schemo, you will notice that the circuit is slimmed down to equal the original dumblelator.

The reason for the updated loop, is a desire to build an all-in-one amp head, with built-in loop + a small effects processor (SE70) in the bottom of the cabinet. Hence, all you have to do is connect guitar and speaker cab and off you go.

1) Serial mode is now identical to the regular dumblelator.

2) Parallel mode is trimmed to equal the frequency curve (not the compression) of serial mode, which has a slight mid boost and a slight 12KHz roll off as documented by Glasman in this post: http://ampgarage.com/forum/viewtopic.ph ... sound+loop

Built-in loop - If you decide to do a built-in the loop, you might what to add cable simulation capacitors of 150-200p at the input and at the output. If so, don't forget to add a 47-68p capacitor to the master volume. This is not an easy task, it takes LOT of experimentation to get it right. Just make a search for post by Dogears or Glasman regarding this topic.

Stand-alone loop - If you already have a regular dumblelator, you can add a switch and two resistors+ to caps in order to get parallel operation.

This version of the parallel loop is the best, I can come up with. However, in parallel I miss the compression and must agree with Dogears and others, that you don't get the compression and that the bass notes are different when using a (Kevin O'Conner (KOC)/ Aiken inspired) parallel loop like this one. Therefore, I have ordered a Suhr Minimix2 (inspired by a lot of you guys), in order to test if the regular Dumblelator series mode with the addition of the minimix2 is the ticket to parallel operation (with compression)

Let me hear the verdict if you decide to give it a go.

Happy to share with y'all (but don't nick it NIK)
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Structo
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Re: 2. version - Parallel Loop for amp garage users only - LOL

Post by Structo »

So you have reduced the two 220K resistors to 100K and bypassed them with ceramics.

I have yet to try the parallel loop again.

I need to work up a layout and see how the switching will have to be wired.

You also left the 1M grid leak off of the second stage.
But you still have the local feedback loop, so you must like that, eh?

No cap on grid?

I need to experiment with this.

What does the $250 Suhr device bring you that the Dumbleator doesn't?
Tom

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boldaslove6789
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Re: 2. version - Parallel Loop for amp garage users only - LOL

Post by boldaslove6789 »

Structo wrote: What does the $250 Suhr device bring you that the Dumbleator doesn't?
I wish I had a Suhr Mini Mix to try to compare to regular serial use

When using my T.C. unit in serial It takes away from my amps regular response.
bluesfendermanblues
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Re: 2. version - Parallel Loop for amp garage users only - LOL

Post by bluesfendermanblues »

Structo wrote:So you have reduced the two 220K resistors to 100K and bypassed them with ceramics.

I have yet to try the parallel loop again.

I need to work up a layout and see how the switching will have to be wired.

You also left the 1M grid leak off of the second stage.
But you still have the local feedback loop, so you must like that, eh?

No cap on grid?

I need to experiment with this.

What does the $250 Suhr device bring you that the Dumbleator doesn't?
Yeah, now the serial mode is identical to the Dumblelator, so some parts had to be slimmed off (like the grid cap and resistor in the first version).

The Minimix2 is used in a regular (serial mode) dumblelator. You connect it to the dumblelator send/return like you would connect any muliteffects device, and hereafter connect yor multieffect to the Suhr.

The Suhr takes care of mixing in the effect in parallel mode.

This gives you both Dumblelator in series mode with compression and parallel. Check it out at Suhr site.
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boldaslove6789
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Re: 2. version - Parallel Loop for amp garage users only - LOL

Post by boldaslove6789 »

Sorry to derail the thread but Is there any info on the Suhr MiniMix on the web to build one or something similar?
bluesfendermanblues
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Re: 2. version - Parallel Loop for amp garage users only - LOL

Post by bluesfendermanblues »

boldaslove6789 wrote:
Structo wrote: What does the $250 Suhr device bring you that the Dumbleator doesn't?
I wish I had a Suhr Mini Mix to try to compare to regular serial use

When using my T.C. unit in serial It takes away from my amps regular response.
You're right..why build, tweak, tweak and tweak a fine amp...only to ruin its tone with poor converters.

Maybe you shoild try the parallel mod,which shoild set you back about 2$.
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bluesfendermanblues
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Re: 2. version - Parallel Loop for amp garage users only - LOL

Post by bluesfendermanblues »

boldaslove6789 wrote:Sorry to derail the thread but Is there any info on the Suhr MiniMix on the web to build one or something similar?
There's a lot of different DIY loopers. Like these:

http://www.generalguitargadgets.com/pro ... zer-projec

http://uk-electronic.de/onlineshop/prod ... 9c9cc3a1d2

Or you could use a mackie mixer (like Bob-I) or get an old Rane splitter mixer. Whatever you choose it will basically do the same.

However, I want the Suhr - its been tried and tested.
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boldaslove6789
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Re: 2. version - Parallel Loop for amp garage users only - LOL

Post by boldaslove6789 »

Thanks but I don't speak that language. :lol: too bad it looks like a possible circuit to build. That PCB and layout in the PDF looks confusing although.
groovtubin
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Re: 2. version - Parallel Loop for amp garage users only - LOL

Post by groovtubin »

boldaslove6789 wrote:Thanks but I don't speak that language. :lol: too bad it looks like a possible circuit to build. That PCB and layout in the PDF looks confusing although.
VERY nice sounding fuzz!

jim@Omegaamps
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Structo
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Re: 2. version - Parallel Loop for amp garage users only - LOL

Post by Structo »

boldaslove6789 wrote:
Structo wrote: What does the $250 Suhr device bring you that the Dumbleator doesn't?
I wish I had a Suhr Mini Mix to try to compare to regular serial use

When using my T.C. unit in serial It takes away from my amps regular response.
What TC unit do you have and why do you think it takes away the response?

I have a TC G Sharp that I run in my dumbleator and it seems to work fine.
Granted, I am used to the way my amp sounds with the dumbleator so maybe I don't hear it.

But, I designed the amp and loop to play nice together so maybe it just works good.
Tom

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Structo
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Re: 2. version - Parallel Loop for amp garage users only - LOL

Post by Structo »

I drew this up yesterday.

This is an untested layout and I'd appreciate another set of eyes on it to see if I made any mistakes.

Drawing edited with correct jacks shown.
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Last edited by Structo on Sun Apr 10, 2011 4:49 pm, edited 6 times in total.
Tom

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bluesfendermanblues
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Re: 2. version - Parallel Loop for amp garage users only - LOL

Post by bluesfendermanblues »

Looks fine to me, Tom
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boldaslove6789
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Re: 2. version - Parallel Loop for amp garage users only - LOL

Post by boldaslove6789 »

Its a TC M300
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Structo
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Re: 2. version - Parallel Loop for amp garage users only - LOL

Post by Structo »

I think most of there rack units are similar.
Now they have the M350 out.

Mine is an older G Sharp but has most of the same delay and reverb settings.

Good sounding piece of kit.
Tom

Don't let that smoke out!
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