What is most transparent loop buffer design

[LPSGME]

I find that my amp's sound, run through my d'lator, is not as pleasing or rich as without it.

Does anyone know if this loop circuit would be more transparent that the standard d'lator design.
https://tubeamparchive.com/download/file.php?id=10921

[LPSGME]

Oh never mind...

Turns out that the high frequency boost switches were wired with the connections to the far ends of the DT switches - so that there wasn't any boost when switched.

I kept thinking - gee, even switching in the HF bypass caps doesn't do much to correct the missing highs I was hearing.

...probably the result of a multi-day Malaysian holiday that took place right before this thing got wired.

[bluesfendermanblues]

The most transperent loop IMO is a parallel loop. However, I haven't heard the dumbleator (serial loop) with the Suhr MiniMix II, the latter turning the dumbleator into parallel operation.

I use the following loop design: https://tubeamparchive.com/viewtopic.php?t=10477

Which I can bypass completely with a relay. I find it hard - if at all possible - to hear a difference in sound with vs without the loop in the circuit (in parallel mode).

The advantage of the parallel loop operation is that the quality of the effect processors digital converters are less important for your sound.

It's a pretty simple design. Try it out and lets hear your opnion.

[greiswig]

I've used Kevin O'Connor's design ("The Ultimate Tone") for a switchable parallel/serial loop. I haven't done a D'Lator so that I can compare them, but to my ears O'Connor's loop is quite transparent even in serial mode, and very very transparent in parallel mode.

[LPSGME]

Thanks, both for the advice.

Now that the bypass caps switches are properly wired [having been not wired correctly] the output's tone is much closer to the input's.

But I think I will wire this d'lator to have the parallel/serial options as, understandably, parallel should be better being that the main sound bypasses the effect unit.

[David Root]

I agree w/Greiswig on KOC's design, I used the all-tube one in one amp (not a D-clone). I couldn't tell the difference on a 4x12 of Emi Delta Pro 12As between parallel and bypass.

[grtamp]

Hi , can anyone explain the Connor's loop? what's difference with D-lator design?
thanks

[Structo]

The Series/ Parallel loop that Bluesfendermanblues designed uses the best features of the O'Connor loop and the Dumbleator.

EDIT:
This is the final schematic. (I should discard earlier versions.....)

[LPSGME]

Why is there a dis-connect between the LNFB [at the 1m and 10m junction] and Grid? It appears as a connection in other diagrams.

And what is the purpose of that 220K from the second stage output through a switch back to the input; nearby the "0" mark?

Is that some sort of gain feedback? If so, why couldn't it just attach to the grid instead of the LNFB as in:
https://tubeamparchive.com/download/file.php?id=10921

[Structo]

You know what?

I posted the wrong schematic!

Sorry, I will correct it.

The two 220k form an elevated ground.

I tried an earlier version of the parallel and didn't care for it at the time.
I have been meaning to try this version.
Ideally you would use rack or line level gear for this instead of stomp box effects but if they are decent and clean then they should work.

Here is a layout of this loop I did a while back.

[TheHandsomeOrk]

I tried Structo's layout in my D'lator build and to me it works fine. I use it in parallel mode with an old Boss RV-2 reverb pedal and it's transparent ( to my ears- can't tell any difference between in/out using bypass switch). The return knob works as a mix control (parallel mode) between dry/wet signal. I
like it so much that I prefer it in the loop than using the amp without it. Kudos to bluesfendermanblues and structo for their fine work ( I'm a happy camper) YMMV.

[talbany]

Tom
Nice work!!

Tony

[Structo]

Thanks, I'm a little embarrassed.
I haven't tried this version yet.

All credit goes to Bluesfendermanblues for the circuit.

[bluesfendermanblues]

Thanks guys

[LPSGME]

Correction to post:

I'm redacting my post (in case anyone read it) as I just noticed I overlooked something. sorry