I'm about to purchase a couple of volume pedals for my pedal board setup. I have a Les Paul and two acoustic guitars, both with pickups and 1/4" out. My amplifier is a half-stack with an all-tube head (B-52 AT-100), a Tom Scholz Power Soak to enable me to drive the tubes at capacity, and the amp has an effects send loop, which I will use to send to and from my pedal board.

I'm particularly looking at Tapestry Audio's Bloomery Volume Pedals, which come in passive and active models.

My specific use-case is to have the first hop on the effects send enter a volume pedal before reaching additional pedals in the chain, with the second volume pedal being connected to the expression input on my Boss PH-3 Phaser and other pedals which support this.

I'm having a hard time determining whether I want an active or a passive pedal, as the Bloomery comes in either active or passive models.

What is the difference between active and passive volume pedals and which should I choose for both use-cases? It seems like I should get an active pedal for the first hop volume control and a passive one to control the expression input on other pedals.


There isn't really any point to using an active pedal volume pedal in your setup. The advantage of an active pedal is that it can offer simultaneously high input impedance and low output impedance. High input impedance is important when you're directly connecting a passive guitar (else the pickup resonance is damped by the load), whereas low output impedance helps avoiding noise interference if there's a long cable from the volume pedal to an amp or whatever.

But in your case neither of that applies; you'd in fact be fine with the opposite: low input impedance and high output impedance, because both input and output go directly to active units – the effect send output is low impedance anyway, and the output to the next FX pedal is a short cable that'll be perfectly stable even at high impedance. In particular, you're most certainly fine with the medium in- and output impedance that most passive volume pedals offer.

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  • Thank you! I was able to learn more about the pedal and posted my own answer. Would you mind taking a look and see if I got it right? Also, does my effects send loop essentially act as a buffer in this case? Would I benefit from getting a buffer pedal? – Naftuli Kay Jul 23 '19 at 23:58
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    Yes, the effects loop acts as a buffer so you don't need an extra one in the pedal. Actually, you should never need any dedicated buffers – rather, buffers should be at the output of every effect and in every guitar. Of course they aren't, because guitarists are hopeless with their “active sounds bad” dogmatism (and most manufacturers don't help, making almost only passive models and the active ones badly designed). – leftaroundabout Jul 23 '19 at 23:58
  • Can you elaborate more on "in every guitar?" Forgive me if I'm missing something, but beyond the pots, pickup select, and humbuckers in my Les Paul, I don't know if there is additional circuitry involved. – Naftuli Kay Jul 24 '19 at 0:02
  • Exactly: most guitars are passive. They shouldn't be; in the guitar is where a buffer would truely make sense, but this has never become a mainstream thing. – leftaroundabout Jul 24 '19 at 6:32

According to the product manual [PDF], it seems that the active pedal has a buffer and the passive one does not:

enter image description here

Feature Comparison

Bloomery / Active

  • No String
  • Tuner Out
  • Solid Steel Construction
  • Dual Buffer
  • Includes Optional Grip Tape
  • 20mA Center Negative 9MM Power

Bloomery / Passive

  • No String
  • Tuner Out
  • Solid Steel Construction
  • Includes Optional Grip Tape
  • DIP Switches

Thus, it seems that the main differences are that the active pedal uses power (obviously) and contains a dual-buffer for preserving tone1, while the passive one does not use power and has DIP switches for configuring the pedal for use as an expression input to other pedals.

Therefore, it seems that for my specific use-case, I'd use the active volume pedal as my first input on my pedal board and the passive volume pedal as the expression control for other effects.

If I had another buffer pedal in front of the first volume pedal, a passive model would make sense for the first pedal, but I don't. It would be cooler if I did have a buffer in front so that I could optionally get both passive pedals and connect each to a different expression input to control up to two pedals at once.

I think what I'll do is purchase the passive pedal first, fool around with it, and then make a decision on whether to go active or passive for the other pedal.

The FAQ seems to suggest that it's possible to use the active pedal to control expression pedals with additional hardware:

The active version of the Bloomery cannot be configured to be an expression unless you use an insert cable through the input and output. (2 mono TS to 1 TRS)

I'm not exactly sure what this means, but I'm curious to find out.

1: Tone Tips: A Crash Course on Buffers

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  • I’m surprised that you can use the active as expression with an insert cable but maybe my understanding is wrong or outdated. I think your plan is a good one. As noted in the other answer, you don’t need a buffer on your pedalboard. I’ve never used one. So having a buffer or active pedal is totally optional. – Todd Wilcox Jul 24 '19 at 2:15

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