PSA - The Dunlop 535QAR is buffered bypass (advertised as "true hardwired)

[Mincer]

Basically this is what Dunlop uses and calls 'true hardwire bypass' (see how the whole circuit is still impacting the signal?):


And this is real true bypass where it's clean as plugging into a few extra inches of cable:


Both work without power (because neither depend on buffered switching). Dunlop often does the former because it allows them to use a slightly cheaper component for the footswitch.

This diagram helps a lot...thanks!

[GuitarStv]

So does anyone know about their newer EQ-6? It always says true-bypass in the descriptions but in the manual it says true-hardwire still.

https://www.jimdunlop.com/mxr-six-band-eq/

According to Dunlop:
"The MXR Six Band EQ covers all the essential guitar frequencies and has been upgraded with noise-reduction circuitry, true bypass switching, brighter LEDs for increased visibility, and a lightweight aluminum housing."

I think your odds are good given that they didn't use their 'true hardwire bypass' switching language . . . but I haven't traced the circuit to be sure.

[dave74]

https://www.jimdunlop.com/mxr-six-band-eq/

According to Dunlop:
"The MXR Six Band EQ covers all the essential guitar frequencies and has been upgraded with noise-reduction circuitry, true bypass switching, brighter LEDs for increased visibility, and a lightweight aluminum housing."

I think your odds are good given that they didn't use their 'true hardwire bypass' switching language . . . but I haven't traced the circuit to be sure.

Well that's just it, they do say it's true-hardwire in the manual, but it's always described as upgraded to true-bypass. Same with the micro flanger, described as upgraded to true-bypass but still listed as true-hardwire it's own manual/pdf.

https://www.jimdunlop.com/content/manuals/M109S.pdf

[dave74]

Just to be clear on the manual I just linked ^^^,,,,,on the left side it says true bypass, and on the right under specs it says true-hardwire.
Same thing exactly with the micro-flanger manual.

[GuitarStv]

Just to be clear on the manual I just linked ^^^,,,,,on the left side it says true bypass, and on the right under specs it says true-hardwire.
Same thing exactly with the micro-flanger manual.

Yeah . . . sounds like someone needs to trace the circuit to be sure. Unfortunately, Dunlop has a shady past when reporting this kind of thing.

[ErikH]

The only way to know for sure if a pedal is TB or not is with a DMM on the switch terminals. If you see zero load or open on the DMM, it's TB. Anything else and it's not. I verified that with a tuner and a couple pedals I had that claimed to be TB. The MXR "true hard-wire" bypass is still a slightly noticeable load on the signal.

[dave74]

It's really a shame that both Boss and MXR have totally missed the mark on bypasses.
Boss at least are completely upfront about it basically saying that buffers can never hurt anything so why not always include them.
MXR use all these purposely deceptive terms to just confuse us lol.

Both companies should realize that we will never want a whole big board full of only their stuff for this reason.
I'd probably have almost all Boss and/or MXR if they just had switchable bypass options like the waza tuner,,,,,or many/most TC pedals.

[GuitarStv]

They've made a few bad ones, but Boss buffers are generally pretty good. You only run into tone issues with them if you're running 5+ pedals.

[dave74]

They've made a few bad ones, but Boss buffers are generally pretty good. You only run into tone issues with them if you're running 5+ pedals.

That's what I have found also. I use them at the beginning and end of the chain and not more than a couple in the loop, but if they were switchable bypass I would have nothing but Boss and MXR because their actual effects are plenty good enough for my taste. I know many of the newer switching systems have that covered, but those are just overkill for my needs. I just wish my LS-2 had the true-bypass option because both my patches within the LS-2 have buffered pedals already in them and the LS-2 just needlessly adds another.

[ErikH]

You do this by measuring with the pedal in bypass mode, nothing connected to the output, the pedal powered up, and look into the input terminals between the positive and ground? How do capacitances usually show up, or are those input impedances mostly resistive?

It can work looking at a resistive load. The key is when bypassed, it should equivalent to those probes touching themselves directly. Any load between them will change that.

[ErikH]

If it is true bypass and you are putting the probe on the right tabs of the switch, or just on the tip lug of the input/output jacks, you should see absolutely zero drag or any reading at all. True bypass wiring removes the circuit, buffers and all, from the signal path completely. The instrument signal travels input to output with zero resistance or capacitance. Anything else showing on the meter means it’s not true bypass.

[ErikH]

There’s no need to measure going to ground. All that needs to be measured is going from the input jack tip lug to the output jack tip lug. The meter will clearly show if the circuit is still in the signal path when bypassed. In the case of the MXR, there’s a clear drag on the signal when in bypass.